Browsing by Subject "Metals -- Environmental aspects -- Montana -- Deer Lodge County"
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Item An assessment of metal exposure and accumulation in passerines inhabiting artificial nest boxes on the Anaconda Smelter Site, Anaconda, MT(Texas Tech University, 2002-12) Adair, Blakely McQuistonThe ubiquitous nature of metals from both natural and anthropogenic sources combined with their necessity in biological processes produces a complex system for study. Metal distributions in abiotic and biotic systems must be examined to accurately assess impact on ecosystems. Wildlife studies of exposure and effect can be challenging, but the results are more complete than evaluation of only metal concentrations. Birds are good sentinel species because they are visible, sensitive to toxicants, and occupy different trophic positions. Therefore, studies assessing avian population status, reproductive success, and toxicological significance of metal exposures can be extrapolated to other wildlife and possibly humans. Biological endpoints, such as ALAD activity and porphyrin concentrations, can act as indicators of exposure to contaminants before signs of overt toxicity occur. Computer models, such as canonical correlation, can aid in describing and predicting the distribution and impact of metals on biological systems.Item Metal exposure and effects in American kestrel (Falco sparverius) nestlings raised on a smelter-impacted superfund site(Texas Tech University, 2002-05) McBride, Tobias JohnNestling American kestrels (Falco sparverius) inhabiting nest boxes placed throughout the Anaconda Smelter Superfund Site, Montana, were monitored for reproductive success and growth over two successive breeding seasons. A gradient of decreasing soil contaminant concentrations occurred with increasing distance away from the smelter stack. The contaminants of concern (COCs; arsenic, cadmium, lead, copper, and zinc) were determined in food items, pellets, fecal/urate, blood, kidney and liver tissues. Hepatic and renal porphyrin profiles were characterized, and erythrocyte ALAD inhibition assessed, for use as indicators of health effects. Site wide in 1999,43 chicks hatched (81%) with 41 surviving to fledging age (95.3% fledging efficiency). In 2000, 34 chicks hatched (59%) with 32 surviving to fledging age (94% fledging efficiency). Nestling growth and demographics did not appear related to tissue contaminant levels. Active boxes were grouped into two site types (Smelter HiU and Opportunity Ponds) based on their proximity to the smelter site. In 1999, Smelter HiU birds had higher blood lead, liver cadmium, lead, and copper, and kidney cadmium. In 2000, only blood samples were collected, with notably increased lead and cadmium from Smelter Hill birds. Inhibition of erythrocyte ALAD activity at the highest blood lead concentrations indicated lead concentrations reached a threshold level sufficient to initiate biochemical effects. An increase in liver 4-carboxyl porphyrin at the highest liver lead levels likewise suggested sufficient exposure to initiate disruption of heme synthesis. Food items were collected from each active nest. COC concentrations were higher in samples from Smelter Hill boxes, with notable increases seen in arsenic and lead. Contaminant levels in food items were sufficiently high for accumulation in nestling tissues, with elevated levels occurring in nestlings closer in proximity to the smelter.