What Is Copper Toxicity?

The NIH Office of Dietary Supplements says copper is an essential mineral naturally present in some foods and available as a dietary supplement, and that it is a cofactor for enzymes involved in energy production, iron metabolism, connective tissue synthesis and neurotransmitter synthesis. It says the daily upper limit for adults, counting food, beverages and supplements, is 10,000 micrograms. ATSDR says it is essential for people to ingest small amounts of copper every day, that too much or too little copper can lead to illness, and that ingesting a high amount of copper, usually in drinking water, can cause vomiting, nausea, abdominal pain or diarrhea.

Tap water is regulated through an action level. Under federal drinking water rules at 40 CFR 141.80, the copper action level is exceeded if the 90th percentile copper concentration in tap samples is greater than 1.3 mg/L. The EPA drinking water regulations table lists gastrointestinal distress from short-term copper exposure and liver or kidney damage from long-term exposure, and says people with Wilson disease should consult their doctor if the copper in their water exceeds the action level.

NIDDK says Wilson disease is a genetic disorder that prevents the body from removing extra copper, causing copper to build up in the liver, brain, eyes and other organs. It says the body needs a small amount of copper from food to stay healthy but too much copper is harmful, and that without treatment Wilson disease can lead to high copper levels that cause life-threatening organ damage.