AIR POLLUTION

1. Presented by:
MOOD NARESH
ASST.PROF
PETW

2. Inde
x:
• Definition
• Types of air pollution
• Causes and effects of air pollution
• Sources of air pollution
• Effects of air pollution
• Prevention of air pollution

3. Definition:
• It is a broad term applied to all the
physical, chemical, and biological agents that
may modify the natural
characteristics of the atmosphere and the
environment.
>There are many different types of air pollutants, such
as gases (such as ammonia, carbon monoxide, sulfur
dioxide, nitrous oxides, methane, carbon dioxide and
chlorofluorocarbons), particulates (both organic and
inorganic), and biological molecules.

4. Types of air pollutants:
Primary air pollutant
Ex: CO
Secondary air pollutant
Ex:formation of ozon
in photochemical
smog

6. air pollution
Outdoor air pollutio
Acid rain Black carbon pollution.
Greenhouse effect
Ozone depletion
Indoor air pollution
Particulate pollution.
Causes and effects

7. Out door pollution

8. mechanism of air pollution due
to smog:

9. lack carbon pollution
Temperature inversion:

10. Acid
rain:

12. Chlorofluorocarbons
Ozone layer in Stratosphere
effected
Ozone depletion

13. Indoor air pollution

14. INTRODUCTION
• Nature is our mother. She offers us all facilities to
lead a comfortable and peaceful life. She brings us
rain. She feeds the human beings who are her
children. The plants, trees, bushes and the grains we
grow all belong to nature. Yet man is not grateful to
nature. He pollutes the surroundings and brings
destruction on himself. Man’s ability to manipulate
the environment has today resulted in Several Serious
problems. The most Serious of these problems, is the
environmental pollution

15. • Environmental pollution can be defined as an
undesirable change in the physical, chemical and
biological characteristics of the environment such
changes are caused by Substances that are introduced
into the environment, by human activities.
•
•
•
•
•
•
•
Air pollution
Water pollution
Noise Pollution
Soil pollution
Marine pollution
Thermal Pollution
Solid waste pollution

16. Air pollution - It may be defined as any atmospheric condition in
which certain substances are present in such concentration that
they can produce undesirable effect on man and his environment.
These substances includes gases (CO2,SO2,NO2,CO,HF,HC etc.),
particulate matters ( smoke, dust, fumes, aerosols etc.) ,
radioactive materials and many others.

17. Composition of clean and dry atmospheric
air
Sr. No. Component Concentration (ppm)
1 Nitrogen 78x10 4
2 Oxygen 21x10 4
3 Argon 0.93 x10 4
4 Carbon dioxide 0.032x10 4
5 Caron monoxide 0.1
6 Methane 1.2
7 Nitrous Oxide 0.25
8 Nitric Oxide 0.0006
9 Hydrogen Sulphide 0.0002
10 Sulfur dioxide 0.0002
11 Ozone 0.04

18. The concentration of pollutants in the
atmosphere is expressed as:
• Mass concentration: It is the ratio of mass of pollutants to
the mass of air plus mass of pollutants.
•
•
Volume concentration: It is the ratio of Volume of
pollutants to the Volume of air plus volume of pollutants.
Mass volume concentration : It is the ratio of mass of
pollutants to the volume of air plus volume of pollutants.
the time concentration of pollutants is
in ppm or microgram per cubic meter
• Most of
expressed
(µg/m3).

19. Conversion of pollutants Concentration
Conc. in µg/m3 =
ppm conc. x molecular wt. of pollutant x 103
22.41
at 0oc and 760 mm of Hg pressure
ppm conc. x molecular wt. of pollutant x 103
24.51
at 25oc and 760 mm of Hg pressure
Conc. in µg/m3 =

20. Sources of Air Pollution
Natural – i)Volcanic eruption- poisonous gases- SO2,CO ,H2S etc.
ii) Forest fires-smoke, dust,CO2 and un-burnt hydrocarbons etc.
iii) Natural organic and inorganic decay
iv) Deflation of sand and dust
v) Pollen grains of flowers, weeds , grasses and trees.
vi) Evapotranspiration- CO2
Manmade- i) Rapid Industrialization- CO2,SO2,CO ,NO, H2S etc.
ii)Transportation- NO2,CO,Hydrocarbons,Nitrous oxide
iii) Burning of fossil fuels- CO2, SO2,CO,NO, CH4
iv) deforestation- balance between O2 and CO2 disturbed
v) Increase in population
vi) Agriculture activities
vii) Solid waste disposal
viii) Radioactive fall out
ix) Construction activities
x) Wars

21. Sources of air
pollutants
• Stationary sources:
Point sources - industrial stacks
•
Area sources - open burning, Evaporation losses
Mobile sources:
Line sources - vehicle, rail engine
Area sources - vehicles on Road

22. Classification of Air pollutants
1. According to Origin-
PRIMARY – emitted directly from source
e.g. i) Particulate matter- ash, smoke, dust, fumes, mist etc.
Mist- liquid droplets smaller than 10µ size formed by
condensation or released from industrial operations.
Fumes – these are solid particles generated by condensation from
gaseous state.
ii) Inorganic gases- SOx, NOx,CO,CO2,HF etc.
SECONDARY – formed by chemical or photochemical
reactions between two or more primary pollutants.
e.g. O3, PAN(peroxy acetyl nitrate), formaldehyde, photochemical
smog etc.

23. 2. According to Chemical Composition-
i)ORGANIC- e.g. Hydrocarbons, esters, aldehydes etc.
ii)INORGANIC- e.g. Sox, Nox, CO,CO2,HF,O3,HCl etc.
3. According to State of Matter
i)NATURAL CONTAMINANTS – e.g. Fog, pollen grains,
bacteria etc.
ii)PARTICULATE MATTER- e.g. Ash, smoke, dust, spray
fumes, mist etc.

24. Meteorology and Air Pollution
• The degree to which air pollutants discharged from various
sources concentrate in a particular area depends largely on
meteorological condition.
The important meteorological parameters that influence air pollution
are classified into primary and secondary parameters.
Primary parameters:
Secondary parameters:
i) Wind direction and wind speed
ii) Atmospheric stability
iii) Temperature
iv) Mixing height
v) Precipitation
vi) Humidity
vii) Solar radiations
viii) Visibility

25. •
•
•
•
Atmospheric stability: In well mixed air which is dry, for every
300m increase in altitude, the temperature decrease by 1.8 oc
.This vertical temperature gradient is know as lapse rate.
The tendency of atmosphere to resist vertical motion is called as
stability. This stability depends on wind speed and lapse rate.
The change of air temperature with altitude has a profound
influence on the vertical lift of the air pollutants discharged into
the atmosphere and hence their dispersion and dilution.
Inversion: The extreme case of stable environment, called an
inversion, occurs when temperature increases with altitude.
Such lapse rate is known as negative lapse rate. Under these
conditions, the atmosphere is very stable and practically no
mixing of pollutants takes place.

26. Types of Inversion
• Radiation Inversion: It occurs at nights,
when the earth loose heat by radiation and
cools the air in contacts with it. The cool air
stratum is covered by warmer air, and
vertical movement is stopped until the sun
worms the lower air, next morning. This
type of inversion is more common in
•
winter because of longer nights.
Subsidence Inversion: It occurs at modest
altitude and remain for several days. It
occurs due to sinking or subsiding of air
mass in anticyclones. The air circulating
around the area descends slowly at the rate
of about 1000m per day. As the air sinks ,it
is compressed and get heated to form a
warm dense layer. This acts as a lid to
prevent the upward movement of
contaminants( pollutants).

27. • Advective Inversion: It is formed when
warm air moves over a cold air. The
inversion can be ground based in the former
case or elevated in later case. An example
of advective inversion occurs when hill
range forces a warm land breeze to flow at
high levels and a cool sea breeze flows at
low level in opposite direction.

28. Pollution sources:
• Anthropogenic sources
• Other anthropogenic sources
• Natural sources
• Contaminants

29. Anthropological
sources:
• combustion-fired powered plants
• Vehicles with internal combustion engine
• Devices powered by two-stroke
cycle engines
• Stoves and incinerators especially coal
ones.
• Wood fires burning inefficiently.
• Farmers burning crop waste.

30. Other anthropological
sources:
• Aerosol sprays and refrigeration.
• Dust and chemicals.
• Military actions like testing of nuclear
bombs,poisonous gases, germ warfare.
• Waste deposition in landfills,which
generate methane.

31. Natural sources:
• Dust from natural sources.
• Methane emitted from decomposition of
animals and cattle.
• Smoke and carbon monoxide
from wildfires.
• Volcanic activity, producing
chlorine,sulphur,and ash particulates.

32. Contaminants:
• Carbon monoxide.
• Chlorofluorocarbons.
• Hydrocarbons.
• Lead and heavy metals.
• Nitrogen oxides.
• Sulphur dioxide.

33. Mercury toxicity
alginate
DENTIST
RY
Acrylic
aerosols

34. Effects of air pollution
on health:
t
• Short term effects:
Irritation to the eyes,nose and
hroat.
Upper respiratory infections.
Headache,nausea,and allergic
reactions.
Asthma and emphysema

35. • Long term effects:
Chronic respiratory diseases.
Lung cancer.
Heart diseases.
Damage to the brain,nerves,liver or
kidneys.

36. Prevention of damaging effects of air
pollution:
• Assessments
• Pollution emission for transportation
vehicles and industry
• Restricting smoking
• Adequate ventilation

37. Prevention

38. References:
• Text book of preventive and community
dentistry
S.S.Hiremath.
• Text book of preventive and social
medicine- park and park.
• www.google.com.