Even though lead usage has declined due to environmental awareness and regulation, several human sources of lead continue to affect birds. Hunting ammunition and fishing gear are ingested by the birds, with toxic effects.
Homepage for the research on occurrence, movement, flux, fate, and effects of agricultural chemicals, such as pesticides, in 25 states by the Midcontinent Agricultural Chemical Research Project (MACRP) with links to study results and publications.
Multiple studies addressing urban water-quality issues, to describe biological, chemical, and physical characteristics of urban water resources over time, and relate those characteristics to natural processes and human activities
Primary homepage for the National Water Quality Assessment (NAWQA) Program studying water quality in river, aquifer and coastal water basins throughout the nation. Links to reports, data, models, maps and national synthesis studies.
Trace elements are inorganic chemicals occurring in small amounts in nature. This web site of the National Water Quality Assessment links to U.S. data, publications, news, and other sites on trace metals, metalloids and radionuclides in water.