Chapter 13Chapter 13Chapter 13Chapter 13Chapter 13
Pollution and its ContrPollution and its ContrPollution and its ContrPollution and its ContrPollution and its Contrololololol
13.1 Introduction
The atmosphere consists of a mixture of gases that completely surround the earth. It extends to an
altitude of 800 to 1000 kms above the earth’s surface, but is deeper at the equator and shallow at the
poles. About 99.9% of the mass occurs below 50 km and 0.0997% between 50 and 100 km altitude.
Major polluting gases/particles are confined to the lowermost layer of atmosphere known as Tropo-
sphere. That extends between 8 and 16 kms above the earth surface.
The main sources of atmospheric pollution may be summarized as follows:
(a) The combustion of fuels to produce energy for heating and power generation both in the
domestic sector as well as in the industrial sector.
(b) The exhaust emissions from the transport vehicles that use petrol, or diesel oil etc.
(c) Waste gases, dust and heat from many industrial sites including chemical manufacturers,
electrical power generating stations etc.13.2 ENVIRONMENT POLLLUTION DUE TO ENERGY USE
A considerable amount of air pollution results from burning of fossil fuels. Fuels are primarily
derived from fossilized plant material and consist mainly of carbon and/or its compounds. The house-
hold sector is the largest consumer of energy in India, accounting for 40-50% of the total energy con-
sumption. As per a report of Planning Commission the share of the household sector in the final use of
energy declined although retaining its dominant share at 58.9% in 1987. The most abundantly used
fossil fuel for cooking is the wood, which is almost 61% of the total fuel demand for cooking. Burning
of traditional fuels introduces large quantities of CO 2 when the combustion is complete, but if there is
incomplete combustion and oxidation then Carbon monoxide (CO) is produced, in addition to hydrocar-
bons. Incomplete combustion of coal produces smoke consisting of particles of soot or carbon, tarry
droplets of unburnt hydrocarbons and CO. Fossil fuels also contain 0.5-4.0% of sulphur which is oxi-
dized to SO 2 during combustion.
The environmental effects of various fuels namely coal; oil, nuclear, etc. are of growing concern
owing to increasing consumption levels. The combustion of these fuels in industries and vehicles has
been a major source of pollution. Coal production through opencast mining; its supply to and consump-
tion in power stations; and industrial boilers leads to particulate and gaseous pollution, which can cause
pneumoconiosis, bronchitis, and respiratory diseases. Another major impact of coal mining is land
degradation, especially of forest areas.