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Society For Risk Analysis Annual Meeting 2005

Session Schedule & Abstracts


P2 -
Poster Session 2

   

Exposure Assessment

P2.1  Human Exposure to Dioxins from Food, 1999-2002. Charnley G, Doull J; HealthRisk Strategies and University of Kansas Medical Center   charnley@healthriskstrategies.com

Abstract: In response to aggressive attempts to control dioxin emissions over the last 35 years, human exposures to dioxins from the environment have declined significantly. The primary source of human exposure to dioxins at present is food. The sources of dioxins in food are not well understood and are probably varied. Data on the levels of dioxins measured in various foods for samples collected from 1999 through 2002 have recently been released by the US Food and Drug Administration as part of its Total Diet Study. Based on those data and on the US Department of Agriculture’s most recent food consumption survey, estimates of dioxin intake for the total US population and for three age groups of children were obtained. Results show that the most recent mean dietary exposures for all groups are below 2 pg TEQ/kg BW/day, the tolerable daily intake established for dioxins by the World Health Organization. Between 1999 and 2002 mean dioxin intakes from food appear to have decreased, but when estimates are adjusted based on a standardized limit of detection and evaluating only those {congener × food} combinations common to all four years, no trend is apparent. When dioxin concentrations below the limit of detection are represented by one-half the limit, approximately 5% of the intake estimates for 2-year-olds and 1% of the intake estimates for 6-year-olds exceed the tolerable daily intake by about 10%, although such upper-percentile estimates should not be equated with excess risk. When non-detectable dioxin values are set to zero (i.e., when only dioxin values actually measured are used), only 1% of intake estimates exceed the tolerable daily intake for 2-year-olds. As expected, about 50% of daily dietary dioxin intake by the total US population is attributable to meat and dairy products, based on the same food group classifications used by the National Academy of Sciences’ Committee on the Implications of Dioxin in the Food Supply. This information may be useful for targeting future risk management activities.

P2.2  Exposure and risk assessment of hazardous air pollutants in Japan. Higashino H., Yoshikado Y., Yonezawa Y., Nakanishi J.; National Institute of Advanced Industrial Science and Technology   haru@ni.aist.go.jp

Abstract: We assessed the risks and consequences of exposure to hazardous air pollutants for human health and have published the results as an exposure and risk assessment document that provides a scientific basis for the decision-making process of regulatory bodies with regard to chemical risk management in the national government. Target substances for the assessment include 11 chemicals which are on the list of Substances Requiring Priority Action published by the Central Environmental Council of Japan in 1996. Emission of these substances has been controlled by the responsible care program since 1997. Because the total emissions of these substances have decreased in Japan in recent years, primarily because of reductions related to responsible care in industry, we should evaluate the outcomes of the program. The remarkable advantage of our method of risk assessment is a detailed exposure assessment. We have developed two different types of models to assess exposure: AIST-ADMER estimates regional concentration distributions, while METI-LIS estimates concentration distributions around factories. Both models were used for the exposure assessment. The risks of exposure to chemicals were evaluated by comparing estimated ambient concentrations with reference concentrations. Reference concentrations were selected by environmental standards for target substances when available, and were determined by surveying the literature concerning current toxicity when the environmental standards were not available. Our results indicate that areas where stationary emissions dominate are very limited for many substances and that emissions not only from the nearest large point source but also from smaller sources in an area contribute to high concentrations, even near large point sources; as such, the responsible care program for industrial stationary sources should be revised.

P2.3  “Scenario-based Exposure Assessment” for Consumer Products/Articles. Papameletiou D.*, Hakkinen P.J., Kephalopoulos S., Zenié A., Reina V.; European Commission   pertti.hakkinen@jrc.it

Abstract: EIS-ChemRisks, the European Information System on Risks from chemicals released from consumer products/articles has been developed over the period 2003-2005 with the objective to provide tools and reference data that enable harmonised exposure assessment procedures for consumer products and articles (e.g., clothing and toys) in the EU. A key deliverable is the EU Exposure Assessment Toolbox. It includes tools and reference data that are supporting the development of a structured stakeholder dialogue, initially in the frame of the General Product Safety Directive (GPSD, 2001/95/EC) via sectorial workshops of EIS-ChemRisks and progressively in the frame of the forthcoming REACH (Registration, Evaluation, Authorisation of CHemicals). The JRC has launched the demonstration phase to test the system by external users on thematic projects, and broad stakeholder access is scheduled to become effective by the end of 2005. In addition to open literature, key data sources include public and industrial risk assessment resources. The information from these data sources is indexed according to standard taxonomies for consumer products and articles, and for exposure data categories. Furthermore, the toolbox offers standard formats and templates for the storage and presentation of the information. Taxonomies have been developed that allow information on exposure scenarios, exposure data, exposure factors, testing methods, and exposure models and algorithms to be indexed and made retrievable in a standardized way. This has been demonstrated on the example of hundreds of case studies from the above international resources. On this basis, the objective of the current demonstration phase is to test the toolbox regarding its functionalities for the development of novel assessments. Several in-house projects are under development, and thematic activities are being established in co-operation with key stakeholders from Public Authorities, NGO’s, Industry, and Academia.

P2.4  Risk of Inhalation Exposure to Bromoform Following Disinfection of Spas and Hot Tubs. Ruhoy I, Hassenzahl DM; University of Nevada, Las Vegas   david.hassenzahl@ccmail.nevada.edu

Abstract: There have been few studies conducted on health effects directly associated with exposure to disinfectant by-products (DBP) in spa water. We assess inhalation risks to spa and hot tub users from carcinogenic DBP produced following disinfection by bromine. The DBP of interest evaluated in this study is bromoform, a trihalomethane. Bromoform, a volatile organic compound (VOC), has been shown to be carcinogenic in experimental animal models. Inhalation exposure dosages were estimated based on breathing zone concentration, inhalation rate, and exposure duration and frequency. Risks were estimated for the median, 80th and 90th percentiles (50%, 20%, and 10% of the exposed populations). Exposure estimates greater than or equal to cancer reference values occurred for approximately 20% - 30% of the exposed populations for chronic exposure to volatilized bromoform in spas. Lifetime cancer risks of one-in-a-million or greater were estimated for approximately 20% - 30% of the exposed population. The potency of bromoform alone imparts a 1 in 2000 chance of cancer risk to the exposed population. Further research to decrease uncertainty and variability are necessary to establish the potential for cancer development in spa users.

P2.5  Evaluation of Potential Acute Inhalation Health Risks Associated With A Waste Slag Pile Located in the Eastern US. Kountzman J.A.*, Hubbard J., Erney S.R.; Black and Veatch Special Projects Corp and Environmental Protection Agency   kountzmanja@bv.com

Abstract: The evaluation of potential acute health effects associated with exposures at hazardous waste sites is often overlooked. Typical risk assessment methodologies for evaluating exposure and toxicity at hazardous waste sites focus on cancer and chronic non-cancer health effects. The methods for evaluating acute exposure and toxicity at hazardous waste sites are not well developed (i.e. acute RfDs and RfCs are not available). This paper presents methods used to evaluate the potential acute inhalation hazard at a waste/slag pile located in the eastern U.S. This assessment supplemented the more typical chronic risk assessment, which was also conducted. Using conservative assumptions, air dispersion modeling (ISCST3) was used to generate short-term (1-hour) maximum concentrations of constituents in dusts generated from the waste/slag pile. Acute COPCs were identified by comparing these maximum predicted 1-hour concentrations to available acute inhalation screening levels obtained from the EPA Air Toxics website. A refined exposure analysis was used to generate RME and CTE exposure point concentrations for the selected COPCs. The lowest available acute toxicity value obtained from the toxicity data sources listed on the EPA Air Toxics website was selected as the acute toxicity criteria for each COPC. The potential for acute noncarcinogenic health effects due to chemical exposure was evaluated by comparing exposure concentrations with the acute toxicity criteria. This comparison, or unitless ratio, is called a “margin of exposure” and is analogous to a “Hazard Index”. Using this methodology, potential acute health effects were characterized. Uncertainties associated with the analysis are discussed. Professional judgment and risk management must be used in determining whether an exceedance of an acute screening value is of concern and whether an MOE is acceptable.

P2.6  Health Risk Assessment on Human Exposed to Environmental Polycyclic Aromatic Hydrocarbons Pollution Sources. Chen S.C.*, Liao C.M., Chou B.Y.H., Chang C.F., Chiang K.C.; Department of Bioenvironmental Systems Engineering, National Taiwan University   cmliao@ntu.edu.tw

Abstract: We presented an analysis to assess public health risks result from human exposure to environmental polycyclic aromatic hydrocarbons (PAHs) pollution sources generated from industry, traffic and rural. A probabilistic risk model is integrated with the potency equivalence factors (PEFs), human exposure probability and the incremental lifetime cancer risk (ILCR) approaches to quantitatively estimate the exposure risk for three age groups of adult, children, and infant. The use of PEFs allows the 21 PAHs concentrations to be expressed as benzo[a]pyrene equivalents to estimate the daily basis occupancy probability regarding industry, traffic and rural. We calculated the ILCR for inhalation and dermal contact pathway. Risk analysis indicates that the inhalation-ILCR and dermal contact-ILCR values for adult have a lognormal distribution with geometric mean 1.04×10-4 and 3.85×10-5 and geometric standard deviation 2.10 and 2.75, respectively, indicating high potential cancer risk; whereas for the infant the risk values are less than 10-6, indicating no significant cancer risk. Sensitivity analysis indicates that the input variables of cancer slope factor, daily exposure level for inhalation have the greater impact than body weight on the inhalation-ILCR; whereas for the dermal-ILCR particle-bound PAH-to-skin adherence factor and daily exposure level for dermal contact have the significant influence than body weight.

P2.7  Risk-Based Strategy Using Wipe Samples for Clean-Closure of Container Storage Units at the Los Alamos National Laboratory, LA-UR-05-1011. Eidson A. F.; Shaw Environmental & Infrastructure Inc.   frank.eidson@shawgrp.com

Abstract: A risk-based approach was developed and implemented to complete closure of Resource Conservation and Recovery Act (RCRA) permitted hazardous waste container storage units (CSUs) at the Los Alamos National Laboratory (LANL). CSUs were buildings used to store hazardous waste generated from various research activities, material processing and recovery operations, and decontamination and decommissioning operations conducted at various LANL Technical Areas. The effectiveness of CSU decontamination was verified through analysis of rinse/wash water and wipe samples and estimations of potential human health risk from exposure to residues on indoor surfaces. There is currently little scientific or regulatory literature pertaining to the estimation of quantification of exposure to volatile and semi-volatile chemicals on indoor surfaces. Elements of risk assessment procedures developed by the World Trade Center Indoor Air Task Force Working Group, the U.S. Environmental Protection Agency and the California Department of Toxic Substances Control were adapted to derive a risk-based strategy for surfaces. The strategy provides an estimate of daily dose resulting from dermal exposure via surface-to-hand contact and ingestion exposure via hand-to-mouth contact. Exposure to contaminants resuspended in dust was estimated based on studies of potential hazards to military personnel exposed to depleted uranium-contaminated soil. For volatile compounds, the maximum (worst case) airborne vapor concentration within a working volume was estimated using wipe sample analysis. Application of this risk-based strategy allowed RCRA closure of the buildings so they can be reused and not destroyed.

P2.8  Do Scientists and Fishermen Collect the Same Size Fish?: Implications for Risk Assessment. Burger J., Gochfeld M., Burke S., Jeitner C., Jewett S., Snigaroff R., Stamm T., Harper S., Hoberg M., Chenelot H., Patrick R., Volz C., Weston J.; CRESP, EOHSI, Rutgers University   burger@biology.rutgers.edu

Abstract: Fish consumption has increased in recent years but concerns about contaminants have prompted agencies to analyze fish for mercury and PCBs, and to issue fish consumption advisories to reduce public health risks. Risk assessors use contaminant levels as the basis for advisories, using two assumptions: 1)scientists collect the same sizes and types of fish that fishermen catch, and 2) mercury and PCBs levels increase with fish size. The assumption that scientists collect the same size fish as those caught by fishermen is important because contaminant levels are different in different size fish. We test the null hypothesis that there are no differences in the sizes of fish collected by Aleut fishermen, scientists, and commercial trawlers in the Bering Sea. Aleuts caught fish using rod-and-reel from boats, as they would in their villages. Scientists collected fish using rod-and-reel, by scuba divers using spears, and from a research trawler operated under NOAA. The fish collected represented different trophic levels, and are species caught by Aleuts. There were no significant differences in length and weight for five species of fish caught by Aleuts, scientists, and fisheries trawls, and for an additional 3 species caught only by Aleuts and scientists. There were few differences in the percent of males in the samples as a function of fishing method or type of fishermen. These data suggest that if scientists collect fish in the same manner as subsistence fishermen, they can collect the same-sized fish. The implications for risk assessment are that scientists should either engage subsistence and recreational fishermen to collect fish for analysis, or mimic their fishing methods to ensure that the fish collected are similar in size and weight to those being caught and consumed by these groups. Our data demonstrate that scientists can collect the same size fish as those caught by Aleuts, making contaminant analysis representative of the risks to fish consumers. This project was funded by DOE (DE-FG 26-00NT 40938) and NIEHS (ESO 5022).

P2.9  Quantitative identification of unknown exposure pathway of certain phthalates in Japan. Itoh H., Yoshida K., Masunaga S.; Yokohama National University   itoh-hiroaki@umin.ac.jp

Abstract: In Japan, the use of certain phthalates has been regulated. These administrative policies were based on the measurement of exposure at the point-of-contact. Did Has this approach really comprehend total human exposure to phthalates without omission? The exposure to ubiquitous phthalates can occur through multiple pathwayroutes. The sufficiency of the comprehension was verified in the present study using the measurement of urinary biomarkers of phthalates, which are the direct evidence of human exposure to phthalates. We recruited voluntary participants, collected urine samples, and measured the concentration of urinary phthalate metabolites using enzymatic deconjugation, offline solid-phase extraction, and HPLC-ESI-MS/MS. From the concentration measured and individual creatinine-excretion rate, we determined the daily intake of respective parent compounds. The result was finally compared to the corresponding intake of each phthalate via diet and air derived from the past studies in Japan. From their mass budgets, the existences of the critical exposure pathways overlooked in the past studies were identified. Surprisingly, exposure via diet and air explained only less than half of the total exposure to dimethyl phthalate, diethyl phthalate and di-n-butyl phthalate. On the other hand, it appears that dietary intake was the solely responsible pathway for human exposure to n-butyl-benzyl phthalate and di-2-ethylhexhyl phthalate. Overall, exposure to phthalates via air contributed to only the minor part of the total exposure to phthalates. The past exposure-assessment studies of phthalates in Japan have overlooked the critical exposure pathways of three of the five phthalates. Overlooking critical exposure pathway of chemicals is equal to underestimating human exposure and human health risk of the chemicals. In other words, identification of new pathway is equal to finding of new risk.

P2.10  Pharmacokinetic Characterization of Potentially Susceptible Subpopulations: Physiologically Based Pharmacokinetic Modeling in Children.. Byczkowski J.Z.; Consultant, Fairborn, Ohio   januszb@aol.com

Abstract: As a result of enhanced exposure of internal targets and their developmental immaturity, young children may represent the subpopulation particularly susceptible to the effects of some environmental chemicals. Their absorption, distribution, metabolism, and excretion (ADME) can be fully described and/or predicted by physiologically based pharmacokinetic (PBPK) models. The modeling approach of several successful PBPK models in children has been reviewed and analyzed. The goal of this presentation is to review the resources and to compile from the available literature a set of PBPK input parameters that characterize the unique ADME of chemicals in children and could be applied in PBPK modeling. The modeling methodology presented here may be used in life-stage-specific derivation of toxicity values and in chemical risk assessments for children exposed to environmental chemicals.

P2.11  Exposure Assessment Modelling In River Basins In Japan. Ishikawa Y.*, Tokai A., Kawaguchi T., Shirahama M., Nakanishi J.; National Institute of Advanced Industrial Science and Technology (AIST) and Nihon Suido Consultants (NSC), JAPAN   y-ishikawa@aist.go.jp

Abstract: In September 2004, the research center for Chemical Risk Management (CRM) of the National Institute of Advanced Industrial Science and Technology (AIST), an independent administrative institution, has developed a software tool for chemical risk assessment in river basins and evaluation of emission reduction measures, named “AIST-Standardized Hydrology-based AssessmeNt tool for chemical Exposure Load (AIST- SHANEL)”. This tool is used to estimate the chemical exposure concentrations in a water system with spatial resolution of 1×1 km mesh and everyday as time resolution by simple data inputting, requiring only PRTR release data, river basin information, and data on the basic physical properties of the chemical substances of interest. As shown in the figure, a variety of information can be easily grasped from calculations with this tool, including the location of high release areas within the river basin, the correspondence between the exposure load and areas with high releases, and the relationship between river flow rates and loads. It is also possible to evaluate ecological risk by obtaining the probability that loads will exceed the concentration affecting aquatic organisms, and to estimate the benefit of reducing chemical releases from factories and improving the removal rate in wastewater treatment plants in reducing chemical loads. Thus, AIST-SHANEL is a useful tool for resolving questions about what measures should actually be taken when chemical risk in a water system is evaluated to be high not only for businesses which release chemical substances and the local governments responsible for managing river basins, but also for general users. The subsequent efforts will be paid to the model extension to Japanese major river basins and small river basins where the exposure concentration is readily affected by local emission, and the revised version of software will be released.

P2.12  Comparison of 2 methods that use 2 day food consumption survey data with longer term (30 day) food intakes to simulate longitudinal dietary exposure analysis. Petersen Stephen R, Petersen Barbara J, Barraj Leila M, Johnston Jason; Durango Software, LLC and Exponent, Inc.   bpetersen@exponent.com

Abstract: Estimating long-term dietary exposure to contaminants by individuals is constrained by the lack of long-term food consumption data. The publicly available data on consumption patterns are either for a limited number of days or for a limited number of food groups without information on amounts consumed. The best available solution appears to be the simulation of long-term consumption patterns from these short-term data. In response to the 1996 Food Quality Protection Act, which mandated that EPA conduct cumulative and aggregate exposure analyses of pesticides from both dietary and residential sources, complex “calendar-based” methods for calculating chronic exposures have been developed. We describe two approaches for simulating long-term consumption patterns using two-day food consumption data and compare these simulated patterns to long-term patterns derived from food frequency data. The first method, the “two-day repeated record” method, uses the same two days of food consumption data repeatedly, in random order, for the duration of the exposure analysis. The second method, the “record-sharing” method, selects cohorts of individuals with similar demographic characteristics and “shares” their daily food consumption records in the creation of the long-term patterns. The results of these analyses demonstrate that the cohort record sharing approach was more consistent with the results reported in the food frequency data for the average individual but consistently underestimated the upper percentiles of the distribution. On the other hand, the two-day repeated record method produced distributions that were more consistent with the food frequency data at the upper end of the frequency distribution. Both methods provide indications of approaches when no frequency data are available

P2.13  Algorithms for Estimating Resting Metabolic Rate and Activity Specific Ventilation Rates for use in Complex Exposure and Intake Dose Models. Graham S.E.*, McCurdy T., Sharma K.; USEPA/NERL   graham.stephen@epa.gov

Abstract: Recent advancements have been made to allow for better estimation of resting metabolic rate (RMR) and subsequent estimation of ventilation rates (e.g., total ventilation (VE) and alveolar ventilation (VA)) for individuals of both genders and all ages. RMR is used in conjunction with activity-specific relative estimates of the energy expended by individuals for each activity that they undertake. These two data are first translated into activity-specific VO2 estimates and then into VE and VA. We are interested in improving the database and the procedures for estimating all of these physiological metrics for use in exposure models. With respect to RMR, we recently completed a meta-analysis of RMR measurement studies to develop improved age-gender specific prediction equations. Over 200 studies were evaluated for this analysis, and the resulting equations have lower residuals than any developed previously. Using data compiled from 32 clinical exercise studies, algorithms were developed to estimate body mass-normalized ventilation rate (VE, L/min kg-1) for 4 age groups (<20, 20-<34, 34-<61, 61+ years of age) and both genders. The algorithm accounts for differences in ventilation rate due to activity level, variability within age groups, and variation both between and within individuals. A multiple linear regression model was first used to estimate significant explanatory parameters (p<0.01) following natural log (LN) transformation of body mass (BM) normalized oxygen consumption rate (VO2). Log transformed age (LN(age)), gender (-1 for males, 1 for females), and LN(VO2/BM) served as independent variables and regressed on multiple VE measurements that were collected during incremental exercise to obtain regression parameter estimates. A mixed-effects model was then constructed utilizing the independent variables as fixed parameters and retaining individuals and study of origin as random effects variables. The mixed-effects model was used to allocate the random error (e) to between-person residuals distributions (inter-individual variability) and within-person residuals distributions (intra-individual variability). Alveolar ventilation (L/min kg-1) was approximated through VE by accounting for activity-specific dead space to tidal volume (VD/VT) relationships. The RMR equations, along with new VE and VA algorithms, become the basis for estimating dose rate received associated with exposure to environmental contaminants as simulated individuals go through their daily life. The coordination of the algorithms are critical to maintaining the time-series of exposure and provide a more realistic approach for estimating exposure and absorbed dose than done previously, particularly when considering simultaneous chemical exposure of different pollutant types. Disclaimer Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

P2.14  Calculating a soil EPC when sampling and exposures are non-random. Strauss H.S.*, Ferson S., McGrath R., Svirsky S.; H. Strauss Associates, Applied Biomathematics, SHD, and US EPA   h.strauss@rcn.com

Abstract: The exposure point concentration (EPC) is intended to represent the average concentration of soil with which a receptor comes into contact. For EPA risk assessments, the EPC is the 95th upper confidence limit for the mean of data collected from random sampling. Important assumptions underlying the EPC are that sampling is random and that an individual comes into contact with the contaminated soil in a random way across the exposure area (or site) under evaluation. In practice, the random sampling assumption is often violated if no adjustment is made for samples that are collected in a non-random manner, such as programs intended to define areas of elevated concentrations. The random exposure assumption may be violated when considering recreational activities such as hunting, fishing, birdwatching, and hiking, where there may be preferential areas or paths used by individuals, or avoidance of areas that are difficult to access because of dense vegetation or obstructions. In order to maintain consistency with the assumptions of random sampling and random exposure within an exposure area, we developed a methodology that included area-weighting to account for non-random sampling patterns and use-weighting to account for preferential use of certain areas within an exposure area. This EPC methodology was applied to PCBs in the floodplain soil of the Housatonic River in Massachusetts. The use-weighting system was based on information about ecological habitat and thus potential accessibility and attractiveness of the area. The area-weighting system also required information about habitat types as they were indicative of the topographic and hydrologic factors that governed the deposition of PCBs in the floodplain. The 95th UCL of the mean was calculated from area- and used-weighted data by generalizing a bootstrap resampling procedure that accounts for skewness.

P2.15  Assessment of Potential Human Health Risks from THMs in Drinking Water at Mexican Communities. Navarro I. *, Lucario E.S., Maya C., Bustos R.A.; National University of Mexico   ing@pumas.iingen.unam.mx

Abstract: Mexico actually has achieved drinking water supply to 90 percent of the population. Chlorinated groundwater supplied to small communities has contributed to diminish gastrointestinal diseases like cholera, typhoid, hepatitis, etc. Health public policy focuses on water quality in order to provide safety levels. In this poster, exposure to adults from tap water ingestion is presented. Tap water samples from eleven rural/urban communities located at central region of the country are analyzed for residual chlorine and chlorination derived compounds (THMs). Drinking water monitoring results show residual chlorine mean concentration of 0.5 mg/L and THMs mean concentration of 0.019 mg/L. Gastrointestinal diseases, chronic diseases on kidney and liver and cancer cases (Leukemia and thrombocytopenia) were identified through an epidemiological study applied at research area. It also provides information to characterize exposure variables for the potential population of concern (water ingestion rate, exposure duration and body weigh). Probability distribution functions (Ca, IR, ED and BW) and point estimate values are used on probabilistic risk estimation. The output risk distributions provide information on variability in risk in the population of concern; probability distributions for the last 10 years of exposure to chloroform and bromoform do not exceed the risk level of concern (1E-06). But risk estimation shows that level of concern falls between 45th and 55th percentiles of bromodichloromethane and dibromochloromethane risk distributions. Additional data collected from later monitoring program, to better define the concentration terms, are discussed along with the impacts on the resulting risk estimates. These results support further evaluation of data and assumptions associated with groundwater characteristics, chlorination dose and THMs formation. Meanwhile, chlorine disinfection must be monitoring in order to supply safety conditions better than those observed.

P2.16  An Approach to Assess Probabilistic Risk for Develop Soil Cleanup Levels in Mexico. Navarro I. *; National University of Mexico   ing@pumas.iingen.unam.mx

Abstract: Mexican environmental agency approved few months ago the first cleanup levels for hydrocarbon contaminated soils. Target levels based on point estimate process could be reconsidered if alternative values are developed by well known risk evaluation. But no risk methodological guidelines are available on Mexican legislation framework. This paper presents preliminary distribution functions developed for exposure duration and body weight variables based on epidemiological surveys. One concluded on rural area and a second on going study from urban population. Sensitive analysis was performed to an exposition model to direct occupational contact exposure to benzene in soil. Discussion of variability and uncertainties on the main exposure variables developed for Mexican context shows relevant differences with the typical default values and between rural and urban Mexican values; arguments on the input variables with point estimates are also discuss. The iterative truncation method was used to identify the concentration at which the risk is acceptable and the maximum concentration that may be left in site. Final discussion on the important features of probabilistic risk assessment focuses on available data, state of the knowledge and significant policy choices that could be made in order to achieve distribution functions for input variables based on a national survey.

P2.17  Monitoring of Dioxin and Co-PCBs in human breast milk and its risk analysis. Han J, Kang Y, Cha S, Kang T*, Park J; LabFrontier Co. Ltd. and *National Institute of Toxicological Research   snchoi@labfrontier.com

Abstract: Breast milk is an ideal medium for assessing exposures to POPs such as PCDD/Fs. POPs enter humans largely as contaminants of dietary animal products, where they sequester in adipose tissue, serum, and breast milk and equilibrate at similar levels on a fat weight basis. The target population on exposure of PCDD/Fs in breast milk is children. Children are not little adults (U.S.EPA). They are more exposed than adults and have different metabolism. Children are less able than adults to detoxify most pesticides and have a longer shelf life. This study conducted to investigate into level of PCDD/Fs and Co-PCBs in breast milk and to assess the infant health risk its exposure based on guidelines for carcinogenic risk assessment proposed by U.S.EPA. In Korea, it is reported that the average concentrations of total PCDD/Fs and Co-PCBs in breast milk were 12.37 pg TEQ/g lipid collected at 1st~10th day after delivery, 8.06 pgTEQ/g lipid at 10th ~30th pay, 7.20 pg TEQ/g lipid at 30th~90th day, and 5.16 pg TEQ/g lipid at 90th~180th day. This study assumed exposure scenario including exposure duration (period of breast feeding), averaging time(lifetime), intake rate of breast milk, body weight, lipid contents in breast milk. The average lifetime daily exposure dose (LADD) is estimated 0.2 pg TEQ/kg BW/day considering breast milk intake rate and body weight of Korean. The LADD is lower than 1~4 pg/kg bw-day as TDI(tolerable daily intake, WHO). Based on LADD, Cancer risk is estimated 2.77E-4, using upper bound cancer slope factor 1.4E-3 suggested by U.S.EPA. Breast-feeding infants have higher intakes of dioxin and related compounds for a short but developmentally important part of their lives. However, the benefits of breast-feeding are widely recognized to outweigh the risks (U.S.EPA, 2000).

P2.18  Progress toward development of an in vitro method for assessing bioaccessibility of arsenic from soils. Lowney YW, Ruby MV, Cushing CA; Exponent, Boulder Colorado   lowneyy@exponent.com

Abstract: Recent reseach has established that soil- or site-specific factors may control the bioavailability of contaminants in soil. Emerging data regarding the relative oral bioavailability of arsenic from soils provide a basis for the development of simple, benchtop extraction methods that may be predicitve of the relative oral bioavailability. Data presented here depict efforts to develop such an in vitro method that will provide data for use in risk assessment of arsenic-contaminated sites.

P2.19  Urbanisation vis a vis water an element of Concern: A Case of Major Urban Area of Tehsil Huzur, Bhopal Block (M.P., India)”. bharat alka*, sharma divya, gupta sunil; MA National Institute of Technology & Bhopal Development Authority   alka_bharat@yahoo.com

Abstract: Today, cities and towns in the developing world are exposed to air and water pollution and problems related to inadequate liquid and solid waste disposal. Indiscriminate discharge of domestic and industrial wastes water has seriously polluted most water resources. Ground water reserves are under continuous threat of pollution as a result of over exploitation as well as seepage of surface pollutants. Already cities are reaching out to more distant sources of water supply. The competition for water among various users is already acute and conflicts are rising. The urban environmental management will need to integrate strategies for addressing environmental problems of the past as well as those of the future. The Poster: Through the poster an attempt has been made to assess the Impact of Urbanization on Environment with particular reference to Water in the Major Urban Areas of Tehil Huzur of the Bhopal District in Madhya Pradesh, India, which has got very interesting physiography as well hydrological character. The objective being- • To suggest water buffer zones where the underground water potential is high so that these areas are conserved for future • To demarcate water recharge areas so that proper recharge mechanisms are established here Maps Prepared and used for Study and Analysis- • Details of the surface water bodies • Geological map • Geomorphologic Map (Showing various drainage density, relief areas, delineating the watersheds and assessing the quantity of water in the catchments) • Structural Map (Built Areas) • Land use and land capability map • Watershed from the Geomorphology Map The output: After thorough analysis the output maps were prepared in the form of the following • Water Buffer Zones map • Proposed Rainwater Harvesting And Artificial Recharge Areas Map

P2.20  Development of cost-effective statistical sampling strategies and optimal design considerations for exposure assessment as part of the National Children’s Study.. Strauss W.J., Ryan L., Quackenboss J., Ozkaynak H., Scheidt P.; Battelle, Harvard University, U.S. EPA National Exposure Research Laboratory, and the National Institute of Child Health and Human Development   strauss@battelle.org

Abstract: This project was performed to develop innovative statistical study design guidance for the acquisition of exposure data over time in a longitudinal study of children who participate in the National Children\\\'s Study (NCS). The NCS is intended to investigate environmental influences on children\\\'s health and development–including understanding any environmental exposures that may cause or exacerbate health impacts. Due to the large sample size and longitudinal nature of the Study, unique statistical issues arise that must be addressed before a cost-effective sampling design can be developed to gather the environmental and personal exposure data. A key issue for the NCS relates to obtaining enough samples to provide adequate statistical power to detect health effects attributable to environmental and personal exposures, while being cost-effective, minimizing participant burden, and staying within the study\\\'s overall budget. Relevant specific issues include identification of potential sources of bias and/or uncertainty in the exposure measures (non-response, subject burden, attrition, and measurement error); and strategies to address these issues, including the use of validation sampling techniques to obtain highly detailed measures on a carefully selected subset of the study population, while using less detailed (and presumably less expensive and less burdensome) measures across the entire NCS cohort. During this presentation, we will demonstrate the utility of using these techniques for developing study protocols for the efficient (and unbiased) study of important relationships between exposure and health outcomes within the NCS.

P2.21  Traditional Tribal Life-ways Exposure Scenario for an Oiled Beach in the Pacific Northwest. Zieber P.A.*, Cardenas A.M., Schoof R.A., Ostrom T.; Integral Consulting, Inc. and Suquamish Tribe   pzieber@integral-corp.com

Abstract: On December 30, 2003, a spill of over 4,000 gallons Bunker fuel into Puget Sound occurred during loading of oil onto a tank barge. The oil came ashore between Point Jefferson and Indianola, on the Port Madison Indian Reservation, oiling parts of the beach and the marsh. The beach holds spiritual, cultural, and historical importance to the Suquamish Tribe, as well as economic importance due to a commercial fishery and subsistence fishing by Tribal members. The Tribe needed to assess the safety of Tribal members eating shellfish and using the beach and marsh. Beach re-opening criteria needed to balance health protection against the economic and cultural need for a prompt re-opening. Evaluation of shellfish and sediment focused on development of risk-based “re-opening criteria” for PAHs. A beach use survey aided in developing a conceptual site model. Child and adult sediment criteria for Tribal beach use were developed for ingestion of and dermal contact with sediment, considering the nature and frequency of activities occurring in the beach and marsh areas. Shellfish criteria were developed using consumption data specific to the Tribe. All exposure assumptions for these unique scenarios are discussed, including sediment ingestion rates, dermal contact rates, sediment adherence, exposure duration, and relative bioavailability. One over-arching issue in development of beach, marsh, and shellfish bed re-opening criteria was lack of published data on persistence of PAHs following an oil spill. Limited information on PAH degradation presented a challenge in developing an appropriate exposure duration value and pointed to a need for publishing environmental monitoring data following oil spills. Shellfish and sediment sampling results six months after the spill indicated the shellfish were safe to eat and the beach and marsh were safe to visit, with some caveats.

P2.22  Study on body weight among the exposure factors for risk assessment in Korean . Kim H.J.*, Lee H.Y., Yoon E.K., Ze K.R., Choi K.S.; National Institute of Toxicological Research   khjyoi@kfda.go.kr

Abstract: Exposure factors are important as a fundamental data for exposure assessment of risk assessment. But in Korea, it has little study of the exposure factors for risk assessment and even if there are exposure factors they are limited to using in exposure assessment. So we carried out the survey of body weight which is frequently used among exposure factors in order to identify the specific value for Korean and use it on the risk assessment for human. A follow-up study design was used to collect the data of the body weight. 1051 Koreans(545 males, 506 females) aged 3-85 years took part in the study. Participants measured their body weight in the morning and evening twice a day every 15 days for themselves and recorded it themselves on the web site for the study for two years. For children, parents quantified and set down their children body weight. We analyzed these data with SAS and evaluated mean, standard deviation and percentile of body weight by sex, age and sex and age. The mean body weight of adult aged 19-64 revealed 63kg. It is larger than the body weight, 60kg using in exposure assessment in Korea to the present.

P2.23  Estimation of Listeria monocytogenes Prevalence in Selected Food Categories from Retail Establishments in Eight States.. LaBarre D.D.*, Hicks-Quesenberry H., Connell H., Kause J., Kadry A.; Food Safety and Inspection Service United States Department of Agriculture   david.labarre@fsis.usda.gov

Abstract: The Food Safety and Inspection Service (FSIS) is the public health agency in the U.S. Department of Agriculture responsible for ensuring that the nation's commercial supply of meat, poultry, and egg products is safe, wholesome, and correctly labeled and packaged. In FY05, under Cooperative Agreement with the Association of Food and Drug Officials (AFDO), FSIS collected and analyzed data from States sampling for Listeria monocytogenes (Lm) in retail foods and environments. FSIS conducted this study in order to better understand and characterize Lm prevalence in retail products and environments because Lm is a recognized ubiquitous foodborne hazard in the food processing and retail environments. Data from ten states were collected from some or all the years from 1999 to 2005. A total of 35,782 records were made available for analysis, of which 35,725 were usable. Fifty-five records lacked sufficient data quality for inclusion. There were 761 confirmed positive Lm cultures and 34,529 negative cultures. The eight State contributors used in the analysis given in descending order of overall prevalence from 5.7% to 0.8% were: New York; Colorado; Florida; Wisconsin; Tennessee; California; Texas; and Georgia.. Retail food categories were minimized to eleven excluding those for environmental swabs that constituted 19.4% (6,701) of the total. The categories used for estimating prevalence were in order of most frequent Lm positives: Miscellaneous Sandwiches (6.7%); Deli Meats (3.4%); Miscellaneous Salads (2.6%); Miscellaneous Other (2.2%); Sausages (1.7%); Fish (1.6%); Cheese (1.2%); Franks (0.4%); Sea Food (0.24%); Ground Meat (0.17%); and Milk (0.07%). These were calculated as a weighted prevalence based on the numbers of records contributed by each State. Environmental swabs fell second in between the categories of Miscellaneous Sandwiches and Deli Meats with a weighted prevalence of 6.0%. The weighted aggregated annual prevalence results showed marked variation. The years of 2000 and 2002 produced higher prevalences, 3.7% and 4.4% respectively. There were several years with either low or intermediate prevalence for Lm at retail. In ascending order, these were: 2005 (0.2%); 1999 (0.6%); 2004 (1.5%); 2003 (2.3%); and 2001 (2.3%).

P2.23B  The monitoring of heavy metals in human bloods of middle school students in Korea. Park H.R.*, Kim M., Kim S.Y., Kwyun K., Choi K.S., Lee H.M.; National Institute of Toxicological Research, Human Exposure Assessment Team, Seoul, Korea   

Abstract: This study was conducted to estimate the contents of heavy metals including lead, cadmium, zinc, copper as well as iron status (serum iron, total iron binding capacity, ferritin etc)in blood samples of middle school students in Korea (n = 300). The contents of heavy metals were determined using the GF-AAS (Graphite Furnace Atomic Absorption Spectrophotometer). The microwave digestion method and dilution method were compared. The dilution method showed the better recovery and detection limit than microwave digestion method. The values of toxic metals in whloe blood of boys & girls were 3.46 & 3.05 for Pb, 0.063 & 0.065 for Cd respectively (ug/dL). Also the values of trace metals in serum of boys & girls were 105.9 & 92.6 for Zn, 98.3 & 99.0 for Cu respectively (ug/dL). The prevalence of iron deficiency was 7.5% in 146 boys and 14.3% in 156 girls. The mean values of lead in girls were higher in iron deficiency, iron deficiency anemia and anemia groups than normal group. The mean values of lead and zinc were higher in boys compared to those in girls(P<0.05), the mean values of cadmium and copper in boys were similar to those in girls. Our results of toxic metals such as Pb & Cd showed lower to CDC's(Centers for Disease Control) blood lead levels of concern for children, 10 ug/dL.

Risk Management 2

P2.24  Individual differences in domestic food handling practices. Fischer A.R.H., Frewer L.J., Nauta M.J.*; Marketing and Consumer Behaviour, Wageningen University, The Netherlands (1, 2), Microbiological laboratory for Health Protection, National Institute for Health and the Environment (RIVM), The Netherlands (3)   arnout.fischer@wur.nl

Abstract: As consumers are the final link in the chain from production (farm) to consumption (fork), knowledge about domestic food handling practices is essential for microbial risk assessment, and the identification of potentials for risk mitigation by risk communication to consumers. A nationally representative survey was conducted in the Netherlands to determine which practices are likely to be conducted by what consumers. Participants reported behavior on 55 different food handling practices. The different food handling practices could all be mapped onto a single dimension, implying an underlying motivation to prepare safe food. The Rasch modeling technique was applied to determine the difficulty of each behavior and the likelihood of each consumer performing a particular behavior. Some potentially safe practices (e.g. use of meat thermometers) were found to be very difficult, while other safe practices were conducted more frequently (e.g. washing of fresh fruit and vegetables). Five segments of consumers were identified, of which highly educated younger single males were those who performed least safe, while low educated older women performed best. Practices likely to be conducted by elderly women, may thus not be likely to be conducted by young males. When experiments and modeling quantify the microbial impact of the different consumer behaviors, consumer groups can be targeted through application of graduated risk communication. In such risk communication this approach can give an estimate which practices might successfully be communicated as they are not too much beyond the current level of the targeted group, the approach can also show which information need not be communicated to whom, because that practice is already likely conducted correctly.

P2.25  Social Trust in Environmental Risk Management Institutions in Chile. Gutierrez V.V., Bronfman N.C.; Universidad Diego Portales, Chile   virna.gutierrez@udp.cl

Abstract: In the field of risk research there is now common agreement that trust in the risk management institutions may be an important factor in perception and acceptance of risks. However, to consider these attitudes correctly and to understand the reactions that people express to environmental hazards it is fundamental to know what factors influence their perception of risk and the acceptability of them. In our preliminary study a survey was developed in which 317 Chilean university students answered the survey. They were required to quantify five variables (Social Risk, Social Benefit, Acceptability, Social Trust and Personal Knowledge) for 6 environmental hazards (climate change, greenhouse effect, ozone layer depletion, increase of ultraviolet radiation, air pollution and suspended particulate matter). Results show that when controlled by Acceptability and Social Trust, the statistical significance of bivariate correlations disappear for all hazards. When second order partial correlations are computed, all relations (Perceived Benefit/Acceptability, Perceived Benefit/Social Trust, and Acceptability/Social Trust) maintain their statistic significance even when they are controlled by the other two free variables. Though, an exception was found for the bivariate correlation between Perceived Risk/Social Trust where its statistic significance disappeared (when it was controlled by the variables perceived benefit and Acceptability). We are now investigating how social trust in regulators influences the acceptability of specifics environmental hazards. To achieve this goal a survey is being designed considering around 30 attributes and 6 to 10 environmental hazards. The survey will be implemented on a statistically significant sample of Santiago population, and data will be analyze using multivariate factor analysis and structural equation modelling procedures. The implications for risk communication and risk management are discussed.

P2.26  Border Inspections Risk Management . Gurian P.L., Ward N.D., Heyman J.M.; Department of Civil, Architectural and Environmental Engineering, Drexel University; The Wharton School, University of Pennsylvania; Department of Sociology and Anthropology, University of Texas at El Paso   plg28@drexel.edu

Abstract: Policy discourse has begun to view international borders as presenting security risks for terrorism, in addition to longstanding concerns over narcotics smuggling. One controversial issue in debates over risk management strategies at borders and in other transit systems has been the use of profiling techniques to identify candidates for more in-depth screening. A game theoretic model is proposed in which illegal crossers may be recruited from either of two societal subgroups. These different subgroups may then be screened at different frequencies by the governmental agency controlling the border. This model predicts that equal numbers of illegal crossers will be recruited from both subgroups and both subgroups will be screened at equal rates by border inspectors. A body of qualitative evidence from ethnographic research on border inspections agents indicates that this model does not apply, as the recruitment and screening of individuals for illicit border crossing activities is not equalized across different societal subgroups. Surveys of border crossers also suggest that screening is not perceived as equal across different societal subgroups. Interviews with U.S. Customs and Border Protections personnel indicate that this inspection process is highly discretionary and intuition-driven. A number of psychological heuristics and resulting biases that could cause these results are discussed. An alternative game theoretic model is proposed which posits that costs of recruitment are not equalized across different societal subgroups. In this case, if the border inspections agents are incentivized solely based on numbers of people apprehended, they may fail to maximize the costs imposed on the agent recruiting the illegal crossers. This has direct implications for how evaluations of the performance of border inspections agents are conducted.

P2.26A  Public Insurance, Private Insurance and Risk Prevention – Has Private Insurance Helped to Reduce Underground Storage Tank (UST) Release Risk? . Yin H.-T.D.; The Wharton School, University of Pennsylvania   haitaoy@wharton.upenn.edu

Abstract: This study aims to empirically investigate the question of whether private insurance promotes risk reduction more effectively than public insurance in the context of Underground Storage Tank (UST) regulations. In order to help tank owners and operators to insure against UST release risk, among others, Michigan (MI), Illinois (IL) and Indiana (IN) implemented UST public insurance called state fund programs around 1990. However, MI made the transition from state fund programs to the private insurance market in 1995. State fund programs simply ascertain if claimants qualify for damages and meet certain criteria, and then pay their claims. Since the cost to participate in a state fund program is not related to the release risk, little incentive is created to encourage risk prevention. In contrast, the availability and cost of UST private insurance is closely linked to the release risk of each individual tank. As a result, theoretically, private insurance will encourage more risk prevention behaviors and therefore reduce UST release risk. Analysis of data on UST release rate in MI, IL and IN supports the theoretical perspective that the use of private insurance provides a valuable opportunity to promote UST release risk reduction. Findings indicate that if IL and IN had made a policy transition like what MI did, their UST release risk could have been further reduced by 1%. In IL, for example, such a policy change would have saved cleanup costs of more than $7,000,000 in the year 2003 (1%* about 9000 UST facilities in IL* $78,054/average facility cleanup cost). The economic benefits of making such a policy change is even bigger if we consider environmental harms associated with releases, and legal, administrative and business interruption costs that may have been associated with cleanup activities. This study suggests that provision for environmental liability should be implemented with privately, instead of publicly, demonstrated financial responsibility for the purpose of encouraging risk prevention. This study also yields important policy implications. For the 38 states that are still operating UST state fund programs, making the transition to the private insurance market may be a good policy option. Such a policy transition is especially attractive to the 13 states whose state fund programs are plagued with significant financial difficulties.

P2.26B  Individual differences in domestic food handling practices. Fischer A.R.H., Frewer L.J., Nauta M.J.*; Marketing and Consumer Behaviour, Wageningen University, The Netherlands(1,2); Microbiological laboratory for Health Protection, National Institute for Health and the Environment (RIVM), The Netherlands (3)   Maarten.Nauta@rivm.nl

Abstract: As consumers are the final link in the chain from production (farm) to consumption (fork), knowledge about domestic food handling practices is essential for microbial risk assessment, and the identification of potentials for risk mitigation by risk communication to consumers. A nationally representative survey was conducted in the Netherlands to determine which practices are likely to be conducted by what consumers. Participants reported behavior on 55 different food handling practices. The different food handling practices could all be mapped onto a single dimension, implying an underlying motivation to prepare safe food. The Rasch modeling technique was applied to determine the difficulty of each behavior and the likelihood of each consumer performing a particular behavior. Some potentially safe practices (e.g. use of meat thermometers) were found to be very difficult, while other safe practices were conducted more frequently (e.g. washing of fresh fruit and vegetables). Five segments of consumers were identified, of which highly educated younger single males were those who performed least safe, while low educated older women performed best. Practices likely to be conducted by elderly women, may thus not be likely to be conducted by young males. When experiments and modeling quantify the microbial impact of the different consumer behaviors, consumer groups can be targeted through application of graduated risk communication. In such risk communication this approach can give an estimate which practices might successfully be communicated as they are not too much beyond the current level of the targeted group, the approach can also show which information need not be communicated to whom, because that practice is already likely conducted correctly.

Ecological Risk Assessment 2

P2.27  Ecosystem vulnerability to non-indigenous species - a global perspective. Berglund H.; Lund University, Sweden   helena.berglund@ekol.lu.se

Abstract: Non-indigenous invasive species can cause large effect on the invaded ecosystem trough predation, herbivory, parasitism and competition and some ecosystem appear to be more vulnerable to invasion than other. In the concept of vulnerability lies not only number of invaders but also the amount of change the invaders impose on the system. So, which are the properties that make an ecosystem more or less vulnerable? Many studies look merely on number or percentage of invaders and don’t consider the effect on the invaded system; this however is what I aim to do. An interesting aspect is the evolutionary history of the system and my main question is if ecosystems evolving under continental contra isolated conditions differ in respect to vulnerability to invaders. In order to get a relative measure on resilience, which is one part of the vulnerability concept, I have used number of species threatened by invaders divided by number of species and put this ratio in relation to number of invaders in each country. This measure is examined in relation to percentage endemic species, area of the continent and land boundaries - variables used to estimate degree of isolation for the different countries. I have also included other variables in the study, such as land use, population density etcetera, that might have an effect on vulnerability to invasion. If we can learn more about the properties affecting ecosystem vulnerability we can use this knowledge in risk assessments to foresee which ecosystems that are more likely to be strongly affected by invaders and why. Hopefully, we can then take action to prevent unnecessary losses of biodiversity and unwanted changes in ecosystem function.

P2.28  Avian Invertivore Bioaccumulation: Using Data to Assess Uncertainty in Exposure. Bennett K., Colestock K., Fair J., Katzman D., Mirenda R., Olson K., Reneau S., Ryti R.; Neptune and Company, Inc., Los Alamos, NM (1,6,7);Los Alamos National Laboratory, Los Alamos, NM (2-5)   rryti@neptuneinc.org

Abstract: An ecological risk assessment is currently being conducted at Los Alamos National Laboratory (LANL) in northern New Mexico. Avian ground invertivores were identified as receptors potentially at risk from metal contaminants within the study area. Western bluebirds (Sialia mexicana) were chosen as representative receptors for avian ground invertivores for the risk assessment. In 1997, an avian nestbox monitoring network was established at LANL and is monitored each year. Insects and eggs were collected from western bluebird nests in nestboxes located within the study area. The insects and eggs were analyzed for metals in order to develop a more accurate model of exposure for the western bluebirds. Concentrations of metals in the eggs and insects were also compared to a range of metal concentrations in nearby (i.e. within the respective foraging areas) soils in order to assess trends in contaminant uptake within these tissues.

Software Development

P2.29  Similarity-Based Recommendation of Models. Weber R., Proctor J.M.; College of Information Science & Technology, Drexel University   rw37@drexel.edu

Abstract: The modeling of complex systems plays an important role in risk analysis. Models can be built when there is knowledge about systems or when sufficient data describing their behavior are available. Models are built in many sciences, and various methodologies are available to build them. Statistical models use data to represent an approximation of a system. When data are available describing instances of the behavior of a system, inductive models (e.g. artificial neural networks) can be induced to generalize the behavior of the system. We introduce a novel way to find models to represent complex systems that does not require knowledge or large amounts of new data. Case-based reasoning (CBR) is a reasoning methodology that relies on stored instances to make decisions. CBR can be utilized whenever situation-decision pairs are recorded. A new decision is made based on the comparison of a new situation with recorded situations. The comparison reveals the most similar situation whose decision is adapted for reuse. Our approach relies on using CBR to recommend a model to represent a complex system when not enough knowledge or data is available to build a new model. In this approach, a new model is recommended based on the similarity between the new complex system and previously recorded systems. Because the recommendation embeds some uncertainty originated in the similarity between the new and recorded systems, our approach also computes an estimation of the certainty of how well the recommended model represents the new system. We demonstrated our method with a data set of software systems and artificial neural network models built to replicate their input-output behavior. Our case-based method recommended models 71.4% of the time that were as accurate as models induced from scratch, and more accurate 9.5% of the time.

Food Safety 2

P2.30  The Interagency Risk Assessment Consortium. Miliotis M.D., Buchanan R.L., Long W.R.*; Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration   Wesley.Long@cfsan.fda.gov

Abstract: The May 1997 Food Safety Initiative Report recommended that all federal agencies with risk analysis responsibilities for food safety establish a Risk Assessment Consortium (RAC). Through the RAC, agencies continue to work collectively to reduce redundancy (among federal agencies), enhance communication and coordination, and promote the conduct of scientific research that will facilitate risk assessments. Over the past eight years, the RAC has involved itself in many topical issues facing the risk analysis community. Examples include clarifying the role of peer review, bounding data quality, creating a data repository through the establishment of a risk analysis clearinghouse, posting data gaps for researchers, examining approaches to data utility, equating human and animal dose-response, relating microbiological criteria to public health goals, evaluating risk assessment frameworks, and encouraging dialogue around risk ranking. Annual open meetings, symposia, and/or conference sessions encourage public input.

P2.31  The transition of consumer’s role in securing food safety and their attitude toward effective risk communication in Japan. Tobe Y.; Food Safety Commission Secretariat, Japan   yoriko.tobe@cao.go.jp

Abstract: In order to secure food safety and security under a scheme of risk analysis, it is required that all stakeholders exchange their opinions and to provide information each other. Furthermore, it is necessary for the stakeholders to realize their roles in the context of risk analysis when they participate in decision making process. Infiltration of the concept of risk analysis among consumers in Japan, where the risk analysis system had just been introduced in 2003, was surveyed and future direction of risk communication as well as consumer education was considered, as following. A questionnaire survey was conducted to analyse how Japanese consumers were aware of their role in food risk analysis on 286 people of 20 years old or older in June- July 2004. 253 answered they thought selection of food shops which pay much attention to food safety could reflect their opinion. Only 98 answered they would attend risk communication through for example attending public meetings. 29 answered there were no room to participate in the system. On the other hand, 199 answered they would act according to their own judgement. Similar tendency has been observed from other questionnaire survey conducted at public meetings organised by the Food Safety Commission and other governmental agencies, that is, most participants attended to the meetings to collect information and few of them came to express their opinion. Most of them also answered their confidence with results of risk assessment and management measures had not necessarily improved although their understanding on risk analysis and the new administrative organisation for food safety in Japan. It was suggested role of stakeholders have to be taken shape and be well recognised among them. For consumer education, responsibility sharing and contribution to results of risk communication should be main targets.



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