Air pollution

SOURCES AND HAZARDS OF
AIR POLLUTION
AB RAJAR
ASSOCIATE PROFESSOR
Email:drabrajar@gmail.com

LEARNING OBJECTIVES
I. Introduction
II. Global Burden
III. Composition of Air.
IV. Sources of Air pollution
V. Health Hazards by polluted Air

INTRODUCTION
 Role of Air in human health:
• Air plays a vital role in our lives.
• It is our immediate environment and performs following functions:
 Supply oxygen for living
 Supply CO2 to plants
 Helps in smelling
 Helps in listening.

COMPOSITION OF AIR
oAir is mechanical mixture of gases.
oThe normal composition of external air i,e, fresh air and expired air
as:
Gases Fresh Air Expired Air
Oxygen 20.93% 16.9%
Carbon dioxide 0.03% 4.4%
Nitrogen 78.1% 78.1%
• Trace gases:
Minute amount of other gases like Argon,Neon,Krypton,Xenon &
Helium are also present in air

Sources of Air pollution

SOURCES OF AIR POLLUTION
• The term air pollution is applied when there is excessive
concentration of foreign matter in the atmosphere, which is harmful
to man & his environment.
• Main sources air pollution are:
1. Changes due to respiration
2. Changes due to combustion
3. Dust and bacteria
4. Industrial pollutants.
5. Organic decomposition
6. Agricultural processes.

1.Changes due to respiration
• A.CHEMICAL:
 A man respire about 15-18 times /mint & gives out about 500cc of air with
each breath.
 The estimated amount of CO2 added /hr by one person is 0.6-0.7 ft3/hour at
rest and it increase upto 2ft3 /hour exercise.
• B.PHYSICAL:
 Increase in temperature (400BTU/hr at rest and 4000 BTU/hr exercise)
 Increase in humidity
 Decrease air moment
 Addition of body odour and smell
 Addition of bacteria and viruses

2-Changes due combustion
• A-COMBUSTION IN DOMESTIC FIRE:
• Impurities are CO2,C0,SO2,H2SO4,CS2 H2S and moisture
• B-USE OF ILLUMINATES:
• Coal gas and water gas
• Oils
• Electricity
• C-EXHAUST FUMES FROM MOTOR VEHICLES:
• CO 4-12%
• CO2 upto 100%
• Hydrocarbon 4%

3-Dust and bacteria
 In ill ventilated rooms the dust contains the scales of epithelium,
pollens and cotton fibers.
 Atmospheric dust contains soot,slica,decaying leaf, animals
excerta,eggs of parasites and bacteria.

4-Industrial pollutants.
 Fumes containing toxic gases
 Discharge of industrial wastes containing chemicals.

5-Organic decomposition and Agricultural processes.
Burning of refuse,
Agricultural activities such as crop spraying,
Pest control and nuclear energy programs also contribute to air
pollution

Indicators of air pollution
i. Sulphur dioxide (S02)
ii. Carbon monoxide (CO)
iii. Nitrogen dioxide (NO2)
iv. Lead (Pb)
v. Oxidants
vi. Smoke
vii. Suspended particles.

HAZARDS OF AIR POLLUTION

Hazards of air pollution
I. Immediate effects
II. Late effects
III. Effects on plants & Animals
IV. Global effects

Ⅰ-Immediate effects of polluted air
• Nausea Vomiting Fever Headache

Ⅱ-Late effects of polluted air
 Pneumoconiosis: group of diseases, due to inhalation of suspended
dust particles resulted in irreversible fibrosis in lungs like:
• Asbestosis,Slicosis, Siderosis etc
• Chronic Bronchitis Primary lung cancer Anemia Tuberculosis.

Ⅲ-Global effects of polluted air
A. Ozone depletion
B. Acid rain
C. Greenhouse effect

A-Ozone depletion
• Ozone:
• A gas having formula O3.It is present at distance of 15-50 km from the earth.
It has encircled the earth like a jacket.
• Function:
• It prevents some waves of ultraviolet radiation from sun, are dangerous for
health.
• CAUSES OF O3 DEPLETION:
• O3 layer is a depleted from chlorofluorocarbon,(CFCs) are present in:
• Air conditioner
• Refrigerator
• Aerosol sprays

Health hazards of Ozone depletion
 UV Radiation if come directly with all wavelengths, cause skin cancer
and cataract.
 If there is 1% fall of ozone than there is:
• 4-6% chance of skin cancer.
• 0.8 -1.5% increase in melanomas.
• 0.2-0.6% increase in cataract cases

B-Acid rain
• The areas where S02 & NO2 are present in environment, the rain become acid
and called as acidic rain.
• MECHANISM:
• When rainfall occurs ,the rain drops combine with N02 & SO2 resulting in:
• NO2 + H2O → HNO3
• SO2 + H20 → H2SO4
 HAZARDS:
• Damage to crops, Rusting of metals, Discoloration of houses.
• Skin Cancer ,Damage of marine life,
• Lead poising due to damage lead pipes.

C-Greenhouse effect
 INTRODUCTION:
• Greenhouses are glass huts seen in hilly areas and in the agricultural
processing areas.
• It is the capacity of certain gases in the atmosphere to trap heat
emitted from Earth’s surface, herby insulting and warming the
planet.
 MECHANISM:
• When light rays fall on any transparent surface, some rays are
reflected and some are refracted. Partial retention of light takes place
in this green house, so temperature in glass house is increased.

Mechanism of Greenhouse effect

C-Greenhouse effect
 HAZARDS OF GREEN HOUSE GASES:
 Global warming
 Increased evaporation from sea.
 Melting of ice at poles of earth.
 Increase in sea level.
 Floods.

THANK YOU
Air pollution is turning Mother Nature prematurely gray.
Irv Kupcinet

Air pollution

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