Mining has a great effect on the quality of the air. Since mines need to blast through rock to get to an ore, dust may be produced in the process. Coal mines release methane, which contributes to environmental issues because it is a greenhouse gas.
The methane is sometimes captured, but only where it is economically feasible to do so. Some cooling plants may release ozone-depleting substances, but the amount released is very small. Non-vegetated or uncapped tailings dams release dust, and when radioactive elements are found in the ore, radiation is emitted. Heavy metals, such as sulfur dioxide, may be polluted into the air by unsafe smelter operations with insufficient safeguards. The gold mining industry is one of the most destructive industries in the world, because of all of the toxins that are released into the air. Acid rain and smog are also some side-effects of mining. Every year, 142 million tons of sulfur dioxide is emitted into the atmosphere because of smelting. That’s 13% of total global emissions.