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. Copper is highly persistent in water, with a half-life greater than 200 days.
Copper often contains arsenic as an impurity.
However, very large single or daily intakes of copper can be harmful. The seriousness of the effects of copper can be expected to increase with both level and length of exposure. Long-term exposure to copper dust can irritate the nose, mouth, throat, and eyes, and cause headaches, dizziness, nausea, and diarrhea. Copper may cause coughing and nose bleeds. Water containing higher than normal levels of copper may cause vomiting, diarrhea, stomach cramps, and nausea.