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Title: Uncertainty factors in screening ecological risk assessments

Abstract

The hazard quotient (HQ) method is commonly used in screening ecological risk assessments (ERAs) to estimate risk to wildlife at contaminated sites. Many ERAs use uncertainty factors (UFs) in the HQ calculation to incorporate uncertainty associated with predicting wildlife responses to contaminant exposure using laboratory toxicity data. The overall objective was to evaluate the current UF methodology as applied to screening ERAs in California, USA. Specific objectives included characterizing current UF methodology, evaluating the degree of conservatism in UFs as applied, and identifying limitations to the current approach. Twenty-four of 29 evaluated ERAs used the HQ approach: 23 of these used UFs in the HQ calculation. All 24 made interspecies extrapolations, and 21 compensated for its uncertainty, most using allometric adjustments and some using RFs. Most also incorporated uncertainty for same-species extrapolations. Twenty-one ERAs used UFs extrapolating from lowest observed adverse effect level (LOAEL) to no observed adverse effect level (NOAEL), and 18 used UFs extrapolating from subchronic to chronic exposure. Values and application of all UF types were inconsistent. Maximum cumulative UFs ranged from 10 to 3,000. Results suggest UF methodology is widely used but inconsistently applied and is not uniformly conservative relative to UFs recommended in regulatory guidelinesmore » and academic literature. The method is limited by lack of consensus among scientists, regulators, and practitioners about magnitudes, types, and conceptual underpinnings of the UF methodology.« less

Authors:
;
Publication Date:
Research Org.:
Univ. of California, Los Angeles, CA (US)
OSTI Identifier:
20062551
Alternate Identifier(s):
OSTI ID: 20062551
Resource Type:
Journal Article
Journal Name:
Environmental Toxicology and Chemistry
Additional Journal Information:
Journal Volume: 19; Journal Issue: 6; Other Information: PBD: Jun 2000; Journal ID: ISSN 0730-7268
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; DATA COVARIANCES; RISK ASSESSMENT; HAZARDOUS MATERIALS; WILD ANIMALS; ENVIRONMENTAL IMPACTS; TOXICITY

Citation Formats

Duke, L.D., and Taggart, M. Uncertainty factors in screening ecological risk assessments. United States: N. p., 2000. Web. doi:10.1897/1551-5028(2000)019<1668:UFISER>2.3.CO;2.
Duke, L.D., & Taggart, M. Uncertainty factors in screening ecological risk assessments. United States. doi:10.1897/1551-5028(2000)019<1668:UFISER>2.3.CO;2.
Duke, L.D., and Taggart, M. Thu . "Uncertainty factors in screening ecological risk assessments". United States. doi:10.1897/1551-5028(2000)019<1668:UFISER>2.3.CO;2.
@article{osti_20062551,
title = {Uncertainty factors in screening ecological risk assessments},
author = {Duke, L.D. and Taggart, M.},
abstractNote = {The hazard quotient (HQ) method is commonly used in screening ecological risk assessments (ERAs) to estimate risk to wildlife at contaminated sites. Many ERAs use uncertainty factors (UFs) in the HQ calculation to incorporate uncertainty associated with predicting wildlife responses to contaminant exposure using laboratory toxicity data. The overall objective was to evaluate the current UF methodology as applied to screening ERAs in California, USA. Specific objectives included characterizing current UF methodology, evaluating the degree of conservatism in UFs as applied, and identifying limitations to the current approach. Twenty-four of 29 evaluated ERAs used the HQ approach: 23 of these used UFs in the HQ calculation. All 24 made interspecies extrapolations, and 21 compensated for its uncertainty, most using allometric adjustments and some using RFs. Most also incorporated uncertainty for same-species extrapolations. Twenty-one ERAs used UFs extrapolating from lowest observed adverse effect level (LOAEL) to no observed adverse effect level (NOAEL), and 18 used UFs extrapolating from subchronic to chronic exposure. Values and application of all UF types were inconsistent. Maximum cumulative UFs ranged from 10 to 3,000. Results suggest UF methodology is widely used but inconsistently applied and is not uniformly conservative relative to UFs recommended in regulatory guidelines and academic literature. The method is limited by lack of consensus among scientists, regulators, and practitioners about magnitudes, types, and conceptual underpinnings of the UF methodology.},
doi = {10.1897/1551-5028(2000)019<1668:UFISER>2.3.CO;2},
journal = {Environmental Toxicology and Chemistry},
issn = {0730-7268},
number = 6,
volume = 19,
place = {United States},
year = {2000},
month = {6}
}