Environmental Implications of Mineral Use 3070USEPA Drinking-Water Standard
Mine tailings site
12345100150050200250300Distance downstream in creek (km)Dissolved uranium (micrograms/liter)
Otton, J.K., Zielinski, R.A., and Horton, R.J., 2010, Geology,Geochemistry, and Geophysics of the Fry Canyon Uranium/Copper Projects Site, Southeastern Utah–Indications ofContaminant Migration. U.S. Geological Survey ScientificInvestigations Report 2010-5075.© Ron Chapple Stock/Alamy
b. Dissolved uranium contaminates a creek downstream of
a former uranium and copper mine in southeastern Utah.a. Tailings—dumped here
in rural Utah—cause air,
soil, and water pollution
and have serious effects
on land use.Jewelry2,398.7 tonsIndustrialElectronics310.6Other
industrial92.7Dentistry57.8Bar hoarding235.6Official coins137Medals,
special coins72.6Retail
investment253.3Exchange-
traded
fundsAdapted from Larmer, B. “The Price of Gold.”National Geographic(January 2009).Environmental Impacts
of Refining Minerals
Approximately 80 percent or more of mined ore con-
sists of impu rities that become wastes after processing.
These wastes, called tailings, are usually left in giant
piles on the ground or in ponds near the processing
plants (Figure 12.9a). The tailings contain toxic ma-
terials such as cyanide, mercury, uranium, and sulfuric
acid. When left exposed, they con taminate the air, soil,
and water (Figure 12.9b).EnviroDiscovery
Not-so-Precious Gold
Gold is a precious metal used primarily for jewelry and as
a medium of exchange in many countries (see figure).
Worldwide demand for gold is increasing, and the
environment is suffering from the increased mining. The
waste from mining and processing ore is enormous: 6 tons
of wastes are produced to yield enough gold to make two
wedding rings. The world’s largest gold mine, located in
Indonesia but owned by a U.S. company, dumps more than
200,000 metric tons of contaminated tailings into the local
river each day, where they threaten waterfowl and fishes, as
well as underground drinking water supplies.
Small-scale miners use other extraction techniques
with destructive side effects: soil erosion, production of silt
that clogs streams and threatens aquatic organisms, and
contamination from mercury used to extract the gold. The
environmental hazards of gold mining do not end when the
gold is carried away: If not disposed of properly, mining
wastes cause long-term problems such as acid mine
drainage and heavy-metal contamination. Additionally,
gold mining operations of all scales use huge amounts of
energy—mostly from burning fossil fuels—to obtain and
process the ore.Relative importance of the many uses of gold
ÛÀiÌ>Ê«>VÌÊvÊÌ>}ÃÊUÊ}ÕÀiÊ£Ó°Smelting plants may emit large quantities of air
pollut ants, particularly sulfur, during mineral processing.
Unless expensive pollution control devices are added to
smelters, the sulfur escapes into the atmosphere, where
it forms sulfuric acid. (The environmental implications