Class 8 Science

Water Pollution

Water is necessary for living beings. All of us need water in order to survive.

Many of you must be drinking water that comes from water purifier. Water purifiers have become a necessity because of high level of pollutants in water.

In this lesson, you will read about causes and effects of water pollution and about prevention of water pollution.

Addition of unwanted substances in water which makes water harmful for living beings and non-living things is called water pollution.

Water Pollutants: Substances which contaminate water are called water pollutants.

Pollution of Ganga

Ganga is an important river for a large section of people of India because millions of people depend on this river for their livelihood. Moreover, Ganga is considered to be a sacred river by majority of people in India.

As per a recent study by World Wide Fund for Nature (WWF), Ganga is one of the most polluted rivers.

Some of the causes of pollution of this river are as follows:

Effects of Water Pollution:

Eutrophication: Enrichment of water body with nutrients is called eutrophication. It happens because of excess amount of chemicals in water. This results in proliferation of algae and other plants in water bodies with stagnant water. Once these plants die, they are consumed by decomposers. The process of decomposition utilizes most of the oxygen from water. This results in deficiency of oxygen for aquatic animals.

Potable Water

Water which is fit for drinking is called potable water. A quarter of the world’s population does not have access to safe drinking water.

Methods of Water Purification:

How to Prevent Water Pollution:

Conservation of Water