Environmental Pollution 

Environmental pollution means ‘the release of harmful substances and energy from waste products of human activities.

What are pollutants?  

Pollutants are defined as any form of energy or matter that causes dilatation and pollution in the existing natural balance of ecosystems.  The three media through which the pollutants are transferred are land, air and water.  

Types of pollution:

They are classified on the basis of medium through which pollutants are transported and diffused. They are:

(i) air pollution, (ii) water pollution, (iii) land pollution and (iv) noise pollution.

Water Pollution

1.  What is water pollution?

Degradation of the quality of water due to indiscriminate use of water is called water pollution. The water becomes unfit for the use because of high concentrations of suspended particles, organic and inorganic substances. In such a situation, the selfpurifying capacity of water is unable to purify the water. 

2.  What are the Causes/sources of water pollution?

i. Natural sources: Due to erosion, landslides, decay and decomposition of plants and animals, etc.

ii. Human sources: industrial, agricultural and cultural activities.

a. Industrial activities: is the most significant contributor.

i. Industries produce several undesirable products including industrial wastes, polluted waste water, poisonous gases, chemical residuals, numerous heavy metals, dust, smoke, etc. 

ii. Most of the industrial wastes are disposed off in running water orlakes. Consequently, poisonous elements reach the reservoirs, rivers and other water bodies, which destroy the bio-system of these waters.

iii. Major water polluting industries are leather, pulp and paper, textiles and chemicals.

b. Agricultural activities:

i. Various types of chemicals used in modern agriculture such as inorganic fertilisers, pesticides and herbicides causes water

pollution.

ii. These chemicals are washed down to rivers, lakes, tanks and under ground water and causes water pollution.

iii. Fertiliser induces an increase in the nitrate content of surface waters.

c. Cultural activities:

i. Such as pilgrimage, religious fairs, tourism, etc. also cause water pollution. In India, almost all surface water sources are contaminated and unfit for human consumption.

d. Urban activities:

i. Such as Sewage disposal, urban run-off causes water pollution.

3.  What are the Effects of water pollution?

a. Water pollution is a source of various water borne diseases.

b. The diseases commonly caused due to contaminated water are diarrhoea, intestinal worms, hepatitis, etc.