Any undesirable physical, chemical or biological change caused to land, water, air and other natural resources is termed as pollution. Theses pollutions bring about several ecological problems and make life difficult for human beings. Though there are various causes for pollution, man himself is the major cause.
Air pollution is due to industrial and automobile exhausts. These contain carbon-di-oxide, Sulphur-di-oxide and oxides of Nitrogen. The ecological problems caused by these gases is that they render the air unfit for breathing. It leads to breathing problems and even causes cancer. Plants are unable to synthesize food. The protective ozone layer is affected thereby exposing human beings and animals to radio–active rays.
Land pollution is due to accumulation of rubbish, polythene and plastic containers, glass, porcelain etc. The use of excess of chemical fertilizers, insecticides, pesticides, DDT etc. pollute both land and water. They lead to many deadly contagious diseases. Oil sleeks in the ocean affect marine life. They affect the ecological balance of marine fauna and flora. Gas leakage, of nuclear reactors pose dangers to our ecology.