Environmental Issues – Notes

Air Pollution And Its Control
An undesirable change in the physical, chemical or biological characteristics of air, water, land or soil that may have detrimental effect on living organisms is called pollution.
Substances that bring about such undesirable changes are called pollutants.
Common air pollutants are automobiles exhausts, chemicals and toxic gases from industries and natural particulate matter such as dist, pollen and ash.
The Usage of CNG, unleaded and low-sulphur petrol and diesel, catalytic converters and the implementation of stringent pollution level norms can reduce air pollution.
Noise is also considered as an air pollutant.

Domestic Sewage And Industrial Effluents
Pollutants entering water bodies are broadly classified as domestic sewage and industrial effluents.
Domestic sewage is the waste water that drains from houses in a town or city.
Domestic sewage contains about 99.9 per cent water and 0.1 per cent impurities such as suspended soils, colloidal and dissolved materials.
Algal blooms, pathogens, thermal waste water and excessive nutrient, pollute water.