PT12 Metals and Bioaccumulation
Exhibit Hall
8:00 AM - Tuesday
(PT163) Heavy metal levels in the sediments and biota of the Monongahela and Alleghany Rivers.
Ambrose, G1, Kostura, A1, MacNeil, J1, 1 Chatham College, Pittsburgh, PA, USA
ABSTRACT- Pittsburgh, which is located at the confluence of the Alleghany and Monongahela river systems, drains a combined watershed of almost 20,000 square miles. Given the region′s legacy of coal mining and steel-making, we have undertaken an ongoing study of the impact of heavy metals on the rivers. Samples of sediment have been collected from sites along the course of both rivers, extracted with acid and analyzed by flame AA to determine the dry-mass levels of cadmium, nickel, copper, iron and zinc. Cd levels in the sediment were low (5-8 ppm) and consistent in both rivers, while Zn levels in the Monongahela were 2-3 times higher than in the Alleghany. Copper levels were also higher in the Monongahela, and both copper and zinc varied significantly by site selection. Markedly higher levels were recorded at a single site in Ronco, PA, where zinc levels in the sediment exceeded 500 ppm and copper approached 350 ppm. To explore the impact of these metal concentrations on the local biosphere, samples of aquatic plants, macro-invertebrates and fish were collected from numerous sites, including the original sediment sample locations. Dry-mass levels of cadmium, nickel, copper, iron and zinc were calculated for all samples. For the fish, heavy metal loading on the gill structures, as well as in the kidney, liver and muscle tissue were determined.
Key words: bioaccumulation, heavy metal, fish