The document discusses air pollution, detailing its causes, types of pollutants, and their effects on human health, plants, and materials. It outlines primary and secondary pollutants, highlighting sources such as industrial emissions, thermal power plants, and vehicles. The Air (Prevention and Control of Pollution) Act of 1981 in India aims to manage air quality, establishing the Central and State Pollution Control Boards to oversee pollution control efforts.

1. AIR POLLUTION: Causes, effects and control
Normal composition of clean air at or near sea is as follows
Gases Percent (by Volume)
Nitrogen 78.084
Oxygen 20.9476
Argon 0.934
Carbon dioxide 0.0314
Methane 0.0002
Hydrogen 0.00005
Other gases minute
Air may get polluted by natural causes such as volcanoes, which
release ash, dust, sulphur and other gases, or by human activities
(emission from vehicles, industries, etc.). Any gas, liquid or solid
substances are considered as a pollutant because of very large
emission rates are harmful and unwanted effects .
The air act defines ‘air pollution’ as the presence of any dangerous
pollutant that makes the air unbreathable.

2. Depending on the form of pollutants present in the environment, they are classified as:
Primary pollutant Secondary pollutant
Directly emitted in the atmosphere in the
harmful form. Five primary pollutants
include Sulfur dioxide, Nitrogen oxide,
carbon monoxide, solid or liquid
particulates and particulates of lead
These are formed by reacting with other
components of the atmosphere to form
new pollutants.
Extremely small particles of solids or liquid
droplets suspended in air are called
particulates.
A volcanic eruption releases smoke and ash
which are considered primary pollutants.
Secondary pollutants form when primary
pollutants interact with other components
to form new pollutants. For example, Sulfur
oxides and nitrogen oxides react with rain
water and forms sulfuric acid and nitric acid,
respectively
70% of total CO emissions come from
vehicles.
Sulfur dioxide released in a power plant or
factory from combustion of fossil fuel.
Nitrogen oxides are produced by
combustion of fossil fuels at high
temperature.
Smog, a combination of smoke and fog,
result of burning coal which releases smoke
and sulfur dioxide.

3. Sources of Air Pollutants: Air pollution results from gaseous emission from
mainly industry, thermal power stations, automobiles, domestic combustion etc.
1. Industrial chimney wastes :
The chief gases are SO2 and NOx (Oxides of Nitrogen)
2. Thermal power stations:
The chief pollutants are fly ash, SO2 and hydrocarbons. The coal consumption of
thermal plants is several million tones
3. Automobiles:
The exhaust from vehicles produces many air pollutants including unburnt
hydrocarbons, CO, Nox and lead oxides (antiknock additive)
7 oxides of nitrogen are NO, NO2, NO3, N2O, N2O3, N2O4 and N2O5.
Nitric oxide (NO) and Nitrogen dioxide (NO2) are important in air pollution study
4. Particulate Matter:
aggregates of small molecules

4. Effects of air pollution
a)Effects on Human: Effects of sulfur dioxide, oxides of nitrogen, and ozone
include eye and throat irritation, coughing and chest pain. Nitrogen dioxide is
known to cause accumulation of excessive fluids in the lungs. Ozone, a highly
irritating gas include dry throat, headache.
Particulates are microscopic solids or liquid droplets can be inhaled and cause
serious health problems .
b)Effect on plants. damage the leaves, interferes with photosysthesis and plant
growth, reduces nutrient uptake. leads to damage from diseases, pests, drought
c)Effect on Materials: Air pollutants breakdown exterior paint, discolored the
irreplaceable monuments (historic buildings)
d)on Stratosphere: Ozone is continuously being created in the stratosphere by the
absorption of short-wavelength UV radiation, while at the same time it is
continuously being removed by various chemical reactions that convert it back to
molecular oxygen Chlorine, nitrogen and bromine, which acts as catalysts,
speeding up the removal process of ozone. CFCs are predominant .

5. Integrated approach for air pollution control :
Air pollution can be controlled by some fundamental approaches:
• Preventive techniques – reduction of pollution at source, removing sulfur from
coal, Setting chambers remove the large particulates
• Reducing the use of Fossil fuels– through modification of process and
equipment
• Improving quality of vehicular fuel – less polluting fuel like hydrogen gas
• Increasing the use of renewable energy- solar energy, wind energy, planting
more trees

6. The Air (Prevention And Control of Pollution ) Act,1981
In India, The Air (Prevention And Control of Pollution ) Act, has been enacted in
1981.
Salient Features of The Air (Prevention And Control of Pollution ) Act, 1981
1. The Air (Prevention and Control of Pollution) Act, 1981 defines "air pollutant" as
any solid, liquid or gaseous substance present in the atmosphere in such concentration
as may be injurious to human beings or other living creatures or plants or property or
environment.
2. The act set up the Central Pollution Control Board (CPCB) at the central level and
State Pollution Control Boards (SPCB) at the state level to advise the government on
any matter concerning the improvement of the quality of the air and prevention, control
and abatement (reducing/removal) of air pollution.
3. The CPCB establish rules for the quality of air and provides technical assistance and
guidance to the SPCB.
4. The function of CPCB and SPCB is to collect, compile and publish the data
regarding air pollution. And also to guide the concerned industry for the effective
prevention and control of air pollution.
5. CPCB and SPCB are authorized to instruct the emission standards from automobiles,
restrict the activities of certain industries and declare the air pollution control areas.