Industrial pollution of the environment is of four types: air, water, land and noise. Air pollution is caused by smoke released by chemical and paper factories, brick kilns, refineries and smelting plants, and burning of fossil fuels in factories ignoring pollution norms. Water pollution is caused by the discharging of organic and inorganic industrial wastes and effluents into rivers. This form of pollution is caused by paper, pulp, chemical, textile, dyeing, petroleum refineries, tanneries and electroplating industries. The major solid wastes released into rivers in India are fly ash, phospo - gypsum, and iron and steel slags. Thermal pollution of water is another form of water pollution, caused by the emission of hot water from factories and thermal plants into rivers and ponds. Dumping of solid wastes renders the soil infertile and useless too. Lastly, noise pollution results from industrial and construction activities, machinery, generators, and saws, pneumatic and electric drills.