Much of this copper is attached to dust and other air particles. Some copper in the environment, however, is less tightly bound to particles and may be absorbed by plants and animals. Dissolved copper compounds commonly used in agriculture, for example, are more likely to threaten human health. Copper can enter the body by ingesting water or food, soil, or other substances that contain copper, or by inhaling copper dust or fumes. Drinking water that contains higher levels of dissolved copper is a common pathway.
Water can absorb copper from pipes and brass faucets as it sits overnight.
The term parts per billion is a way of expressing the concentration of a contaminant in a liquid or air. The body is very good at blocking high levels of copper from entering the bloodstream. Copper is necessary for good health, but large daily intakes of copper can be harmful. Long-term exposure to copper dust can irritate the nose, mouth, and eyes, and cause headaches, dizziness, nausea, and diarrhea. Although large amounts can cause liver and kidney damage, copper is not known to cause cancer.