Society For Risk Analysis Annual Meeting 2003

Session Schedule & Abstracts


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Chair(s):
.0  International Standards for Phytosanitary Measures: Guidelines for Pest Risk Analysis. Zlotina, M. A. *, Culliney, T. W., Lakin, K. R.; USDA APHIS PPQ Center for Plant Health Science and Technology   marina.a.zlotina@aphis.usda.gov

Abstract: The World Trade Organization Agreement on the Application of Sanitary and Phytosanitary Measures (the SPS Agreement) sets out the rights and obligations for governments establishing measures that restrict trade for the protection of plant, animal and human health (food safety). The SPS Agreement requires that measures be based on risk assessment or international standards established by specific organizations. The International Plant Protection Convention (IPPC) is the organization responsible for international standards applying to the establishment of phytosanitary measures. International Standards for Phytosanitary Measures (ISPMs) are developed through the work program of the IPPC’s Interim Commission on Phytosanitary Measures (ICPM). To date, 19 ISPMs have been adopted, including standards for risk analysis. The ISPMs that cover Pest Risk Analysis (PRA) have become particularly important in modern phytosanitary practice because they provide technical guidance on the processes that justify the application of phytosanitary measures. Pest Risk Analysis as described by the standards consists of three steps: (1) initiation of the risk analysis; (2) pest risk assessment; and (3) pest risk management. Initiation involves identifying pests or pathways for which PRA is needed. Pest risk assessment is used to determine whether a pest is a quarantine pest and the risk associated with its introduction in terms of consequences and likelihood. Pest risk management involves identifying and evaluating measures to mitigate the risk. Mitigation options should be proportional to the identified risk. Risk analyses may be qualitative or quantitative, and could be initiated by a pathway, by a pest, or by a policy change. This paper considers in greater detail guidelines for a pathway initiated PRA, such as international trade in a new commodity or a commodity from a new origin.

.0  ChemSim Model and Its Use for Ecological Risk Assessments . David Morin, Donald Gutzman, Jonathan Tigner; Environment Canada   david.morin@ec.gc.ca

Abstract: Environment Canada is mandated under the Canadian Environmental Protection Act to conduct ecological risk assessments of substances proposed for, or already in commercial use. Exposure characterization is an integral component of all risk assessments and consists of evaluating the transport and fate of substances released to the environment. The purpose of this presentation is to provide an overview of a model being developed to characterize environmental concentrations in watercourses following the release of substances. ChemSim is a suite of tools that are being designed to characterize environmental exposure when limited empirical data are available. In these circumstances, suitable models must be used to compensate for data gaps. The foundation of ChemSim is a database with site specific data such as industry type, location, receiving watercourse and the characteristics of this watercourse. Once complete, ChemSim will combine available substance specific estimated release quantities with information from the database to generate aquatic exposure values at the identified facility or for a category of industrial facilities. ChemSim estimates the concentration of substances within mixing zones at different distances from the point of discharge, thereby increasing the realism of the exposure characterization. Deterministic approaches can be used to characterize exposure concentrations in the receiving watercourses for individual points in time. It is recognized, however, that the variability of receiving water concentrations is dependent on both hydrologic conditions and the range of effluent release quantities. Where possible, it is useful in ecological risk assessments to address both the probability and magnitude of contaminant concentrations to which organisms will be exposed. ChemSim incorporates probabilistic approaches to take full advantage of available information on distributions of effluent release quantity and stream flow values.

.0  Risk, Rules, and Personal Responsibility: Ethics in Applying Public Policy Tools . Keith, S.E.; State University of New York--College of Environmental Science and Forestry   SKeithes@aol.com

Abstract: Bureaucratic decisions can often appear cold, degrading, or negligent to the person whose life is affected by such decisions, particularly when explained in technical terms of rules and risk measurements. This perception of a cold, distant, and disrespectful government is more likely to occur in areas involving perceptions of justice or equity such as social welfare or environmental protections, but occurs also in local motor vehicle bureau offices. However, governmental intent in creating rules and regulations arises in concern, thoughtfulness, and the desire to remedy public problems that affect individuals, even in the most political of decisions. As risk measures and management of are increasingly used as decision-making tools, public disaffection has been seen to increase, either through anomie or anger. Thus, the use of risk as a decision tool, creates a tension for bureaucrats given the constitutional structure in which they work, the US belief in individual liberties, and the frequent lack of public understanding of the technical tools of policy. Risk-based environmental decision-making presents an interesting case of the ethical dilemmas faced by public administrators who are personally obligated to protect the rights of their clients and target populations while constrained by rules that are perceived to harm those clients. Drawing from the literature of organizational theory, risk management, and individual cases, this paper presents an argument toward a larger ethic for the use of risk management techniques in public administration.

.0  Temporal, Genetic, and Dose Factors Affecting Chlorpyrifos Developmental Neurotoxicity. Judd, N.L., Schumacher, K.M., Faustman, E.M.; University of Washington, Institute for Risk Analysis and Risk Communication   nlj@u.washington.edu

Abstract: There is increasing concern about neurodevelopmental effects of low level organophosphate (OP) exposure on the fetus and neonate. This toxic mechanism and the many genetic and temporal factors influencing it are not well understood. Many recent studies of the contribution of specific OP metabolic pathways to toxicity have focused on chlorpyrifos(CP) because the developing brain appears particularly sensitive to this OP. Several polymorphic enzymes are involved in CP metabolism and the onset of their expression during critical windows of susceptibility is variable, so many genetic and temporal factors may influence CP developmental neurotoxicity. Our assessments indicate that polymorphisms of CYP2B6, CYP2C19, CYP3A4, and PON1 affect both production and detoxification of CP-oxon, which is thought to be an important mediator of CP’s effects on the developing nervous system. Analysis of CP dose and biomarker data indicates that a surge in CYP2B6 and CYP3A4 expression immediately after birth may lead to increased CP-oxon production, making this period particularly vulnerable. Our studies evaluated the contribution of genetic variation in these enzymes to CP-oxon production. The utility of genetic information for identification of susceptible individuals is explored using quantitative and qualitative methods. Key areas of uncertainty and data gaps identified include limited information about specific timing of onset of enzyme expression, relative activities of normal CP metabolic pathways, and potential for compensation by different metabolic pathways. Addressing these issues is critical to better understanding mechanisms of CP and other OPs’ developmental neurotoxicity and application potential for genetic testing for reduction of CP developmental neurotoxicity. Research supported USEPA NIEHS Center for Child Environmental Health Risks Research (EPA-R826886, NIEHS 1 P01 ES09601) and Center for the Study and Improvement of Regulation at Carnegie Mellon University.



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