M4-P
5:30 PM
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M4-P.1 Expansion of a computer simulation of the public health system. Kilpatrick KE*, Hedberg CW, Schaffner DW; Texas A&M, University of Minnesota, Rutgers University schaffner@aesop.rutgers.edu
Abstract: The objective of this research is to create a computer simulation of the public health systems response to a deliberate attack on the food supply. This simulation will allow policy makers and risk managers to estimate the speed with which various types of attacks propagate through the system. The simulation may identify weak points or bottlenecks where the allocation of additional resources may aid in prevention. The simulation will identify the degree of benefits obtained improved ability to detect at various points in the system. The system will allow for comparison between different types of responses to a deliberate attack to determine which are most effective. The current model has been developed in Analytica, but contains a limited amount of real public health data. This poster will present an expansion of the current model to include data from the Enteric Disease Timeline Study (EDITS). Statistical distributions were fit to the EDITS data and analyzed using BestFit. The EDITS dataset contains information on five foodborne pathogens: Salmonella, Shigella, Campylobacter, E. coli O157:H7 and Listeria. For each pathogen, information on the dates for Onset of Illness, Specimen Collection Date, and Initial Routine Report are available. Additional information on the date that the incident was communicated from the local to the state public health Department, or the date the patient was interviewed by public health officials may also be present. Finally information on the dates that culture isolates were submitted to the CDC and set up and analyzed by pulse-field gel electrophoresis may be present in the database.
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M4-P.2 An evaluation of microbiological risk assessment principles and frameworks. Parkin R*; George Washington University Medical Center parkinr@gwu.edu
Abstract: Microbiological risk assessment (MRA) is an important mechanism for evaluating environmental and health risks related to food and water supplies. In order to maximize the utility of a MRA, the methods and results must be clear, reasonable, and transparent. A first step in achieving transparency is the development of a consistent framework that lays out a structure for conducting the assessment. Given their respective statutory obligations and history, different scientific and regulatory bodies adopt approaches that reflect their respective institutional culture. Currently there are several frameworks and approaches for conducting a MRA, each of which have strengths and weaknesses. These include the WHO/FAO framework, CODEX principles, ILSI framework, general US EPA guidelines, and numerous other publications. In Part I of this symposium, several speakers presented issues relevant to MRA in their respective agencies. The goal of the interagency MRA workgroup is to extract the best practices from these frameworks in an effort to provide practical guidance for future regulatory risk assessments protecting human health and the environment and to effectively communicate the context and utility of the assessments. This presentation will provide the results of a recent analysis of MRA principles and frameworks, focused on identifying the key contributions of current MRA approaches.
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M4-P.3 A new policy tool to choose water quality goals under uncertainty. Chu H*, Crawford-Brown D; University of North Carolina at Chapel Hill hachu@email.unc.edu
Abstract: Traditional approaches to establishing regulatory limits on exposure to water-borne pollutants examine the predicted number of health benefits under a variety of scenarios that are judged to include a margin of safety in estimating risk. While this approach, rooted in the precautionary principle, has merit, it does not allow the analyst to understand the increased cost of compliance that can be associated with a given margin of safety. This can lead, in turn, to inconsistent degrees of protectiveness across different regulatory limits and, more troubling, to economic inefficiency in allocating limited resources to bring about improvements in the public health. This paper provides a new methodology of risk-cost-benefit analysis to formally assess the relationship between different degrees of protectiveness and the cost of compliance, examining this issue through the lens of four case studies: Radon, TCE, Perchlorate and Arsenic in drinking water. Monte Carlo methods are used to generate probability distributions reflecting the distribution of risk across a population and the uncertainty in those estimates. This information is then combined with cost estimates of varying proposed Maximum Contaminant Levels to develop " price-of-confidence surfaces" from which a decision-maker can select an MCL that provides reasonable confidence that an adequate fraction of the population is protected against unacceptable levels of risk. The final product of this study is a policy tool which can be applied coherently across the regulation decisions for different contaminants.
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M4-P.4 Methods to analyze uncertainty and sensitivity in mathematical models to aid medical decision making. Duintjer Tebbens RJ*, Thompson KM, Hunink MGM, Mazzuchi TM, Lewandowski D, Kurowicka D, Cooke RM; Delft University of Technology, Harvard School of Public Health, Erasmus Medical Center rduintje@hsph.harvard.edu
Abstract: Mathematical models provide helpful tools to inform decision makers about risks and trade-offs. However, model inputs typically remain uncertain and for a model to be most informative, analysts should strive to factor in uncertainty rather than presenting just single point estimates. Many methods exist to analyze and quantify the importance of model output uncertainty and to identify the inputs that contribute to the uncertainty. We review and discuss a number of methods for uncertainty analysis (UA) and sensitivity analysis (SA), including partial derivatives, one-way and multi-way SA, design-of-experiments analyses, Morris\\\' method, and probabilistic methods (yielding regression and correlation coefficients and correlation ratios). We test these methods for UA and SA on an existing dynamic economic evaluation model for a hypothetical vaccination program. We found that the different UA and SA methods make different implicit assumptions and consequently may lead to different insights from the analysis. Considerations in choosing an appropriate method include the motivation (e.g., determining the importance rankings of individual inputs, understanding interactions and non-linearities in the model, and/or obtaining a sense of the model’s robustness), the complexity of the model, and the number of uncertain inputs.
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M4-P.5 Statistical and predictive Salmonella serotype prevalence analysis of NARMS data. Mathers JJ*; Alpharma Inc. jerry.mathers@alpharma.com
Abstract: Two complementary methods were developed for the systematic analysis of non-Typhi Salmonella serotype data sets. The US National Antibiotic Resistance Monitoring System (NARMS) branches have reported the ‘top 15' most prevalent non-Typhi Salmonella serotypes, in addition to detailed antimicrobial resistance data, from human (CDC) and animal (USDA) programs since 1996-97. The retail meat (FDA) program has reported since 2002. Data representing over 37,000 isolates were extracted from 15 annual reports from 1996-2003, and compiled into normalized spreadsheet formats. A Spearman rank order test was applied to common serotypes to evaluate statistical significance. A prediction index (PI%) was calculated from the common/total serotypes ratio, and the determination index of reported prevalence among the common serotypes for any two data sets. The results for NARMS data showed statistically significant and strong overall year-to-year associations within both CDC (p<.01, PI=92.9%) and USDA (p<.01, PI=71.1%) programs, respectively. The inter-program analysis during the same period showed lower statistical significance and association, however (p<.1, PI= 29.0%). Comparisons to the FDA retail meat sets for 2002 had a similar low association (PI<18%), however the first report year had comparatively fewer isolates. The results showed that both CDC and USDA NARMS programs had statistically significant and consistent yearly sampling and reporting of ‘top 15' serotype sets from 1996-2003. The USDA sets were not strongly associated with CDC human diagnostic sets, however, suggesting relatively lower attribution levels from production animal sources.
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M4-P.6 Assessment of norovirus exposure from consumption of Puget Sound shellfish impacted by large vessel wastewater discharges. Meschke JS, Kissel JC*, Beck NK, Shirai JH, Smith JA; University of Washington jkissel@u.washington.edu
Abstract: Admiralty Inlet and Puget Sound contain valuable commercial, tribal and recreational shellfish resources. Shellfish are filter feeders and may bioaccumulate human enteric viruses introduced into their growing waters through discharges of human waste. These shellfish may then pose a risk to consumers if consumed raw or minimally cooked. Norovirus is a small enteric virus that causes acute gastroenteritis and that is environmentally persistent and frequently implicated in shellfish-borne outbreaks. In the last 5 years, large cruise vessel traffic in Puget Sound has increased dramatically. These cruise vessels currently operate under a memorandum of understanding with the State of Washington that dictates level of treatment and allowable wastewater discharges to Puget Sound. However wastewater treatment processes are not typically designed specifically for removal of enteric viruses. Recent publicity over outbreaks of norovirus on cruise vessels has resulted in elevation of concern over the impact of the wastewater discharges by cruise vessels on shellfish harvesting areas in Puget Sound. The purpose of this study was to assess the incremental risk of norovirus infection attributable to consumption of shellfish harvested from areas potentially impacted by cruise vessels. A probabilistic exposure model has been developed incorporating level of viral discharge from shipboard waste treatment plants, near field dilution, far field dilution, virus uptake and elimination by shellfish, and shellfish consumption patterns. The exposure model was coupled with existing dose-response data for norovirus. Results of this study are intended to support efforts by the Washington State Department of Health to establish scientifically based shellfish harvest closure or zero discharge zones around the shipping corridor.
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M4-P.7 The attitude to medical and food related gene-technology in The Netherlands. Gutteling JM*, Kuttschreuter M, Pin RR; University of Twente - The Netherlands margot.kuttschreuter@utwente.nl
Abstract: Gene-technology covers a broad field. Applications in medical science, for instance, relate to (neonatal) screening and the development of genome-based treatments. Another application relates to dna-based evidence in forensic investigations. Genetic modification of food products might also be considered to belong to the domain of gene-technology. Various studies show that European and Dutch citizens have second thoughts concerning applications of gene technology, especially related to food products. Since the early 1980s models have been developed to explain and predict the public reaction toward technological developments, from the perspective of risk perception. These studies have provided an understanding of cognitive determinants of the perception of technology development. Recently, social factors like trust have been added to the model. We studied the relationships between trust, experience, knowledge, interest, attitude towards gene-technology, worry and the intention to buy genetically modified foods. In November 2005 a national survey was in the Netherlands conducted among 725 respondents who were interviewed by telephone. Amos was used to test a general model describing the cognitive process which leads to the attitude towards gene-technology and its behavioral correlates. Trust, experience, knowledge and interest were hypothesized to determine the attitude towards gene-technology, whereas worry and the intention to buy genetically modified foods were assumed to depend on this attitude. The general model fitted the data. The application of the model to the fields of food related gene-technology and medical screening will be discussed.
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M4-P.8 Automated medical adverse event reporting and analysis. Young J*, Gelston GM, Pronovost PJ, Whitney PD, Saripalli R; Battelle Memorial Institute, Johns Hopkins University School of Medicine gariann.gelston@pnl.gov
Abstract: In the environment of a busy ICU, collection and analysis of incident reports seems overwhelming. This poster discusses the viability of using electronic tools to effectively collect and analyze incident reports to support patient safety efforts, providing information to design effective interventions and reduce the risk of adverse events. Johns Hopkins has been testing and evaluating the beginning of such a system. The ICU Safety Reporting System (ICUSRS) is web-based and incorporates a systems approach to reporting and analysis of incidents. Our goals include implementing ICUSRS in a cohort of ICUs, comparing the information provided by reporting near misses and adverse events with respect to both the quantity and content of errors, examining providers' perceptions and the effects of participation on safety-related attitudes, and exploring the usefulness of this system for safety improvement initiatives at the institutional and professional society levels. The reports collected by the ICUSRS contain information in categorical and text form. Automated text analysis technologies can be applied to these reports to support the analysis and development of intervention design to improve patient safety. The approach, lessons learned, and additional data visualization and process mapping are included in this discussion.*
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M4-P.9 Can the "anti-pharma" literature be justified and where is it taking the public perception of risk? Chakraborty S; swetac@andrew.cmu.edu
Abstract: Public perceptions of the pharmaceutical industry have experienced highs and lows ever since Big Pharma came into being. FDA Regulations have steadily tightened control over the industry throughout the decades, consistent with public view. Recent literature has mercilessly scrutinized Big Pharma, which forces the question: To what extent is this literature "anti-pharma" and where is it taking public perception of risk in the pharmaceutical industry? This is the question pursued in this paper, which examines the scrutiny befalling the pharmaceutical sector. It is imperative to remember that the pharmaceutical industry, like any other industry, is an investor driven business, with the primary responsibility to maximize profits. To this extent, the public must be cautioned against perceiving the industry as strictly an educational body with philanthropic goals. Once this distinction is cleared up, some of the harshest accusations against Big Pharma may be better understood. This paper will examine Big Pharma's past behavior as a means for explaining its current methods of communicating risk. It will look at the where the scrutiny is taking the industry, and what can be done to improve public perceptions of its powerful global impact.
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M4-P.10 Federal agency compliance with the procedural elements of the error correction procedures required by applicable information quality guidelines. Belzer RB*; Regulatory Checkbook belzer@regulatorycheckbook.org
Abstract: In 2002 the OMB issued government-wide information quality guidelines to implement new statutory requirements (44 USC. § 3516 note). These guidelines established, inter alia, provisions enabling any affected party to seek the correction of erroneous information and directed each agency to establish an internal administrative procedure to evaluate and respond to these petitions. Comprehensively evaluating agency performance requires a complex review of the substantive issues presented in dozens of individual petitions. This paper begins with the simpler and less controversial task of analyzing each federal agency's compliance with the procedural elements of OMB's and its own information quality guidelines. Adherence to reasonable procedural norms is an essential prerequisite to effective implementation of the information quality guidelines. Agency performance is ranked in league tables to permit all affected and interested parties (as well as the public at large) to judge for themselves in accordance with their own values.
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M4-P.11 Risk-risk tradeoff analysis grounded in reality. Finkel AM*; Princeton University and UMDNJ School of Public Health afinkel@princeton.edu
Abstract: In theory, any risk-reducing intervention can "backfire" and exacerbate an existing risk, create a new risk, or transfer risk from one subpopulation to another. Pioneers in the "risk versus risk" literature made compelling arguments that to properly estimate the benefits of regulatory and other interventions, one must "add back" the offsetting risks to any reductions achieved in the target risk. Increasingly, oversight of federal and state agency action has required "risk versus risk" analysis, and has served to deter agencies from policies whose net risk reduction arguably fails a benefit-cost test. In this presentation, I will argue that the time has come to take a hard look at risk-tradeoff analysis, by asking two fundamental questions about whether this theoretical phenomenon in fact exists outside the proverbial laboratory: (1) have previous claims of substantial offsetting risks been borne out empirically with the passage of time?; and (2) if such cases exist, do they argue for less aggressive intervention against target risks, or perhaps or more aggressive intervention against offsetting risks? I will examine three different risk-risk tradeoffs that were invoked during OSHA's attempt to reduce methylene chloride levels in the workplace, and offer general lessons from my observation that two of the three untoward outcomes apparently never materialized. I will also discuss a broader array of cases, including purported tradeoffs between reduction in consumption of mercury-contaminated fish and exacerbation of heart disease, increased fuel economy standards and motor vehicle safety, and spermicidal condoms and HIV transmission. Common patterns among these and other cases will lead to a set of proposed refinements to risk-tradeoff analysis that may reduce confusion, posturing, and misplaced suspicion of a valuable tool for improving risk management.
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M4-P.13 The inclusion of precautionary provisions into the European regulation of chemicals and food. Renn O*, Elliott D; University of Stuttgart and DIALOGIK Corporation ortwin.renn@sowi.uni-stuttgart.de
Abstract: The precautionary principle has been adopted in a variety of forms at international, European Union and national level. It is applied across an increasing number of national jurisdictions, economic sectors and environmental areas. It has moved from the regulation of industry, technology and health risk, to the wider governance of science, innovation and trade. As it has expanded in scope, so it has grown in profile and authority. In particular, as Article 174(2) in the EC Treaty of 2002, precaution now constitutes a key underlying principle in European Community policy making. The EU Communication on precaution highlights three important issues in developing the precautionary principle. First, the precautionary principle ‘should be compatible with the classic division of risk analysis: risk assessment, risk management, risk communication. In the Communication the precautionary principle is largely understood as belonging to the stage of risk management but it should also inform the risk assessment process. Second, the Commission's Communication highlights the need for ‘proportionate, non-discriminatory and transparent actions'. It further stresses the benefit of using costs-benefit analysis, based on best scientific data. The Communication also points out the need to ‘involve as early as possible and to the extent reasonably possible all interested parties'. Third and finally, the Communication allows for a wide range of risk management initiatives. In particular, such measures need not be of a legally binding nature and as noted above, should be able to be revised. The paper will show how these principles have been implemented in the chemical and food sector. Special emphasis will be given to REACH and the European Food law.
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M4-P.14 Shallow buried transuranic waste: A gap analysis. Neill H R*, Neill R H; University of Nevada - Las Vegas helen.neill@unlv.edu
Abstract: The US DOE estimates that 126,000 cubic meters of radioactive transuranic (TRU) waste were disposed prior to 1970 and buried under shallow ground cover at six federal facilities. We present a brief history of TRU waste disposal laws and practices and identify inconsistencies in exhumation requirements for shallow buried TRU waste disposed before and after 1970. We identify two sites with waste buried under less than two meters of shallow ground cover, Idaho National Engineering and Environmental Laboratory (INEEL) where DOE plans removal and Los Alamos National Laboratory (LANL) where DOE plans to leave shallow buried TRU waste in place. Next, using DOE's site specific criteria, we consider in more detail the implications of removal versus leaving in place at LANL. We conclude that to reduce long term risks to the general public and environment, decisions whether to exhume or leave in place relatively large amounts of buried TRU waste at sites such as LANL should be based on expected impacts and feasibility, not an arbitrary cut off time.
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M4-P.15 Applying the mental models framework to carbon monoxide risk in Ciudad Juarez, Mexico. Gurian PL*, Velazquez G, Montoya T, Perez F, Corella-Barud V; Drexel University, Universidad Autónoma de Ciudad Juárez, University of Texas at El Paso
Abstract: Two-thirds of households in Ciudad Juarez, Mexico that rely on un-vented heaters have carbon monoxide levels that exceed the World Health Organization’s health guidelines. These exposures have been associated with an elevated risk of fatality and a range of sub-clinical health problems that may affect productivity and well-being. This study is applying the Mental Models approach to the development of a risk communication instrument. The Mental Models approach involves eliciting the public’s baseline understanding of a risk and then identifying key knowledge gaps to be targeted by risk communication instruments. In this case, developing a prescriptive risk-communication instrument involves making difficult choices between the effectiveness of advice, if followed, and the likelihood that advice will be followed. For this reason the public’s willingness to adopt particular risk reduction measures was also elicited during the survey process. The survey revealed a key misperception in that 79% of respondents mistakenly believe that they can smell carbon monoxide and 30% seriously overestimate the cost of an alarm. These misconceptions may contribute to the fact that only 7% of respondents own carbon monoxide detectors. Several risk mitigation strategies are reported to already be in widespread use, such as opening windows while the heater is on and turning off the heater before going to sleep. Respondents indicate a willingness to purchase alarms when informed of the cost. Advocating the use of carbon monoxide alarms may be an effective strategy, particularly if the risk communication efforts address misconceptions that carbon monoxide has an odor and indicate the true price of the alarms. The use of heaters with oxygen depletion sensors is also promising but would be substantially more expensive. This research suggests that surveys of baseline attitudes towards risk mitigation alternatives may be helpful in addressing difficult trade-offs in developing prescriptive risk communications. It also confirms the usefulness of the Mental Models approach for developing health behavior communications for a lower-socioeconomic status population in Latin America.
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M4-P.16 Risk perception, disability, and the fear avoidance profile. Krawciw Don*; Medical Consultant Workers Compensation Board of British Columbia Donald.Krawciw@worksafebc.com
Abstract: This presentation aims to introduce the risk research community to advances in our understanding of disability medicine and explore potential avenues of future collaboration. Disability, particularly from occupational musculoskeletal injuries such as low back pain, has increased over the past 25 years even though objective measures of health are improving. Disability has been associated with a high score on the Fear Avoidance profile. This psychological profile, developed in the UK in the 1980's, measures an individual's fear of reinjury with activity. It represents a synthesis of risk perception profile and psychological anxiety traits. Research has shown that not only the fear avoidance profile of patients, but of physicians, influences decisions about work restriction and disability. n other words, an individual's risk tolerance plays a large role in recovery from injury. "Experiential" risk perception/tolerance may be represented on a continuum between "typical" and "pathological," culminating in psychological diagnoses such as hypochondriasis and somatization disorder. Future work to synthesize risk perception and psychological anxiety research would offer great promise, particularly to advance our understanding of current levels of work disability after injury.
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M4-P.17 Male/female (gender) differences in attitudes towards genetically engineered salmon. Qin W*, Brown JL; Penn State University wuq100@psu.edu
Abstract: Foods containing genetically engineered (GE) ingredients account for over 70% of the processed foods on the US market. Consumer attitudes towards GE foods will determine the future development and expansion of this technology. Recent US surveys revealed that women were less approving of GE foods than men, and sex differences persisted even after hearing more detailed risk/benefit information. This study aimed to understand sex differences in attitudes towards GE foods through examining male/female reactions to a specific GE application-GE salmon, and testing two plausible hypotheses (safety concerns and institutional trust) to explain these sex differences. To accomplish these, a survey of 501 individuals was conducted at two grocery stores in a regional chain that differed in customer socio-economic status. At each location, half of the sample was males and the other half was females, and age was stratified according to PA census dada. Based on previously identified low awareness of GE salmon, we provided GE salmon information in-between the pre and post questions. Before reading the information, participants reported their attitudes towards genetic engineering in food production and GE salmon, and knowledge about GE salmon. After reading the information, participants reported their knowledge, trust in organizations that may regulate GE salmon, "outrage" reactions, and attitudes towards consequences of introducing GE salmon into the food system. Data obtained from this survey will be analyzed using structural equation modeling. The results of this study 1) will help researchers understand the basis for sex difference in attitudes if evident; 2) will facilitate design of an effective communication strategy tailored to the target audiences (i.e., men vs. women) about this and other GE animal applications; and 3) will inform policy makers and regulators regarding public reactions to this GE application.
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M4-P.18 Risk perception and environmental remediation of former Soviet military sites in Hungary. Briggs CM*; Lehigh University chb206@lehigh.edu
Abstract: The removal of Soviet military forces from Hungary in 1991 left behind a legacy of ground and surface-water contamination, prompting an extensive remediation program of more than 100 sites. The national remediation program has been shaped by two political transitions, providing an excellent example of how environmental risk perception and communication have shifted from communism to the European Union. This research analyses how justifications for risk policies evolved, from preliminary assessments and the setting of limit values, to dissemination of information under the KÃRINFO remediation database. In particular, this research examines the connection of scientific assessments and knowledge to risk policies, based upon interviews with key policy-makers and scientists involved in the remediation process. The remediation program was implemented under conditions of short time frames, high uncertainty, low levels of communication, lack of participatory political experience, and severe budget constraints. Unlike the assumption that remediation policies were led by expert knowledge, risk policies were often tempered by perceptions of Hungary's relationship to the former Soviet Union and the European Union, thereby shifting policy effectiveness criteria. This presentation identifies the most relevant factors influencing scientific risk communication under post-1991 conditions, and lessons that can be drawn for other transitional political systems.
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M4-P.19 Conjoint analysis as a tool for risk communication. Alriksson S.*; University of Kalmar, Sweden stina.alriksson@hik.se
Abstract: The steel industry in Sweden is working to solve several sustainability problems related to the production and use of steel products, such as; emissions of carbon dioxide, toxic substances and metals, use of non-renewable energy and use of raw materials to mention a few. To deal with some of these sustainability and risk related problems a research project called the Steel Eco-Cycle has been initialised, where one of the subprojects focuses on attitudes towards these environmental issues. Conjoint analysis is used as a tool for assessing preferences among different individuals and groups of people. A preparatory study has now been performed to evaluate attitudes towards emission of carbon dioxide, use of non-renewable raw materials, use of energy deriving from non-renewable energy sources and emission of dioxins. The study was performed on three groups of people; undergraduate students, representatives from the Swedish steel industry and members of public. The participating students came from the University of Kalmar and were divided into three groups depending on their major subject; environmental sciences, environmental technology or industrial organisation and economics. Preliminary results seem to imply that the experienced threat from toxic substances (such as dioxins) overcomes the respondent's feelings towards other environmentalh as global warming deriving from emission of carbon dioxide. Even though some sub-groups can be found with the participants, the results do not indicate any clear groupings of the participants.
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M4-P.20 Cell phones as a risk communication tool: An exploratory study of Orleans parish residents following hurricane Katrina. Gordon JC*, Willard AM; Kansas State University gordon@ksu.edu
Abstract: This study investigated when, how, and why Orleans Parish residents used cell phone technology and text messaging after Hurricane Katrina. Survey participants indicated text messaging remained functional even when cell phone voice calls could not be completed. The number of people sending and receiving five or more text messages a day tripled in the days following impact. Of the participants who used text messaging after Hurricane Katrina, each one reported using it in attempts to assess the well-being and location of family members and friends. Prior to Hurricane Katrina, 64.1% of respondents personally had a cell phone. Slightly more than 60% of cell phone owners (60.2%) had text messaging capability. Before Hurricane Katrina, 62.3% of cell phone owners sent and received text messages, and after the storm, that number increased to 72.5%. The significance of this study is reflected in the sheer number of cell-phone owners in the United States - more than three-fourths of Americans own cell phones, according to a recent study. The growth is expected to continue, according to a Forrester Research report that predicted 85% of American homes will have at least one cellular phone by 2010. Text messaging, also known as SMS (short message service), has an average use of close to 4.5 billion a month. In 2005, it was estimated that about one-third of the 200 million cell-phone owners in the US regularly used text messaging. This study focused on how residents in a disaster area used their cell phones and text messaging as risk communication tools and suggests these technologies will continue to evolve as a vital link between people in times of crisis.
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M4-P.21 Race, information sources, and evacuation behavior among southeast Louisiana residents for hurricane Katrina. Gordon JC*, Harrington LB, Paul BK; Kansas State University gordon@ksu.edu
Abstract: Six researchers collected data using a researcher-administered survey instrument from mid-October of 2005 through January of 2006 from residents of seven southeast Louisiana parishes. Interviews were collected in those parishes under study which included Jefferson, Lafourche, Orleans, Plaquemines, St. Bernard, St. Charles, and Terrebonne parishes. All or parts of the seven parishes were under mandatory evacuation orders when Hurricane Katrina hit in August of 2005. Data were collected from 491 individuals. Females were overrepresented constituting 60% of respondents. Forty-six percent of respondents were African-American. Fifty percent were Caucasian. Asians, Hispanics, American Indians, and others represented four percent of the sample. An impressive 68.7 % of respondents, 336 people, did evacuate before Katrina's landfall with almost 80% of those evacuees traveling 75 or more miles away. More than a quarter (31.3%) of all respondents, either evacuated after the storm (102 respondents) or did not evacuate at all (51 respondents). Among respondents from Orleans Parish (the most populated and most affected parish under study), only 56.4% of respondents evacuated before the storm. Specifically within Orleans Parish, 77.3% of white respondents evacuated before Katrina compared to only 46.3% of African-Americans. Among Orleans Parish respondents, 36.3% evacuated after Katrina hit and 7.3% did not evacuate their primary place of residence. The most commonly sited reason for not evacuating was underestimated the severity of the storm. Ninety-six percent of respondents said they would evacuate given the same circumstances again. Sources of information rated as most important as one was making a decision whether to evacuate were television, family, radio, local government officials, friends, state government officials, newspaper, and the Internet in descending order. This study contributes to our understanding of factors associated with compliance and noncompliance with mandatory evacuation orders.
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M4-P.22 Visualizing risk with maps: Practical theories for risk communication. Bostrom A*, Anselin L, Galvez L; Georgia Institute of Technology abostrom@gatech.edu
Abstract: A critical step in designing risk communication materials to supplement interactions between technical experts and non-experts is the translation and representation of technical information about risk and uncertainty. Mental models research is readily applied to inform the design of text messages, but visual communications often trump text in their impact and appeal. Many environmental health risks have a spatial dimension that government agencies and other authorities represent using geographic information systems, in maps. Where a temporal dimension is also involved, dynamic mapping is becoming increasingly popular. This talk explores the relationship between risk perception and visualizations of risk, as the basis for a framework for developing and testing visualizations of risk and uncertainty in maps that can usefully inform risk mitigation decisions. The framework is illustrated by application to HAZUS (a multi-hazard loss assessment tool developed and distributed by FEMA) and another prototype tool designed for similar applications.
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M4-P.23 Management of psychological risk factors. Williams RA*; US FDA RWilliam@cfsan.fda.gov
Abstract: A particularly challenging aspect of risk management is how to formally integrate the public's psychological perceptions of risk into both risk prioritization and decision making. This paper will address the question, what should knowledge of psychological factors and stakeholder concerns tell us about risk prioritization and risk management options? The answer will largely be determined by how effectively these concerns can be addressed by government agency tools. This paper will begin by summarizing what these factors are, how some government documents have tried to address them in risk management concept papers, and discuss where federal agencies may suitably address these concerns. The general finding is that, to a large extent, most tools in the hands of federal health and safety agencies are poor vehicles for addressing many psychological aspects of risk but are better suited to manage reduction in probabilities of population-based risk. A new strategy is suggested for addressing psychological concerns about hazards.
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M4-P.24 Communicating the risk of pesticide exposures to agricultural workers. Petersen DD*; US EPA and University of Cincinnati petersen.dan@epa.gov
Abstract: The goals of the US EPA pesticide worker safety program are to protect human health and the environment by ensuring the competency of pesticide applicators, to minimize pesticide exposure to occupational pesticide users and agricultural field workers, to assure use of pesticides, and to engage health care providers in improving the recognition and management of pesticide poisonings. The worker safety program includes statutory requirements, regulations and label requirements. To augment these components, US EPA uses education, outreach and training, guidance documents, partnerships, compliance assistance and capacity building, and oversight of implementing agencies. A new hazard communication pilot study was undertaken to identify the best ways to communicate pesticide risk with agricultural workers. In many areas, most agricultural workers are native spanish speakers, and literacy rates can be low. Effectively communicating the risks of various pesticide exposures can be challenging. We developed and tested a variety of color-coded, icon-based tools for communicating PPE use, potential symptoms of over-exposure and actions workers could take to avoid pesticide exposures. The symbols were tested with agricultural workers in both Florida and California in the spring of 2006. A hazard training program was developed based upon the best-rated symbols, and again the training program was evaluated in focus groups in Florida and California agricultural workers during 2006. Through research, and stakeholder review, US EPA has identified gaps in the framework of the agricultural worker protection regulations. These gaps compromise US EPA's ability to ensure the safe use of pesticides and the protection of pesticide exposed agricultural workers. To reduce risk, ensure competency, promote consistency, and raise the standards of the federal program to those of many states, regulatory amendments are necessary. These studies identify risk communication tools that can be used to help fill these gaps.
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M4-P.25 Establishing an environmental risk assessment paradigm for genetically modified organisms. Wolt JD*; Iowa State University jdwolt@iastate.edu
Abstract: Regulatory approvals for the environmental release of genetically modified organisms (GMOs) require consideration of the environmental safety of the GMO within the context of the scale, nature, and region of deployment. Numerous and sometimes overlapping regulatory requirements may govern the environmental risk assessment (ERA). Depending on the type and extent of the envisioned release as well as the political jurisdiction of the release, the competent authorities involved may extend from institutional to national biosafety committees; and the regulatory standards may be country-specific, regional (as within the EU, NAFTA, or other regional compacts), or international (the Cartagena Protocol on Biosafety, CPB) in scope. Signatories to the Convention on Biodiversity are faced with the task of implementing ERA consistent with Annex III of the CPB for the transboundry shipment of what are termed living modified organisms. Despite this apparent complexity, there are clearly common elements in terms of the nature of relevant information and the questions addressed when undertaking an ERA for GMOs. Annex III of the CPB defines steps in the environmental risk assessment process that are consistent with the common framework for ecological risk assessment. These steps entail establishing the nature of concern (problem formulation); identifying the potential adverse effects (hazard identification); estimating the likelihood of exposure (exposure characterization); evaluating the consequence of exposure (effects characterization); and estimating risk (risk characterization). Implementation of ERA under the CBD can be facilitated by developing commonly recognized core data elements and risk assessment approaches. A growing body of literature presents conceptual approaches to - and case instances of - ERA for GMOs that may be broadly implemented. Current state-of-the-science of ERA for GMOs will be presented on the basis of this literature.
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M4-P.26 The influence of media reporting on the perception of risk associated with genetically modified food in Japan. Nishizawa M*; University of Stuttgart nishizawa@sowi.uni-stuttgart.de
Abstract: Media reporting about food- and health-related risks is known to influence how people perceive risks. Drawn from the analyses on the reporting of GM food in selected Japanese daily newspapers between 1991 and 2004, this poster shows that societal concerns about GM food were influenced by the negatives images that the mass media projected. It argues that there is a need to pay more attention to the process of social amplification of risk by media exposure which often hinders effective science communication practices.
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M4-P.27 When public health enters the public eye: Print media coverage of autism and vaccination. Clarke C*; Cornell University cec54@cornell.edu
Abstract: Vaccination is considered the quintessential success story in public health. However, a 1998 Lancet article first questioned whether vaccines could cause childhood autism. This article touched off a firestorm of controversy worldwide and presented significant risk communication challenges involving both the benefits and risks of vaccination. Six years later, in May 2004, the Institute of Medicine (IOM) released a report that concluded that there was no association between the two. This report, like the larger controversy, received intense media coverage. People often use the media as a source for health information. Theoretical frameworks such as Social Amplification and Agenda-Setting, moreover, suggest that it has the potential to influence public evaluation of the issues covered. This paper investigates how a probability sample of North American newspapers reported on the vaccine-autism controversy, via a content analysis of articles appearing from 1998 to 2006. Specifically, this study seeks to quantitatively (1) examine how the IOM report affected media attention (if at all), (2) describe media coverage of a controversial public health issue from its very beginning, (3) provide a foundation for future theoretical work on media effects regarding this issue and (4) discuss implications for vaccine risk communication using the media.
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M4-P.28 Context, participant experiences, and long term outcomes of a structured decision aiding approach to watershed planning. Baird AM*; Ohio State University baird.41@osu.edu
Abstract: The poster will present case study findings on the use of structured decision aiding approach led by Ohio State University Extension and a nonprofit watershed organization to involve stakeholders in watershed planning. Specifically the case study will investigate the context, participant experiences, and long-term outcomes stemming from the development of the Lower Alum Creek Watershed Action Plan in Columbus Ohio. This study adds to previous case study reports on structured decision aiding for environmental planning by using in-depth qualitative techniques to explore connections between process steps, stakeholder decisions, contextual influences, and long-term outcomes. Findings provide evidence that link steps in the decision aiding process (e.g., defining problems) to decisions and specific actions by stakeholders, and presence of parallel processes including social learning (development of a common framework in understanding and joint action) and reduction in social amplification of risk. Additioanly participant frustrations with pacing and are revealed. Findings also include key contextual elements that influenced participant experiences and decision outcomes including local politics, available funding sources, and uncertainty over involvement and perceptions regarding power of stakeholders. The poster concludes with guidance to help scaffold future structured decision aiding approaches.
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M4-P.29 Stakeholder involvement in radiological monitoring and risk communication: The community environmental monitoring program. Hartwell WT*, Shafer DS, McCurdy G, Tappen J; Desert Research Institute, Nevada System of Higher Education ted.hartwell@dri.edu
Abstract: Since 1981, the Community Environmental Monitoring Program (CEMP), managed by the Desert Research Institute (DRI) for the US Department of Energy, has involved stakeholders in operation, data collection, and dissemination of information on radiological surveillance for communities surrounding the Nevada Test Site (NTS). The network includes 28 monitoring stations across a wide area of Nevada, Utah and California. Since 2000, significant enhancements have been made to the network's data collection and transmission capabilities. These include installation of a full suite of meteorological instruments at each station, allowing for improved interpretation of how meteorological events affect background gamma radiation. State-of-the-art dataloggers, capable of several weeks of on-site data storage are used, and an upgraded communications system includes a combination of DSL and wireless internet, land line and cellular phone, and satellite technologies. The main radiological instruments are pressurized ion chambers for measuring gamma radiation, and particulate air samplers, primarily for alpha/beta detection. Data are managed through a platform maintained by DRI's Western Regional Climate Center, which allows for near real-time upload and display of current and archival information in tabular and graphical formats on a public web site. In normal operating mode, the CEMP is designed to ensure there are no offsite radiological releases associated with past nuclear testing or current NTS activities. However, the CEMP is also part of the emergency response network in the event of an unplanned radiological release, and is serving as a platform for testing new environmental sensors. Archival data for each station is available on-line and can be used for site-specific risk calculations for different exposure scenarios. Additionally, the CEMP provides training workshops for stakeholders involved in the program, and educational outreach to address public concerns about health risk and environmental impacts from past and ongoing NTS activities.
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M4-P.30 Parental decision making about children's health: Using mental models research to inform contingent valuation surveys. Hoffmann S*, Bostrom A, Krupnick A, Adamowicz V; Resources for the Future, Georgia Institute of Technology, University of Alberta hoffmann@rff.org
Abstract: Typically, stated preference surveys ask an adult respondent to report their household willingness to pay. At the same time, a separate literature on family decision making suggests that household decisions are the result of a bargaining process dependent on income pooling and shares. Bateman shows that unless adults in a multi-adult household fully pool income, the standard approach of asking one adult to provide household WTP will not give an accurate estimate of household WTP. Indeed, in the context of decisions about children's health, this model can be expanded further to suggest that parents' risk perceptions, risk attitudes, knowledge about and responsibility for children's health and care and marital happiness could affect the response they make to choices over their children's health and, implicitly, to their willingness to pay for risk reductions to their children. This means that asking only one person to represent the household's decision in a stated preference study could result in inaccurate or even biased measures of household willingness to pay. In this paper, we analyze the results of a survey of thirty couples in the Atlanta area, who were asked separately and together a variety of questions about how they make decisions and about the variables listed above. The decision making questions include direct statements by parents describing how they made a specific decision; responses to closed-ended questions about decision making in general and for specific contexts, such as children's health, and a hypothetical decision about lead paint mitigation. These decisions are analyzed to qualitatively identify factors that indicate whether couples' decision-making processes are better characterized by a unitary or bargaining model. We draw on the team mental models literature to provide a methodology for measuring and characterizing agreement between spouses.
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M4-P.31 Reporting of risk estimates and confidence intervals in autism research. Corrales MA*; US EPA corrales@post.harvard.edu
Abstract: The CDC's estimates of diagnosed autism are 5.5-5.7 per 1,000 school-aged children. There is no consensus on the main causes of most cases of autism, and a wide range of potential causes are still debated with little quantitative information to put these issues in perspective or prioritize research funding. This analysis focuses on the growing biomedical literature on autistic spectrum disorders. We examined quantitative risk information provided in relevant abstracts, and summarized relevant data. PubMed was searched for records related to autism and related disorders, with several thousand entries identified. Several hundred abstracts from the International Meeting for Autism Research (IMFAR) were also examined. Directly relevant PubMed entries with abstracts have grown since 1996 from roughly 200 to almost 800 yearly. From 1994-1999, only 60 (4.8%) of these mentioned the word "risk" in the title or abstract. This grew to 245 (8.2%) during 2000-2005. An extremely small fraction of the more than 3,000 autism-related PubMed entries from 2000-2005 included terms such as "relative risk" (in 17 titles/abstracts from 2000-2005) or "odds ratio" (in 13). The term "95% CI" appears in only 3-4 abstracts per year from 2000-2005, and less than once a year from 1994-1999. A similar pattern appears in the more than 500 IMFAR 2006 abstracts. The odds ratio or similar metric was reported in only 11 of these abstracts, or approximately 2%. Autism-related studies that report associations with risk factors often use differing definitions of cases or risk factors, and generally use very small samples. Risks are rarely estimated, and prevalence of a risk factor is often unknown. Confidence intervals on estimated values are frequently unreported. A very small proportion of these research studies reported quantitative risk-related information in their abstracts, and a similar pattern holds for results reported in the full text.
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M4-P.32 Using risk analysis to enhance adoption: Integrating the elements. Hooker NH*, Tucker M, LeJeune J, Doohan D; Ohio State University hooker.27@osu.edu
Abstract: Social scientists must cooperate with natural scientists to ensure effective risk management decisions are made based on a complete understanding of the risk assessment procedure. Results of this integration of specializations must be communicated in an appropriate manner to promote behavioral change. Risk analysis serves as a framework for such interdisciplinary collaboration. This paper focuses on the development of tools which enhance the adoption of risk prevention and mitigation strategies in the presence of negative externalities. The importance of adapting risk management approaches to the complex ecological, business and sociological milieu of agricultural and food risk scenarios are of particular concern. Problems range from invasive species controls to food safety and bioterrorism. In such situations, adoption/diffusion of risk reduction strategies may be below the social optimum. Slow adoption or incomplete diffusion in a classic Rogers' sense may incur irreversible public health or environmental consequences. A generalizable model of socio-demographic, environmental and technological factors which influence motivation to use risk mitigation strategies in such situations has remained elusive. Idiosyncratic drivers of adoption/diffusion behavior must be better understood. Case studies are exploring these drivers, including Nicandra physalodes an invasive weed in row-crop agroecosystems and the relationship between farm management practices and the emergence of antibiotic resistant bacteria. Traditional risk management outreach programs have not succeeded in engaging farmers in active information seeking nor in containment and eradication activities. Interviews and focus groups with farmers and scientific experts indicate the breadth and complexity of factors considered when making livestock management decisions. In both cases stakeholders didn't fully understand the potential broader biological or public health consequences of their actions.
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M4-P.33 Who should be saved? Evaluating child safety from societal perspective. Kishimoto A*, Tsuge T, Takeuchi K; AIST kishimoto-atsuo@aist.go.jp
Abstract: The declining birthrate and the increasing reports in mass media of the crimes and accidents whose victims are children make people demand much more child safety in Japan. Against such a background, it should be reexamined whether the benefit estimation based only on willingness-to-pay (WTP) of adults for his own risk reduction is still effective. We conducted two internet surveys to estimate the monetary value of the child safety from societal perspective. In the first survey, we asked those surveyed to choose one of the two environmental programs each designed to save certain numbers of children, adults, and the elderly. Results show that the value of rescuing a child might be about 2.8 times that of rescuing an adult. Since the expected life of the child is about twice that of the adult, this suggests that the appropriate indicator of "effectiveness" in cost-effectiveness analysis from the societal perspective is "the expected life-years." The second one intended to elicit WTP for child safety as public goods by applying double-bounded contingent valuation survey. The hypothetical policies were designed to decrease the total mortality risk of children respectively by 1% and 5%. We estimated that the median WTP is 7,500 yen for reducing 1% and 11,000 yen for 5%, which passed the external scope test. We attempt to derive a preliminary value of rescuing a statistical child. Based on the first survey, we apply the ratio 2.8 to the Japanese "value of a statistical life" of about 350 million yen and we have the value of rescuing a statistical child of about 980 million yen. Based on the second survey, we divide the median WTP by the number of children saved and multiply the result by the number of family households (about 3,500), and we have 1.54 - 5.29 billion yen. We have found that these two values are fairly close.
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M4-P.34 Valuing cancer risk reductions for adults and children. Dockins C*, Simon NS; US EPA dockins.chris@epa.gov
Abstract: Although most benefit cost analyses to date have been conducted using scientific and economic valuation estimates derived for adult populations, there is increased interest in conducting analyses by specific age group or life stage. Advances in the scientific community have recently resulted in age-specific assessments of risk and exposure to various environmental contaminants. Similar advances are now sought in the economics field. Currently, little is known about how the public values reductions in risk to health for children. Nor is it evident how other risk characteristics (e.g. the type of risk, the uncertainty associated with the health outcome, and the populations affected) affect an individual's willingness to pay for programs to reduce these risks. This paper begins to address these gaps by reporting the results of a pilot survey developed to elicit individual willingness to pay for cancer risk reductions to children and adults. The pilot survey was administered in the State of Minnesota by the Minnesota Department of Health in the Spring and Summer of 2004. Designed to estimate willingness to pay for (1) reduced risk of cancer to adults from adult exposures to persistent environmental contaminants (PECs) and (2) reduced risk of adult cancers from childhood exposures to PECs, the survey instrument uses double-bounded dichotomous choice questions to elicit values from respondents. Risk reductions and latency periods are communicated to respondents with graphics and respondents' understanding of the graphics and scenarios explicitly tested. Furthermore, to test whether individuals differ in their public and private preferences for risk reduction, the survey includes both a private (labeling) program and a broad-based public program.
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M4-P.35 Risk, benefit, and cost analysis in European union impact assessments: Two case studies. Torriti J*; King's College London jacopo.torriti@kcl.ac.uk
Abstract: Risk regulation and risk analysis instruments are often seen as vanguard methods to decision-making, or as supports to help take decisions under uncertainty. But do regulators base their decisions on their potential risks and benefits? The European Union (EU) offers a challenging setting to address this question. It has often been accused of using the precautionary principle as the main approach to regulation. More recently, it has instituted an Impact Assessment (IA) system where elements of risk, benefit and cost convene within the same reports. Analysts interpret the introduction of IAs as a move away of the regulatory philosophy from precaution. In theory, IAs would guarantee a system to fulfil business stakeholder demand for an approach to decision-making different from the precautionary principle. The paper explores the challenges that the European Commission faced through the IA on two specific directives: Sustainable Use of Pesticides and Unfair Commercial Practices. Both directives, although different in their nature and scopes, present circumstances where in theory risk and economic analysis could be applied as supports to decision-making. The paper analyses the use of cost-benefit analysis and risk analysis techniques in the IAs and seeks to understand the reasons for methodological patterns (e.g. qualitative versus quantitative) in the IAs. Conclusions are based on content analysis of the IA reports and interviews with European Commission officials. The analysis of these case studies raises some questions as to the future use of risk analysis techniques by EU institutions.
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M4-P.38 The human health risk assessment based on land use adjustment to lead contaminated site and countermeasure cost analysis in Japan. Yasutaka T*, Matsuda H; Yokohama National University tetsuo.yasutaka@k2.dion.ne.jp
Abstract: Recently, the number of lead contaminated sites has been increasing in Japan, so the countermeasure cost of contaminated soil increase the burden to land owner. In Japan, to prevent human health effect by direct ingestion and inhalation of the lead contaminated soil, Soil Contamination Countermeasures Law which is established in February 2003, provided the soil content standard for lead (SCSL) (150mg/kg). In North America and Europe countries had developed several ways, for example, site specific risk assessment, to solve such problems. However, SCSL in Japan is a uniform standard value regardless of land use, in spite of a daily lead intake via contaminated soil varies with land use. In addition, risk assessment method to determine SCSL didn't sufficiently evaluate the human health risk by contaminated soil in Japan. Because it doesn't take account of high risk group, which is children and expectant mother for lead, and overestimates the daily intake of lead from food, water, air, and not contaminated soil. In this research, first, we attempt to calculate the Management Target Values (MTV) of the lead contaminated soil for several land use by probabilistic human health risk assessment. MTV is maximum lead concentration in contaminated soil which is calculated below the acceptable risk for several land uses. Our risk assessment methods consider high risk groups and estimate daily intake of lead from several medium. Second, we evaluate cost reduction rate of countermeasure by application of evaluated MTV to 10 lead contaminated sites. It was found from the result that the maximum MTV is 5,389mg/kg for an industrial and commercial land use, minimum MTV is 161mg/kg for a residential land use which is same level as SCSL. The average countermeasure cost reduction rate by MTV is 1% for a residential use, 96% by an industrial use. In conclusion, it is possible that the greater part of countermeasure costs cut down by introducing MTV, if land use is industrial and commercial.
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M4-P.39 Characteristics of ambient air volatile organic compounds in the vicinity of central Taiwan science park. Hsu HT*, Chang TY, Kuo SW, Tsai CT, Chiang MT; China Medical University hthsu@mail.cmu.edu.tw
Abstract: Taiwan government establishes science parks in order to recruit high-tech companies, encourage innovation in Taiwan, upgrade industries, balance regional development, and reach national economic growth targets. The Central Taiwan Science Park (CTSP) is categorized into five major industries that form a core technological superiority in central Taiwan. These industries are the nanoscience-based optoelectronics industry, integrated circuits industry, biotechnology industry, precision machinery industry, and telecommunications industry. However, many studies have shown that these industries can generate various air pollution emissions including hazardous air pollutant, benzene. In this study, we established a bimonthly sampling program to collect VOCs in the vicinity of the science park from March to November, 2005. Since traffic is also one of the emission sources for benzene, the traffic volumes were investigated simultaneously during VOCs sampling. By using line source dispersion model, comparison was made between sample data and simulation results. The measured and simulated results fit well for the data taken in March and May. However, the level of fitness became worse for the data taken in July, September, and November. It indicated that other than traffic source, there were other emission sources contributed to the pollution in our sampling site. When conducting a ratio of benzene to toluene analysis, we found that the ratios were in the range of 0.041-0.14. These ratios were different from the traffic source (0.5). By comparing the ratio taken in this study with the results of another study taken in industrial science park in Shin-Chu, a very similar ratio was found (0.047-0.1666). It is suggested that industries such as integrated circuits and optoelectronics might be the one to responsible for these VOCs emission.
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M4-P.40 Excess lifetime cancer risk assessment for municipal solid waste incinerator: A multimedia exposure assessment. Hsu HT*, Chou WS, Kuo CT; China Medical University hthsu@mail.cmu.edu.tw
Abstract: In Taiwan, incineration is used as a dominant municipal solid waste treatment method. Presently, there are about 20 large incinerators to handle 90% of municipal solid wastes which are over 9 million metric tons per year in quantity in Taiwan. Particulate matters emission from these incinerators including heavy metals have been of great public concerns. In this study, we used a multimedia, multiple pathway, and multiple route exposure model (CalTOX) to estimate the daily intake of toxic heavy metals by an exposed person in the vicinity of a municipal solid waste incinerator in central Taiwan. By inputting local model parameters such as average annual rainfall, land surface runoff, landscape properties, yearly average wind speed, and Taiwanese human exposure factors, we estimated the excess lifetime cancer risk caused by the emission of Arsenic, Chromium, Cadmium, Lead, and Nickel. The results indicated that ingestion is the dominant exposure pathway. It contributed about 90% of total daily intake of heavy metals associated with the emission from municipal solid waste incinerator. Finally, from the viewpoint of the management of human health, our study showed that the excess lifetime cancer risk was in the range of 10-8 - 10-10 for the selected site.
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M4-P.41 Probabilistic assessment of non-cancer risk from dietary intakes of carbamate residues in fruits and vegetables for consumers in Taiwan. Wu KY*, Huang YF, Chiang SY; National Health Research Institutes - Taiwan kywu@nhri.org.tw
Abstract: Carbendazim is a carbamate fungicide and widely used in grains and vegetables and fruits. Carbendazim could cause mutation and liver lesions and be spontaneously converted from benomyl and thiophanate-methyl. In Taiwan, the Agriculture Chemicals and Toxic Substances Research Institute (ACTSRI), Council of Agriculture routinely monitors residues of pesticides in fruits and vegetables and frequently reports the presence of carbendazim residues. The potential health effects of consumers from dietary intake of this residue have been of concerns. Thus the objective of this study was to assess the potential health risk from dietary intake of carbendazim residues. The ranges and means of carbendazim concentrations in each fruit and vegetable were annually published by ACTSRI. The distribution of this residue was constructed for each fruit and vegetable by using statistical method to estimate a standard deviation for each set of data. The distribution of intake rate of each fruit and vegetables for Taiwanese was estimated by using the amounts of annual production, import and/or export. Monte Carol was used to assess the distribution of hazard indexes for each fruit and vegetable. Our results show that the 95% upper limit of hazard index distributions for each fruits and vegetables assessed, and the distribution of total hazard indexes are less than 1. Given the uncertainty of the carcinogenicity of carbendazim and distribution of intake rate of each fruit and vegetable, these results suggest that the applications of carbendazim, benomyl, and thiophanate-methyl comply with current regulations in Taiwan, and the presence of carbendazim residues in fruits and vegetables would not cause additional risk for the majority of consumers in Taiwan.
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M4-P.42 Bounded rationality along the policy chain in Vietnam. Cullen A, Anderson CL, Stamoulis K, Gordon A; alison@u.washington.edu
Abstract: Experimental evidence, largely from the U.S. and Europe, challenges traditional assumptions about individual decision making under uncertainty and over time. Our interest is in whether behavioral economics, particularly differences in bounded rationality, explains systematic biases in resource allocation and program design. Using original data from Vietnam, we test a theory of decision making based on effort, association, and expected value of the outcome. Based on this analysis we find that individual perceptions of control, value and responsibility are influenced by information, both internal (through association) and external (through exposure). We extend the query to inter-individual variability in views of fairness, cognitive effort, and decision heuristics. Our findings indicate that in the rural commune setting in Vietnam, individuals are more likely to satisfice than maximize, and there are significant differences between policy makers and program recipients. These results have important implications for the design of poverty alleviation programs and other public policy endeavors.
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M4-P.43 Bioavailability of arsenic in soil: Some additional insight. LaVelle JM*; CDM lavellejm@cdm.com
Abstract: Bioavailability of arsenic in soil is a continuing issue for appropriate human health risk assessment associated with arsenic exposure. Recent results of in vitro and microprobe analysis of arsenic at a former secondary lead smelter and a former mining/milling site provide some additional perspective on this issue. In vitro analysis of arsenic bioavailability at a former lead smelter site was entirely consistent with low or zero assessability of arsenic in soils from non-contaminated areas, and increasing content of highly assessable arsenic in contaminated soils closer to the former location of the smelter stack. Results of the in vitro assay between to independent laboratories were consistent, demonstrating the reproducibility of the methods. Estimates for possible remediation goals for arsenic at this site for a given risk target were perhaps an order of magnitude higher than typical default values, when bioavailability information was taken into account. In vitro analysis of arsenic bioavailability at a former mine/mill site suggested that, regardless of soil concentrations, the amount of available arsenic was small. Results suggest that potential arsenic-related exposure may be only a fraction of exposure estimated using default assumptions. Electron microprobe analysis of soils indicated that arsenic was observed within the soil matrix and in forms typically non-assessable in the in vitro assay. Iron content of soils at this site was high (25,000 mg/kg or higher), and arsenic was likely associated with insoluble iron species. The current results re-confirm that knowledge of information on bioavailability of arsenic is critical to risk assessment at sites with arsenic soil contamination. Quantitative use of information on bioavailability of arsenic may provide the risk manager with addition options for remediation and/or mitigation.
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M4-P.44 Barriers to the effective implementation and regulation of a risk-informed fire safety regime within the UK. Mackenzie S*, Moore D, Kilpatrick T, Hardcastle C; Robert Gordon University, Glasgow Caledonian University s.mackenzie@rgu.ac.uk
Abstract: In 2005 the UK regulatory and legislative frameworks shifted toward the adoption of a full risk informed fire safety regime. Employers or persons having control over the majority of existing workplaces, now retain a specific statutory responsibility to conduct a formal assessment of fire risk and to also take reasonable steps to reduce the identified risk to an acceptable level. This paper evaluates the main barriers to the effective implementation of the risk informed fire safety regime and emphasis is placed on the following: (i) the main drivers leading to the implementation of a risk informed fire safety regime, (ii) the current and proposed legislative provisions which pertain to the assessment and management of fire risk within existing workplaces, (iii) the barriers to the effective regulation of a risk informed fire safety regime, (iv) factors which affect model selection, (v) factors affecting input parameter variation on fire risk assessment procedures, and, (vi) factors affecting the implementation of effective risk reduction and risk management strategies. The project represents a long standing collaboration between the authors and draws the primary findings from ongoing research projects with a wide range of stakeholders groups, and individuals within the UK.
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M4-P.45 Scottish fire risk research and education: Foundations and futures. Mackenzie S*, Taylor K, Moore D; Robert Gordon University s.mackenzie@rgu.ac.uk
Abstract: A number of factors have contributed to the uncoordinated fire risk research and education investment, infrastructure development, policy integration and stakeholder involvement in Scotland. This shortfall has potential to impact on Scottish region's (i) economic competitiveness of current fire research and educational providers, (ii) development of new research and educational provisions to fill current shortfalls (iii) the resourcing of fire research and education users needs, and implementation of (iv) the Fire (Scotland) Act 2005, (v) Building (Scotland) Act 2003, (vi) the Fire Service Modernisation agenda, and (vii) wider social policy agendas for Scotland. Improvements to date have resulted predominantly from informal networks between the established fire research teams in Scotland and wider stakeholder community. With each fire team undertaking independent, although interlinked, branches of research and educational provision. Development of these informal relationships into formal collaborations between individual academic units, and extension to the wider academic and stakeholder communities, would provide the foundations to allow for integrated fire research and educational provisions in Scotland. The proposals for development of the necessary focal point, infrastructure and dissemination portal to allow adoption of such strategic approach to fire risk research, education and policy provisions in Scotland are presented in this paper.
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M4-P.46 Modeling infrastructure risk. Lambert J, Sinka D, Skanata D, Byrd D*; University of Virginia byrdd@cox.net
Abstract: The North Atlantic Treaty Organization (NATO) held an Advanced Research Workshop (ARW) about computational programs of infrastructure risk in Primosten, Croatia on May 9-13, 2006. The Society for Risk Analysis and Enconet International Zagreb cosponsored the ARW. The program included posters and/or papers by most of the approximately forty (40) engineers and scientists. The objective, exploring different methodologies and related applications, recognized four major topics : Modeling Complex Systems, Simulation Models, Probabilistic Modeling and Non-probabilistic Modeling. Extensive discussion concentrated on the following issues: the state of the art and practice, gaps between the arts and practices, ways to bridge the gaps, and future research directions.
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M4-P.47 Safety assessment for systems of critical infrastructure. Shoji G, Kurozumi N*; University of Tsukuba gshoji@kz.tsukuba.ac.jp
Abstract: Infrastructures are exposed to functional impairment resulted from a shutdown and an accident due to a disaster. Since their functions are critically related to sustain our socio-economic activity, quantitative disaster risk analysis for the above systems is strongly required. Hence, this paper focused onto the functional impairment of infrastructures, and their objective risks due to a disaster were clarified by the risk assessment. First, six infrastructures are selected to be analyzed; railways, airways, telecommunication network systems, electric power supplies, water supplies, and gas supplies. The damage of airways, railways, and gas supplies was evaluated by the numbers of affected persons, that of telecommunication network systems by the numbers of affected circuits, and that of power supplies and water supplies by the numbers of affected households. Their risk curves were verified to relate the damage level of the system and its cumulative possibility (CP) by mining the archived records on Japanese newspapers from 1983 to 2004. The slope of the risk curve of airways becomes steeper compared with that of railways. It results in that the tail-end of the risk curve of railways reaches to higher consequence level than that of airways. The CP at the consequence level from 500 households to 300,000 ones in case of water supplies becomes lower than that in case of electric power supplies. The CP at the consequence level from 5,000 circuits to 50,000 ones, which represents the middle and the high consequence levels in case of telecommunication network systems, becomes higher than that at the other consequence levels. The CP at the low consequence level from 500 persons to 1,000 ones in case of gas supplies becomes four times higher than that at the other consequence levels. Based on the analysis, we second proposed a framework of criteria for the assessment of the risks related the functional impairment in infrastructures due to a disaster.
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M4-P.49 Evaluation of uncertainties associated with risk analysis of the indoor vapor intrusion pathway. Kountzman JA*; Black & Veatch Special Projects Corp. kountzmanja@bv.com
Abstract: Indoor vapor intrusion from soil and or groundwater continues to be the focus of increased interest as a component of the analysis of risk associated with volatile contaminants. This can be an important pathway; however, because information regarding various factors is often unknown, a considerable level of uncertainty may be associated with the analysis. Risk assessment guidance for the evaluation of the vapor intrusion pathway has been developed by the US EPA and numerous state agencies. Generally, these guidance documents address predictive modeling methods, soil vapor and indoor air sampling methods, data evaluation strategies, as well as community relations and mitigation options. Data on actual indoor air concentrations are typically unavailable. Predictions are often made based on soil or groundwater data alone. The purpose of this poster is to present some of the underlying differences between some of the existing methods, compare risks based on predictive modeling to risks based on measured soil gas or indoor air sampling, and to provide quantitative estimates of uncertainty associated with the models used to evaluate this pathway. The models considered for comparison include the Johnson and Ettinger Model, EMSOFT Model, and VOLASOIL Model. Measured soil gas and or indoor air data from several sites is used to quantify the magnitude of uncertainty associated with the various models selected for comparison. As with any risk assessment methodology, different levels of uncertainty are associated with each of the different modeling methods and site specific conditions. Recommendations are provided for model selection based on quantitative estimates of uncertainty.
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M4-P.50 Comparison of model predictions of absorbed pesticide dose to biomonitoring data. Diskin KA*, Heiger-Bernays WJ, Price PS; Boston University School of Public Health, The LifeLine Group, Inc. KDISKIN@BU.EDU
Abstract: The LifeLine model is a probabilistic model being used by regulatory agencies in the US and Canada to assess cumulative and aggregate exposures to pesticides or other chemicals. The LifeLine model assesses risk to the general population or sensitive subpopulations from dietary, drinking water or residential exposures. This work describes the methodology used to obtain the data necessary to perform an assessment of chlorpyrifos exposures using LifeLine. Prior to its being restricted, chlorpyrifos was one of the most widely used organophosphate pesticides. The US population was exposed to chlorpyrifos through food and water consumption or through residential uses of chlorpyrifos. Not surprisingly, urinary metabolites of chlorpyrifos, including 3,5,6-trichloropyridinol (TCP) have been detected in human urine as part of the ongoing NHANES study. Using the NHANES metabolite data on an individual basis, an absorbed dose of chlorpyrifos was calculated for each individual. To convert the data from a urinary concentration (ug/l) to an absorbed dose (ug/kg/day) requires creatinine correction. However, since the urine samples are spot samples, we use a method described in the literature to generate the amount of creatinine excreted per day to calculate an absorbed dose of pesticide. The individuals from NHANES are grouped by demographic characteristics to create sub-populations and compared to the estimates of dose produced by the LifeLine model on matched sub-populations. A sensitivity analysis of critical parameters will be performed. The results of these analyses provide insight on model performance.
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M4-P.51 Atmospheric dispersion model for exposure and risk assessment version 2: Development of a sub-grid module. Higashino H*, Shinozaki H, Nakanishi J; National Institute of Advanced Industrial Science and Technology haru@ni.aist.go.jp
Abstract: AIST's Atmospheric Dispersion Model for Exposure and Risk Assessment (ADMER) estimates regional spatiotemporal distribution of concentrations of chemical substances - for instance, the Kanto and Kinki areas - and issues predictions of the monthly averages at spatial resolutions of 5 x 5 km within six time zones (i.e., 4 hours average). ADMER offers a wide range of basic functions - grid emission preparation, meteorological data processing and analysis, and estimated concentration analysis, including exposed population calculations. ADMER has already held 2000 or more users, and is one of the most popular software for the assessment of exposure to hazardous air pollutants in Japan. However, we are receiving a lot of proposals for the improvement, as users are increasing. One of the most frequent requests from users is finer spatial resolution. We have developed the sub-grid module of ADMER which can estimate a distribution of concentrations at three different kind of spatial resolutions of 100 x 100 m, 500 x 500 m, and 1 x 1 km within the basic ADMER grid (5 x 5 km). Sub-grid calculation is only performed at a selected ADMER grid. Contributions from emissions of other than selected ADMER grids are estimated at resolutions of 5 x 5 km by previous method of ADMER. Concentration at each sub-grid was estimated by overlapping the contributions from all source grids (all sub-grids within the selected grid and all ADMER grids in the analytical domain) onto all the sub-grids within the selected grid. We also carried out the model validation. Benzene was selected as a target substance for testing the effect of sub-grid module. The results given by ADMER with sub-grid module were consistent with measured data, and they were largely improved rather than by only ADMER. The version 2.0 of ADMER which includes a sub-grid module will be available by the end of 2006. It will be available to the general public and will be downloaded and used free of cost.
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M4-P.52 Risk assessment and management of chloroform in Japan. Ishikawa Y*, Kawasaki H, Hayashi T; AIST y-ishikawa@aist.go.jp
Abstract: The purpose of this study is to perform risk assessment of chloroform in Japan and propose the risk reduction measures. Significant releases of chloroform to the environment occur indirectly through reactions of chlorine with organic chemicals and as by-products during the addition of chlorine to drinking water and wastewaters for disinfection. Therefore, we estimated the emission amounts and exposures of chloroform released not only directly but also indirectly as disinfectant by-products through chlorination of water and paper bleaching with chlorine. Most of environmental releases of chloroform are to the atmosphere. Chloroform released to surface waters or soil will be transported to the air because of its high volatility. In Japan chloroform has been detected in ambient air and indoor air more frequently, whereas in surface water, groundwater and drinking water chloroform has been rarely detected. The general population in Japan is exposed to chloroform principally through inhalation of indoor air and ingestion of tap water. We estimated intake from daily showering, bathing, housekeeping and swimming in the pool by considering volatilization from tap water to indoor air. In terms of human health effects, we assessed both cancer and non-cancer effects. From the point of view of ecological risk, it was concluded that few risks were generally expected for aquatic organisms. Current releases of chloroform from manufacturing factories have been decreased gradually because of the voluntary measures of hazardous air pollutants in Japan. It was considered that the decreases led to the fact that exposure concentrations of chloroform in ambient air had been decreasing, which suggests that we will not have to encourage stricter control than the present. As for indoor air, we may need to exchange the air for outdoor air.
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M4-P.53 Combined intake and pharmacokinetic model to predict serum TCDD concentrations. Jolliet O*, Towey T, Wenger Y, Adriaens P, Chang SC, Hedgeman E, Demond A; University of Michigan ojolliet@umich.edu
Abstract: The University of Michigan Dioxin Exposure Study was undertaken in response to concerns among the population of Midland and Saginaw Counties that the PCDD, PCDF and PCB's contamination of soils in the Tittabawassee River flood plain and areas of the City of Midland could lead to elevated people's body burdens. This paper aims to model the factors that explain variation in serum congener levels of PCDDs, PCDFs, and PCBs and compare it with measured blood samples on 900 inhabitants in this region as well as in a control region for background exposure. Historic concentrations of dioxins and furans in food: The shape of the historic curve for TCDD in the terrestrial meat supply was modeled using a best fit curve obtained using historic measured meat PCDD/F TEQ data and calibrating the general historic curve with recent measurements of TCDD in the food supply. Variation in intake of food with age and body-weight were based on the US EPA consumption curve as a function of age and adapted according to individual answers to a detailed survey on food consumption. Building on the Physiologically Based PharmacoKinetic (PBPK) model from Van der Molen, body fat mass and body liver mass were adjusted to each individual as a function of Body Mass Index. The PBPK model was then reprogrammed using Berkeley-Madonna17 and used to simulate the change in serum TCDD levels in individuals born between 1900 and 1985. The model describes well how TCDD serum concentration varies in the population with age at different times. The shape of the serum concentration curve changes significantly with time due to both the reduction in food concentration and the increased accumulation with age. In 1975, it is convex with a clear saturation for people over the age of 50; it becomes almost linear by 2005.
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M4-P.55 Exposure assessment of air pollution in residential area and school environments using GIS related to lung function among school children. Lin MH*, Ho WC, Shiao GM, Hartley W, Lin RS; China Medical University linmh911@yahoo.com
Abstract: To assess air pollution related to lung function among school children is an important public health task. Exposure assessment used to be a key step in assessing human health risk. Based on the high density of air monitoring stations in Taiwan, this study is using GIS to assess the air pollution exposure in residential area (school district) and school environments. The health risk will focus on lung function among school children. Geostatistical procedure is using kriging estimate method in 500m × 500 m grid squares. In addition to air pollution exposure as a continuous variable in the analyses, US EPA National Ambient Air Quality Standards 2006 criteria will be followed and air pollution exposure levels (very low, low, medium, high, and very high) related to lung function will be assessed. The study population was random sampling of 10% of junior high school students to complete lung function test and standard questionnaires in Taiwan area (N= 92,548). The lung function tests followed the 1977 criteria of the American Thoracic Society (ATS) Snowbird Conference, and the ATS update statement of 1987. In order to assess residential area and school environments related to its effects on lung function, the regression model is using. The controlling variables include gender, age, body weight, body height, allergic disorders, family history, parental education level, exercise, cigarette smoking, environmental tobacco smoking, alcohol beverage consumption, child's bedroom, allergens and weather factors. School children spend most of time in school and house. School usually is located in more traffic polluted area than household. Several multi-city studies in USA and worldwide point out that traffic-related pollution potentially more responsible for asthma. To achieve the best protection for the respiratory health of school children, it is important to assess children exposed to air pollution in both school and household environments.
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M4-P.56 A probabilistic approach to risk assessment applied in a food industry context. Membre JM*, Gorris LGM; Unilever jeanne-marie.membre@unilever.com
Abstract: Probabilistic approaches to risk assessment have proven valuable in governmental contexts (e.g. for assessing risks to consumers associated with particular food products on the market). The present study provides an example of how such an approach can be used to support decisions made by food safety managers. In many countries, there is consumer demand for more convenient, fresh, natural foods of high organoleptic quality, which implies lighter preservation system and lower heat-treatment. A mild heat treatment provides opportunities for pathogenic spore-forming bacteria like non-proteolytic Clostridium botulinum and Bacillus cereus, to survive and after a lag time to grow even at low temperatures and make the product unsafe. However, with a minimum heat treatment of 10 minutes at 90°C, only Bacillus spores are considered to have the opportunity to grow. In the scientific literature it is reported that the lag time (including spore recovering and germination) depends on the heat treatment intensity, subsequent storage temperature, pH, water activity and on the post-process spore level. Lag time depends also on food matrix and microbial strain. On the other hand, the chilled supply chain, from the food manufacturer to the consumer's plate, includes storage in various fridges (warehouse, retailer, consumer) for different times and with several transportation steps. Therefore, to combine all these pieces of information and to capitalize on information coming from different sources (literature, internal experts and experimental data), the Markov Chain Monte Carlo Bayesian technique was carried out. Finally an exposure assessment model including natural variability due to process, product, microorganisms and consumer practice, was produced. The model outputs were delivered as distributions of values and not as single point estimates. Their use by our food risk managers are discussed.
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M4-P.57 Exposure assessment simulation for microbial behavior of Salmonella during poultry processing. Pradhan AK*, Li Y; University of Arkansas; Abani Pradhan: Winner of the Student Merit Award for the Exposure Assessment Specialty Group apradhan@uark.edu
Abstract: A simulation model was developed for exposure assessment of Salmonella during poultry processing to assess the effects of different processing steps on the microbial behavior. The model computed the prevalence and number of Salmonella in broilers or their carcasses from arrival at a processing plant to chilling process. Published literature was reviewed, relevant data were complied, and experimental data from challenge tests were fitted to define probability distributions to characterize the incidence and variation of pathogen events affecting the behavior of Salmonella in broilers. Uncertainty analysis was performed using Monte Carlo simulation, sUS EPArating knowledge uncertainty and stochastic variability to describe the lack of knowledge and natural variability in model estimates. A typical poultry processing scenario was simulated using Monte Carlo simulation technique for a batch of 1,000 broilers considering, initial contamination between 2 to 4 log CFU per bird, scalding at 50 C for 2 min (soft scald), spray-washing with tap water for 20 sec, and chilling with 50 ppm of chlorine in a chiller tank at 1-4 C for 50 min. Simulation results indicated that the prevalence of Salmonella contaminated birds reduced from 30% upon arrival to 14% after chilling. For contaminated broilers, the mean bacterial loads of Salmonella in log CFU per bird were 3.2 for arrival, 1.9 for scalding, 2.8 for defeathering, 3.8 for evisceration, 3.0 for washing, and 2.1 for chilling. Different processing conditions such as scalding at 50 C and 55 C for 2 min, washing with tap water and water containing 50 ppm of chlorine for 20 sec were simulated to compare their effects on the behavior of Salmonella in broilers. This model could be used as a tool to assist processors and managers in estimating the effect of processing on microbiological quality of broiler carcasses, and in making food safety management decisions to control Salmonella contamination during poultry processing.
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M4-P.58 Physiologically-based toxicokinetic models for toxic metal mixtures: Development and demonstration of a mechanistically-consistent framework . Sasso A*, Georgopoulos PG; Rutgers University asasso@ccl.rutgers.edu
Abstract: Physiologically Based ToxicoKinetic (PBTK) models have become the tools of choice for predicting the fate of environmental contaminants in humans. While several PBTK models have been developed for different environmental chemicals, many of them are not mechanistically consistent. This is especially true for the case of toxic metals, where half-lives in the human body range from a few days (e.g. chromium, arsenic) to a few decades (e.g. lead, cadmium). Several differences in the formulation of these models exist with respect to (a) physiological structure (body tissue volume and blood flow ratios), (b) general modeling assumptions (for transport and transformation of the chemicals within the body), and (c) exposure-relevant activities. These PBTKformulations are in general different depending on the chemical that is being modeled. It is therefore not feasible to perform consistent and simultaneous modeling of multiple contaminants in humans (individuals and populations). However, these contaminants typically exist in multiple media (soil, food, and air) as mixtures, and are known to interact at both the toxicokinetic and toxicodynamic levels in humans. This poster introduces a mechanistically consistent, generalized PBTK model for toxic metals. Preliminary case-studies at both the individual and population level are illustrated.
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M4-P.59 Identification of emission source of antimony and antimony compounds into the air. Tsunemi K*, Tokai A; CRM, AIST k-tsunemi@aist.go.jp
Abstract: The major use of antimony trioxide is as flame retardant synergist in plastics and textile back coatings where it is co-used with bromine based halogenated compounds such as polybrominated diphenyl ethers (PBDEs). Antimony trioxide is also used as polymerization catalyst used in PET resin manufacture and as a frictional additive in automotive brake linings. Antimony trioxide is classified as a 2B carcinogen by the International Agency for Research on Cancer or category 3 carcinogen by European Union. In Japan, antimony and antimony compounds are classified as class 1 designated chemical substances by the PRTR law. Thus, it should be concerned that antimony and antimony compounds are emitted into the air at production, use and disposal stages of life cycle. However, it is not clear which stage is the main emission source though life cycle of these substances. Therefore, emission into the air was estimated at production, use and disposal stages of antimony and antimony compounds in order to identify main emission source for risk management. First, reported emission data of PRTR were used at the production stage. Next, the emission from automotive brake linings was estimated because main source of emission at the use stage is the abrasion of brake linings. Furthermore, the emission at the disposal stage was estimated by analyzing the substance flow of antimony in Japan through production, shipment and disposal. The amount of domestic supply, gross additions to stock and waste generation were estimated, and the emission by waste incineration was estimated in consideration of the factors of stripping ratio and the efficiency of dust separators. As a result, the emissions at the use and disposal stages were larger than that at the production stage. Thus, it was assumed that the atmospheric concentration of antimony is as high in urban areas with high population density and heavy traffic as in local industrial areas.
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M4-P.60 Methods for assessing the effect of a randomized community educational intervention on the take-home pathway of organophosphate pesticide exposure. Vigoren EM*, Griffith WC, Coronado GD, Thompson B, Faustman EM; University of Washington, Fred Hutchinson Cancer Research Center gorst@u.washington.edu
Abstract: Research suggests that young children are exposed to pesticides that accumulate in the home when farmworkers carry pesticides home on their skin and clothing. Twenty-four communities in the Lower Yakima Valley of Washington State (a region for growing orchard crops such as apples) were recruited into a randomized community trial to examine the effect of an educational intervention about the take-home pathway of organophosphate pesticide exposure. Communities were blocked into pairs, based on type of community and population size, and randomized. A survey assessed job tasks, exposures, and workplace and home practices related to pesticides. A cross-sectional sampling of farmworker households with a child between the ages of 2 and 6 was identified. Urine samples were collected from the farmworker and child for analysis for urinary pesticide dialkyl metabolites, and dust samples were collected from the homes and vehicles for analysis for pesticide residues. After two years of community educational intervention, a new cross-sectional sample of farmworkers was drawn from the 24 communities. Primary measures of effect were changes in the urinary pesticide metabolite concentrations and pesticide residue concentrations in dust samples from the intervention communities compared to the control communities, adjusting for baseline. Three major challenges in analyzing the trial are the year-to-year variability in pesticide use and growing season, a large variability between individuals, and an even larger variability day-to-day within individuals. These sources of variability caused a large fraction of the data to be below detection limits, and methods were developed to account for this characteristic. Validation of the intervention is an important part of protecting the health of children in agricultural communities.
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M4-P.61 Retrospective exposure assessment of asbestos related to skilled craftsmen at a petroleum refinery in Beaumont, Texas (1940-2005). Williams PRD*, Paustenbach DJ, Balzer JL; ChemRisk, Consultant pwilliams@chemrisk.com
Abstract: In this retrospective exposure assessment, historical 8-hr TWA asbestos exposures were estimated for 12 different categories of craftsmen at a large petroleum refinery located in Beaumont, Texas. This included the following trades: insulators, pipefitters, boilermakers, masons, welders, sheet metal workers, millwrights, electricians, carpenters, painters, laborers, and maintenance workers. The assessment quantitatively accounted for (1) the historical use of asbestos-containing materials at the refinery, (2) the typical workday of craftsmen and opportunities for exposure to asbestos, (3) industrial hygiene air sampling data collected at this facility (and other refineries) since the early 1970s, (4) published and unpublished data sets on task-specific dust or fiber concentrations in various industrial settings since the late 1930s, and (5) the evolution of respirator use and other workplace practices that occurred as the hazards of asbestos became better understood over time. A probabilistic (Monte Carlo) model was used to account for the variability in the data and the uncertainty in our knowledge of selected input parameter, and significant reliance was placed on our collective professional experiences working in the fields of industrial hygiene, exposure assessment, and process engineering. Insulators at this refinery were estimated to have experienced 50th (and 95th) percentile 8-hr TWA exposures of 9 (16) fibers/cc from 1940-1950, 8 (13) fibers/cc from 1951-1965, 2 (5) fibers/cc from 1966-1971, 0.3 (0.5) fibers/cc from 1972-1975, and 0.005 (0.02) fibers/cc from 1976-1985 (estimated exposures are <0.001 fibers/cc after 1985). Estimated 8-hr TWA exposures for all other craftsmen were at least 50 to 100 times less than that of insulators, with the exception of laborers, whose estimated 8-hr TWA exposures were approximately 1/5th to 1/10th of insulators. In spite of some data gaps, we are confident that our estimates of 8-hr TWA asbestos exposures properly characterize the typical range of values for these categories of workers over time.
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M4-P.62 Use of a simulation to estimate benzene exposure from degreasing elevator parts. Sheehan P*, Malzahn D, Goswami E, Kalmes R, Hicks J, Mandel J; Exponent psheehan@exponent.com
Abstract: Exposures to mineral spirit solvents used in parts-washing units have been measured and published, but no published measurement data exist for parts degreasing activities using these solvents away from a parts-washing unit. To evaluate a worker's potential exposure to benzene while using a bucket of solvent and rags to clean parts, a simulation was conducted. The objective of the simulation was to measure benzene in air to estimate a worker's exposure to benzene from a mineral spirits solvent used to clean parts during the repair of an elevator head pulley at an agricultural processing facility. The simulation was based on a description of the repair event and conditions provided by a worker who was familiar with the activity. At the site of the original repair project, greasy bearing housings and associated components were cleaned by dipping the parts into a bucket of solvent and washing the grease from the parts by hand using shop towels. Personal, area, and background samples were collected for benzene analysis during the entire day of the re-enactment. All of the individual measurements were below the detection limits of 0.003 to 0.008 ppm. Based on the results of the simulation, the worker's potential exposure from both inhalation and dermal uptake of benzene from cleaning activities was estimated to be 0.2 mg, which is equivalent to inhaling air containing 0.004 ppm benzene over the 12-hour repair period. This concentration is indistinguishable from the background benzene concentrations measured at the site and reported in the literature for ambient air at urban and rural locations in the United States.
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M4-P.63 Maximizing the population exposure benefits of motor vehicle retrofits. Greco S; Harvard School of Public Health sgreco@hsph.harvard.edu
Abstract: Installing diesel particulate filters (DPF) on urban buses is a common upgrade or retrofit under consideration by transit authorities and other stakeholders to reduce fine particulate matter (PM2.5) emissions. As resources are generally limited, transit authorities may be faced with choices regarding which buses and which routes to upgrade. Optimization based on public health benefits would be desirable, as the population exposure impacts of motor vehicle emission reductions can vary greatly in an urban area, but sufficiently detailed populations and air quality observations in space and time are not generally available to incorporate spatial and temporal variations in the emissions-to-exposure relationship. In this study, we investigate using the intake fraction (emissions-to-exposure relationship) to maximize the public health benefits resulting from DPF retrofits. We consider a case study of 25 Massachusetts Bay Transportation Authority bus routes, and develop route-specific PM2.5 intake fractions based on previously-developed estimates for all road segments in the Boston area. The implications of optimization based on the intake fraction is illustrated by first evaluating the benefits associated with retrofitting half of the buses from each route, and then comparing these benefits to those obtained by retrofitting the same number of buses, but exclusively from the high intake fraction routes. Under our baseline model assumptions, we found benefits to increase by 20% when optimized based on intake fractions, with net benefits (benefits less costs) increasing by a factor of two. The concentration-response (C-R) function and the value of a statistical life (VSL) were extremely influential in the benefit-cost analysis, with lower bound C-R and VSL estimates yielding negative net benefits and the upper-bound C-R function increasing net benefits by an order of magnitude compared to baseline assumptions. Regardless of model uncertainties, our analysis demonstrates a viable approach for maximizing the population exposure benefits of motor vehicle retrofits, and subsequent analyses will investigate how the benefits are distributed among impacted communities, to arrive at socially optimal control strategies.
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M4-P.64 Risks from geologic disposal and extended storage of used nuclear fuel. Garisto NC, Davis MW, Eslami Z*; SENES Consultants Limited zeslami@senes.ca
Abstract: The Nuclear Waste Management Organization (NWMO) has a mandate from the Government of Canada to consult with the public and to recommend an approach for managing Canada's used nuclear fuel. Three main approaches were explored and evaluated by the NWMO. These are disposal in a Deep Geological Repository, extended storage at nuclear reactor sites and centralized extended storage, either above ground or below ground. Conceptual designs were developed for these used nuclear fuel management options studied by the NWMO. All these designs meet regulatory safety and environmental requirements. Regulatory compliance does not imply that these concepts can be implemented under zero-risk conditions. Like any major industrial project, a nuclear used fuel facility may affect the health of project workers and of members of the public living near the site or along affected transportation routes. This paper compares potential risk to the public, risk to workers and risk to the environment for the three approaches listed above. The possible effects associated with these approaches are not limited to those resulting from exposure to radiation, but also include conventional industrial risk and risk from non-radiological contaminants. The risk assessment presented is based on a combination of operating experience at the nuclear sites in Ontario (Pickering, Darlington, Bruce), uranium mining experience, as well as Canadian and international assessments of used nuclear fuel disposal and storage.
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M4-P.65 Exposure to n-hexane, toluene, and benzene aboard ocean-going tankers. Warmerdam J, Pierce J, Finley B*; ChemRisk jwamerdam@chemrisk.com
Abstract: Workers in the oil production industry may be exposed to a wide range of hydrocarbon chemicals, primarily through inhalation and dermal contact. These chemicals have varying degrees of toxicity and chemical behaviors. A significant amount of literature exists regarding petroleum worker exposures at fixed facilities on land, including dose reconstructions, mortality/cancer rate analyses and other descriptive evaluations. Possible exposures experienced by sea-going workers have received relatively little attention, and there is a paucity of literature regarding the magnitude of inhalation exposures to the volatile fraction of crude oils experienced by these workers aboard, particularly, sea-going crude oil tankers. We relied on historical on-board industrial hygiene data, employee work records and self-reported activities to estimate the magnitude of exposure to benzene, toluene, and n-hexane experienced by individuals aboard these vessels. Because little data exist regarding airborne concentrations of n-hexane aboard oil tankers, total hydrocarbon (THC) measurements were used, in conjunction with the fraction of THC that is n-hexane in crude oils, to calculate airborne n-hexane concentrations. A Monte Carlo model was developed that incorporated available concentration information during nine distinct work tasks that comprised a majority of work performed by crew members on these vessels during crude oil loading and while these vessels were underway. It was determined that airborne concentrations were location- and activity-dependent, with the highest levels experienced during work performed in partially enclosed spaces or near tank vents. Lifetime exposures to n-hexane, toluene, and benzene were calculated to be 9.6, 0.7, and 1.1 ppm-year at the 50th percentile and 28.4, 2.6, and 6.1 ppm-year at the 95th percentile. These estimated exposures are well below the levels expected if permissible exposure limit concentrations were experienced over a working lifetime (20,000 ppm-year for n-hexane, 8000 ppm-year for toluene, and 40 ppm-year for benzene).
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M4-P.67 Analysis of the Tulalip and Squaxin Island Tribes fish consumption survey. Wilkins AAC*, Polissar NL, Moya J, Neradilek B, Liao S, Toy KA, Mittelstaedt GD; US EPA Wilkins.Amina@epa.gov
Abstract: A survey based study was completed to estimate fish consumption rates for two Native American tribes within the Pacific Northwest. Raw data from 190 tribal members age 18 and over and for 69 children ranging from birth to five years were analyzed and distributions of fish consumption rates for adults and children within each tribe were calculated in terms of grams per kilogram of body weight per day (g/kg-day). The mean consumption rate for all fish including shellfish for Tulalip tribe adults was 1.0 g/kg-day and boundaries for the 95 percent confidence intervals were 0.8 (lower) and 1.6 (upper). The mean consumption rate for all fish and shellfish for Squaxin Island tribe adults was 1.0 g/kg-day with 95 percent confidence intervals ranging from 0.8 to 1.3 respectively for upper and lower bounds. Adults in both tribes were shown to have considerably higher consumption rates than the 0.2 g/kg-day reported for the general population (US EPA, 2002). In conclusion, consumption patterns between the two tribes varied by age, gender and by fish group (anadromous, pelagic, bottom, shellfish, other, all finfish, and all fish). Since eating habits and fish consumption patterns can vary among various populations, this study is part of an effort to improve exposure assessments by providing data to reflect and evaluate exposures for two Native American tribes within the Puget Sound area.
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M4-P.68 Method and tools for developing occupational risk assessments for chemicals with limited data. Maier A, Gadagbui B, Santory J, Ranslow P, Becker E, Parker A*; Toxicology Excellence for Risk Assessment, Consortium for Environmental Risk Management parker@tera.org
Abstract: Human health professionals are often called upon to assess worker risk from potential chemical exposures in the absence of validated sampling techniques or occupational exposure limits (OELs). In such cases, alternative tools and approaches are needed to develop robust quantitative risk assessments. Such tools and approaches have been developed and applied as part of US EPA's Sustainable Futures Initiative - a voluntary program with the goal of encouraging application of pollution prevention principles and the development of inherently low hazard new chemicals. The hazard screening approach involves identification of physical/chemical properties and production information, used in conjunction with exposure assessment models such as ChemSTEER to estimate potential exposures. Human health hazard for non-cancer and cancer effects are identified based on a broad search of the literature. In many cases, data on the chemicals are very limited, and toxicology data on structural analogues and degradation products, as well as quantitative structure activity relationships are used to develop health toxicity benchmarks in the absence of published OELs. Decision criteria for identifying potential health concerns, for selecting analogues, and for weighing alternative lines of evidence have been developed and refined in the implementation of this program. Using these approaches, effect level benchmarks are identified, and combined with estimates of exposure to develop risk assessments for various scenarios. This risk assessment approach allows for the rapid collection and review of datasets and identification of potential toxicological concerns early in product development and for data-poor compounds. Key decision criteria and lessons learned in applying these tools and methods will be presented.
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M4-P.69 An integrated decision tool for evaluating chemical safety in laboratory research studies involving animals. Maier A, Utrecht J, Parker A*; Toxicology Excellence for Risk Assessment, University of Cincinnati parker@tera.org
Abstract: Toxicology and other research studies using whole animal exposures remain a cornerstone of chemical and drug safety evaluation. These studies involve potential health consequences for researchers, laboratory personnel, and animal handlers. Therefore, approaches for assessing potential health concerns associated with study protocols is needed. To meet the requirements of Institutional Animal Care and Use Committees and other groups, we have developed an integrated approach for risk assessment of activities associated with conducting animal research experiments. This approach brings new tools to support the traditional elements of risk assessment. First, an evergreen database structure has been developed that summarizes key hazards of toxicants or drugs used in each newly evaluated protocol. This database synthesizes and provides a critical evaluation of toxicological data for each agent. Second, a decision-logic for evaluating the potential exposure has been developed based on physical and chemical characteristics, routes of administration and use scenarios, and toxicokinetic data. Third, a qualitative approach for aligning potential hazard and exposure to corresponding control strategies has been developed. This approach has been applied to over 100 laboratory use protocols, and offers a tool for increasing the consistency in defining hazards as well as improving the documentation of the underlying rationale for workplace control recommendations.
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M4-P.70 Screening level integrated ecological and human health risk assessment for Lake Whatcom. Maginnis C*, Landis W; Western Washington University maginnc@cc.wwu.edu
Abstract: A screening level integrated ecological and human health risk assessment was conducted for Lake Whatcom in Whatcom County Washington, using the Relative Risk Model (RRM). Lake Whatcom is a multi-use, multi-jurisdictional watershed that serves as the only drinking water source for approximately 85,000 people, while also supporting diverse fish and wildlife species. This is the first study that utilized the RRM for an integrated risk assessment by incorporating human health into the ecological risk assessment framework. Since humans live in the watershed as well as drink the water, they are exposed to risks through many routes. City of Bellingham water customers, mostly residing outside the Lake Whatcom watershed, depend on the treated drinking water from the lake. However, human land use activities degrade water quality, and in turn affect fish, wildlife, and human health. As with any multiple use source water area, diverse stakeholder groups support a range of values which lead to complex and somewhat conflicted land use policies. This screening level ecological and human health risk assessment quantified the relative risks to humans, fish, wildlife, and water quality from chemical, physical, and microbial sources of contaminants. The sources exist within both geographically based ecological risk regions and water customer based human health regions. Risk characterizations were composed by identifying sources in each risk region, and the potential impacts to endpoints from these sources. These risk characterizations provided a rank-based assessment of ecological and human health risks existing in a multi-use drinking water supply. Using Crystal Ballâ„¢ software, uncertainty and sensitivity analyses determined which model inputs drove the overall risk ranks. The RRM can be applied to the Lake Whatcom watershed as a way for managers to reduce sources of risk to both ecological and human health from land use.*
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M4-P.71 Prediction of population level effects to brown trout (Salmo trutta) resulting from exposures to zinc in the Upper Arkansas River, Colorado. Burris JA*, Toll J, Graves A, Negley T; Syracuse Research Corporation, Windward Environmental LLC, Syracuse Research Corporation burris@syrres.com
Abstract: A modeling effort was conducted to understand potential effects of zinc toxicity on the stability of a population of brown trout (Salmo trutta L.). In the Upper Arkansas River, there is spatial and temporal overlap with brown trout young of the year (YOY)and areas receiving zinc contaminated runoff from historic mining operations. Remedial decision making required understanding potential future effects of zinc exposures for YOY to the brown trout population. A model was developed based on 1) a structure depicting the life stages of a brown trout; 2) estimates of survival and fecundity parameters for each life stage; 3) projections of population growth rate and stable population structure; and 4) parameters which had the greatest influences on vital population statistics. A probabilistic population model was developed to examine population level effects of excess mortality to brown trout YOY. The parameters used to define the model were estimated from values representative of brown trout populations in Europe and North America. The projections of the model were sensitive to all parameters that contribute to the onset of reproduction. The weight of evidence suggests that survival of YOY is most important, but is inconclusive about the rankings of other survival and fecundity parameters. The model was used to determine the influences of reductions of YOY survival on the overall population growth rate. If YOY survival is higher than 20-25%, then the marginal effect of excess mortality on population growth is relatively low. The effect increases steadily as survival of YOY declines below 20%. Levels of YOY mortality that resulted in unsustainable population growth rates were then compared to estimated mortality corresponding to zinc concentrations observed in the portion of the Arkansas River receiving contaminated snowmelt.
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M4-P.72 Environmental androgens produced in paper mill effluent: A risk analysis. Jenkins RL*, Howell WM, Angus RA, Wilson E, Kirk ME, Moore RA, Brown AE; Samford University rljenkin@samford.edu
Abstract: Environmental androgens in biologically effective concentrations was demonstrated > 20 years ago when a population of the eastern mosquitofish was discovered in which the females were all masculinized. Since then, other populations of masculinized mosquitofish have been discovered living in small coastal streams in Florida that receive paper mill effluent. In recent years we have studied the the Fenholloway River which has been described as one of the nation's most polluted rivers and carries discharge from a large paper mill in Perry, Florida. Using androgen receptor transcription (ART) assays to detect and mass spectrometry (MS) to quantify, androstenedione (AED) was measured at 0.14 nM in the water column of the Fenholloway River. Higher concentrations of AED (2.4 nM) and its biosynthetic precursor progesterone (155 nM) were identified in sediment from the Fenholloway. We hypothesized that androgens in paper mill effluent were generated by microbial degradation of the high levels of progesterone from the mill pulp. To test this hypothesis, we conducted a two phase experiment: 1) A common soil bacterium, Mycobacterium smegmatis, was incubated with progesterone. Using ART assays and high-pressure liquid chromatography (HPLC) AED and andrastadienedione (ADD) were biotransformed from progesterone; 2) the sediment of the Fenholloway River was reanalysized using an ART assay, HPLC, and MS which verified appreciable amounts of AED and ADD. A risk analysis of environmental androgens is considered with respect to human health, effects on wildlife, corporate costs and the economic benefit of the paper mill to the community. Alternative solutions are proposed for the removal of androgens from the Fenholloway River.
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M4-P.75 Novel tools for supporting the consistent risk evaluation of materials of emerging regulatory interest within the DoD and elsewhere. Tomljanovic C*, Cohen S, Lloyd S, Mirsky R, Boyer T; Concurrent Technologies Corporation (CTC) chuck-t@ctc.com
Abstract: Because of the imminent enforcement and creation of new environmental regulations by the US EPA, it is imperative that new techniques are developed to evaluate materials of emerging regulatory interest within the US DoD to determine the severity and impact of these regulations on DoD facilities. The Emerging Contaminant Assessment Tool (ECATSM) and Impact Criteria Assessment Tool (ICATSM) are two novel tools that can be used by specialists within the Materials of Evolving Regulatory Interest Team (MERIT) program to accurately and consistently assess the impact of these regulations. ECATSM facilitates a database review of key information categories, and, based on input from the user, classifies the contaminant under an MERIT Action List, Watch List, or Reject/Archive List. The classifications can be used to determine the likelihood and impact of new regulation on the DoD. Furthermore, ECATSM automatically generates graphs that allow the user to simultaneously compare the impact of multiple contaminants on various DoD impact factors. ICATSM, in contrast, evaluates the risk across several impact areas for emerging contaminants used at DoD facilities. The user scores the likelihood and severity of an adverse impact, and ICATSM maps the contaminant on a risk cube that graphically displays the risk likelihood and consequence. Each region of the risk cube corresponds to an Action List, Watch List, or a Reject/Archive List. These classifications can be used to determine the level of action required by the DoD to manage contaminant risks. Complying with the new regulations can potentially cost the DoD millions of dollars and take years to for response; consequently, ECATSM and ICATSM will be important tools for assessing the risk that materials of evolving regulatory interest pose to the DoD. This poster explores the potential applications for ECATSM and ICATSM and the advantages to using these tools for consistent risk analysis for materials of emerging regulatory interest.
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M4-P.76 Prioritization of chemicals for forensic science identification: Designing a model to predict laboratory capability needs. Gallagher L*; Environmental Science and Research, Ltd. Lou.Gallagher@esr.cri.nz
Abstract: Emergency response to large-scale events resulting from chemical releases (accidental or deliberate) requires capability to provide rapid identification of the chemicals involved. A system for identifying which chemicals/classes of chemicals are of greatest concern to public health and the environment must be specific and responsive to the changing environment in which human health, economic well-being and environmental integrity of the country exist. It must also incorporate varying levels of risk tolerance expressed by multiple stakeholders and specify the risk environment. Initial consultation with a wide range of government, military and business stakeholders identified an immediate need to develop emergency response capability in chemical forensics. An initial list of chemicals was compiled using lists derived overseas, expert scientific opinion and consultation with key stakeholders within New Zealand. A priority list of chemicals for initial evaluation in New Zealand forensic capability has been established. Shared consensus on the principles of the list are: (1) Likelihood of an accidental or intentional chemical release event in New Zealand (requires adaptation to changing landscape of chemical security and intelligence information), (2) Possible delivery potential and severity of effects of a chemical release in New Zealand, and (3) Varying aversion levels/tolerances to chemical event scenarios by individual agencies. Methods for agency interaction and timely updates of threat perception, expert opinion on the likelihood of release, and the range of possible consequences associated with chemical releases have not been established. Multi-level risk modelling will incorporate live data entry, a range of chemical behaviour scenarios, and expert opinion to prioritize individual chemicals/classes of chemicals based on shared consensus and the initial list of chemicals derived in this research.
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M4-P.77 Integrated risk information system screening level review of chemical substances . Jones SJ*, Rieth S, Holdsworth G, Whittaker MH, Hester ST, Hendricks JA; US EPA, Oak Ridge Institute for Science and Education, ToxServices jones.samantha@epa.gov
Abstract: The Integrated Risk Information System (IRIS) is a publicly-accessible database containing US EPA reviews of potential adverse health effects that may result from chronic (or lifetime) exposure to chemical substances found in the environment. These reviews are documented in IRIS summaries, which contain qualitative and quantitative health information, including reference doses for noncancer health effects resulting from oral exposure, reference concentrations for noncancer health effects resulting from inhalation exposure, cancer weight-of-evidence designations, oral cancer slope factors and inhalation unit risks. Currently, more than 500 summaries have been posted on IRIS. Summaries prepared since 1996 also include supporting Toxicological Review documents. To determine how well IRIS toxicity values reflect the current scientific literature, US EPA conducts screening-level reviews of the available literature for chemicals in the IRIS database and makes the results available on the IRIS database web site. The screening-level review for each chemical describes the results of a methodical scan for health effects studies that have been published or released since the date of the posting of the IRIS assessment or the last screening-level review. While this scan is not a comprehensive search of all relevant health and toxicological studies, it is a useful tool for prioritizing reassessments of IRIS summaries and for providing users with a summary of potentially relevant, new literature. This poster presentation will show how the screens are conducted and the results of the most recent screen of the chemicals in the IRIS database.
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M4-P.78 Simultaneous compliance and complex risks: The conflict between contaminant driven regulations and multi-media threats . Moses MS*, Guidotti TL; GWU SPHHS eohmsm@gwumc.edu
Abstract: Simultaneous compliance, having to comply with different, potentially incompatible rules at the same time, is a real-world challenge facing all regulated entities, including water utilities. The majority of environmental statutes and regulations, many of which were initially written in the 1970's and 1980's, are either media specific, contaminant-focused, or technology-based. While these regulations have been effective to-date in addressing highly-contaminated, single media environmental threats, the increasing complexity of treatment alternatives and their often unintended consequences (i.e., change in the reduction potential of the water) necessitate the re-evaluation of this regulatory approach. The Washington, DC, Water and Sewer (DC WASA) authority experienced this challenge first hand in 2003. DC WASA was the focus of a year of unrelenting media attention for exceeding the Lead and Copper Rule (LCR) requirements. The problem stemmed from efforts to comply with the Disinfection Byproducts Rule while complying with other drinking water regulations. Specifically, DC WASA switched from disinfecting water with chlorine to chloramine which altered treated water chemistry and increased (or, more likely, reduced the resistance to) leaching of lead from service lines. DC WASA was the first major municipal utility to learn a new law of unintended consequences: simultaneous compliance with the Disinfection Byproducts, LCR, and the Total Coliform Rule presents unpredictable problems. Other utilities have now repeated the experience, although none with as dramatic consequences. We face increasing conflict between single contaminant or media-specific regulations and the management of complex, multi-media environmental threats. Consequences need to be anticipated insofar as is possible through a multi-contaminant, multiple-risk approach. The Superfund Risk Assessment Paradigm can be used as one model for such an approach.
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M4-P.79 Risk-based cleanup goals for indoor surfaces. McKean DL*; US EPA mckean.deborah@epa.gov
Abstract: US EPA's role within programs such as Superfund has been the assessment and cleanup of contaminated environmental media such as soil, air and water. However, in response to Homeland Security Presidential Directives and in support of the National Response Plan, the Agency's role has expanded to include the cleanup of contaminated buildings and their contents. Consequently, there is a need to determine the level of cleanup required following accidental or purposeful contamination of a building. In other words, ‘How clean is clean?' The Risk Assessment Guidance for Superfund (RAGS), Part B provides methodologies to calculate risk-based, provisional remediation (cleanup) goals for environmental media. There is a need to expand this effort to estimate cleanup goals for building surfaces. A methodology is proposed and presented for the derivation of risk-based surface cleanup goals including equations and example exposure assumptions. Cleanup criteria for environmental media have typically relied upon the use of default values to characterize standard industrial or residential land use exposures. Using broad categories to classify buildings for the purpose of developing cleanup goals may be more problematic. Therefore, it is suggested that any implementation of the methodology be ‘building/situation-specific'. As a demonstration of the method, example risk-based surface cleanup goals are presented for a variety of chemicals on both porous and non-porous surfaces.
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M4-P.80 The alliance for risk assessment: A multi-stakeholder approach for risk issue resolution. Maier A*, Wullenweber A, Kroner O, Dourson M; Toxicology Excellence for Risk Assessment maier@tera.org
Abstract: We hypothesized that the rate of chemical use and development has outpaced the development of risk values and resolution of risk assessment methodology questions needed by the risk assessment community. We conducted a series of outreach and canvassing activities to identify the degree to which risk assessors from diverse organizational affiliations find this to be the case. We also evaluated, based on input from State risk assessors and analyses of the International Toxicity Estimates for Risk (ITER) database, the degree to which risk values and methodologies differ among various regulatory organizations. We identified significant opportunities and interest among various stakeholders to increase output and communication of harmonized risk assessment guidance (risk values and methods). Based on this need, an Alliance for Risk Assessment (ARA) has been proposed. The ARA is a proposed multi-stakeholder collaboration dedicated to producing science-based, independently-derived and peer-reviewed risk assessment issues guidance for environmental decision-making. The ARA aims to increase the capacity for developing risk values and facilitate the harmonization of risk assessment processes as a shared resource for diverse organizations. Central to the ARA is the development of the Hazard Assessment Notification System (HANS), a proposed National Library of Medicine’s web-based platform for coordinating and sharing information on chemical risk issue development. Other components of the ARA include shared resources for technical assistance in risk vale development, risk methods research, peer consultation and peer review. The presentation highlights the needs analysis and the process by which the ARA will provide a mechanism for communicating chemical risk issue resolution, while improving the allocation of time and resources to ensure that the community of risk assessment scientists rises to meet the challenge of growing demands.
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M4-P.81 Diverging policies and risk-taking perspectives towards climate change in the insurance industry. Graves KL*; Michigan Technological University klgraves@mtu.edu
Abstract: Hurricane Katrina raised awareness of the possibilities of natural hazards that American citizens have been facing throughout all of history. The devastation after the hurricane opened much discussion on the frequency and intensification of natural disasters, as well as on such global forces as climate change. Within the Insurance Industry, these discussions have become particularly prevalent. With the estimation that Katrina will have cost approximately $60 billion for 1.75 million property/casualty claims, it would be inconceivable of an industry with such monetary vulnerability to environmental hazards to ignore the possibility and pattern of devastating climate events. While the United States Insurance Industry has just begun to take notice of the impacts of a climate shift, the European industry is already actively involved in the climatompanies have a climate change policy and are actively pushing for regulatory change regarding carbon emissions, while some companies have made personal commitments of action, such as Allianz who in 2005 announced an investment of $500 million in renewable energy. My research demonstrates the possible risks of a changing climate for the insurance industry in the United States, while considering the differences in risk perception from that of the European industry. It will also look at the social and governmental perspectives on how the industry should respond to a growing risk.
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M4-P.82 Risk managers, take your own pill. King MT*, Moses KD, Field S, Fussell L; Futron Corporation mking@futron.com
Abstract: Integrated Risk Management Application (IRMA) is a web-enabled application database for documenting and communicating information about risks to organizational goals in a manner that enhances the probability of program success. Futron has tailored IRMA for various Government and industry customers as a means to track and mitigate organizational risks of different capacities. While risk information is similar from program to program, program characteristics, such as the organizational components, program goals and objectives, and major program threats, require significant variations in the risk management process. To support aspects of the risk management process other than documentation and communication (e.g., identification, analysis, handling, tracking), the risk management database should be tailored to meet the needs of the program. For example, IRMA was tailored to fit NESC needs for tracking incoming safety concerns and was renamed NESC Assessment Risk Management Application (NARMA). One member of Futron has recently started a pilot program to modify and make use of IRMA to track risks for Futron's own internal projects. This poster will describe the sophistication of customizing IRMA to create Futron's Integrated Risk Management Application (FIRMA), as well as the complexity that results from having risk managers use their own tools.
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M4-P.83 Risk path finder: A tool for supporting discovery of risk scenarios. Maeda Y*; Shizuoka University maeda@sys.eng.shizuoka.ac.jp
Abstract: A prototype of Risk Path Finder, a tool for supporting discovery of scenario of emergence of new risks, was developed. This system facilitates the determination of the relationships between causes and consequences of risk events from a pile of documents. In other words, it visualizes relationships in a large number of terms and documents and enables users to find causal paths from the sources to risk events. Food safety risks are dealt with in this prototype. Over 300,000 documents about food safety risks are collected from WWW by using GoogleWebAPIs. For handling the documents, the system utilizes GETA, the generic engine for transposable association, and DualNAVI, A user-interface for text retrieval by using GETA.
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M4-P.85 Collaborative public-private risk assessment in vessel traffic safety: Two case studies. Ross RG*; US DHS Science and Technology bob.ross@dhs.gov
Abstract: Following the EXXON VALDEZ oil spill, Congress passed the Oil Pollution Act of 1990 (OPA '90) which required numerous oil spill prevention improvements. One was that the Coast Guard study transportation of oil in major ports to assess the need for a Vessel Traffic Service (VTS) in each. Traditional statistics and probabilistic modeling risk assessments were already in progress for 23 major ports, when OPA '90 was passed. These assessments were based primarily on historical Coast Guard accident data. When delivered, the results were rejected by stakeholders from various parts of the maritime community, as well as by Congress, and the Coast Guard was instructed to conduct further analyses. These were to be prepared with greater stakeholder participation and with an eye toward safety improvements other than a VTS. At about the same time, proposals to establish offshore vessel routing schemes off the California coast were being hotly contested by industry and environmental advocates. This paper describes collaborative risk assessment and risk-informed decision-making processes used to satisfy stakeholder objections to earlier approaches and to bring the issues in question to successful resolutions. The Port and Waterways Safety Assessment (PAWSA) process was developed as a broadly applicable vessel traffic risk assessment process. PAWSA blends a number of techniques and tools including Analytical Hierarchy Process, anchored rating scales, general morphological analysis, expert judgment, and outside facilitation. Further, PAWSA takes advantage of a comprehensive vessel traffic management "tool kit" to deliver results tailored to individual ports and waterways. The process used in California was similarly collaborative but used a different analytic approach. Taken together, both PAWSA and the California coastal traffic assessment processes strongly support the idea that collaborative processes, even those involving parties with seemingly irreconcilable differences, can be successful.
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M4-P.86 Goldpan: An aid to risk analysis. Smith R*, Moses K; Futron Corporation rsmith@futron.com
Abstract: Goldpan is a tool that is able to carry out quantitative, probabilistic risk analysis processes for both large and small projects. By allowing the user to map one or more cost and/or schedule risks to any or all linked tasks of a complex, integrated, master schedule, the user is able to analyze the impacts on the project. The cost and schedule plans can be adjusted by manipulating the consequences and the likelihoods of the risks. Once the risk is defined and mapped to the schedule, Monte Carlo simulations are conducted to produce graphical output models. From these histograms, the user is able to conduct further analysis, such as building Pareto charts to pinpoint the most influential risk and/or task. This poster illustrates the various steps involved in using Goldpan, and the benefits the software provides to the risk analysis process.
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M4-P.87 Evaluation of uncertainty and decisionmaking in selected US Army risk assessments. von Stackelberg K*, Nelson M, Famely J, Southworth B, Bridges T; Menzie-Cura & Associates, Inc., Environ, US ERDC kvon@menziecura.com
Abstract: We report the results of an assessment using risk assessments conducted for United States Army sites to: Identify human health and ecological pathways that are most often considered at Army sites; Identify chemical and exposure pathway combinations associated with human health and ecological risk estimates that exceed regulatory thresholds; and, Identify, categorize, and score the importance of sources of uncertainty in Army risk assessments. Risk assessment typically relies on models that describe physical processes and expected impacts under different management alternatives, including the no action alternative. There is considerable uncertainty in the development and application of these models, depending on the amount of available site-specific data and knowledge of local physical processes. Differences in these models can result in orders of magnitude differences in the uncertainty in predicted risk estimates between risk assessments with very similar conceptual models, receptor species, and COPC concentrations. This work identifies and recommends better analytical practices and targeted scientific research for improving risk estimates at Army sites. The report identifies important sources of uncertainty (lack of knowledge) where such additional analysis or research may improve confidence in these estimates. The categorization and scoring of uncertainty sources builds on previous work for the United States Army Corps of Engineers regarding dredged material management. We also report on the basis for decisionmaking at the sites, if available, and relate the decision to the results of the risk assessment.
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M4-P.88 Common operating and response environments supporting rapid risk assessment. Whelan G*, Millard DW, Gelston GM, Walter DW; Pacific Northwest National Laboratory gariann.gelston@pnl.gov
Abstract: Accurate situational assessment and decision making along with efficiency of action are crucial to improving emergency response, whether these emergencies occur in a military or civilian sector. Pacific Northwest National Laboratory has developed a framework to address emergency response which also has value as a daily operational response framework. The framework provides a tool to manage multiple disparate avenues of information. It aids the organization of critical information flow among multiple communication nodes in an emergency, serves as an aid to the decision making process, and facilitates segregation of information into multiple levels for optimal information management. Research and findings in the context of a biological event situation and a multiple asymmetric event response scenario are discussed. This presentation highlights linkages between science/technology and the emergency response community, allowing two way communications and providing a scientific basis for decision-makers to take action and for researchers to perform post-event assessments. This approach provides both integration and feedback opportunities. The interoperability layer enables existing activities to perform double duty by applying them to science and technology lessons learned and as input to preparedness activities. The basis of this research is integration and feedback requirements for a sustainable system that can be applied to preparedness, response, recovery and mitigation. This flexible and extensible integration of science and technology and actionable command/control operations guidance provides a basis for assessing the effects and consequences to human health and the environment from disruptive events. The extensible nature of this approach also capitalizes on emerging and continuous research in improved modeling and data collection technology interoperability by providing a platform to build and modify a response approach.
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M4-P.89 Evacuations, quarantines, and antibiotics: Canadians' reported willingness to adhere to emergency response directives in the event of a major crisis. Gibson S*, Lemyre L, Lee JEC, Krewski D; University of Ottawa stacey.gibson@uottawa.ca
Abstract: In research and policy, there has been increasing focus on improving individual and institutional responses in the event of major emergencies and crises. While specific considerations apply in particular scenarios, such as with a terrorism attack, universal attributes of response also exist, including the effective dissemination of emergency response directives to the public. Unfortunately, these directives are not always adhered to, with disastrous consequences. As part of a larger study on public perceptions of terrorism in Canada, this study aims to determine the extent to which Canadians believe they would comply with government directives in the event of a major emergency. Participants (N=1502) rated the extent to which they would adhere to the following directives in the event of a terrorism attack: Evacuate the city/region, receive a vaccination, take prescribed medication such as antibiotics, undergo decontamination treatment, remain inside a building for protection (sheltering-in-place), isolate oneself from others (quarantine), and go to a public shelter. Results suggest that for all directives, the great majority of individuals reported they would indeed follow the directives. Approximately half the respondents reported that they would be extremely willing to follow the directives, while only a small percentage of respondents would be unlikely to comply. Additionally, it was found that the tendency to comply with directives was related to age. Specifically, younger Canadians reported less willingness to follow directives. Nevertheless, these results suggest that Canadians would respond favourably to government directives in the event of an emergency, which could mitigate the adverse outcomes often associated with these events.
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M4-P.90 The Canadian public's understanding of institutional preparedness and response. Lee JEC*, Lemyre L, Gibson S, Krewski D; University of Ottawa jlee007@uottawa.ca
Abstract: More than ever, emergency preparedness is recognized as a shared responsibility between all levels of government, community organizations, and the public. In light of the integral part played by institutions in public education on preparedness, it seems natural to expect that a link might exist between individuals' level of personal preparedness and their perceptions of different institutions. Before this can be assessed, however, it should be determined whether the public meaningfully distinguishes these institutions on the basis of their specific preparedness-related roles and responsibilities. Most commonly used in scale and test validation, factor analysis uncovers simple trends in the pattern of relationships among a set of variables. Hence, this technique may help determine the extent to which different institutions are perceived as having common or divergent preparedness-related roles and responsibilities. The current study presents findings from a national survey (N=1502) wherein Canadians expressed the level at which they perceive various institutions to be prepared for an emergency as well as their degree of confidence in the ability of these parties to respond. Data from a random sub-sample of 50% of respondents were subjected to exploratory factor analyses to identify latent dimensions of perceived institutional preparedness and of perceived institutional response. The resulting structures were then validated in confirmatory factor analyses performed on data from the remaining cases. Findings reveal that Canadians conceptualize institutional preparedness as a single construct. However, confidence in the ability of government institutions to respond to an emergency is clearly distinguished from that of institutions such as non-governmental, health, or local community organizations.*
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M4-P.91 Safety assessment for systems of critical infrastructures. Shoji G*, Kurozumi N; University of Tsukuba gshoji@kz.tsukuba.ac.jp
Abstract: Infrastructures such as power supplies, water supplies, and gas supplies are exposed to functional impairment resulted from failure due to a disaster. Since their functions are critically related to sustaining our socio-economic activity, quantitative risk analysis due to a disaster for the above systems is strongly required. Hence, this paper focused on the functional impairment of infrastructures, and their objective risks due to a disaster were clarified by the risk assessment. First, five infrastructures are selected to be analyzed; electric power supplies (EPS), water supplies (WS), gas supplies (GS), telecommunication network systems (TNS), and mobile telecommunication network systems (MTNS). When their risk curves were derived, the damage of EPS, WS, and GS was evaluated by the numbers of affected households, and that of TNS and MTNS was evaluated by the numbers of affected circuits. Their risk curves were verified to relate the damage level of the system and its cumulative possibility (CP) by mining the archived records on Japanese newspapers from 1983 to 2004. The risk curves related to EPS, WS, and GS indicated that the CP of GS is higher than that of EPS and WS in the affected households of less than 1000 and more than 200000, and the CP of EPS is the highest among above three systems in the affected households from 1000 to 200000. The risk curves of TNS and MTNS indicated that the both risk curves is nearly same in the affected circuits of less than 1000, and the CP of MTNS is higher in the affected circuits of more than 1000. In view of the causes of the damage, it is illustrated that EPS was mainly affected by natural disasters and WS by natural disasters and failure of element consisting systems, and GS by accidents and failure of those. Since the obtained risk curves for the damage of subject infrastructures is objective based on the actual records, then we second proposed a framework of criteria for the assessment of the risks related to the functional impairment of infrastructures due to a disaster by statistically modeling risk curves and idealizing their mathematical functions.
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M4-P.92 Sensitivity analysis of anthrax dispersion models. Scarpinato T*, Coleman M, Thayer W, Santanam S; Syracuse University mcoleman@syrres.com
Abstract: In the wake of the terrorist attacks of 2001, anthrax spore dispersion and resuspension modeling is of particular interest. The dispersion of such spores is dependent upon building geometry, air circulation, source configuration, initial number of spores released, spore size, resuspension factors and additives affecting adhesion and gravimetric forces. We reviewed existing indoor air dispersion models that have been developed to predict the distribution of anthrax spores from intentional releases. We reviewed the currently available dispersion models for indoor environments to identify their conceptual and mathematical structure (e.g., their governing equations). For each model we also identified the parameters that have the largest effect on the model's output using sensitivity analysis. Based on the results of the sensitivity analysis we suggest priorities for model improvement and future research in estimating values for key model parameters. The model review also provides a concise summary of the conceptual and mathematical structures of the available models.
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M4-P.93 An improved decompression sickness dose-response model for emergency planning. Weathersby PK*, Gault KA; NSMRL and NEDU, US Navy weathersbyp@earthlink.net
Abstract: A standard decompression sickness (DCS) model "USN93" extrapolates poorly to high levels of DCS. This model embodies (in a hazard function) the commonly assumed mechanism that inert gas loaded into tissue under high pressure will be supersaturated during and after decompression, thus allowing bubble formation and growth. The calculated supersaturation is equated to the hazard term. Model USN93 was designed for, and predicts well in, low-risk normal operational Navy diving (< ~5% DCS). It was calibrated exclusively with high-quality data from 1977 to 1992. USN93's structure forces a linear extrapolation of response when "dose" is expressed as saturation pressure followed by immediate rapid decompression. Animal experiments under these conditions show a marked non-linear sigmoid response, leading to an expectation that humans would respond similarly. We have re-formulated the USN93 decompression model, allowing the hazard to be the supersaturation squared. We also used some high incidence calibration data from the 1940s. Both formulations fit the 3704 human observation fitting data set equivalently well by maximum likelihood. Only the newer formulation reproduced the sigmoid dose-response suggested by animal work. The new formulation fits most known high dose data well, while not losing the low-dose fit of USN93. The new model appears suitable for use in emergency preparations, such as following a disabled submarine disaster. In particular, it predicts that DCS should not be the limiting factor in submarine escape beyond the current US system stated capability of 600 feet.
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M4-P.94 Variability resulting from using different models in derivation of cancer risk values. Byczkowski JZ*; Consultant januszb@aol.com
Abstract: Recently, the US OMB in its proposed Bulletin on Risk Assessment section on modeling of cancer risk (p. 18), called for "...performing multiple assessments with different models and reporting the extent of the differences in results..." While the idea seems to be prudent and scientifically justifiable, a question arose about the extent of variability that may be introduced into the process of derivation cancer risk values by using different models. A goal of this report was to determine how much variability is introduced to cancer risk values derived for exemplary chemical X by applying different dose-response and animal-to-human extrapolation models according to the US EPA - IRIS methodology. The same typical experimental carcinogenicity mouse bioassay data set for slowly metabolized chemical was used as input into each model. The outputs were compared with the range of population-derived estimates for the cancer risk values of chemical X, based on heterogeneity of cytochrome P450 (CYP) metabolic activity in humans. The distributions of the slope factors (SF) of chemical X in humans were estimated, along with confidence intervals for a simulated human population, using a physiologically based pharmacokinetic model interlinked with a multistage dose-response module for carcinogenicity and coupled with a Monte Carlo analysis. Despite the different models and dose metrics used, the SF values obtained for chemical X were within the range of the population-derived estimates as long as the same linear dose-response relationship was assumed.
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M4-P.95 Prospects and limitations for the use of mode-of-action information and biological modeling to characterize internal dose. Clewell HJ*; CIIT Centers for Health Research hclewell@ciit.org
Abstract: Biological modeling, particularly physiologically based pharmacokinetic (PBPK) modeling, is increasingly being used in risk assessments to characterize measures of internal dose as a more biologically appropriate basis than administered dose for determining equivalent exposures across species and dose-route. However, the advantage of using internal dose comes at a cost of dealing with a number of uncertainties that can be ignored in a default approach. These uncertainties can be categorized into several tiers: (1) uncertainty regarding the mode of action for toxicity, (2) uncertainty regarding the appropriate measure of internal dose for a given mode of action, (3) uncertainty regarding the validity of the model structure, and (4) uncertainty regarding the model parameters. Several case studies on applications of PBPK modeling in risk assessment will be presented to illustrate the nature of these uncertainties and to demonstrate approaches for dealing with them, ranging from decision tree analysis to hierarchical Bayesian analysis. The extension of biological modeling from PBPK dosimetry into the pharmacodynamic realm in order to model internal measures of interaction and response will also be discussed, and the associated additional challenges will be illustrated with examples. As biological modeling continues to deal with systems of ever-increasing complexity, including cell signal networks, the challenges associated with their evaluation will become more severe. Nevertheless, the value of biological modeling in risk assessment far outweighs the drawbacks.
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M4-P.96 Dose response modeling with monoalkylphthalates: Assessing cellular targets for mechanisms-based risk assessments. Clewell RA*, Ross SM, Gaido KW, Andersen ME; University of North Carolina - Chapel Hill, CIIT Centers for Health Research; Rebecca Clewell: Winner of the Student Merit Award for the Dose-Response Assessment Specialty Group rclewell@ciit.org
Abstract: Fetal exposure of rats to some phthalates, including dibutylphthalate (DBP) and diethylhexylphthate (DEHP), disrupt sexual development. These effects are associated with the monoalkylester metabolites' (MBP and MEHP) inhibition of testosterone (T) synthesis. The molecular target is unknown, causing significant uncertainty in risk assessment. Steroidogenesis requires LH signaling of both cyclic AMP and the release of arachidonic acid (AA) by cytosolic phospholipase A2 (cPLA2). We propose that monophthalates may bind cPLA2, reducing intracellular AA and T. In this project, we conducted dose-response assessments for phthalates based on internal dose to test this mechanism of action (MOA). Pharmacokinetic models were used to compare phthalate potency across different endpoints in the T pathway: T inhibition in vivo, and progesterone (PG) and AA inhibition in vitro. PBPK models were used to estimate internal dose required to cause 50% inhibition (IC50) of T in the male rat fetus after maternal DEHP and DBP exposure (30 and 9 uM). These values were compared to IC50s estimated from measured inhibition of PG and AA release in the MA-10 mouse cell line. MEHP and MBP reduced radiolabeled AA release within 1 min of LH-stimulation, yielding IC50s of 7 and 5 uM. PG inhibition measured with an ELISA assay 6 hrs after LH treatment gave IC50s of 40 and 17 uM for MEHP and MBP. These values compared favorably with those for in vivo T inhibition, suggesting cPLA2 may be a target for phthalates and encouraging additional tests for specific aspects of the hypothesis. Understanding of the MOA can reduce uncertainty in interspecies differences through targeted data collection. Evaluation of published dose-response data for AA inhibition in human platelets yielded an IC50 of ~10 uM for MEHP. The similarity of this value to that of the mouse Leydig cell may suggest that species differences in susceptibility are a result of factors other than the phthalate-cPLA2 interaction.
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M4-P.97 Using dose-response data from in vivo mutagenicity studies to inform evaluation of cancer mode of action. Haber LT*, Moore MM, Allen BC, Ship AM, Heflich RH, Gentry PR, Kodell RL, Dourson ML; Toxicology Excellence for Risk Assessment haber@tera.org
Abstract: Quantitative cancer risk assessments typically utilize high dose rodent tumor data. Under the new US EPA Cancer Risk Assessment Guidelines, the quantitative model chosen for cancer risk assessment is based on the mode-of-action (MOA) of the chemical under consideration. In particular, it is based on whether the weight of evidence supports the chemical causing tumors through a DNA-reactive MOA or another MOA. It is assumed that DNA-reactive carcinogens (sometimes also called mutagenic carcinogens, although the latter is a broader term) have low-dose linear dose-response curves. This default assumption of linearity for such carcinogens is widely debated but, to date, there has been insufficient evidence to resolve the issue. Traditionally, the assessment of mutagenicity and of genotoxicity has been a simple "yes/no" determination. We are currently evaluating the potential for a more complete analysis of in vivo mutagenicity data, including the analysis of dose-response data, to inform the risk assessment process and support the choice of a low-dose extrapolation model. Dose-response analysis of mutagenicity data can provide estimates of the predicted levels of mutagenic activity at various dose levels, including those corresponding to the doses in the tumor assays. By examining those predictions and comparing them to the observed incidence of tumors, one can ascertain if an assumption of a mutagenic precursor appears to be consistent with the tumor response. The essence of our approach involves generating carefully designed in vivo mutagenicity dose-response data in the tumor target tissue in a transgenic in vivo shuttle vector model, with doses selected based on the tumor dose-response.
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M4-P.98 Interspecies differences in enzyme activities, based on in vitro measurements: A resource for PBTK modeling. Hattis D*, Schlosser P, Lynch M; George Perkins Marsh Institute - Clark University, US EPA, Boston University School of Public Health dhattis@aol.com
Abstract: One of the best ways to characterize an uncertainty is to reduce it to a readily observable variability among putatively analogous cases. One such uncertainty is in the projection of enzyme activities among species in the course of developing physiologically-based toxicokinetic (PBTK) models of internal dose. We have assembled a substantial data base of interspecies comparative measurements of various types of metabolic enzyme activities that are likely to be relevant to the metabolism of different toxicants. Overall, the data cover 904 species-specific group-level measurements of individual Michaelis-Menten or other enzyme activity parameters, organized into 286 interspecies comparative sets for 108 different toxicants. 133 of the interspecies comparative sets are for oxidizing enzymes classified in CYP/P450 or FMO (flavin-containing monooxygenase) groups, 25 for epoxide hydrolases, 19 for glutathione-S-transferases, 41 for esterases, and 28 for glucuronidation and other phase 2 conjugation enzymes (40 sets of interspecies comparisons are for enzymes that are other types or unclassified as of yet). We will analyze these data for possible differences in distributions of rodent/human activity ratios, and allometric coefficients for multiple species including humans. A challenge for the analysis is to properly account for an observed correlation of measurement/estimation errors between Vmax and Km observations in interspecies comparisons of Vmax/Km ratios. A further challenge is to reconcile different bases for the expression of activity in the source data (e.g. per unit microsomal protein vs. per million cells, vs. per unit liver volume) to the bases needed for PBTK modeling.*
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M4-P.99 Inter-individual differences in in vitro enzyme activities: A resource for PBTK modeling. Lynch MT*, Hattis D, Schlosser P; Boston University School of Public Health, George Perkins Marsh Institute - Clark University, US EPA megkeaney@yahoo.com
Abstract: Physiologically-based toxicokinetic (PBTK) modeling is a potentially helpful tool to quantify the human inter-individual variability in internal doses of toxicants. Depending on the end-effect to be modeled, PBTK-based assessments could be used in combination with other data either to quantitatively assess risks directly, or to derive indicated adjustments for the pharmacokinetic portion of the uncertainty factor for inter-individual variability. We have therefore built and analyzed a database of observations of in vitro human variability in the activity of phase I and phase II enzymes responsible for the biotransformation of both pharmaceuticals and environmental toxicants. We will present individual and aggregate analyses of data on the observed human variability for Vmax, Km, and Vmax/Km ratios for various groups of CYP/P450 enzymes and Phase II conjugating enzymes. Specifically, the log(GSD) (Standard Deviation of the log transformed values) was used to quantify the variability in each parameter. Measures of Km and Vmax and therefore Vmax/Km were found to be more variable than measures of activity in the majority of enzyme classes. Vmax and Km values were found to be positively correlated with one another. Specific numerical results will be presented and discussed. After incorporation into PBTK models, the results of this analysis could be used along with measures of variability or uncertainty in other model parameters to evaluate human TK variability, which in turn would allow for potential replacement of the default uncertainty factor of 3 for human inter-individual TK differences.*
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M4-P.100 Development of methods for biomarker validation and biomarker-base dose-response analysis. Hack E*, Savage, Jr. RE, Haber L, Maier A; Toxicology Excellence for Risk Assessment hack@tera.org
Abstract: For over two decades, scientists have been touting the importance of the application of biomarkers in reducing disease and protecting individuals from the harmful effects of exposure to occupational and/or environmental chemicals. However, few successes have been realized. This is due in part to the fact that while many molecular events have great potential as biomarkers, validation has been problematic. While established guidelines for biomarker validation exist, methods for their implementation and case studies testing the methods are rare. Using benzene as a case study, a system for integrating complex and multifaceted data, validating biomarkers, and incorporating the biomarkers into an occupational risk assessment was developed. A biomarker database and decision rules were developed to organize the diverse types of data. A hierarchical analytical framework consisting of Hill criteria, regression, graphical comparisons, and Bayesian networks was developed to test and validate biomarkers along the entire exposure-disease continuum. The framework provides an approach for considering a variety of biomarkers from the exposure-disease continuum for the enhancement of occupational risk assessment. For benzene, urinary trans,trans-muconic acid emerged as a biomarker of exposure, 8-hydroxydeoxyguanosine as a biomarker of effect preceding leukemia, and changes in progenitor blood cell formation as effect biomarkers leading to anemia and leukopenia. The biomarker-based dose-response analysis for leukemia produced an OEL 10-fold lower than the traditional concentration versus disease response regression modeling.
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M4-P.101 Use of genomic technologies and isotonic dose-response modeling in the development of a biochemical marker of effect for pyrethroid insecticides. Harrill JA*, Wright FA, Crofton KM; University of North Carolina at Chapel Hill harrill.josh@epa.gov
Abstract: Pyrethroids are pesticides that disrupt nervous system function by prolongation of sodium currents through voltage-sensitive sodium channels present in nerve membranes. Pyrethroid usage has increased as use of other pesticides has declined. A sensitive, dose-responsive and class specific biomarker of effect is not available for pyrethroids. Developing this type of endpoint will aid the risk analysis process by providing a rapid quantitative assay for use in characterizing the cumulative risk of mixtures of pyrethroids. The present study uses genomic technologies, quantitative real-time PCR and protein expression to identify candidate biomarkers of effect. Long-Evans rats (n = 8-12 / group) were orally dosed with either permethrin (1, 10, 100 mg/kg), deltamethrin (0.3, 1.0, 3.0 mg/kg) or vehicle and global gene expression profiles were created using Affymetrix Rat 230 2.0 microarrays hybridized with labeled cRNA derived from CNS cortical tissue. Identification of dose-responsive transcripts was performed using a novel combination of statistical techniques. An isotonic regression statistic (M-score, Hu et al. 2005) was used to identify transcripts in the microarray study that display significant dose-related alterations in expression for each model compound. This method assumes a monotone dose-response relationship, but otherwise makes no assumptions about the precise form of the dose-response curve. We used this approach in conjunction with permutation calculations of false discovery rates (FDR) to provide multiple-comparison error control. Genes are prioritized for confirmation by qRT-PCR based on the strength of the dose-response, commonality of the response profile between compounds and the estimated FDR. Several transcripts have been identified as potential dose-responsive biomarkers of effect and have been confirmed by qRT-PCR. Future studies will test the reliability and specificity of the identified biomarkers by using a variety of pyrethroid and non-pyrethroid compounds.
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M4-P.102 Testing strategies to estimate neurotoxic risk on cumulative exposure to pyrethroid mixtures. Wolansky MJ*, DeVito MJ, Tornero-Velez R, Hughes MF, Ozkaynak H, Shafer TJ, Gordon CJ, Harrill JA, Crofton KM; National Research Council, US EPA, University of North Carolina wolansky.marcelo@epa.gov
Abstract: The Food Quality Protection Act requires US EPA to consider the cumulative risk of pesticides with a common mechanism-of-toxicity. Evidence supports a mechanistic commonality for pyrethroid insecticides: these chemicals all act on neuronal sodium channels. The lack of a predictive biomarker for pyrethroids implies that previous approaches (e.g., organophosphates) for estimating cumulative risk are not viable. In order to estimate the cumulative risk of pyrethroids, we are developing an exposure-dose-response model. Cumulative and aggregate exposures are being estimated from environmental and food residue data using SHEDS models. Human and animal PBPK models are being built using both in vitro and in vivo animal data to facilitate extrapolation between species, and to allow estimation of rat brain concentrations at human exposure levels. Effects data are being generated using both in vivo (autonomic, sensory, and motor effects; rat), and in vitro (neuronal firing and ion flux) models to develop relative potencies at various levels of neuronal organization. Mixtures are being tested to determine whether additivity theory will predict cumulative effects based on administered dose or target tissue dose. The overall goal is to use the above models to relate human exposures to target tissue dose, extrapolate target tissue dose from humans to rats, and use the effects data to define the degree of adverse outcome (if any) associated with human exposures. Progress to date includes preliminary analyses of environmental data, construction of initial PBPK models using in vivo kinetics and in vitro metabolism data, development of dose-response data for in vitro and in vivo endpoints and calculation of relative potencies, and initial testing of additivity with a mixture of 11 pyrethroids. This research will provide quantitative estimates of potential risks posed to humans from aggregate and cumulative exposures to pyrethroids in food and the environment.
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M4-P.103 Changing assessments: Meeting new challenges. Preuss P*, Tuxen L, Zenick H, Cote I; US EPA cote.ila@epa.gov
Abstract: The face of environmental public health risk assessment is changing. The environmental public health community has been and is focused on the effects of individual chemicals on human health. In particular, understanding the role of chemically-induced molecular and cellular changes in disease is emphasized in current risk assessments. This task has been made significantly more complex by issues such as the multifactoral nature of disease, and the complex relationship between ecosystem health and public health. The importance of these complexities is self-evident; how to appropriately incorporate these complexities into risk assessment and decision-making is, however, not as clear. Two major challenges for risk assessors are: evaluating when additional data are important for decision-making; and collecting, integrating, and using complex information on a variety of scales. This presentation will elaborate on issues encountered by the environmental public heath community in regards to assessing attributable risks.
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M4-P.104 Comparative sensitivity of bird species of the gulf coast to environmental DDT contamination: A meta-analysis of existing dose-response data for egg residue of DDE and eggshell thinning. Neuber KS*, Bradley AE, Durda JL; Integral Consulting, Inc. abradley@integral-corp.com
Abstract: Due to its persistence, DDT and its degradation products, DDE and DDD are still present in the environment of the Gulf Coast. There is a large body of published work available that measures the effects of DDE in egg residue on eggshell thinning and associated reproductive impacts for various species. It has been estimated that excess eggshell thinning of approximately 20 percent over a breeding population will result in a negative impact on population-wide reproductive success. Given that there is a fairly consistent population effect threshold of 20 percent eggshell thinning, it is theoretically possible to estimate and compare the concentrations of DDE in egg residue that result in the population effect threshold. We examined available data by first establishing acceptability criteria to identify reliable quality data for analyzing dose response. Next, we evaluated published studies and reported data against these criteria and ranked them according to usability. Where data were considered usable for a particular genus or species, they were included in a meta-analysis to establish a single dose-response relationship for each genus or species. Based upon the estimated population-level adverse effect level of 20 percent eggshell thinning, a toxicity reference value for DDE in egg residue was determined for each dose-response assessment. The resulting toxicity reference values were then compared across species to rank various species in terms of reproductive sensitivity to DDE in egg residues. The results of the comparison should prove useful in the identification and selection of sensitive species for future monitoring of the health of Gulf Coast ecosystems and site-specific ecological risk assessments.
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M4-P.105 Exposures to trihalomethanes in humans resulting from drinking water use. Wilkes CR*, Lipscomb JC, Kedderis GL; Wilkes Technologies, Inc. c.wilkes@wilkestech.com
Abstract: The concentrations of four commonly-identified trihalomethanes (THM; chloroform, bromodichloromethane, chlorodibromomethane and bromoform) in US drinking water systems are regulated as a group. The goal of this paper and a companion paper investigating internal doses is to evaluate the metabolic interactions of mixtures of chemicals sharing common metabolic pathways. This project evaluated the exposure, uptake and internal doses resulting from normal household water use via oral, dermal and inhalation routes. An exposure model was used to represent the relevant factors including chemical volatilization, human activity patterns, building characteristics, and chemical concentrations in the water supply. Various data sets (including the National Human Activity Pattern Survey, Residential End Use Water Study, Residential Energy Consumption Survey, and appliance manufacturer data) were integrated using Monte Carlo sampling techniques, accounting for variability in human behavior, building characteristics, and ventilation rates. Drinking water THM concentrations were based on data collected through US EPA's Information Collection Rule. THM drinking water concentrations used in this study were estimated at the 95th percentile of the concentration distribution in drinking water, representing "high-end" exposures. The exposure model was linked to a physiologically based pharmacokinetic model, with the results provided directly as inputs, allowing an evaluation of internal doses (presented in a companion paper). For all simulated population groups, the estimated absorbed dose from the inhalation route dominated the estimated total exposure, often surpassing the other route-specific exposures (oral, dermal) by ten-fold or more. The exposure and uptake results are presented as distributions for each of the selected population groups as a function of route of exposure and chemical.
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M4-P.106 Internal doses of trihalomethanes in humans resulting from drinking water use. Kedderis GL*, Wilkes CR, Lipscomb JC; Consultant gkedderis@msn.com
Abstract: The exposure to four commonly-identified trihalomethanes (THM; chloroform, bromodichloromethane, chlorodibromomethane and bromoform) in US drinking water systems may lead to metabolic interactions. The THMs are metabolized by the same cytochrome P450 enzyme to toxicologically-active metabolites and competitive inhibition may modulate risk. The goal of this paper and a companion paper investigating the exposure and uptake of the THMs is to evaluate the potential metabolic interactions of mixtures of chemicals sharing common metabolic pathways. The exposure and uptake model (described in a companion paper) was linked with physiologically based pharmacokinetic models using approaches previously applied to chloroform. Specific human models were developed to simulate the body characteristics of an adult male and female of child-bearing age as well as a 6 year old child. With joint, concomitant exposure to the THMs under near-extreme drinking water concentrations, metabolic interaction was not apparent under typical conditions of enzyme expression. When enzyme content was reduced by 10,000-fold, metabolism of the individual THM chemicals was only impacted 20% or less, indicating a low likelihood of metabolic interactions. These results indicate that the internal dosimetry of these compounds under the anticipated conditions of human exposures is unlikely to be changed under the conditions of a simultaneous exposure to the four-chemical mixture, versus single-chemical exposure.
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M4-P.108 Evaluation of the available data for use in a toxic equivalency approach to the risk assessment of microcystins. Carlson-Lynch H*, Stickney J, Odin M; Syracuse Research Corporation hclynch@syrres.com
Abstract: Microcystins are cyclic heptapeptide toxins produced by a variety of cyanobacteria (blue-green algae). Human exposure to microcystins may occur through consumption of contaminated drinking water, incidental consumption during recreational activities, or through consumption of blue-green algal nutrition supplements. Microcystins are potent hepatotoxins (intraperitoneal LD50 approx. 50 µg/kg) causing apoptosis and degeneration of hepatocytes through a well-studied mode of action involving the inhibition of protein phosphatases. To date, over 80 microcystin congeners have been identified. However, toxicological data supporting the identification of quantitative toxicity values are available only for microcystin-LR. Little work has been done to explore the availability of data to support a toxic equivalency factor (TEF) approach to noncancer risk assessment of microcystin congeners. To address this knowledge gap, the toxicological literature was searched for toxicity and protein phosphatase inhibition data for microcystin congeners. Lethality data (LD50s) and in vitro protein phosphatase inhibition data (IC50s) were extracted and used to derive estimates of TEFs. For the few congeners with both LD50 and IC50 data, TEFs based on protein phosphatase IC50s are generally consistent with TEFs based on intraperitoneal LD50s, although TEFs based on protein phosphatase inhibition are more variable. Issues associated with the use of a toxic equivalency approach for risk assessment of environmental exposure to microcystins are discussed, and recommendations for further research are provided. In particular, the scarcity of data on the oral absorption of microcystins increases the uncertainty in using TEFs based on either intraperitoneal lethality or in vitro protein phosphatase inhibition studies for assessing the risk from oral exposure to microcystins. Further research on the gastrointestinal absorption of different microcystin congeners would reduce this uncertainty.
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M4-P.109 Estimating risk of benzene-induced leukemia by a radiation equivalence value. Nakayama A*, Isono T, Ohnishi I, Igarashi J, Kikuchi T, Morisawa S; Kyoto University nakayama@risk.env.kyoto-u.ac.jp
Abstract: Risk estimates of radiation are based on the Life Span Study cohort originally comprised 120,321 Hiroshima and Nagasaki atomic bomb survivors and their non-exposed controls and they are used as a reliable protection standard. Meanwhile chemical risk assessment is not as reliable as radiation since usually there are not enough epidemiological data, thus, it relies much on animal experiments and the extrapolation from animal to human could bring large uncertainties. After some epidemiological studies, benzene is regarded as a causative agent of leukemia, as well as radiation. Benzene is metabolized to some toxic metabolites and they induce chromosome aberrations in hematopoietic cells, which are the primary cause of leukemia. Radiation also induces chromosome aberrations in hematopoietic cells and evokes leukemia. Therefore, we came to consider if we could describe clastogenicity of benzene as radiation dose ant the possibility to extend radiation risk assessment system to chemical substances. In this study, we evaluated the radiation equivalent dose of benzene using clastogenicity of its metabolites, catechol and hydroquinone. The expressions are described below; D(CAT) = exp(0.115C(CAT)-0.003C(CAT)^2)-1 (R=0.99) D(HQ) = exp(0.126C(HQ)-0.006C(HQ)^2)-1 (R=0.99) D: Equivalent dose for CAT (catechol) or HQ (hydroquinone) [Gy] C: Concentration of CAT or HQ [µM] Using these radiation equivalent dose, leukemia risk induced by 1µg/m3 benzene inhalation for lifetime was estimated as 2.8x10^-7, which is about a part of tenth to thirtieth of estimates, 2.8x10^-6 -7.8 x10^-6, by US EPA.
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M4-P.110 Comparison of criteria for deriving chemical toxicity values. Weinrich AJ*, Reid JB, MacDonell MM, Crawford D; US EPA, Argonne National Laboratory Weinrich.Alan@EPA.gov
Abstract: The US EPA, National Center for Environmental Assessment, Superfund Technical Support Center (STSC) derives provisional peer-reviewed toxicity values (PPRTVs) for chemicals that lack toxicity values in the US EPA Integrated Risk Information System (IRIS). STSC derives PPRTVs in response to requests from US EPA regions and state agencies for use in risk assessments at Superfund sites. STSC applies the scientific criteria and protocols used in IRIS assessments with an abbreviated review process. In the absence of IRIS values and PPRTVs, STSC identifies toxicity values from other sources, including the US Agency for Toxic Substances and Disease Registry, California US EPA, and the US EPA health effects assessment summary tables. This paper compares criteria employed by these and other sources to derive toxicity values. Examples of criteria being compared include the following: • Intended uses • Exposure media and routes of entry • Cancer vs. noncancer endpoints • Effect tiers • Exposure durations and assumptions • Data quality and selection criteria • Selecting points of Departure • Uncertainty factors • Review requirements • Update frequency • Availability of values and documentation These comparisons will provide important information for determining which toxicity values may be most appropriate for various needs of the Superfund program.
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M4-P.111 A comparison of noncancer risk assessment data across organizations . Wullenweber A, Nance P, Gadagbui B*; Toxicology Excellence for Risk Assessment nance@tera.org
Abstract: Risk assessment data is used throughout the world to make important public health decisions. This data is developed by a variety of organizations and may vary due to different methods, scientific judgments, or the use of more recently published data. This analysis compared noncancer risk assessment data from the Agency for Toxic Substances and Disease Registry, Health Canada, the National Institute of Public Health and the Environment (RIVM - The Netherlands), NSF International, the US EPA, and independent parties. For a series of chemicals, we have compared the available data from these organizations in terms of the risk value, year, basis, and methods. We have further evaluated those that have a greater than 3-fold difference in risk values and discussed the root of these differences. This analysis suggests the importance of being able to conduct side-by-side comparisons of available data to more readily identify and evaluate current risk values for application in public health decision-making.
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M4-P.112 Minnesota's health risk limits for groundwater rule revision effort. Goeden HM*, Shubat PJ; Minnesota Department of Health helen.goeden@state.mn.us
Abstract: The Minnesota Department of Health (MDH) evaluates the health risks of contaminated groundwater and establishes human health protection values called "Health Risk Limits" (HRLs). HRLs are expressed as micrograms of contaminant per liter of groundwater (ug/L) and represent a level that is without appreciable risk to human health whether ingested only once or daily for a lifetime. Historically, HRLs were thought of as protecting against adverse health effects from long-term exposure and combined an adult intake rate (2 L/day and 70 kilogram body weight or approximately 29 mL/day) with a chronic reference dose or cancer slope factor. As part of the rule revision MDH evaluated a variety of risk characterization approaches as recommended by the US EPA Review of the RfD/RfC Processes report. The evaluations included assessments of: 1) the range of potential HRL values for different durations of exposure and duration reference values, 2) the relationship between the time point at which a toxic effect was observed in the chronic study that was the basis of the RfD and the duration of exposure used in derivation of the HRL, and 3) the cancer toxicity data on early-life stage sensitivity to carcinogenesis. Based on these assessments, the MDH is proposing changes to protect more highly exposed individuals and more sensitive life-stages, and to identify additional health endpoints. Specific changes proposed include: (1) Use of an infant intake rate (0.221 L/kg-d) as the default when the most sensitive effect results from exposure during the developmental period, (2) Use of a minimum chronic exposure period (i.e., the first 8 years of life or 0.076 L/kg-d) as a default for chronic effects, including cancer, (3) Application of a policy-based default 2-fold adjustment of the cancer potency slope to account for potential extra risk from early-life exposures, and (4) Inclusion of health effect(s) reported in studies other than the critical study at dose levels similar to the critical study LOAEL.
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M4-P.113 Volatile organic compounds in the nation's drinking-water supply wells: What findings may mean to human health. Toccalino PL*, Norman JE, Rowe BL; US Geological Survey ptocca@usgs.gov
Abstract: Ground water is used as a drinking-water supply for approximately half of the Nation's population. Untreated ground-water samples from about 2,400 domestic wells and 1,100 public wells were analyzed for 55 volatile organic compounds (VOCs) as part of the US Geological Survey's National Water-Quality Assessment (NAWQA) Program. Because domestic and public wells serve as drinking-water supplies, it is important to describe what the VOCs detected in these well samples may mean to human health. VOC concentrations were compared to Maximum Contaminant Levels (MCLs) and Health-Based Screening Levels (HBSLs) in a screening-level assessment to provide an initial perspective on the potential relevance of these concentrations to human health. VOC concentrations of potential human-health concern were defined as concentrations greater than MCLs or HBSLs; these concentrations occurred in about 1 percent of domestic-well samples and 2 percent of public-well samples. Fumigants accounted for about two-thirds of the VOC concentrations of potential human-health concern in domestic well samples. In public well samples, solvents accounted for about three-fourths of the VOC concentrations of potential human-health concern. Evaluating the potential human-health relevance of VOC concentrations in domestic- and public-well samples is complex. NAWQA studies were not designed to evaluate the specific effects of VOCs on human health, and screening-level assessments are not a substitute for comprehensive risk assessments. Screening-level assessments, however, can provide an early indication of when concentrations approach levels of potential human-health concern and prioritize VOCs that may merit additional study or monitoring.
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M4-P.114 Nicotine bridging: A new method to extend smoke constituents biomarker measurements from clinical studies to other cigarette mainstream smoke constituents. Urban H-J*, Schorp M; Philip Morris Product SA, PMI Research & Development hans-joerg.urban@pmintl.com
Abstract: Philip Morris International is working to develop new products with the aim to reduce exposure to potentially harmful constituents in tobacco smoke. The overall goal is to reduce the risk associated with cigarette smoking. Smoke constituents exposure estimated from biomarkers measured in human smokers in clinical studies is limited to only a small number of smoke constituents. The majority of smoke constituents cannot be assessed using biomarkers due to their very low concentrations in body fluids, rapid metabolic changes, and lack of biomarker specificity. In contrast, the yields of a large number of cigarette smoke constituents can be determined using smoking machines. Our objective was to develop a model which may be used to estimate exposures to a large number of smoke constituents on the basis of measured nicotine uptake distributions in smokers. The first step in developing the model was to obtain a detailed understanding of smoke constituent deliveries under simulated human puffing conditions. Smoking topography and nicotine uptake distributions guided the setting of the smoking machines. The second step included regression analysis of the "analyte-to-nicotine" relationships. In a third step (i.e "nicotine bridging"), smoke constituents exposure distributions (proportional to measured nicotine uptake) were derived. For the comparison of cigarettes in the context of a reduced exposure assessment, the estimated uptake distributions were examined using two indices as tools for comparison: a) the percentage of change, based on the mean or mode of the distributions and b) the overlap between the two distributions. The above approach was used to compare cigarette smoke constituent exposure between a novel Electrically Heated Cigarette Smoking System and a conventional lit-end cigarette.
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M4-P.115 Systems biology evaluation of toxicogenomic microarray data using GO-Quant to analyze how toxicants alter gene pathways and functional gene categories. Griffith WC*, Yu X, Nanspers K, Dillman III JF, Ong H, Vredevoogd MA, Faustman EM; University of Washington, University of California at San Francisco, U.S. Army Medical Research Institute of Chemical Defense griffith@u.washington.edu
Abstract: Microarray technology can explore expression levels of tens of thousands of genes, or even complete genomes, after exposure to toxicants; however, the interpretation of the results is time-consuming and challenging. A large volume of data are generated on expression levels, and problems of performing numerous statistical tests may result in a significant number of false positive results for changes in gene expression, when comparisons are made across single genes. We propose that, to make the best use of toxicogenomic data for risk assessment, comparisons across toxicant doses and time must evaluate how gene pathways, rather than single genes, are altered. Gene ontology (GO) and pathway mapping are powerful approaches to generate a global view of biological processes and cellular components affected by toxicants. To facilitate quantitative interpretation of dose- or time-dependent genomic data, we propose to use average expression values of genes associated with specific functional categories derived from the GO database to analyze gene pathways. We developed a program (GO-Quant) to estimate the average intensity or ratio for gene pathways significantly altered by functional gene category based on MAPPFinder results. To demonstrate its application, we applied this approach to a previously published dose- and time-dependent toxicogenomic dataset. Our results indicate that the above systems approach can describe quantitatively the degree to which functional gene systems change across dose or time, and provide quantitative estimates which are important for risk assessment and evaluation of mode of action for toxicity, for each specific functional GO term.*
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M4-P.116 Health-based advisory levels for homeland security. Adeshina F*, Sonich-Mullin C, Ross RH, Butler J; US EPA, Oak Ridge National Laboratory, Argonne National Laboratory adeshina.femi@epamail.epa.gov
Abstract: The Homeland Security Presidential Directive No.5 requires that Federal agencies must develop national emergency preparedness for terrorist incidents or natural disasters. However, for many chemical and biological agents, health-based exposure guidelines are not available. Hence, the US EPA National Homeland Security Research Center, in collaboration with the Department of Energy Argonne National Laboratory and Oak Ridge National Laboratory, is developing health-based provisional advisory levels (PALs) for the general public, including susceptible and sensitive subpopulations of all age groups. These exposure values can be applied for national emergency programs, community planning, and public health protection. Specifically, they are applicable for establishing health-based criteria for re-entry into buildings, re-use of water, and cleanup of contaminated facilities. Scientific judgment and credible data are applied in identifying appropriate toxicity endpoints for establishing the point of Departure (POD) for deriving PAL values. These represent acute (24 hours), short-term (1-30 days), and long-term (30 days to 2 years) oral and inhalation exposures to industrial chemicals, biologicals, radionuclides, and warfare agents. The three tiers (PAL1, PAL2, and PAL3) for each exposure period are distinguished by the degree of severity of toxic effects. Draft PAL values are evaluated both by an US EPA working group, and an external multidisciplinary panel to ensure scientific credibility and wide acceptance.
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M4-P.117 Review of the Minnesota Department of Health's Minimum Chronic Period Evaluation. Strawson J*, Rodricks J, Turnbull D, Dourson M, Nance P; ENVIRON Corporation strawson@tera.org
Abstract: The Minnesota Department of Health (MDH) is evaluating the Minnesota Ground Water Health Risk Limits for Ground Water Rule in response to Minnesota Legislative action to strengthen the protection of sensitive sub-populations. A key component of the MDH revision process is the investigation of whether children's exposure assumptions can appropriately be used with chronic Reference Doses (RfDs) in order to derive non-cancer Health Risk Limits (nHRLs) for groundwater, which includes drinking water, for lifetime exposure. This investigation is based in part on a U.S. EPA definition of chronic exposure as "more than approximately 90 days to 2 years in typically used laboratory animal species" and an assumption made by MDH that early-lifetime exposures (i.e. \x{F0A3}10% of lifespan, 7 years for human) could result in critical effects typically identified as a result of true chronic exposures. On the basis of its evaluation, MDH implies that current lifetime nHRLs are uniformly too high, because they do not account for the known higher consumption rates of children. In contrast, other health agencies take the view that the appropriate health risk value to use with children's exposures is one specifically based on children's data (or young experimental animal data), or a short-term or subchronic RfD by default, and not the chronic RfD. MDH has evaluated the toxicology data on the 80 chemicals that currently have draft nHRLs to determine if less than "chronic" exposures can lead to critical effects. MDH reports conclusions on 25 of these chemicals. Four chemicals show effects at the LOAEL only at > 10% of a lifetime and 7 could not be assessed because of lack of interim data. MDH determined that only 14 of these chemicals show effects at the chronic LOAEL within \x{2264} 10% of a lifetime. The MDH results from these 14 chemicals, along with the definitions and assumptions stated above, form the basis for the MDH suggestion that a chronic RfD should be used with children's exposures to develop nHRLs. When we analyzed these same 14 chemicals, however, we find some support for MDH's assumption for only 5 chemicals. In contrast to MDH, we find that with 6 chemicals this support does not exist, and with 3 chemicals, the available information is insufficient to make any statement. We conclude that there is insufficient support for MDH's assumption that the critical effect at the LOAEL is frequently observed at exposure time points 10% of the lifespan. Both the MDH analysis and our work use readily available information from the MDH database of nHRLs. However, both investigations suffer from the lack of comparable toxicology information in the same species at different times; or absent this, from the lack of comparative toxicokinetics and toxicodynamics in different species. Both investigations also lack a standardized approach to defining the severity of toxic effect. Ideally, the MDH assumption that 10% lifetime exposure can result in "critical" effects might be better evaluated by review of data from chronic studies that include interim toxicity assessment time points, such as the data contained in the NTP database. The NTP data could be mined for information from different times points (short-term, subchronic, interim sacrifice and terminal sacrifice). Moreover, the same species are used and protocols are standardized, including t
database would make either of these investigations more definitive.
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