Are You Buying ‘Dirty' Gold Jewelry?

Then there is the mercury.
The cheap but toxic metal is widely used in processing artisanal gold. The byproduct, elemental mercury, enters the water system, where microscopic organisms convert it into organic methylmercury, which then is eaten by fish, traveling up the food chain to humans.
“Birds and mammals that eat fish are more exposed to methylmercury than any other animals in water ecosystems,” states the U.S. Environmental Protection Agency (EPA) website. “Similarly, predators that eat fish-eating animals are at risk.”
http://www.takepart.com/video/2014/09/05/are-you-buying-dirty-gold-jewelry