POLLUTION MEANS - dirty ness . Air, sand, water etc,other useful things are now polluted. There are 4 most important types of pollutions :- Air pollution, water pollution, sound pollution and automobile pollution. Because of these 4  pollutions today the people are suffering from many diseases. In air pollution , the dirty drainage particles will mix  and pollute the air . Dirty tap water will flow through small streams  and they will combine with river water which joins into ocean.Today the sound pollution is also a severe problem.Automobile pollution means - the pollution which is caused by the automobile factories or vehicles. automobile industries are releasing toxic gases polluting the air . small vehicles like cars, bikes release toxic smoke and large vehicles like trucks release more smoke.