Page 169 - Health, Population and Environment Education 9

B. Water Pollution
Water pollution is undesirable change in the physical,
chemical and biological characteristics of water due
to addition of unwanted substances in water that
adversely affects the survival of living beings in water.

When there is addition of sewage, drainage and
wastes from different sources in water, there is
increase of water pollution. As a result, there is change
in physical and chemical condition of water. Even Fig: 17
the plants, animals, and insects that live in water are
affected. There is serious impact on water ecosystem Water Pollution
as well as spreading of various types of water borne diseases to people.

Causes of water pollution
There are various causes of water pollution. Some of them are as follows:
a. Random discharge of wastes from settlement areas and markets in water causes water
pollution.
b. Joining of sewage and drainage from settlement areas into water resources increases
water pollution.
c. Joining of industrial discharge directly into water resource leads towards water
pollution.
d. Various activities like washing clothes, cleaning utensils, bathing, etc. in water
resources causes water pollution.
e. Random and excessive use of chemical fertilizers on land causes water pollution.
f. Occurrence of natural calamities like flood, landslide, soil erosion leads towards
water pollution.
g. Deposition of dust, dead bodies, etc. in the water resources increases water pollution.
h. If the dumping site is near to the water resources, it increases water pollution.

Effects of water pollution
Water pollution affects land and water ecosystems. The living beings including human
beings are adversely affected by water pollution. Some of the effects of water pollution
are as follows:
a. Water pollution causes spreading of different diseases like diarrohea, dysentery,
cholera, typhoid, jaundice, hepatitis, etc.
b. Industrial discharge containing harmful substances destroy water ecosystem.
c. It contaminates drinking water.
d. If people bathe in polluted water, they will suffer from various skin diseases and
allergies.
e. It spreads bad smelling in the surroundings.
f. It adversely affects land animals and birds, etc.

GREEN Environment Population and Health Education Book-9 169