Kinetics, dose-response, excretion, and toxicity of methylmercury in free-living Cory's shearwater chicks

✍ Scribed by Luis R. Monteiro; Robert W. Furness

• Book ID: 102199948
• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 128 KB
• Volume: 20
• Category: Article
• ISSN: 0730-7268
• DOI: 10.1002/etc.5620200827

✦ Synopsis

Abstract

Methylmercury (MHg) kinetics, dose–response, excretion, and toxicity were experimentally evaluated and compared between small (one to two weeks old) and large (six to seven weeks old), free‐living Cory's shearwater chicks. The half‐time for the terminal elimination phase of MHg in blood (5.7 d) and the average percentage of ingested MHg deposited in the blood volume (12%) were independent of the age at exposure. Therefore, these data were employed to derive a relationship between steady‐state blood concentrations and dietary intake of MHg in bird chicks. Plumage:blood ratios were independent of dose and could be used as partition coefficients. Dose–response relationships in plumage and blood were linear over the wide range of exposures employed. Blood dose–responses of MHg in small and large chicks were similar. Excretion percentages into the final plumage varied between 42 and 60% of intake. The body condition of experimental chicks did not indicate sublethal toxicity of the doses administered; hence, the exposure levels provide maximum avian no‐observed‐adverse‐effect levels for external symptoms in wild seabird chicks.