A weight-of-evidence approach for assessing metals contamination in freshwater streams

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:49553

Gendusa, T C; Billig, P ^[1]

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1. CDM, Inc., Helena, MT (United States)

The quotient method is among the most commonly used approaches for assessing the potential effects of metals on aquatic biota in freshwater streams. That method compares a single contaminant and media-specific exposure-point concentration to a single, selected critical effects concentration. Such approaches are, however, appropriate only for conducting screening-level assessments. Risk estimations based solely on general data such as ambient water quality criteria (AWQC), for example, can be insufficiently sensitive to site-specific conditions, and may therefore be inappropriately applied. There are also uncertainties with estimating risks to a wide variety of aquatic biota using only a single literature-based or site-specific effects concentration. For example, uncertainty is increased where the relative sensitivities of tested species compared to resident species is unknown; where the potential effects of site-specific conditions on toxicity are not considered; and where toxicity data are extrapolated from one species to several other, non-related species. The authors present here a simple weight-of-evidence approach for estimating risks to aquatic biota in streams which incorporates several of these approaches. This approach eliminates reliance on single exposure point and effects concentrations, and is based instead on a graphical presentation of both literature and site-specific effects concentrations and the site-specific frequency, magnitude, and spatial distribution of metals in surface water and sediment.

• OSTI ID: 49553
• Report Number(s): CONF-9410273--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
AQUATIC ORGANISMS
METALS
SENSITIVITY
STREAMS
TOXICITY
WATER POLLUTION