TEMPORAL AND SPATIAL DIFFERENCES IN GEOCHEMICAL FINGERPRINTS OF METAL SOURCES IN POND SEDIMENTS FROM URBAN AND RURAL WATERSHEDS IN BROOME CO., NY

There is an unusually high incidence rate of childhood cancer in Hillcrest, NY. Concerned citizens wanted to know if past emissions from now defunct local metal plating facilities resulted in exposure of the residents to elevated concentrations of pollutants. Such community concerns can be addressed through analysis of historical records of anthropogenic activities as preserved in sediment cores. Sediment was collected from a storm water retention pond in Hillcrest as well as from reservoir sediments from rural locations in Broome Co.. The pond in Hillcrest was constructed in the 1940s to control runoff from impervious surfaces from the adjacent 120-acre Binghamton Army Supply Depot. Metal concentrations, lead isotope ratios, and decay products of 210Pb and 137Cs were used to determine source specific differences in the spatial and temporal distribution of pollutants in the sediment cores. Compared to reservoir sediments collected from rural locations, sedimentation rate normalized trace metal concentrations of Zn, Pb, Ni, Cu, Cr, Cd and As were elevated in the urban pond sediments. The deposition of Pb in urban pond sediment peaked in the late 1970's and the temporal Pb concentration profile corresponds well with consumption records for leaded gasoline. Superimposed on the Pb profile is an overprint of co-varying Zn, Ni, Cu, Cr and Cd concentrations; a suite of metals commonly used in the metal plating process. Therefore, elevated metal concentrations in Hillcrest pond sediment resulted from runoff associated with the atmospheric deposition of metals from both regional and local anthropogenic sources on the adjacent urbanized, impervious watershed. Collection of several sediment cores from each pond and reservoir also allowed geochemical fingerprints of land use change (housing construction and deforestation) and evidence for use of lead-arsenate based pesticides to be preserved in urban and rural locations.