POLLUTION is defined as an unwanted change in the physical, chemical and biological characteristics of air, land and water.
Pollution are of mainly three types:
SOIL POLLUTION: is caused by urban waste, industrial waste, biological agents, radioactive pollution.
AIR POLLUTION: is caused by smoke from vehicles, combustion of coal and petroleum, thermal power plants.
WATER POLLUTION: is caused by waste effluents, industrial effluents, surface run-off, thermal pollution, radioactive wastes, marine pollution.
There may be Noise pollution also.
We can reduce pollution by not letting wastes enter river bodies,air,soil and water.
All kind of pollution have an adverse effect on human beings, plants and animals.