Mining is a process by which the earth is drilled, usually by heavy machinery, to extract minerals and other materials from beneath the soil. Mining is carried out to retrieve a number of substances such as coal, gold, iron, diamonds, potash and uranium. While mining yields important substances for sale and industrial production, mining also affects the natural environment.
Ecosystems are affected by the physical perturbations of mining operations, as well as the chemical alterations in soil and water. Mining activities vary, but can include soil compaction and conversely, removal of the topsoil. These alterations disrupt nutrient dynamics by minimizing the availability of nitrogen and phosphorus, lower the pH through the acidification of the soil and can introduce toxic metals and acids. Depending on the scale and nature of the mining operation, these effects can be localized to the location of the mining or, through local hydrology, can extend to nearby aquatic systems, such as stream, wetlands and lakes.
All mining activities create considerable waste, including acid runoff and chemical byproducts of refining. Coal mines are particularly prone to acid runoff. When large amounts of rainwater enters functioning or abandoned mines, the water becomes acidic and contaminated with heavy metals. The Environmental Protection Agency estimates that 40 percent of western U.S. watershed have been contaminated by mine waste. In the United States, the mining industry is the top toxic polluter. The problems are frequently more pronounced in under-regulated developing countries, where mining companies can be free to pollute with impunity. Water pollution from mines has been known to decimate aquatic life, and seriously impact bird and mammal populations. Water sources used by humans have also been contaminated, posing serious risks to human health.
Mining operations often contaminate the soil with toxic heavy metals and acids. Acids can lower the pH of the soil,...
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