Final Program - Society for Risk Analysis

time and temperature, determining the importance of E. coli O157:H7 in leafy greenslag time models, and validation of the importance of cross-contamination during thewashing process.M2-J.2 Schultz BD; schultz.brad@epa.govU.S. Environmental Protection AgencyCUMULATIVE RISK ASSESSMENT AND MULTIDIMENSIONAL IN-DICATORSMany community groups have asked for a cumulative risk assessment (CRA)or cumulative impact assessment for their communities; they believe that some traditionalrisk assessments have ove rlooked major issues facing their communities. In responseto this call, US EPA published its Framework for Cumulative Risk Assessmentin 2003 and has undertaken a number of other efforts; the US National ResearchCouncil published Science and Decisions; and many other activities have been andare being undertaken by governmental and non-governmental organizations. Progress,however, continues to be slow on this challenging problem and several differentapproaches have been taken. This presentation briefly breaks down these CRAapproaches into several categories and describes an approach of multidimensionalindicators for accelerating scientific advances and application to multiple real-worldcommunities. These multidimensional indicators allow for core advances which canbe used for a variety of CRA approaches and rely heavily on improved exposure estimationapproaches at community scales. It also holds promise for incorporating nonchemicalstressors into community-based cumulative risk assessments more widely.P.68 Schultz BD, Zartarian VG, Geller A, Barzyk T, O’Shea S; schultz.brad@epa.govUS Environmental Protection AgencyEXTENDING YOUR COMMUNITY-BASED RESEARCH TO OTHERCOMMUNITIES: US EPA’S C-FERST (COMMUNITY-FOCUSED EXPO-SURE AND RISK SCREENING TOOL)Community-based research on environmental exposures and risks has empoweredmany communities, reduced environmental injustices, and otherwise improvedmany communities. Gaps remain, however, in the development of readily-availabledata and tools critical to informing community activities. In order to provide toolsand information to more communities, EPA is developing the Community-FocusedExposure and Risk Screening Tool (C-FERST) to assist with community assessmentsand lead toward actions to improve the health and well-being of communities. Forresearchers, C-FERST can provide a venue for extending their research beyond individualcommunities and expand the impact of scientific research. C-FERST focuseson research which can be used in any community in the U.S., such as ambientconcentration, human exposure, and health effects, from spatially-explicit modelingresults covering large geographic areas; also included are measurement methods andrisk reduction approaches which have broad geographic applicability. The intent ofC-FERST is to foster meaningful community-based cumulative risk assessments andcumulative impact assessments. Collaborative research opportunities and needs existfor exposure modeling efforts, model evaluation, measurement methods, source apportionmentapproaches, risk reduction efforts, community sustainability best practices,the effects of ecosystem services on human health and well-being, and otheractivities widely applicable across the U.S. and, sometimes, other countries. The presentationwill discuss how research activities in these areas could be part of EPA’sweb-based GIS decision support tool for conducting cumulative human exposureand risk screening assessments, to help build sustainable and healthy communities.This presentation will describe how previous research is being delivered to communitiesand a description of how future research could be delivered, including your currentor future research.M2-B.3 Schuver HJ; schuver.henry@epa.govUS Environmental Protection AgencyVAPOR INTRUSION: RISKS AND BENEFITS OF AN ALTERNATIVEAPPROACHA growing body of evidence indicates that recalcitrant chemical vapor intrusion(VI) is highly variable (spatially heterogeneous and temporally episodic). VI risks cannotbe reliably estimated (e.g., +/- 25%) without samples of the indoor air, and continuousor numerous indoor air samples over a long duration (e.g., 1 yr) are needed,from each building. Given the number of samples needed and disruptive and timeconsumingnature of chemical indoor air sampling, including ‘background’ sourceremoval/assessment and sampling, and the high analytical costs, the reliable assessmentof current and future chemical VI risk is often impractical. The cost for reliablyassessing chemical vapor intrusion approximates the cost of implementing vaporcontrols. Also, a fraction of the buildings where costs were expended for a reliable assessmentof VI will find unacceptable exposures, and also incur costs for vapor controlsto be installed, operated, and monitored for an extended period of time. Finally,it is globally recognized that the risks of VI are dominated by the risks from Radonwhich can be easily measured in indoor air and can be found to present >100x thegenerically-estimated source-based risk for chemical VI. An approach is proposedwhere buildings overlying chemical VI sources are assessed by assisting public volunteersto continuously measure the naturally-occurring general tracer of soilgas VI,Radon, in their indoor air for a period of one year (unless risks are excessive). Whereradon levels are found to present risks >100x the potential generic chemical VI risk,Responsible Parties will be recommended to offer building occupants a pre-emptive‘>100:1 Radon Zone 2+’ vapor control system, as a more beneficial alternative tocontinued attempts at VI assessment for chemicals alone. Continuous post-mitigationmonitoring of indoor Radon levels can ensure the effectiveness of VI controls and169