The gold mining industry is the world’s largest mercury pollutant, accounting for over 37% of global mercury pollution. Mercury-gold amalgamation is often used as an inexpensive and easy method to extract gold from its ore. A mercury-gold amalgam is created by combining mercury with gold ore. The mercury-gold amalgam is then heated with a torch, distilling the mercury, and isolating the gold. Torching the amalgam releases a significant amount of mercury vapor, which is inhaled by miners. The leftover tailings containing unrecovered mercury are released into the environment, usually into the waterways the processing centres are built adjacent to.
Mercury vapor inhaled by miners can create severe health problems such as impaired cognitive function and kidney damage. Non-miners exposed to mercury fumes can also be harmed. Children exposed to mercury pollution are at risk of physical deformities, neurological damage, and decreased IQ.
In the environment, microbes transform mercury into methylmercury, which is a potent neurotoxin, in a process called methylation. Methylmercury is absorbed in small quantities by small aquatic life, which are then eaten by predators. Through biomagnification, the quantity and concentration of methylmercury increases as it is passed on the way up the food chain. Mercury concentrations are the highest at the top of the food chain where humans, birds, and predatory mammals reside.
Named Minamata disease after an infamous series of mercury poisoning cases in Japan, methylmercury poisoning damages the human central nervous system. This can lead to loss of motor function, as well as other neurological effects. Minamata disease also affects surrounding wildlife, causing animals to exhibit grossly abnormal behaviours on top of difficulty reproducing.
Ghana, once known as the Gold Coast, is one of the world’s top 10 gold producers. Its government is concerned about the long-term health effects on people working in the industry, as the country lacks the facilities to detect and treat mercury poisoning. Hence, Ghana is in the early stages of implementing the Minamata Convention, which calls for the phasing out of the use of mercury from several sectors, including gold mining. However, the cost of phasing out the use of mercury could be a reason why some African countries are hesitating to join the convention. On the other hand, the insidious dangers of mercury poisoning far outweigh its low cost and accessibility as a gold extraction method.
Clean Mining, part of the Clean Earth Technologies Group, uses a mercury-free non-toxic gold recovery agent. The process does not release any tailings into the environment, as clean ore can be buried back in the earth after a de-watering process. The reagent can also be recycled, resulting in a safe, eco-friendly mining method.
Clean Mining is part of the Clean Earth Technologies group.