Definition of Pollution
Pollution can be defined as an undesirable change in the chemical, physical or biological characteristics of air, soil, water and other physical domains that may harmfully affect the life or create a potential health hazard of any living organism. It can occur naturally, for example through volcanic eruptions, or as the result of human activities, such as the spilling of oil or disposal of industrial wastes.
Any substance that causes pollution is called pollutant. A pollutant may include any chemical or geochemical substance (dust, sediment, etc.), biotic component or its product, or physical factor (heat) that is released either naturally or intentionally by the man into the environment.
Classifications of Pollutant
Pollutants can be broadly classified into two groups:
- Biodegradable pollutants
- Non-biodegradable pollutants
1. Biodegradable pollutants
Biodegradable pollutants are broken down by the activities of micro-chemical cycles. They act as a pollutant when they are not degraded at the right time. e.g., domestic waste products, agricultural residue, etc.
2. Non-biodegradable pollutants
Non-biodegradable pollutants do not break down into simple and harmless products. They are pollutants irrespective of their quantity. They enter in the food chain and consequently cause biomagnification. e.g. insecticide, pesticides, Hg, Pb, arsenic, plastic, radioactive wastes, etc. These pollutants could be in the form of solid, liquid or gas.
Classifications of Pollution
There are several types of pollution, and they may come from different sources and have different consequences. These are classified as
- On the basis of part of environment where it occurs most
- On the basis of its origin
- According to the physical nature of pollutant
1. On the basis of part of an environment where it occurs most
a). Air Pollution
b). Water Pollution
c). Soil Pollution
2. On the basis of its origin
a). Natural (e.g. volcanic eruptions)
b). Anthropogenic (man-made pollution such as industrial pollution, agricultural pollution, etc.)
3. According to the physical nature of pollutant
a). Gaseous Pollution
b). Bio Pollution
c). Dust Pollution
d). Noise Pollution
e). Radioactive Pollution, and much more.