One of the most serious
problems facing the world today is pollution, that is the contamination of air,
land and water by all kinds of chemicals such as poisonous gases, waste
materials and insecticides. Pollution has upset the balance of nature, destroyed
many forms of wildlife and caused a variety of illnesses. It occurs in every
country on Earth but is most prominent in industrial countries.
Breathing polluted air
is very common to most people, especially those living in cities. In heavily
industrialized areas, fumes from car exhausts and thick smoke from factory
chimneys can be seen darkening the atmosphere. This would reduce visibility and
make the air unpleasant to breathe. Large scale burning of fossil fuels, such
as coal, gas and oil, in homes and industries also produces a wide range of
pollutants. This includes sulfur dioxide which damages plants, destroys
buildings and affects health. Other known pollutants are carbon monoxide,
nitrogen dioxide and dirt particles. The fumes produced by car exhausts and
factories would normally disperse in the air, but sometimes they are trapped by
air layers of different temperatures. The result is a fog-like haze known as
smog. Britain and some other countries introduced smokeless zones and smokeless
fuels some years ago and smog no longer occurs, but it still remains a very
real problem in Japan and the United States.
The motor car is a
major source of pollution. In densely populated cities where there are millions
of cars on the roads, the level of carbon monoxide in the air is dangerously
high. On windless days, the fumes settle near ground level. Fumes from car
exhausts also pour out lead and nitrogen oxide.
The testing of nuclear
weapons, and the use of atomic energy for experimental purposes in peaceful
times have exposed some people to levels of radiation that are too high for
safety. Crop-spraying by aircraft also adds chemical poisons to the air.
Domestic rubbish is
another very serious pollution problem. The average American citizen throws
away nearly one ton of rubbish every year. Much of this consists of plastic,
metal and glass packaging that cannot be broken down naturally. Instead it lies
with old refrigerators, broken washing machines and abandoned cars in huge
piles for years without decaying. Each year the problem of rubbish disposal
becomes more serious.
Sewage causes another
form of pollution. Most of it flows straight into rivers, where it is broken
down by tiny bacteria. The bacteria need oxygen for this process, but because
of the vast quantities of sewage, the bacteria uses up all available
oxygen in the water, causing the death of countless fish and other river life.
Rivers provide a very convenient outlet for industrial waste, as well as being
a source of water for cooling in nuclear and other power plants.
Like rivers, oceans
have been used as dumping grounds for waste of all kinds. One of the recent
sources of sea pollution is oil and millions of tons of it spill into the sea
each year. Oil not only pollutes beaches, it also kills fish and seabirds.
Summary: Pollution, covering the
contamination of air, land and water, is one of the most serious problems
facing the world today. Pollution has destroyed ecological balance and wildlife
and caused various illnesses. Air pollution caused by fumes from factories, car
exhausts and crop-spraying has reduced visibility and caused breathing
problems. Nuclear testing and use of atomic energy exposes people to high
radiation levels. Burning of fossil fuels damages plants, buildings and human
health. Undecayed domestic rubbish also presents problems. The bacteria
breaking down sewage, oil and industrial waste uses up valuable oxygen needed
by fish and plants. hence killing flora and fauna.
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