Comparison of screening-level and Monte Carlo approaches for wildlife food web exposure modeling

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:230895

Pastorok, R; Butcher, M; LaTier, A; Ginn, T ^[1]

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1. PTI Environmental Services, Bellevue, WA (United States)

The implications of using quantitative uncertainty analysis (e.g., Monte Carlo) and site-specific tissue residue data for wildlife exposure modeling were examined with data on trace elements at the Clark Fork River Superfund Site. Exposure of white-tailed deer, red fox, and American kestrel was evaluated using three approaches. First, a screening-level exposure model was based on conservative estimates of exposure parameters, including estimates of dietary residues derived from bioconcentration factors (BCFs) and soil chemistry. A second model without Monte Carlo was based on site-specific data for tissue residues of trace elements (As, Cd, Cu, Pb, Zn) in key dietary species and plausible assumptions for habitat spatial segmentation and other exposure parameters. Dietary species sampled included dominant grasses (tufted hairgrass and redtop), willows, alfalfa, barley, invertebrates (grasshoppers, spiders, and beetles), and deer mice. Third, the Monte Carlo analysis was based on the site-specific residue data and assumed or estimated distributions for exposure parameters. Substantial uncertainties are associated with several exposure parameters, especially BCFS, such that exposure and risk may be greatly overestimated in screening-level approaches. The results of the three approaches are compared with respect to realism, practicality, and data gaps. Collection of site-specific data on trace elements concentrations in plants and animals eaten by the target wildlife receptors is a cost-effective way to obtain realistic estimates of exposure. Implications of the results for exposure and risk estimates are discussed relative to use of wildlife exposure modeling and evaluation of remedial actions at Superfund sites.

• OSTI ID: 230895
• Report Number(s): CONF-9511137--; ISBN 1-880611-03-1
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ARSENIC
BIOLOGICAL ACCUMULATION
BIOLOGICAL INDICATORS
CADMIUM
COMPARATIVE EVALUATIONS
COPPER
ECOLOGICAL CONCENTRATION
FOOD CHAINS
IDAHO
LEAD
MATHEMATICAL MODELS
MONTANA
MONTE CARLO METHOD
REMEDIAL ACTION
RISK ASSESSMENT
RIVERS
TRACE AMOUNTS
US SUPERFUND
WATER POLLUTION
ZINC