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.
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.
Overview of three research programs including determining levels of mercury at selected sites in water, sediment and fish, mercury emissions into the atmosphere, and mercury cycling in the Everglades National Park, Florida.