Question

What are the major causes of water pollution? Explain.

Answer 1

Several human activities leads to presence of several undesirable substances in water which causes water pollution. Various sources of different water pollutants are shown below.

Pollutant	Source
Micro-organisms	Domestic sewage
Organic wastes	Domestic sewage, decaying animals and plants, animal excreta and waste, discharge from food processing industries.
Plant nutrients	Chemical fertilizers
Toxic heavy metals	Chemical factories and industries
Sediments	Strip mining and soil erosion
Pesticides	Chemical used for killing fungi, weed, insects
Radioactive substances	Mining of uranium-containing minerals
Heat	Water used for cooling in industries.