Environment Pollution is defined as ‘an addition or excessive addition of certain materials to the physical environment (water, air and lands), making it less fit or unfit for life’.
Pollutants are the materials or factors, which cause adverse effect on the natural quality of any component of the environment.
Classifications
- According to the form in which they persist after release into the environment.
- Primary pollutants: These persist in the form in which they are added to the environment e.g. DDT, plastic.
- Secondary Pollutants: These are formed by interaction among the primary pollutants. For example, peroxyacetyl nitrate (PAN) is formed by the interaction of nitrogen oxides and hydrocarbons.
- According to their existence in nature.
- Quantitative Pollutants: These occur in nature and become pollutant when their concentration reaches beyond a threshold level. E.g. carbon dioxide, nitrogen oxide.
- Qualitative Pollutants: These do not occur in nature and are man-made. E.g. fungicides, herbicides, DDT etc.
- According to their nature of disposal.
- Biodegradable Pollutants: Waste products, which are degraded by microbial action. E.g. sewage.
- Non-biodegradable Pollutants: Pollutants, which are not decomposed by microbial action. E.g. plastics, glass, DDT, salts of heavy metals, radioactive substances etc
- According to origin
- Natural
- Anthropogenic