๐”– Bobbio Scriptorium
โœฆ   LIBER   โœฆ

Assessment of risks to ground-feeding songbirds from lead in the Coeur d'Alene Basin, Idaho, USA

โœ Scribed by Bradley E Sample; James A Hansen; Anne Dailey; Bruce Duncan


Publisher
Society of Environmental Toxicology and Chemistry
Year
2011
Tongue
English
Weight
935 KB
Volume
7
Category
Article
ISSN
1551-3777

No coin nor oath required. For personal study only.

โœฆ Synopsis


Previous assessment of ecological risks within the Coeur d'Alene River Basin identified Pb as a key risk driver for groundfeeding songbirds. Because this conclusion was based almost exclusively on literature data, its strength was determined to range from low to moderate. With the support of the US Environmental Protection Agency (USEPA), the US Fish and Wildlife Service collected site-specific data to address the uncertainty associated with Pb risks to songbirds. These data, plus those from the previous Coeur d'Alene Basin ecological risk assessment, were integrated, and risks to ground-feeding songbirds were reevaluated. These site-specific data were also used to develop updated preliminary remedial goals (PRGs) for Pb in soils that would be protective of songbirds. Available data included site-specific Pb concentrations in blood, liver, and ingesta from 3 songbird species (American robin, song sparrow, and Swainson's thrush), colocated soil data, and soil data from other locations in the basin. Semi-log regression models based on the association between soil Pb and tissue Pb concentrations were applied to measured soil concentrations from the previous risk assessment to estimate Pb exposures in riparian and adjacent upland habitats throughout the Coeur d'Alene Basin. Measured and estimated tissue or dietary exposure was tabulated for 3 areas plus the reference, and then compared to multiple effects measures. As many as 6 exposure-effect metrics were available for assessing risk in any one area. Analyses of site-specific tissue-and diet-based exposure data indicate that exposure of ground-feeding songbirds to Pb in the Coeur d'Alene Basin is sufficient to result in adverse effects. Because this conclusion is based on multiple exposure-effect metrics that include site-specific data, the strength of this conclusion is high. Ecological PRGs were developed by integrating the site-specific regression models with tissue and dietary effect levels to create exposure models, which were solved for the soil concentration that produced an exposure estimate equal to the effect level (i.e., the ecological PRG). The lowest PRG obtained for any species' exposure-effect measure combination was 490 mg/kg for subclinical effects due to Pb in the blood of American robins; the highest was 7200 mg/kg for severe clinical effects due to Pb in the blood of song sparrows. Because the lowest ground-feeding songbird PRG was comparable to multiple cleanup goals developed for the basin (i.e., soil invertebrates, wildlife populations, and human health), in addition to the site-specific cleanup level of 530 mg Pb/kg sediment for the protection of waterfowl (USEPA 2002) the USEPA has made a risk-management determination that a site-specific Pb cleanup level of 530 mg/kg in soil would be protective of songbirds in the


๐Ÿ“œ SIMILAR VOLUMES


Lead exposure and poisoning of songbirds
โœ James A Hansen; Daniel Audet; Brian L Spears; Kate A Healy; Roy E Brazzle; David ๐Ÿ“‚ Article ๐Ÿ“… 2011 ๐Ÿ› Society of Environmental Toxicology and Chemistry ๐ŸŒ English โš– 301 KB

Previous studies have found widespread Pb poisoning of waterfowl in the Coeur d'Alene River Basin in northern Idaho, USA, which has been contaminated by mining and smelting activities. We studied the exposure of ground-feeding songbirds to Pb, sampling 204 American robins (Turdus migratorius), song