Page 263 - New Medley 5 Semester 2

Natural environment Man-made environment
therefore, they change the natural environment. Human activities make

the environment dirty. This is called pollution.

Generally, there are four types of pollution. These are: air pollution,

land pollution, water pollution and noise pollution.

Air Pollution

Smoke is the main cause of air pollution.
It is created by the burning of fossil fuels
like coal, diesel and petroleum. When these

are burnt, they produce poisonous gases

like carbon dioxide, carbon monoxide, etc.
These gases makes the air polluted and
cause breathing problems. Other sources

of air pollution are smoke from factories,

volcanoes, forest fires. Even the bursting of
crackers on festivals and marriages causes Air pollution
air pollution. You should not burst firecrackers. In urban areas, smoke

from vehicles pollutes air. Massive air pollution in found in metro cities

like Delhi, Kolkata and Mumbai.

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