Relation of lead exposure to sediment ingestion in mute swans on the Chesapeake Bay, USA

Journal Article · Sun Nov 01 04:00:00 EST 1998 · Environmental Toxicology and Chemistry

DOI:https://doi.org/10.1002/etc.5620171121· OSTI ID:675445

Beyer, W N; Day, D; Morton, A ^[1]; Pachepsky, Y ^[2]

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1. Geological Survey, Laurel, MD (United States). Patuxent Wildlife Research Center
2. Dept. of Agriculture, Beltsville, MD (United States). Beltsville Agricultural Research Center

Although wildlife risk assessments are generally based on the accumulation of environmental contaminants through food chains, wildlife may also ingest contaminants incidentally with sediment. Forty-two mute swans (Cygnus olor) were collected from unpolluted portions of central Chesapeake Bay, Maryland, USA, in spring 1995, and their intestinal digesta were analyzed for 13 metals (aluminum [Al], boron, barium, cadmium, copper [Cu], iron, magnesium, manganese, nickel, lead [Pb], strontium, vanadium, and zinc) and for acid-insoluble ash, a marker of sediment. Swan livers and sediment samples also were analyzed for the same metals. Group method of data handling demonstrated that the digesta Al, which is associated with clays, was the best predictor of digesta Pb. Adding concentrations of other metals as predictors did not improve the accuracy of the estimates of Pb concentrations from Al concentrations. The r{sup 2} of the equation relating the log of digesta Pb to the log of digesta Al was 0.86, whereas the r{sup 2} of the equation relating the log of digesta Pb to the log of digesta acid-insoluble ash was 0.50. Accounting for the sediment ingested was critical to determining the exposure of mute swans to Pb, as well as to some of the other metals, and sediment ingestion should be considered in ecotoxicological risk assessments of waterfowl. The mean of 7.4% acid-insoluble ash in the digesta corresponded to an estimated 3.2% sediment in the diet. The Pb concentrations in the digesta were two to three times the concentration that would have been predicted from sediment Pb concentrations; presumably, the swans had ingested clays high in Pb that had settled on the vegetation. The swans were probably not exposed to high Cu concentrations but nevertheless had hepatic Cu concentrations that would be considered very high if found in other species.

• Sponsoring Organization: USDOE
• OSTI ID: 675445
• Journal Information: Environmental Toxicology and Chemistry, Journal Name: Environmental Toxicology and Chemistry Journal Issue: 11 Vol. 17; ISSN ETOCDK; ISSN 0730-7268
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
AQUATIC ORGANISMS
BIRDS
CHESAPEAKE BAY
FOOD CHAINS
LEAD
METALS
SEDIMENTS
WATER POLLUTION