1. Air Pollution : Causes, Effects and Control
Dr. A. K. Upadhyay
Scientist
Department of Soil Science & Agricultural Chemistry
College of Agriculture, JNKVV, Jabalpur (M.P.)
2. Air Pollution
❖ Air pollution and weather are linked in two ways. One
concerns the influence that weather conditions have on
the dilution and dispersal of air pollutants. The second
connection is the reverse and deals with the effect that
air pollution has on weather and climate..
❖ Air is never perfectly clean. Volcanic ash, salt particles,
pollen and spores, smoke, and windblown dust are all
examples of “natural air pollution.” One of the most
tragic air-pollution episodes occurred in London in
December 1952, when more than 4000 people died.
What is Air Pollution?
It is the contamination of air by impurities that
adversely affect the living organisms and the non-living
organisms.
3. The two main sources of air pollution are:
➢ Natural sources
❖ Volcanoes: A large amount of sulphur, chlorine and
ash particulates are released from volcanoes.
❖ Vegetation decay: Forest fires released carbon
monoxide, wind and storms carry particulate matter.
➢Man-made sources
❖ The incomplete combustion from vehicles and
❖ Factories released carbon monoxide, sulphur dioxide
and nitrogen monoxide gases etc.
Sources / Pollutants of Air Pollution
4. Primary pollutants, which are emitted directly
from identifiable sources.
Secondary pollutants, which are produced in the
atmosphere when certain chemical reactions take
place among primary pollutants.
Photochemical smog, a noxious mixture of
gases and particles, is produced when strong
sunlight triggers photochemical reactions in the
atmosphere.
Ozone is the major component of photochemical
smog.
Air
Pollutants
Airborne particles and gases that occur
in concentrations that endanger the
health and well-being of organisms or
disrupt the orderly functioning of the
environment.
Pollutants
2 categories
Smog
Sources / Pollutants of Air Pollution
6. Major Air
Pollutants
Carbon Monoxide
Produced by the incomplete
burning of carbon-
containing fuels, such as
petrol, coal and wood.
Particulates
Produced by refuse
incineration, factories, diesel
vehicles, construction sites,
and coal/charcoal burners.
Particulates are solid or
liquid particles which are so
small that they remain
suspended in the air for a
long period of time.
Ozone
Produced by the reaction of
oxygen gas with free atoms of
oxygen which are formed from
the reactions between nitrogen
oxides and hydrocarbons in
sunlight.
Produced by petrol or
diesel burning engines and
coal/oil furnaces.
Nitrogen oxides
Sulphur dioxide
Produced by burning of
fossil fuels (e.g. fuel oil
and coil). A large
proportion is produced
by power stations and
metal smelters which
burn sulphur-containing
coal, and also by the
manufacturing industries
which burn fuel oil.
Hydrocarbons
Formed from the
evaporation of materials
such as petrol, diesel
and solvents when
exposed to air.
Sources / Pollutants of Air Pollution
7. Effects of Air Pollution
Interferes with photosynthesis,
carbohydrate production
Cancer, asthma, birth defects,
eye & respiratory system
irritation and genetic mutation.
Contribute to sick building
syndrome indoors
Acid rain: soil, buildings &
materials, forest & aquatic life.
Prolonged exposure to high CO
concentrations, unconsciousness,
convulsions and death would
occur; severe effects on the baby
of a pregnant woman.
It is important to remember that air pollutants are transboundary , i.e. they know
no borders and travel easily from their sources towards other locations spreading
pollution throughout the world.
8. Effects of Air Pollution
Health effects
❖ Air pollution is most harmful to the very old and the very young.
❖ Many elderly people may already suffer from some form of heart
or lung disease.
❖ The sensitive lungs of new born infants are also susceptible to
harm from dirty air.
❖ There is much evidence linking lung cancer to air pollution,
although the actual cause-and–effect relationship is still
unknown.
❖ Typical effects of sulfur dioxide, oxides of nitrogen and ozone
include eye and throat irritation, coughing and chest pain.
❖ Nitrogen dioxide is known to cause pulmonary edema, an
accumulation of excessive fluids in the lungs.
❖ Ozone, a highly irritating gas, produces pulmonary congestion;
symptoms of ozone exposure may include dry throat, headache,
disorientation, and altered breathing patterns.
9. Effects of Air Pollution
Effect on Materials
❖ Air pollutants breakdown the exterior paint in cars and houses.
❖ Air pollutants have discolored irreplaceable monuments, historic
buildings, marble statues and other heritage and natural beauty
sites.
Effect on plants
❖ Some gaseous pollutants enter leaf pores and damage the crop
plants.
❖ Chronic exposure of leaves to air pollutants damages waxy coating,
leads to damage from diseases, pests, drought and frost.
❖ Chronic exposure interferes with photosynsthesis and plant
growth, reduces nutrient uptake and causes leaves to turn yellow,
brown or drop off.
❖ At higher concentrations of SO2 most of the flower buds become
stiff and hard and fall off.
❖ Prolonged exposure to higher levels of air pollutants from Iron
smelters, coal burning power plants and industries, vehicles can
damage trees and plants.
10. Effects of Air Pollution
❖ Incomplete burning of petrol and diesel results in
released of carbon monoxide a highly poisonous gas
which reduces to oxygen carrying capacity of blood.
❖ Sulphur dioxide released from power plant and
petroleum refineries results in respiratory problem like
permanent lung damage.
❖ Suspended particles released by automobiles and power
plant reduce visibility when inhaled they caused
diseases.
❖ Smog results in breathing difficulties like asthama, cough
and sneezing.
❖ CFC deplete ozone layer which protect us from harmful
UV rays of the sun.
❖ Increasing of carbon dioxide in the atmosphere which
result in global warming.
12. ➢Better quality fuels like unleaded petrol can helpful to
reduce harmful emission from automobiles.
➢Using cleaner fuel alternatives like compressed natural
gas (CNG) and liquefied petroleum gas (LPG) helps to
reduce emission of pollutant.
➢Using vehicle emission control devices like catalytic
converter can help to minimized automobile pollution.
➢A catalytic converter changes toxic pollutant present in
exhaust gas to less toxic pollutant.
➢Using public transport can help to control number of
vehicles on road.
➢Vehicles should be maintain according to the emission
norms.
➢In factories, better fuel burning equipments should be
used.
Control of Air Pollution
13. The following items are commonly used as pollution
control devices by industry or transportation devices.
They can either destroy contaminants or remove them
from an exhaust stream before it is emitted into the
atmosphere .
• Mechanical collectors (dust cyclone)
• NOx control
• Electrostatic precipitators
• VOC abatement
• Baghouses
• Acid gas / SO2 control
• Scrubbers
• Mercury control
Control of Air Pollution
14. ➢Better quality fuels like unleaded petrol can helpful to
reduce harmful emission from automobiles.
➢Using cleaner fuel alternatives like compressed natural
gas (CNG) and liquefied petroleum gas (LPG) helps to
reduce emission of pollutant.
➢Using vehicle emission control devices like catalytic
converter can help to minimized automobile pollution.
➢A catalytic converter changes toxic pollutant present in
exhaust gas to less toxic pollutant.
➢Using public transport can help to control number of
vehicles on road.
➢Vehicles should be maintain according to the emission
norms.
➢In factories, better fuel burning equipments should be
used.
Control of Air Pollution
15. ➢Electronic precipitator should be installed in the factories to
reduce pollution.
➢Reduce use of coal energy and uses of alternate renewable
energy like solar energy, wind energy and hydro energy can
helps to reduce dependence of fossil fuel like coal.
➢In home, liquefied petroleum gas should be used for
cooking.
➢Switching of lights and fans when not in use, help to
conserve energy at home.
➢Planting of more trees can help to absorb in excess carbon
dioxide.
➢Tree planting camp like billion tree planting can help to
combat problems of global warming due to pollution.
➢Public awareness campaign also help to create awareness
among people to effectively save energy and reduce
pollution.
Control of Air Pollution
