Big cities suffer from smog
from large factories. Cars with their engines have become the main source of
pollution in industrial countries. The forests Africa, South America and Asia
are cut down for the needs of industries in Europe and the USA. As a
result some species of animals, birds, fish and plants have disappeared and
keep disappearing. Rivers and lakes dry up. One of the most known examples is
the Aral Sea, which has become much smaller
due to men’s activity.
The pollution of the air
and of the world’s oceans and the thinning of the ozone layer nowadays are the
main problems arising from man’s careless attitude to ecology.
In Russia and the
former Soviet republics there are some areas where the environment is in a poor
state. The Aral Sea, Lake Baikal, the Kuzbass, Semipalatinsk
and Chernobyl
are such problematic regions.
For decades nuclear weapons
were tested near Semipalatinsk,
and the ground is contaminated with radiation there.
More than 20 years ago a
pulp-and-paper factory was built on the shore of Lake
Baikal. As a result of the pollution, more than 50 % of the world’s purest
water has been ruined. The whole ecological system of the lake has change
greatly.