Various types of chemicals used in modern agriculture such as inorganic fertilisers, pesticides and herbicides are also pollution generating components. These chemicals are washed down to rivers, lakes and tanks.
These chemicals also infiltrate the soil to reach the ground water.
Fertiliser induces an increase in the nitrate content of surface waters.
Cultural activities 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.
Water pollution is a source of various water- borne diseases.
The diseases commonly caused due to contaminated water are diarrhoea, intestinal worms, hepatitis, etc.
The World Health Organization shows that about one-fourth of the communicable diseases in India are water-borne.