T5 AM Terrestrial Ecotoxicology
Tuesday, 15 November 2005: 8:00 AM - 11:40 AM in 321-323

(BEY-1117-659388) Exceptionally high exposure of deer to lead near the Continental Mine in Idaho.

Beyer, W¹, Gaston, G², Campbell, J², Audet, D², Hansen, J², O'Connell, Jr., A¹, ¹ U.S. Geological Survey, Patuxent Wildlife Research Center, Beltsville, MD, USA² U.S. Fish and Wildlife Service, Upper Columbia Fish and Wildlife Office, Spokane, WA, USA

ABSTRACT- The now inactive Continental Mine in the Kaniksu National Forest in the Selkirk Mountains of northern Idaho produced silver and lead for many years in the midst of habitat supporting bear, moose, elk, woodland caribou and abundant mule deer and white-tailed deer. Soils on the mine site and sediments of Blue Joe Creek, down slope of the mine, have been severely contaminated with lead. Deer pellets were analyzed to estimate the exposure of deer to metals. Pellets collected on the mine site contained an extremely high mean concentration of lead, over 900 mg/kg, dry weight. Deer were found to be ingesting large amounts of soil or sediment, shown to be the source of the lead. The estimated exposure, if chronic, was high enough to be lethal to cattle and horses. The findings demonstrate the importance of direct ingestion of contaminated soils as a route of exposure that it may not be adequately considered in most ecological risk assessments.

Key words: deer, mining, lead