High Gold Price Triggers Rainforest Devastation In Peru

Miners use mercury to amalgamate gold, separating it from sediment. They then heat the amalgam, usually over an open flame, to vaporize the mercury. When they sell the chunk of gold at a shop in Puerto Maldonado or a smaller town, a shop employee heats the gold again, to avoid paying the miner for the weight of residual mercury.

Miners spill mercury onto the ground and into waterways during amalgamation, and miners, gold shop personnel and pedestrians passing by the shops inhale mercury vapor. Luis Fernández, a tropical ecologist at the Carnegie Institution for Science at Stanford University, has found high mercury levels in some fish in the Puerto Maldonado market and in the air inside and outside gold shops in that city.
http://news.mongabay.com/2011/1011-fraser_gold_mining_peru.html