Final Program - Society for Risk Analysis

ment (CEA), which provides both a framework for systematically organizing complexqualitative/quantitative information and a process to evaluate such information usingcollective judgment. The CEA framework encompasses the inception of the materialor product, environmental fate (transport/transformation) of releases during theproduct life cycle/value chain, exposure-dose of biotic and abiotic receptors, and impactsof both primary materials and secondary by-products. The CEA process buildson the information compiled in the framework and uses collective judgment methodsincorporating diverse technical and stakeholder perspectives to evaluate the implicationsof complex and incomplete information. Although CEA can be applied forboth research planning and risk management purposes, in this presentation we primarilyfocus on how CEA differs from LCA as an assessment approach for evaluatingthe environmental implications of carbon nanomaterials. Disclaimer: This abstractdoes not necessarily represent the views or policies of the U.S. EPA.M4-J.5 Pradhan AK, Latorre AA, Van Kessel JS, Karns JS, Schukken YH; akp@umd.eduUniversity of Maryland, University of Concepcion-Chile, USDA/ARS-Beltsville, Cornell UniversityQUANTITATIVE RISK ASSESSMENT OF LISTERIOSIS DUE TO CON-SUMPTION OF RAW MILKThe objectives of this study were to estimate the risk of illness due to L. monocytogenesin raw milk sold by permitted dealers, and the risk for people on farms whoconsume raw milk. Three scenarios were evaluated for raw milk sold by dealers: rawmilk purchased directly from bulk tanks, from on-farm stores, and from retail. To assessthe effect of mandatory testing of raw milk by regulatory agencies, the numberof listeriosis cases per year were compared where (i) no raw milk testing was done,(ii) only a screening test to issue a permit was conducted, and (iii) routine testing wasconducted and milk was recalled if it was L. monocytogenes positive. A greater riskof listeriosis was associated with consumption of raw milk obtained from retail andfarm stores as compared with milk obtained from bulk tanks. This was likely due toadditional time-temperature combination steps in the retail and farm store models,which increased the chances for growth of L. monocytogenes in raw milk. A closerelationship between prevalence of L. monocytogenes in raw milk and the values ofdisease incidence was observed. Hence, a reduction in the number of cases per year inall populations was observed when a raw milk-testing program was in place, especiallywhen routine testing and recalling of milk was conducted.T4-C.2 Price PS, Juberg DR; pprice@dow.comThe Dow Chemical CompanyAPPLICATION OF A SOURCE-TO-OUTCOME MODEL TO QUANTI-TATIVELY ASSESS VARIABILITY IN DOSE AND SENSITIVITY IN HU-MANSA source-to-outcome model was created for dietary exposures of chlorpyrifosby linking probabilistic dietary exposure models with a PBPK/PD model of an earlykey event in the toxicity pathway for the cholinergic effects of the compound. Thismodeling addresses several concerns raised in Chapter 5 of the NAS report “Scienceand Decisions”. First, the modeling goes beyond the margin-of-exposure or hazardindex approaches used in traditional non-cancer risk assessments and provides informationon the fraction of the population affected by a given dose (i.e., exposure). Second,the model allows the quantitative investigation of inter-individual variations inboth exposure and response (variation in sensitivity) for different age groups (adults,children, and infants). Third, by focusing the modeling on an obligatory change thatoccurs early in the toxicity pathway, the model avoids the complexities and uncertaintiesin modeling the occurrence of apical effects. One important finding from theproject is that while there are background rates of some apical effects of chlorpyrifos,current dietary exposures to humans are not predicted to cause any change in the frequencyof these apical effects in marginal populations. This suggests that a low-dosenonlinear individual and population dose-response model is most appropriate for thiscompound.M4-D.4 Rak A; andrew.rak@noblis.orgNoblisNAPHTHALENE DOSIMETER FOR ASSESSMENT OF EXPOSUREFOR FUEL HANDLERS: A CASE STUDYThe identification of an emerging chemical is only the first step in a multi-stepsequence used by the Department of Defense (DoD) to manage risks from emergingcontaminants. Once a chemical is identified, the time and resources required to identifyand implement solutions to address potential risks can be significant. The case ofnaphthalene demonstrates the long lead time required to identify and implement riskmanagement actions (RMAs) to address those risks presented by the changing regulatorylandscape. Naphthalene was one of the first emerging contaminants to be identifiedby the DoD’s scan-watch-action process and it remains on the DoD’s Action Listof high priority emerging contaminants. The potential change in the regulatory categorizationfrom a “possible” to a “likely” human carcinogen could have a substantialimpact on how DoD manages occupational exposure to fuel. Jet fuel (JP8), which isa universal fuel for most military equipment, contains 1-3% naphthalene by weight.According to the National Academy of Sciences, fuel is the single largest source ofchemical exposure to DoD personnel. At the same time that regulators are evaluat-161