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Pollution
Pollution is the addition to the
ecosystem of something which has a detrimental effect on it.
The major forms of pollution are
listed below along with the particular pollutants relevant to each of them:
-
Air
pollution, the release of chemicals and particulates into the atmosphere.
Common examples include carbon monoxide, sulfur dioxide, chlorofluorocarbons
(CFCs), and nitrogen oxides produced by industry and motor vehicles.
Photochemical ozone and smog are created as nitrogen oxides and hydrocarbons
react to sunlight.
-
Water
pollution via runoff, leaching to groundwater, liquid spills, wastewater
discharges, eutrophication and littering.
- Soil contamination occurs when
chemicals are released by spill or underground storage tank leakage. Among
the most significant soil contaminants are hydrocarbons, heavy metals, MTBE,
herbicides, pesticides and chlorinated hydrocarbons.
- Radioactive contamination,
added in the wake of 20th century discoveries in atomic physics.
- Noise pollution, which
encompasses roadway noise, aircraft noise, industrial noise as well as
high-intensity sonar.
- Light pollution, includes
light trespass, over-illumination and astronomical interference.
- Visual pollution, which can
refer to the presence of overhead power lines, motorway billboards, scarred
landforms (as from strip mining), open storage of trash or municipal solid
waste.
- Thermal pollution, is a
temperature change in natural water bodies caused by human influence, such
as use of water as coolant in a power plant.
Source: Adapted from National
Science and Technology Council Committee on Environment and Natural Resources,
Air Quality Research Subcommittee-National Park Service
The
Earth's Worst
Polluted Cities 2007
Credit:
Blacksmith Institute
Sumqayit,
Azerbaijan—This area gained the dubious distinction of landing atop
the Blacksmith Institute’s list of the world’s most polluted sites. Yet
another heir to the toxic legacy of Soviet industry, this city of 275,000 bears
heavy metal, oil and chemical contamination from its days as a center of
chemical production. As a result, locals suffer cancer rates 22 to 51 percent
higher than their countrymen, and their children suffer from a host of genetic
defects, ranging from mental retardation to bone disease.
“As much as 120,000 tons of
harmful emissions were released on an annual basis, including mercury,” says
Richard Fuller, founder of Blacksmith, an environmental health organization
based in New York City. “There are huge untreated dumps of industrial
sludge.”
Chernobyl, Ukraine—The
fallout from the world’s worst nuclear power accident continues to accumulate,
affecting as many as 5.5 million people and leading to a sharp rise in thyroid
cancer. The incident has also blighted the economic prospects of surrounding
areas and nations.
DzerzHinsk, Russia—The
300,000 residents of this center of cold war chemical manufacturing have one of
the lowest life expectancies in the world thanks to waste injected directly into
the ground. “Average life expectancy is roughly 45 years,” says Stephan
Robinson, a director at Green Cross Switzerland, an environmental group that
collaborated on the report. “Fifteen to 20 years less than the Russian average
and about half a Westerner’s.”
Kabwe, Zambia—The
second largest city in this southern African country was home to one of the
world’s largest lead smelters until 1994. As a result of that industry, the
entire city is contaminated with the heavy metal, which can cause brain and
nerve damage in children and fetuses.
La Oroya, Peru—Although
this is one of the smallest communities on the list (population 35,000), it is
also one of the most heavily polluted because of extensive lead, copper and zinc
mining by the U.S.–based Doe Run mining company.
Linfen, China—A
city in the heart of China’s coal region in Shanxi Province, Linfen is home to
three million inhabitants, who choke on dust and air pollution and drink arsenic
that leaches from the fossil fuel.
Norilsk, Russia—This
city above the Arctic Circle contains the world’s largest metal-smelting
complex and some of the planet’s worst smog. “There is no living piece of
grass or shrub within 30 kilometers of the city,” Fuller says.
“Contamination [with heavy metals] has been found as much as 60 kilometers
away.”
Sukinda, India—Home
to one of the world’s biggest chromite mines—chromite makes steel stainless,
among other uses—and 2.6 million people. The waters of this valley contain
carcinogenic hexavalent chromium compounds courtesy of 30 million tons of waste
rock lining the Brahmani River.
Tianying, China—The
center of Chinese lead production, this town of 160,000 has lead concentrations
in its air and soil that are 8.5 to 10 times those of the national health
standards. The concentrations of lead dusting the local crops are 24 times too
high.
Vapi, India—This
town at the end of India’s industrial belt in the state of Gujarat houses the
dumped remnant waste of more than 1,000 manufacturers, including petrochemicals,
pesticides, pharmaceuticals and other chemicals. “The companies treat
wastewater and get most of the muck out,” says David Hanrahan, Blacksmith’s
London-based director of global operations. “But there’s nowhere to put the
muck, so it ends up getting dumped.”
Credit:
EPA, Environment Canada, UNEP, NASA |
