Air quality is also compromised by gold mining, which releases hundreds of tons of elemental mercury into the air every year. Regular gold mine operations negatively affect the environment in a number of ways. For example, operating large mining equipment requires fuel and produces greenhouse gas emissions. However, potential mine accidents and leaks pose an even greater threat to nearby land and water resources.
The U.S. Environmental Protection Agency estimates that the development of a proposed gold and copper mine in Bristol Bay, Alaska, would destroy at least 24 miles of streams that support the world's largest red salmon fishery. However, extracting just one ounce of gold from the ore can cause 20 tons of solid waste and significant mercury and cyanide contamination. The cyanide used in these mines to filter gold from the ore caused such high levels of pollution that people cannot use nearby water resources until they have undergone extensive and costly treatment and purification.
In two open-pit gold mines in Montana, the cyanide used to filter gold from the ore caused such high levels of contamination that people could not use nearby water resources until they had undergone extensive and costly treatment and purification. Mercury has long been used in artisanal and small-scale gold mining (ASGM) to extract gold from mineral sediments and rock deposits. In addition, mercury used in artisanal and small-scale gold mining operations can become airborne and pollute both air and water. Gold has been a popular and valuable component of jewelry for centuries.
It is resistant to solvents, does not tarnish and is incredibly malleable, making it relatively easy to mold. Gold nuggets are popular with collectors, but they are rare; most gold is found in the form of tiny particles buried in gold ore. Two open-pit gold mines in Montana closed in 1998, but they continue to cost state taxpayers millions of dollars in water recovery and treatment efforts. This form of small-scale gold mining has little effect on the body of water, but the large-scale practice of extracting gold from the mineral can have enormous negative effects on water quality.
In general, the effects of gold mining on the environment (water, air and land) are serious and extremely negative. Most forms of gold mining involve moving large amounts of soil and rock, which can be detrimental to the surrounding wildlife habitat. Ultimately, this environmental damage affects us. In addition to drinking water contamination, AMD by-products, such as mercury and heavy metals, reach the food chain and make people and animals sick for generations.
Some gold can be found by searching for gold in rivers; heavy gold will remain in the pan, while less dense rocks and minerals float.