Artisanal Gold Mining Is Dangerous. Here Is Why

When people think of gold mining, they may likely remember quaint images of people panning for gold sediment by a flowing river, similar to what American settlers did in California during the mid-19th century. Gold mining methods have advanced considerably since then, and even in smaller operations that cannot afford large machinery, amateurs have turned to cheap chemical compounds to help them isolate gold from other minerals. These methods, known as artisanal gold mining, can pose dangers to both miners and the environment, depending on what chemical compounds are used. Among the most common substances is mercury.

According to the Blacksmith Institute, artisanal miners add mercury to silt, which causes gold particles to collect into an amalgam with the mercury. Blowtorches, open flames or other sources of heat are applied to the amalgam to burn off the mercury and isolate the gold. In the process, gaseous mercury is released into the surrounding area. Whatever is not inhaled by people collects in the environment, where it can impact various organisms. Rivers, lakes, streams and other bodies of water may become the ultimate destinations for mercury as it collects, according to the U.S. Environmental Protection Agency. Once in the water, it can bioaccumulate up the food chain in fish, which may get eaten by humans. Mercury that has been consumed through fish and other seafood has been linked to a range of health problems, including arthritis, kidney problems, neurological damage, respiratory failure, psychotic reactions, memory loss, miscarriages and death.

These effects are cause for even more worry considering how widespread artisanal mining is. These small operations tend to be popular in areas stricken by poverty, particularly in Africa, Southeast Asia and Latin America, where abandoned but active gold mines are plentiful. The Blacksmith Institute estimated that at least 25 percent of the world's gold supply is collected through artisanal mining. This process is responsible for about 30 percent of anthropogenic environmental mercury contamination. There are between 10 million and 15 million artisanal and small scale gold miners around the globe. Among these miners are 4.5 million women and 600,000 children.

Part of rectifying the hazards of artisanal mining is assessing people's level of mercury exposure. Unfortunately, some of the methods used in these evaluations – air sample analysis, fish collection and so on – are not feasible in some of the resource-poor countries where artisanal mining is prevalent. Environmental and medical scientists who live in areas where artisanal gold mining is common often have few resources to assess the full impact of the practice. One team of researchers from the Environmental Geochemistry Research and Engineering Laboratory of the Universidad Politécnica de Madrid in Spain devised a way to measure these negative effects using probabilistic models, as published in the journal Chemosphere. This strategy involved collecting data surrounding 12 gold mines in Colombia, including biometrics, lifestyle, consumption, air sample analyses from amalgamation workshops and nearby roads, and fish evaluations.

Results suggested that mercury exposure exceeded acceptable limits around these mines by up to 200 times. Even within the mining population, exposure was up to 50 times more than recommended limits. The UPM researchers reiterated that their tool cannot completely replace clinical assessments of the dangers of mercury exposure from artisanal mining. However, it may be useful in estimating the negative impact, particularly within communities that would benefit from cheaper strategies.