Final Program - Society for Risk Analysis

ameters, and enabled a more robust analysis for formaldehyde releasing detergentsand fabric softeners.T3-B.2 McDougal JN, Guy RH, Leighton T, Bronaugh RL, Shah PV, Olin SS,O’Brien TM, Canady RA; solin@ilsi.orgWright State University, University of Bath, UK, US Environmental Protection Agency, US Foodand Drug Administration, ILSI Research Foundation, EcolabA TIERED APPROACH TO DERMAL EXPOSURE ASSESSMENT FORANTIMICROBIAL PESTICIDESThe Threshold of Toxicological Concern (TTC) is a risk assessment tool forchemicals with limited toxicity data, providing health-protective intake limits (TTCvalues) for broad structure-based toxicity categories. The TTC concept evolved fromFDA’s Threshold of Regulation for food contact materials (1995) and has been usedroutinely by the Joint FAO/WHO Expert Committee on Food Additives and theEuropean Food Safety Authority for the evaluation of flavoring substances. Manyother applications have been explored in the past few years, and this paper presentsan application of the TTC involving potential dermal exposures to antimicrobial pesticides(biocides). The basic TTC decision tree was constructed through analysis ofa database of chronic oral toxicity studies, and the resultant TTC values assume oralexposure and systemic dose. Antimicrobial pesticides, however, have a number ofcommon uses with potential skin exposure. Thus, a tiered screening level approachhas been developed to estimate the internal dose from skin uptake of antimicrobialsin typical exposure scenarios for comparison with appropriate TTC values. Examplesinclude contact with workplace liquid formulations or with treated (or contaminated)clothing. Although skin uptake of the antimicrobials has not been extensively studied,the rate of skin penetration for a chemical can be correlated with its physicochemicalcharacteristics and therefore it is possible to make approximate, conservative predictionsof uptake. The tiered dermal approach described here uses progressively morerealistic (and data intensive) assumptions in estimating the amount of antimicrobialpenetration through skin to screen for level of concern. The approach can be usedto identify antimicrobial chemicals for which the potential for harm from dermalexposure is negligible or where the collection of additional toxicity, exposure or physicochemicaldata will be necessary to make better estimates of risk. (This abstract doesnot necessarily represent EPA or FDA policy.)P.120 McKenzie A, Sloan B, Blewett C, Nicol A-M; alimck@interchange.ubc.caCarex Canada, University of British ColumbiaRADON IN THE PUBLIC EYE: A REVIEW OF THE EVIDENCE FORRADON RISK PERCEPTION, RISK COMMUNICATION AND MITIGA-TION POTENTIALRadon is a known human carcinogen and the second leading cause of lungcancer in Canada. Studies indicate 7% of Canadian homes and public buildings exceed200 Becquerels per cubic metre (Bq/m3), the current regulatory level. Thoughresearch shows a 100 Bq/m³ increase in radon results in an 11% increase in risk oflung cancer, studies indicate only 41% of Canadians are aware of the risks posed byradon in indoor environments. We examined the state of the literature on the public’sknowledge, risk perception and willingness to act in relation to radon exposure. Relevantquantitative papers examining evaluations of radon risk communication programsand educational campaigns, experimental interventions, and risk perceptionsurveys were identified (n=56). Data was collated and entered into a spreadsheet foranalysis. More than twenty different tools were used to increase awareness about thehazards of radon in the home. Overall, improvement in knowledge about the risks associatedwith radon was only weakly correlated with undertaking mitigation strategies.Targeted messaging was more successful that broad messaging. The only variablesassociated with remediating were higher educational attainment and higher householdincome. A targeted, multistep approach to radon risk communication is proposed toincrease willingness to remediate. For families, including risks to children or includingchildren in campaigns may make risks more salient. Other suggestions include craftingprograms that address education, testing and mitigation as separate entities. Riskcommunication strategies that take this approach will also allow for the issue of remediationcost to be addressed specifically for low-income households where necessary.Radon is a widely spread and insidious agent the Canadian public is poorly informedabout. Appropriately designed educational campaigns will be a key tool in the promotionof awareness and the initiation of self-protective behaviour.P.18 McMillan NJ, Tollar E, Wightman J, Huckett J; mcmillann@battelle.orgBattelleITRA SENSITIVITY STUDY: SUBWAY EVENT RESPONSE ANALYSISHomeland Security Presidential Directive (HSPD) 18 (Medical Countermeasuresagainst Weapons of Mass Destruction) requires a risk assessment of Chemical,Biological, Radiological, and Nuclear terrorism for the purpose of risk based decisionsupport in the area of medical countermeasure acquisition and development. In supportof HSPD-18, a sensitivity study on the effectiveness of medical and detectionbasedresponses in reducing casualties and deaths in a set of chemical and radiologicalevents was conducted. This analysis details the analytic models used to predict the143