Exposure of insects and insectivorous birds to metals and other elements from abandoned mine tailings in three Summit County drainages, Colorado

• Published in: Environmental monitoring and assessment 2009-06, Vol.153 (1-4), p.161-177, Article 161
• Main Authors: Custer, Christine M, Yang, Chi, Crock, James G, Shearn-Bochsler, Valerie, Smith, Kathleen S, Hageman, Phillip L
• Format: Article
• Language: English
• Subjects: Abandoned mine tailings; Abandoned mines; Aminolevulinic acid; Animal, plant and microbial ecology; Animals; Applied ecology; Atmospheric Protection/Air Quality Control/Air Pollution; Aves; Biological and medical sciences; Birds; Cadmium; Colorado; Contaminated sediments; Contamination; Creeks & streams; Deer; Dehydration; Drainage; Drainage area; Earth and Environmental Science; Ecology; Ecotoxicology; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on protozoa and invertebrates; Effects of pollution and side effects of pesticides on vertebrates; Environment; Environmental Management; Environmental monitoring; Environmental Pollutants - analysis; Environmental science; Exposure; Feces; Food Chain; Fundamental and applied biological sciences. Psychology; Geochemistry; Geography; Geologic Sediments - analysis; Geology; Heavy metals; Industrial wastes; Insecta; Insectivorous birds; Insects; Lead; Liver; Metal concentrations; Metalloids; Metals; Metals - analysis; Mine tailings; Mine wastes; Mining; Mining industry; Monitoring/Environmental Analysis; Samples; Sediment pollution; Sediments; Statistical analysis; Statistical methods; Studies; Summit Co; Tailings; Tissue; Toxicity; Tree swallows
• ISSN: 0167-6369; 1573-2959
• DOI: 10.1007/s10661-008-0346-y

Concentrations of 31 metals, metalloids, and other elements were measured in insects and insectivorous bird tissues from three drainages with different geochemistry and mining histories in Summit Co., Colorado, in 2003, 2004, and 2005. In insect samples, all 25 elements that were analyzed in all years increased in both Snake and Deer Creeks in the mining impacted areas compared to areas above and below the mining impacted areas. This distribution of elements was predicted from known or expected sediment contamination resulting from abandoned mine tailings in those drainages. Element concentrations in avian liver tissues were in concordance with levels in insects, that is with concentrations higher in mid-drainage areas where mine tailings were present compared to both upstream and downstream locations; these differences were not always statistically different, however. The lack of statistically significant differences in liver tissues, except for a few elements, was due to relatively small sample sizes and because many of these elements are essential and therefore well regulated by the bird's homeostatic processes. Most elements were at background concentrations in avian liver tissue except for Pb which was elevated at mid-drainage sites to levels where δ-aminolevulinic acid dehydratase activity was inhibited at other mining sites in Colorado. Lead exposure, however, was not at toxic levels. Fecal samples were not a good indication of what elements birds ingested and were potentially exposed to.