Fact Sheet - Artisanal Gold Mining and Mercury Pollution

The artisanal gold mining process can lead to mercury exposure through inhalation and ingestion. Vapor mercury is released into the air when the amalgam is heated, and is frequently inhaled by miners and their families. Excess liquid mercury used in the amalgamation process is often washed away with the remaining silt and can enter into water systems and accumulate in fish, contaminating the food chain for communities downstream. Though mercury most commonly accumulates in large, predatory fish, traces have also been found in birds, reptiles, and mammals, all of which can spread mercury to humans if consumed.
http://www.worstpolluted.org/fact-sheet-2011-artisanal-gold-mining-and-mercury-pollution.html