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Abstracts (PDF file, 1.8MB) - Society for Risk Analysis

Abstracts (PDF file, 1.8MB) - Society for Risk Analysis

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SRA 2013 Annual Meeting <strong>Abstracts</strong><br />

P.20 Deveau, M*; Krewski, D; Nong, A; University of Ottawa;<br />

Health Canada; michelle.deveau@uottawa.ca<br />

Assessing the impact of human metabolic variability on<br />

the health risks of occupational and environmental<br />

exposures to chloro<strong>for</strong>m<br />

Approximately 15,000 Canadians are occupationally exposed to<br />

chloro<strong>for</strong>m, primarily in the recreational sector.<br />

Non-occupational exposures can occur when chloro<strong>for</strong>m is<br />

<strong>for</strong>med as a disinfection byproduct in drinking water.<br />

Occupational and environmental exposure limits are designed<br />

to prevent liver toxicity from metabolites and neurological<br />

effects from the parent compound. Because chloro<strong>for</strong>m is<br />

primarily metabolized by the 2E1 iso<strong>for</strong>m of cytochrome P450<br />

(CYP2E1), variability in the levels of the enzyme in the human<br />

population could influence susceptibility to the compound. The<br />

objective of this research was to investigate the effect of<br />

interindividual variability in CYP2E1 activity on the health risks<br />

of chloro<strong>for</strong>m and to identify whether existing exposure limits<br />

sufficiently account <strong>for</strong> these differences. To do this, a human<br />

physiologically based pharmacokinetic (PBPK) model <strong>for</strong><br />

chloro<strong>for</strong>m was used, and distribution data on CYP2E1 in<br />

human liver were inputted into the model to simulate exposure<br />

scenarios <strong>for</strong> selected occupational and environmental<br />

exposure limits. Estimates were obtained <strong>for</strong> 5th percentile,<br />

average and 95th percentile metabolizers. As expected, the 5th<br />

percentile group metabolized less chloro<strong>for</strong>m, resulting in<br />

higher blood chloro<strong>for</strong>m concentrations. Likewise, the 95th<br />

percentile metabolizers had higher levels of metabolism.<br />

However, the differences amongst the groups were less than<br />

2-fold, despite much higher variability levels <strong>for</strong> CYP2E1 and<br />

microsome concentrations; there<strong>for</strong>e, these factors only have a<br />

minor impact on the risks of liver toxicity and acute<br />

neurological effects within the population. The population<br />

variability in CYP2E1 appears to be sufficiently addressed in<br />

the selected occupational and environmental exposure limits.<br />

M4-D.1 DeWaal, CS; Center <strong>for</strong> Science in the Public Interest;<br />

cdewaal@cspinet.org<br />

<strong>Risk</strong> Communication: Preparing <strong>for</strong> the Unexpected<br />

<strong>Risk</strong> communication is a central aspect of risk analysis. This<br />

multi-faceted activity is essential to effectively managing a food<br />

safety event, including an outbreak of disease or<br />

food/ingredient contamination event. Broadly defined, it<br />

encompasses communication between technical experts,<br />

regulators and the public about threats to health, safety or the<br />

environment. During a food safety emergency, dissemination of<br />

accurate in<strong>for</strong>mation is essential. <strong>Risk</strong> communicators armed<br />

with a strong understanding of underlying risks and using<br />

non-technical terms can ensure that the public responds to a<br />

food safety hazard appropriately, and reduces the likelihood of<br />

the dissemination of misin<strong>for</strong>mation leading to increased<br />

consumer concern. This paper will examine two case studies on<br />

risk communication, including the emergence of BSE in the US<br />

and antibiotic resistance in foodborne pathogens. It will also<br />

discuss databases available to assist risk communicators.<br />

W4-H.3 Dieckmann, N*; Peters, E; Gregory, R; Oregon Health<br />

& Science University; Decision Research; The Ohio State<br />

University; dieckman@ohsu.edu<br />

The Motivated Evaluation of Numerical Uncertainty<br />

Ranges<br />

Numerical uncertainty ranges are often used to convey the<br />

precision in a <strong>for</strong>ecast as well as the range of possible future<br />

states of the world. However, the interpretation of uncertainty<br />

ranges is often ambiguous. In two studies, we examine the<br />

extent to which end users vary in their perceptions of the<br />

relative likelihood of values in a numerical range and test<br />

specific hypotheses about how these perceptions are generated<br />

and how they might affect decisions. We discuss four primary<br />

findings from these studies: 1) There is substantial variation in<br />

how people perceive the distribution underlying numerical<br />

ranges; 2) Common cues to the correct interpretation (i.e.,<br />

including a best estimate) explain some, but not all, of the<br />

variance in perceptions; 3) People show a tendency to perceive<br />

the distribution underlying a range in worldview-consistent<br />

ways, particularly in controversial domains like climate change;<br />

4) The influence of distributional perceptions on choices was<br />

much stronger among the less numerate. We feel there are<br />

significant opportunities to improve uncertainty communication<br />

to maximize the likelihood that users will make accurate,<br />

unbiased evaluations of uncertain quantities. In highly charged<br />

domains like climate change, any changes we could make to<br />

help facilitate communication between opposing stakeholders<br />

would be well worth the ef<strong>for</strong>t.<br />

T1-G.1 Dietz, T*; Henry, AD; Michigan State University;<br />

tdietz@msu.edu<br />

Social Learning <strong>for</strong> Climate Change Governance<br />

An effective human response to climate change will require an<br />

adaptive risk management approach based on strategies that<br />

promote successful social learning. The importance of social<br />

learning is driven by uncertainties in how coupled human and<br />

natural systems will respond to climate change, in how climate<br />

change will interact with many other ongoing social and<br />

environmental changes, and in how soci-technical systems will<br />

evolve. These factors ensure that effective strategies <strong>for</strong><br />

addressing climate change will need to be based on flexible<br />

strategies that allow societies, organizations and policy<br />

networks to learn from ongoing experiences and adjust<br />

responses over time given new in<strong>for</strong>mation and environmental<br />

conditions. We examine the known obstacles to effective social<br />

learning by drawing policy network research, and offer<br />

suggestions on how social learning might be facilitated through<br />

the innovative design of risk management institutions.<br />

December 8-11, 2013 - Baltimore, MD

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