Abstracts (PDF file, 1.8MB) - Society for Risk Analysis
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.136 BRACCA, M; MONZON, A; DEMICHELIS, SO*;<br />
ENVIRONMENT LABORATORY - DDPYT - UNLA;<br />
sandrademichelis@yahoo.com<br />
Bad decisions increases health risks: reopening of an<br />
abandoned asphalt plant a case of study.<br />
The overall goal of this work is to diminish risk by planning the<br />
recovery of use and the habitat remediation of an abandoned<br />
asphalt plant (now micro-dump) belonging to the municipality<br />
of Lanus. The site is surrounded by housing and obsolescence<br />
and waste is an environmental liability that requires early<br />
intervention, After EIS, recommended the elimination of<br />
landfill, neutralization of obsolete material, the relocation of the<br />
asphalt plant and soil remediation. The situation analysis<br />
concludes that the ground is not suitable <strong>for</strong> development and<br />
operation of plant and waste and debris existence justifies its<br />
intervention. The government proposed not to move the plant,<br />
but reactivate. The negative impacts will occur on human<br />
health in case of reopening are associated with the appearance<br />
of asphalt fumes, with immediate consequences <strong>for</strong> those<br />
exposed directly and increased risk of various cancers. As <strong>for</strong><br />
the environmental and health damage existing waste cause pest<br />
invasion, air pollution, leachate generation that pollute<br />
groundwater The transfer proposal showed investment will be<br />
much more expensive than the reopening; however, these do<br />
not include the health costs it will generate <strong>for</strong> government<br />
since public health is covered by state; there<strong>for</strong>e preventive<br />
measures are proposed as the relocation of the plant is better<br />
than reopening, by clearing the dump and the property,<br />
remediation of soil gas extraction methods and aeration will<br />
result in diminish damages. At present authorities prefers<br />
reopen it but they did not per<strong>for</strong>m EIS. If the proposal of<br />
eradication fails and the reopening of the plant will take place,<br />
a program that includes surveillance and mitigation must be<br />
developed.<br />
T4-J.2 Brand, K; University of Ottawa; kbrand@uottawa.ca<br />
Outcome in<strong>for</strong>med Departures from a Default Science<br />
Policy Assumption<br />
Default assumptions are integral to chemical risk assessments,<br />
serving to bridge knowledge-gaps that would otherwise derail<br />
quantitative assessment. Each default assumption generally<br />
enjoys both an evidential base (establishing it as a reasonable<br />
approach <strong>for</strong> filling its respective knowledge-gap) and a policy<br />
sanction of being more likely to err on the side of caution.<br />
Under certain circumstances a departure from a default<br />
assumption (e.g., one concerning dose-response relationship<br />
shape) may be both warranted and championed; the focus of<br />
the champion being upon avoiding the prospect of ``regulatory<br />
overkill'' whereby excessive and undue regulatory costs stem<br />
from the adoption of an unwarranted default. The question of<br />
an appropriate standard of proof to demand be<strong>for</strong>e warranting<br />
such a departure has been the source of longstanding<br />
discussion. In this talk I offer a standard expected utility (SEU)<br />
framework <strong>for</strong> in<strong>for</strong>ming this question. Under the SEU<br />
framework a sliding scale is prescribed as the appropriate<br />
standard of proof, and revealed to depend centrally upon the<br />
ex-ante outcomes that hinge upon the choice (between the<br />
default and alternative assumption). The implications of this<br />
framework <strong>for</strong> future deliberations over whether to depart from<br />
a default assumption are discussed as are some of the<br />
challenges that may be posed when implementing it in practice.<br />
T3-B.3 Brewer, LE*; Teushler, L; Rice, G; Wright, JM; Neas, L;<br />
ORISE Fellow in the Research Participation Program at the U.S.<br />
EPA, Office of the Science Advisor (LEB); U.S. EPA, National<br />
Center <strong>for</strong> Environmental Assessment (LT, GR, JMW); U.S. EPA,<br />
National Health and Environmental Effects Research<br />
Laboratory(LN); brewer.beth@epa.gov<br />
Using directed acyclic graphs in cumulative risk<br />
assessment (CRA)<br />
CRA is an emerging scientific approach <strong>for</strong> integrating human<br />
heath and ecological risks from aggregate exposures to<br />
physical, biological, chemical, and psychosocial stressors. A<br />
shift in emphasis from the traditional single-chemical risk<br />
assessment paradigm to community-focused assessments that<br />
combine risks from chemical and non-chemical stressors would<br />
benefit from a structured analysis of the potential pathways<br />
linking cause and effect. Directed acyclic graphs (DAGs) depict<br />
causal associations and provide an improved method <strong>for</strong><br />
communicating complex relationships linked by quantitative or<br />
qualitative data. Rules <strong>for</strong> constructing DAGs are more rigorous<br />
than <strong>for</strong> conceptual models typically created in the problem<br />
<strong>for</strong>mulation phase of a risk assessment, and a simple algorithm<br />
applied to the graph allows <strong>for</strong> the identification of confounders<br />
that is critically important to causal inference. As<br />
stressor-effect pathways are further elucidated through<br />
literature review and data collection, the DAG can be revisited<br />
and modified resulting in a model representative of the best<br />
evidence available <strong>for</strong> risk estimation. A DAG can there<strong>for</strong>e be<br />
utilized in three phases of CRAs: to identify potential<br />
confounders in planning, scoping, and problem <strong>for</strong>mulation; to<br />
clarify assumptions and illustrate the weight of evidence<br />
approach in the analysis phase; and to communicate risks to<br />
stakeholders and decision-makers in a clear, transparent<br />
manner. In sum, DAGs provide the strong logical structure<br />
necessary <strong>for</strong> understanding the complex causal relationships<br />
among stressors and effects, and <strong>for</strong> assessing cumulative risks<br />
to human health and the environment. (The views expressed in<br />
this abstract are those of the authors and do not necessarily<br />
reflect the views or policies of the U.S. EPA.)<br />
M2-D.3 Brinkerhoff, CJ*; Salazar, KD; Lee, JS; Chiu, WA; Oak<br />
Ridge Institute <strong>for</strong> Science & Education, Oak Ridge, TN;<br />
ORD/NCEA-IRIS, US EPA, Washington DC; ORD/NCEA-IRIS, US<br />
EPA, Research Triangle Park, NC; brinkerhoff.chris@epa.gov<br />
Development of a PBPK Model <strong>for</strong> ETBE and TBA in Rats<br />
and Its Application to Discern Relative Contributions to<br />
Liver and Kidney Effects<br />
Ethyl tert-butyl ether (ETBE) is an oxygenated gasoline<br />
additive. ETBE is rapidly absorbed and metabolized to<br />
acetaldehyde and tert-butyl alcohol (TBA). Published studies <strong>for</strong><br />
both ETBE and TBA in rats have reported liver and kidney<br />
effects including increased organ weights, and nephropathy.<br />
The magnitudes of these effects vary by chemical and route of<br />
exposure. Additionally, exposure to ETBE by inhalation<br />
produced an increased incidence of liver adenomas in male<br />
rats, but ETBE delivered in drinking water or TBA in drinking<br />
water did not. This difference could be due to the higher<br />
internal dose of ETBE in the inhalation study compared to the<br />
ETBE and TBA drinking water studies. A physiologically-based<br />
pharmacokinetic (PBPK) model could estimate internal doses to<br />
aid in interpreting these differences in effect however there are<br />
no existing models of ETBE in rats or of direct administration of<br />
TBA. We have developed and applied a PBPK model of ETBE<br />
and TBA in rats. The PBPK model was parameterized with<br />
toxicokinetic data in rats from iv and inhalation studies of TBA<br />
and from oral and inhalation studies of ETBE. The PBPK model<br />
was used to make quantitative comparisons of the internal<br />
blood concentrations of ETBE and TBA associated with kidney<br />
and liver effects. The dose-response relationships <strong>for</strong> ETBE<br />
blood concentration and liver adenoma incidence across<br />
inhalation and oral routes support the hypothesis that the<br />
differences in the incidence of liver adenomas are due to<br />
differences in internal dose of ETBE. The model is also being<br />
used to evaluate differences between administered and<br />
metabolized TBA in dose-response relationships <strong>for</strong><br />
nephropathy and kidney and liver weight changes. The views<br />
expressed in this abstract are those of the authors and do not<br />
necessarily represent the views or policies of the U.S.<br />
Environmental Protection Agency or other affiliations.<br />
December 8-11, 2013 - Baltimore, MD