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Water pollu on
Water becomes polluted when harmful substances flow into it. The water of the river
is made dirty by various human ac vi es—bathing, washing clothes and dumping the
waste. This eventually reduces the amount of water available for drinking.

Some of the main causes of water pollu on are -
 Domes c sewage and garbage
 Harmful pes cides used by farmers
 Chemicals from soaps and detergents
 Used in washing
 Animal waste

Polluted water has a number of harmful effects. These harmful effects are not only
limited to humans but also affect aqua c animals and plants. Polluted water contains
germs that cause various diseases in human beings. Pollutants reduce the oxygen in
water which is essen al for aqua c life. When pollutants such as oil clogs up the pores
and fur of aqua c animals, they cannot breathe, keep warm or even float.

Water cycle
The main source of water on Earth is rain. The water vapour which evaporates from
various water bodies rises into
the atmosphere, where it meets
cool air and condenses as
droplets of moisture.

These drops in the air gather
together and form clouds seen by
us. A er some me the water
droplets in the clouds become so
heavy that they fall back on the
Earth again as rain. This process is
called precipita on.

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