Final Program - Society for Risk Analysis

W2-B.6 Wang D, Collier Z, Mitchell-Blackwood J, Keisler J, Linkov I; daisyw@andrew.cmu.eduCarnegie Mellon University, US Army Engineer Research and Development Center, US EnvironmentalProtection Agency, University of Massachusetts, IL-US Army Engineer Research andDevelopment CenterUSING MULTICRITERIA DECISION ANALYSIS (MCDA) TO PRIORI-TIZE THE EXPOSURE POTENTIAL OF EXISTING AND EMERGINGCHEMICALSIn the United States (U.S.) and the European Union (EU), manufacturing processesconsume tens of thousands of different chemical substances. Not only is theexposure potential for the majority of these substances unknown, but there is alsolittle data to make exposure predictions. Regulatory agencies in the U.S. and EU areinterested in developing high-throughput screening level tools which would be ableto predict exposure potential for multiple chemical compounds and perform underconditions of high information uncertainty. Different exposure models (e.g., LIST)are currently available to assess and prioritize the exposure potential of chemicals, yetthese models require a substantial volume of information. Specifically, parameterizationis required for a number of linked process model components to characterizesource, fate-and-transport, distribution in environmental media and finally exposureas a result of human activity and usage. Moreover, the former processes are oftendriven by predictive models used to ascertain chemical properties (i.e. QSAR). Inherentuncertainty in the structure of these model could result in variability in predictionsof these driving factors. This presentation introduces a Multi-Criteria DecisionAnalysis (MCDA) framework to prioritize the exposure potential of chemicals, whichintegrates expert judgment with available data on chemical properties. MCDA is aclass of systematic methods used to evaluate alternatives that must be compared onmultiple criteria or factors. To develop this framework, the most important parametersof the various models utilized in the EPA Exposure Challenge were made tocreate a generalized, adaptive, and parsimonious model.W2-I.4 Watt JM, Fay N; j.watt@mdx.ac.ukMiddlesex University, London, UK, Treework Environmental Practice, Bristol, UKSTAKEHOLDER ENGAGEMENT IN PRACTICE - THE EXPERIENCEOF THE NATIONAL TREE SAFETY GROUP IN THE DEVELOPMENTOF A NATIONALLY RECOGNISED APPROACH TO TREE SAFETYMANAGEMENT IN THE UKResearch has demonstrated that the overall risk to the public from falling treeswas extremely low, representing about a 1 in 10 million chance of an individual beingkilled in any given year, which means that the risk falls well into the broadly acceptablezone of the Health and Safety Executives (HSEs) Tolerability of Risk (TOR)Framework (2001). The research also showed that there is limited societal concernabout risks of this type (although there may be adverse publicity in the immediateaftermath of an individual incident). The analysis indicated that trying to furtherreduce such a small risk is exceptionally difficult given that there may be as many as4 billion trees in the UK and that it would be unlikely that adjustments to the currentmanagement regime would reduce the risk the health and safety in any significantway. Nonetheless, there was concern that some individuals may continue to berisk averse and defensive in their management of tree safety due in large part to afear of prosecution. A stakeholder forum, the National Tree Safety Group (NTSG),therefore emerged to develop a nationally recognised approach to tree safety management.This paper looks at the formation and progress of the NTSG and revealsthe emergence of a number of conflicting viewpoints and the way in which they wereaccommodated. The NTSG drew on parallel developments in relation to public safetyin non-work environments and advocated that the evaluation of what is reasonableshould be based upon a balance between benefit and risk. This calculation can onlybe undertaken in a local context, since trees provide many different types of benefitin a range of different circumstances. Thus the NTSG sought to move forward ontwo fronts - firstly an engagement with the Health and Safety Executive (HSE) andsecondly to provide guidance towards management that is proportionate to the actualrisks posed by trees.W2-G.4 Weinrich AJ, Jinot J; weinrich.alan@epa.govUS Environmental Protection Agency National Center for Environmental AssessmentUSE OF WORKER EPIDEMIOLOGICAL DATA TO ASSESS INHALA-TION RISK FROM 2-MERCAPTOBENZOTHIAZOLE2-Mercaptobenzothiazole (MBT) is used in the production of rubber productsand as a microbiocide preservative. The only inhalation exposure guidance arethe American Industrial Hygiene Association (AIHA) Workplace EnvironmentalExposure Level (WEEL) 8-hour time-weighted average (TWA) of 5 mg/m3, derivedfrom oral toxicity data, and the German Maximum Concentration Value in theWorkplace (MAK) TWA of 4 mg/m3, based on a conclusion that MBT inhalationwas without detectable health effects. Both exposure guidelines note MBT is a skinsensitizer, while the AIHA WEEL also indicates systemic risks from skin absorption.Oral exposure data indicate evidence of liver tumors in mice, and hematopoietic, pituitary,adrenal, pancreatic, preputial, and subcutaneous tissue neoplasms in rats. Serialepidemiological studies in worker populations from West Virginia (USA) and northWales (United Kingdom) have suggested exposure to MBT might increase the risk ofseveral cancers. However, coexposure to other workplace carcinogens has impededevaluation of cancer risks from MBT. In 2009, Sorahan reevaluated data from theworker population in Wales and identified a subset of 363 workers for whom risks oflung and colon cancer and multiple myeloma could be adjusted to account only forMBT exposure. The lung cancer data did not exhibit a dose-response trend and only191