Pollution is defined as any undesirable change in the physical, chemical and biological properties of air, water and land that may cause harm to man and other species. In other words pollution is the accumulation of contaminants in the natural environment that is responsible for negative impact created thereafter. Pollution is mainly the byproduct of human activities such as industrial residues and sometimes natural activities such as volcanic ashes, smoke from bush fires and so on.

Population is the number of peoples who are living in any limit area at that time the living that total number of people's called population.