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Society For Risk Analysis Annual Meeting 2004

Session Schedule & Abstracts

W26 - Education in Risk Analysis II: Program Content

San Jacinto   3:30 - 5:00 pm

Chair(s): David Hassenzahl
W26.1  Mathematical Modeling for Integrated Environmental Health Risk Assessment. M.J. Small, J.B. Milford, A. Ramaswami; Carnegie Mellon University; University of Colorado, Boulder; University of Colorado, Denver

Abstract: An integrated environmental health risk assessment (EHRA) involves a structured evaluation of: the sources and emission rates of contaminants to the environment; the subsequent fate-and-transport of contaminants that lead to ambient concentrations in the air, water, soil and biota (fish, vegetation, etc.); the exposure of humans or other environmental receptors to these compounds; and the resulting human health, ecological or economic effects. A course is described that provides the basic methodological and mathematical tools for conducting this type of assessment. While the course emphasizes processes and models for predicting pollutant fate and transport, including analytical and numerical air, surface water, groundwater and multimedia pollution models, modules are also included for each of the other steps of an EHRA. The course emphasizes both mechanistic and probabilistic methods for predicting and characterizing the distributions of ambient concentrations, exposure, dose-response, and risk. The course is supported by a new text, Integrated Environmental Modeling: Pollutant Transport, Fate and Risk in the Environment (Ramaswami, Milford and Small; Wiley), scheduled for release in early 2005. Prepublication copies of the text will be available to discuss alternative curricula that could be used in environmental engineering, public health, and risk assessment courses.

W26.2  Is that variability or uncertainty? Effective tools for teaching PRA to risk assessors and risk managers.. P.E.* Goodrum; Syracuse Research Corporation

Abstract: Probabilistic modeling techniques such as Monte Carlo analysis have been established as an informative and viable approach for quantifying variability and uncertainty in risk assessment. With the advent of new probabilistic models and regulatory guidance, the approaches have become even more accessible to the risk assessment community. The current challenge is to ensure that the techniques are applied with a clear understanding of underlying assumptions and uncertainties, and that this information is communicated to decision makers and stakeholders. Training courses on probabilistic risk assessment (PRA) can play a critical role in ensuring that practitioners start off on the right foot. This session will include a review lessons learned from experiences teaching short courses in PRA as well as semester-long courses on uncertainty analysis in environmental modeling. What are effective graphics and which graphics should be avoided? How do you best illustrate concepts of Monte Carlo simulation, distinguish between variability and uncertainty, and show results of a probabilistic sensitivity analysis? What skills sets are needed to understand more advanced methods, including Bayesian Monte Carlo analysis, geostatistics, and MicroExposure event simulation? And, what are some common pitfalls that students may struggle with when applying probabilistic methods to risk assessment? Answers to these questions and more will be based on feedback received from students who were both novices and experts in the field of PRA.

W26.3  Why people don't get risk analyses: the fault is in ourselves. W.T.* Tucker, S. Ferson; Applied Biomathematics

Abstract: The lay public has difficulty grasping the meaning of risk analyses. The sometimes spectacular failures of risk communication are often blamed on their ignorance of technical issues or their mistrust of industry or government. We suggest that often neither ignorance nor mistrust is fundamentally responsible for the difficulty. Instead, humans seem wired by natural evolution to use a mental calculus for reckoning uncertainty and making decisions that can be substantially different from probability theory. Psychologists have observed two primary components of risk perception (dread and unknownness). We argue that the unknownness dimension is a result of incertitude about event frequencies, and the dread dimension comes from incertitude regarding the adversity of an event when it occurs. It appears that humans deal with uncertainty on these axes separately and with distinct mental calculi. We also suggest that several important biases of risk perception recognized by psychometricians can be interpreted as adaptive strategies for responding to incertitude and variation. Humans evolved in a strongly autocorrelated environment that rewarded pattern recognition skills and sometimes punished indecision more sternly than it did a suboptimal decision. Asymmetries in the consequences of decisions led to selective pressures during evolution. Given this history, we deduce evolutionary reasons why (i) people routinely misestimate risks, (ii) people are insensitive to prior probabilities, (iii) the notion of independence is so difficult to correctly interpret, and (iv) people concentrate on the worst case (and ignore how unlikely it is). If these biases are fundamental to human perception and not removable by general education or specific training, perhaps risk analysts should make their calculations and arguments more natural, interesting, and compelling to humans. We describe such an approach to risk assessment and communication.

W26.4  Teaching Microbial Risk Assessment. Peg Coleman; Syracuse Research Corporation

Abstract: Although the major driver of many microbial risk assessments is the magnitude of pathogen growth, few assessments have any high quality scientific data to verify actual likelihood and magnitude of pathogen growth for the exposure assessment scenarios modeled. In general, microbial risk assessors calculate expected values of the magnitude of growth without accounting for the possibility of no growth or the actual variability in microbial growth under representative conditions of the modeled scenarios. As noted by the previous symposium presenter, effective protection of public and environmental health requires a level of knowledge for both risk assessors and risk managers. To address this need to understand the impact of scientific data and models for microbial risk analysis, Syracuse Research Corporation is developing a Microbial Risk Assessment Center of Excellence (MRACE) that will leverage SRC expertise and resources for education of stakeholders, particularly scientists, managers, and students of risk analysis. Initiatives undertaken in the first year of establishment of MRACE will be described, as well as partnerships established to enhance the scientific basis of risk management decisions for microbial hazards, both indigenous and intentional threats in food, air, and water supplies.

W26.5  Online Risk Education: Potential, Problems, Promise. W.R.* Long, B.D. Paleg, C.E. Yoe, D.K.Y. Lei; Food and Drug Administration, University of Maryland at College Park, College of Notre Dame, University of Maryland at College Park

Abstract: The effectiveness of an online risk education program among traditional college students, English as a Second Language (ESL) students, and students in parts of the world where internet access is limited was evaluated. The study platform was the JIFSAN Food Safety Risk Analysis Overview Distance Learning short course. The research had four primary aims: 1) to assess the appropriateness (depth, complexity, relevance, length) of the course content among traditional graduate and undergraduate students; 2) to assess the comprehension and usefulness of the program to ESL speakers; 3) to better understand the complexities of internet learning in parts of the world where internet access is limited and 4) to assess the value of the course in stimulating cross-cultural understanding of international perspectives on risk related to food safety. Using WebCT course software, we compare student perceptions of their level of engagement with computerized records of their actual involvement. English speaking students found international perspective and cultural awareness to be of high value, and ESL students preferred placement in assignment groups with students from other cultures, even though it made participation more challenging. We will present our experiences, successes, and the challenges for on-line risk analysis training and education.

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