Most IUDs are made of copper, too. Today, the daughters of these mothers are dutifully taking their birth control pills every morning, thus magnifying the problem. Until plastic pipes became cost effective, builders routinely put copper pipes in homes and offices. Copper can easily leach into the drinking water as the pipes age. If you spend any significant amount of time in a swimming pool, the water may be the cause of your copper toxicity.
Copper is the most effective way to kill algae in swimming pools.
Dumping algaecide in the pool raises the water's copper levels enough so that the trace element can enter into your skin. Finally, your diet might be the reason. Unfortunately, some of the best foods on the planet are high in copper in relation to zinc. It's possible you've been poisoning yourself and didn't know it. Brown spots on the face are a good sign.