Environmental Problems, Their Causes, and Sustainability 1

16-6 ENVIRONMENTAL EFFECTSOF USING MINERAL RESOURCESWhat Are the Environmental Impactsof Nonrenewable Mineral Resources?Degradation, Waste, and PollutionExtracting, processing, and using mineral resourcescan disturb the land, kill miners, erode soils, producelarge amounts of solid waste, and pollute the air,water, and soil.The mining, processing, and use of mineral resourcestakes enormous amounts of energy and often causesland disturbance, soil erosion, and air and water pollution(Figure 16-13).Mining can harm the environment in a number ofways. One is scarring and disruption of the land surface.The Department of the Interior estimates that at least500,000 surface-mined sites dot the U.S. landscape,mostly in the West. Cleanup costs are estimated in thetens of billions of dollars.Another problem is collapse of land above undergroundmines. This subsidence can cause houses to tilt,sewer lines to crack, gas mains to break, and groundwatersystems to be disrupted.Toxin-laced mining wastes can be blown or depositedelsewhere by wind or water erosion. Anotherproblem is acid mine drainage. It occurs when rainwaterseeping through a mine or mine wastes carries sulfuricacid (H 2 SO 4 , produced when aerobic bacteria act oniron sulfide minerals in spoils) to nearby streams andgroundwater (Figures 16-1 and 16-14, p. 344). This contaminateswater supplies and can destroy some formsof aquatic life. According to the U.S. EnvironmentalProtection Agency, mining has polluted about 40% ofwestern watersheds.Mining can also result in emission of toxic chemicalsinto the atmosphere. In the United States, the miningindustry produces more toxic emissions than anyother industry—typically accounting for almost half ofsuch emissions. Finally, some forms of wildlife can beexposed to toxic mining wastes stored in holdingponds and leaking from such ponds.What Is the Typical Life Cycle of aNonrenewable Metal Resource? GoingAround in CirclesMetal ores are extracted from the earth’s crust,purified, smelted to extract the desired metal, andconverted to the desired products.Figure 16-15 (p. 345) depicts the typical life cycle of ametal resource. It begins with extracting ore from theearth’s crust.Ore typically has two components. One is the oremineral containing the desired metal and the other isStepsEnvironmental EffectsMiningexploration, extractionDisturbed land; mining accidents;health hazards; mine wastedumping; oil spills and blowouts;noise; ugliness; heatProcessingtransportation, purification,manufacturingSolid wastes; radioactive material;air, water, and soil pollution;noise; safety and healthhazards; ugliness; heatUsetransportation or transmissionto individual user,eventual use, and discardingNoise; ugliness;thermal water pollution;pollution of air, water, and soil;solid and radioactive wastes;safety and health hazards; heatFigure 16-13 Natural capital degradation: some harmful environmental effects of extracting, processing, andusing nonrenewable mineral and energy resources. The energy used to carry out each step causes additionalpollution and environmental degradation.http://biology.brookscole.com/miller14343