Tissue screening concentrations for use in assessing ecological risks of chemical residues in aquatic biota

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

OSTI ID:212007

Shephard, B K ^[1]

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1. URS Consultants, Seattle, WA (United States)

Ecological risk based screening concentrations for tissue residues have been developed for aquatic biota. Termed tissue screening concentrations (TSCs), they are generally applicable (i.e. non-site specific) to a wide variety of both freshwater and marine biota. Chemical residues in tissues at concentrations below the TSC are presumed to pose little or no risk to aquatic biota, allowing chemicals to be quickly eliminated from further consideration in a risk assessment. To date, relatively few widely applicable screening tools are available to ecological risk assessors. The toxicological basis for TSCs is applicable to both metals and organic compounds. Toxic responses in aquatic biota are directly related to waterborne concentrations of chemicals, and at equilibrium, tissue residues in biota are also proportional to the chemical concentration in water. Therefore, the toxic response in biota is directly related to the tissue residue. A TSC is calculated by multiplying a toxicity value (such as a chronic ambient water quality criterion) by a bioconcentration factor. The selection of the toxicity information and bioconcentration factors for TSC calculation is critical to the success of this screening method, and will be illustrated for cadmium, mercury, and PCB. A literature review comparing whole body tissue residues associated with toxic responses to the TSCs indicated that for most chemicals, the calculated TSCs provide an adequate level of protection so that TSCs can be used as a screening tool in ecological risk assessments. TSCs do not currently provide an accurate assessment of chemicals which are rapidly metabolized to either more or less toxic compounds by biota. The mean safety factor for the 74 chemicals with calculated TSCs is 14. Field tests of the TSCs indicate they identify the same site contaminants of concern as other methods used to assess ecological risks at hazardous waste sites.

• OSTI ID: 212007
• Report Number(s): CONF-9511137--; ISBN 1-880611-03-1
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
AQUATIC ORGANISMS
CADMIUM
MERCURY
POLYCHLORINATED BIPHENYLS
SENSITIVITY
TISSUE DISTRIBUTION
TOXICITY
WATER POLLUTION