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. It takes several days for copper to be excreted. Copper and its salts are highly soluble in water concentrations of 1,000 mg and more will mix with a liter of water.