Environmental pollution

While walking on path we can see different vehicles running and throwing harmful gases. We have to close our nose, difficult to breath, eyes pain. Pollution is caused by undesirable and harmful elements in our environment. Such undesirable elements may be poisonous substance, disease germs, dust and dirt particles, harmful bacteria, etc. pollution is the unwanted substance or pollutants which adversely alters the natural or man made environment. Any substance which causes pollution may be solid, liquid or gas. Pollution is the thus direct or indirect change in any components of the biosphere.