Exposure and effects of polychlorinated biphenyls and metals in raccoons and selected rodents at the Paducah Gaseous Diffusion Plant in Western Kentucky

The Paducah Gaseous Diffusion Plant in Western Kentucky is an industrial facility built in the 1950s to enrich raw uranium for fuels and bomb materials. Polychlorinated biphenyls, metals, and other contaminants have been released into the environment through various industrial processes over the past fifty years, and are thought to have moved into the surrounding areas through erosion and run-off.

Contaminant concentrations in tissues of wildlife species were measured to monitor the amounts and spatial distribution of contaminants at this site. A residue study using white-footed mice (Peromyscus leucopus) and rice rats (Oryzomys palustris) as indicator species documented the movement of contaminants into the lowest levels of the terrestrial food web and identified highly contaminated areas. Rice rats were the best biomonitors for PCB contamination and white-footed mice the best indicators of metal contamination at this site.

Results of the rodent study raised questions about the potential bioaccumulation of contaminants into higher trophic-level organisms inhabiting the areas surrounding the plant. Raccoons (Procyon lotor) were chosen to assess distribution of contamination on a larger scale and to evaluate the potential for bioaccumulation of contaminants in upper trophic-level organisms. Raccoons were captured, radio-collared, and tracked to determine spatial utilization of potentially contaminated areas. Concentrations of PCBs and metals were determined in raccoon tissues. Physiological biomarkers of exposure, including a variety of cytochrome P450 measurements, porphyrins, and other physiological markers were measured to evaluate adverse responses to contaminant exposure.