Technology has not only opened the door to mining almost anywhere, it has also increased the industry's potential for destruction. The mining method companies choose is almost always the one that allows maximum yield under existing conditions at minimum cost. Consequently, most modern mines employ surface excavation techniques that damage the environment much more than the more costly yet cleaner subsurface techniques. Moreover, because a profitable return is the primary consideration in deciding how and where to mine, the Developing World, with its lax environmental policies and thirst for investment, has become an attractive option. Mining has historically proven to be one of the most damaging and dangerous industries.
Industrial mining produces numerous negative environmental impacts.
These range from relatively benign erosion to mercury pollution and other chemical contamination that may persist for centuries after mining operations have ceased. Mining's most significant impacts occur during its exploitation phase, though certain exploratory practices also harm the environment. For example, transporting track-mounted drill rigs across mineral concessions and building secondary roads fragments habitat and opens previously unreachable areas to human habitation. Activities associated with the exploitation phase, especially open-pit mining, usually generate enormous quantities of solid waste. Furthermore, chemicals used for processing minerals and ore during the exploitation stage often find their way into the groundwater or nearby rivers.