USGS arsenic data for ground-water samples across the U.S.:
--Download data updated to March 30, 2000:
(2.8 mb Text file,
6.8 mb Excel file)
--Download data used in WRI 99-4279 (1973-1997):
(1.9 mb Text file) (superseded)
Trace-element data for 541 streambed-sediment samples across the conterminous US:
(Excel file)
Analysis of trends in concentrations of seven metals (Cd, Cr, Cu, Pb,
Hg, Ni, and Zn) in sediment cores from 35 reservoirs and lakes in
urban and reference settings show that decreasing trends predominate.
Read the full report.