The Influence of Organic Acids on Mercury Bioavailability: Insight from an Earthworm Assessment Protocol

Between 10 and 15 million artisanal and small-scale miners in more than 50 countries directly rely on gold mining for their livelihoods. Mainly due to the rudimentary techniques that characterize artisanal mining, these activities are frequently accompanied by extensive environmental degradation and deplorable socio-economic conditions. Mercury, cheap, easy-to-use and effective, is commonly used to recover gold through amalgamation. Due to its misuse, between 800 and 1000 tonnes of mercury are released into the air, water, and soils by artisanal gold miners every year. This generates serious health hazards for miners involved in gold extraction, as well as for surrounding community inhabitants, who may be exposed via high levels of mercury in fish they consume. The metallic mercury discharged by miners into the environment has the potential to undergo many changes, including the transformation to a readily bioavailable and highly toxic form of mercury, methylmercury. A laboratory methodology using the ear...