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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, preventing plants and soil microorganisms from thriving, and can also react with various minerals in the soil that are required by plants, such as calcium and magnesium. The hydrogen ions from the acid absorb the soil particles, preventing other nutrients required by plants to remain in the soil. These chemical alterations can interact with soil compaction. Because water isn't moving through the soil profile, some of the metals and acids can get carried away by the water, extending the mining effects throughout greater portions of the landscape. Elkins, Parker, Aldon and Whitford report in their article 'Responses of Soil Biota to Organic Ammendments in Stripmine Spoils in Northwestern New Mexico,' in the 'Journal of Environmental Quality,' 1984, that the addition of organic matter to mined lands can increase water retention in the soil, as well as the microbial process of nutrient accumulation and processing, potentially offsetting and minimizing the ecosystem effects from mining operations.

Mining releases particles of various kinds into the air, which has an impact on air quality. Some of these substances are harmless, such as dust particles, while others can be potentially dangerous. Dangerous particles include arsenic, cadmium and lead. Over time, and in sufficient quantities, these dangerous particles can have an effect on human health, especially respiratory health. Emphysema is one potential effect of prolonged inhalation of dangerous particles. These particles can also be ingested or absorbed through the skin.