The average concentration of copper in lakes and rivers is 4 ppb. Lakes and reservoirs recently treated with copper compounds to control algae or receive cooling water from a power plant may have high concentrations of dissolved copper. Soil generally contains between 2 and 250 ppm copper, although concentrations close to 7000 ppm have been found near copper production facilities. Another common source of copper in soil results from spreading sludge from sewage treatment plants. This copper generally stays strongly attached to the surface layer of soil.
Food naturally contains copper.
People ingest about 1 mg of copper every day. Copper rapidly enters the bloodstream and is distributed throughout the body after ingestion. Other foods eaten with copper can affect the amount of copper that enters the bloodstream. The human body is efficient in blocking high levels of copper from entering the bloodstream. Copper is excreted through feces and urine.