What is air and water pollution?

Air pollution is the introduction of chemicals, particulates, or biological matter into the air that cause harm or discomfort to humans or other living things. The sources of air pollutants are both natural and artificial. Air pollution has many different forms, including smog, photochemical smog, ozone depletion, acid rain, radioactive contamination due to nuclear power plants.

Water pollution is the contamination of water bodies with harmful substances that adversely change either its chemical properties or its ability to support life. Rivers are often polluted by runoff from lawns and fields where pesticides have been applied.