RESUMO
The Oak Ridge Reservation, established in Tennessee during World War II as a research, development and process facilities support for the Manhattan Project, released large quantities of organic, inorganic and radionuclear contaminants into the environment. Their effects are particularly evident in aquatic ecosystems, as chemical concentrations in water, and as a disease in biodiversity and species richness. East Fork Poplar Creek and its tributary, Bear Creek flow inside the Reservation and have highly degraded natural habitats, unsatisfactory water quality and impoverished biota. PCB concentrations exceed recommended criteria for aquatic life safety and appear as a primary cause of environment degradation and reduced species richness. An uptake model, FGETS (Food and Gill Exchange of Toxic Substances) was used to analyse fish biodiversity and distribution in the two streams in relation to bioaccumulation of PCB congeners 1254 and 1260. Bioaccumulation of the two polychlorinated biphenyls was estimated in four different species of fish common in Tennessee rivers and streams: Catostomus commersoni, Lepomis macrochirus, Cyprinus carpio and Micropterus salmoides to integrate the available set of data and to evaluate the entity of human impact on these escosystems.
