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Minerals: A Nonrenewable Resource
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ENVIRONMENTAL IMPLICATIONS
ENVIRONMENTAL
IMPLICATIONS
There is no question that
the extraction, processing, and disposal of minerals harm the
environment. Mining disturbs and damages the land, and processing and
disposal of minerals pollute the air, soil, and water. As noted in the
discussion of coal in Chapter 10, pollution can be controlled and
damaged lands can be partially restored, but these remedies cost money.
In most cases, the environment mental cost of minerals is not
made a part of their actual price to consumers. Most developed countries
have regulatory organisms in place to minimize environmental linage from
mineral consumption, and many developing nations are in the process of
putting them in place. These regulatory programs include polices to
prevent or reduce pollution, restore mining
iks, and exclude certain
recreational and wilderness from mineral development.
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Environmental Impacts of Refining
Minerals
Approximately 80 percent or more of
mined ore consists of impurities that become wastes after
processing. These wastes, also called tailings, are usually
left in giant piles on the ground or in ponds near the processing
plants.
Toxic substances and dust from
tailings left exposed in this way can contaminate the air, soil, and
water. Unless expensive pollution control equipment has been added
to smelting plants, they emit large amounts of air pollutants during
mineral processing. (See Focus On: Copper Basin, Tennessee, for a
specific example of environmental degradation caused by smelting.)
Lead, arsenic, and cadmium are some of the toxic pollutants that may
be discharged into the atmosphere. Cadmium, for example, is found in
zinc ores, and emissions from zinc smelters are a major source of
environmental cadmium contamination. In humans, cadmium is linked to
high blood pressure; diseases of the liver, kidneys, and heart; and
certain types of cancer. In addition to airborne pollutants,
smelters emit hazardous liquid and solid wastes that can cause soil
and water pollution. |
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Restoration of Mining Lands
When a mine is no longer profitable to
operate, the land can be reclaimed, or restored to a semi natural
condition. Approximately two-thirds of the Copper Basin in Tennessee has
been partially reclaimed, for example. The goals of reclamation include
preventing further degradation and erosion of the land, eliminating or
neutralizing local sources of toxic wastes, and making the land
productive for purposes other than mining. Restoration can also make
such areas visually attractive,
A great deal of research is available on
techniques of restoring Kinds that have been degraded by mining, called
derelict lands. Restoration involves filling in and grading the land to
its natural contours, then planting vegetation to hold the soil in
place. The establishment of plant cover is not as simple as throwing a
few seeds on the ground, Often the topsoil is completely gone or
contains toxic levels of metals, so special types of plants that can
tolerate such a challenging environment must be used. According to
experts, the main limitation on the restoration of derelict lands is not
lack at knowledge but lack of funding.
Reclamation of areas that were surface
mined for coal is required by the Surface Mining Control and Reclamation
Act of 1977- This law orders coal companies to restore areas that have
been surface mined, beginning in 1977. Surface-mined land that was
damaged prior to 1977 is gradually being restored as well, using money
from a tax on currently
No law is in place to require restoration
of derelict lands produced by mines other than coal mines, however. A
mining law that was passed in 1872 and that currently makes no provision
for reclamation may be revised by Congress in the next
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