The gastrointestinal tract and acute effects of copper in drinking water and beverages.

Copper is an essential element for all living beings. Exposure to copper results almost exclusively from the ingestion of food and water. Generally, potable water contains low levels of copper, but high concentrations of this mineral have been found in water from private wells or when water or beverages with low pH have been conducted through copper piping. Some authors have associated acute gastrointestinal symptoms (diarrhea, abdominal pain, nausea, and vomiting) with elevated levels of copper in water or beverages, but without excluding other confounding factors that could produce such symptoms. Recently, various controlled studies have demonstrated that a concentration of 2 mg Cu/L of potable water does not produce an increase in gastrointestinal symptoms in infants, and that in women, only concentrations greater than 3 mg Cu/L increase the number of episodes of nausea, vomiting, and abdominal pain, but not diarrhea. This critical analysis of scientific publications verifies the WHO provisional level for copper in drinking water (2 mg/L) as safe for human health.