Dec 072012
 

Environmental pollution can simply be defined as the addition of any unwanted or undesirable changes in the physical and biological characters of the environment. As a result of pollution, human life, useful organisms, living conditions, environment, ecosystem, raw materials etc. are being greatly affected due to which they are being badly damaged. This can even lead to their permanent destruction. Various human activities have resulted in the phenomenon of environmental pollution.

Pollutants


Pollutants are the chemical substances or any other things which change the natural balance of the environment and thus result in pollution. These pollutants get accumulated or collected in the environment in huge quantities due to different human activities. Pollutants stimulate, initiate or terminate the vital reactions of an organism. These activities may also bring about changes in the organisms and thus entire ecosystem may also be modified.

Types of Pollutants
According to their degradability, pollutants can be classified into two different types which are listed and described below:

  1. Degradable (Bio-degradable) pollutants: Domestic sewage, cloth, paper, wood etc. lie under degradable pollutants because they can easily be decomposed by the microorganisms present in the environment. However, the decomposition becomes difficult when such materials get accumulated in the environment in a large quantity.
  2. Non-degradable pollutants: Non-degradable pollutants are those pollutants which are neither decomposed by microorganisms nor do they break down by physical and chemical agents which are present in the environment. There is no treatment in nature for their recycling. Therefore, they continue to be accumulated in the nature and occupy large useful space on the earth. For example, aluminium cans, plasticwares, compounds of mercury, Dichloro Diphenyl Trichloroethane (DDT), glass etc. Non-degradable pollutants not only accumulate in the environment but pass from one organism in the food chain to another until it reaches the last trophic level. During this transport, the amount of pollutants continues to increase with each level. This is called biomagnification. The pollutants from more toxic substances come in combination with other substances when they pass through different trophic levels. Such substances are harmful and even kill the biotic components of the ecosystem.