INTRODUCTION OF POLLUTANTS

1. INTRODUCTION
The environment is composed of air, water and land,
technically called as atmosphere, hydrosphere and
lithosphere which together constitute the biosphere.
•In the biosphere human beings, plants, animals, birds,
fishes, insects and microorganisms (algae, bacteria and virus)
exist.
•Atmosphere provides oxygen, while the hydrosphere and
lithosphere provides food, water and shelter.
•There is a balance between the living organisms and the
environment.

2. •Disturbance in any components of environments is likely to
have a harmful effect on the ecosystem.
•Whenever a change, physical or chemical occurs in the
atmosphere, hydrosphere or lithosphere, all living beings are
affected
•This change is termed as pollution and the agents that cause
these changes are called as Pollutants.
This change either in the physical, chemical or biological
characteristics of physical environment is undesirable and
harms human life, other living organisms and cultural assets.

3. In general pollution is defined as an undesirable and excessive
addition of substances to water, air and land which adversely
alters the natural quality of the environment.
The Quality of life is based on clean environment which
generally is aggregated into air quality, water quality, noise
levels etc.

4. “Pollution can be defined as an undesirable change in the
physical, chemical or biological characteristics of our air,
water and land that may or will harmfully affect the life or
creates a potential health hazard and threaten the survival
or activities of humans or other living organisms.”
Pollution is thus direct or indirect change in any
environmental components that is adversely affecting the
industrial progress, cultural or natural assets or general
environment.

5. POLLUTANTS
Any substances presents in the environment in harmful
concentration ,which adversely alters the environment by
damaging the growth rate of species and by interfering with
the food chains, is toxic and affects the health, comfort and
property is called as pollutants.
The substance which spoils or pollutes the environment is
called pollutants.

6. •It includes dust from house and garbage from home,
effluents from industries, emission of smoke from
automobiles.
•It also includes smoke generating from industries and
automobiles, domestic and commercial sewage, radioactive
substances from nuclear plants and discarded household
articles (tins, bottles, broken crockery etc.)

7. Classification of Pollutants
 Depending upon their existence in
nature
A. Quantitative Pollutants
B. Qualitative Pollutants

8. A. Quantitative Pollutants
Substances that occurs in the environment, who acquire the
status of a pollutant when their concentration gets increased
due to the various activities of man.
Carbon Dioxide, if present in the atmosphere in
concentration greater than normal due to automobiles and
industries, causes measurable effects on humans, animals,
plants or property is classified as a quantitative pollutant.

9. B. Qualitative Pollutants
These are those substances which do not normally occur
in nature but are added by man. e.g. insecticides.

10.  Depending upon the form in which
they persist after being released into
the environment
A. Primary Pollutants
B. Secondary Pollutants

11. A. Primary Pollutants
•These are those which are emitted directly from the source
and persist in the form in which they are added to the
environment.
•Examples are ash, smoke, fumes, dust, nitric oxide, sulphur
dioxide, hydrocarbons etc.

12. B. Secondary Pollutants
•These are those pollutants which are formed by the primary
pollutants by chemical interaction with some constituent
available in the atmosphere.
•Examples are sulphur trioxide, nitrogen dioxide, aldehydes,
ozone etc.

13. As per ecosystem point of view, i.e.
according to their natural disposal
A. Bio-degradable pollutant
B. Non-degradable pollutants

14. A. Bio-degradable pollutants
These are the pollutants that are quickly degraded by natural
means.
•These are the pollutants which can be decomposed,
removed or consumed or reduced to acceptable levels either
by natural or artificial process.
•It includes pollutants such as human sewage and animal and
crop waste.
•Heat or thermal pollution, and domestic sewage are
considered in this category as these can be rapidly
decomposed by natural processes or by engineered systems
such as municipal treatment, plants etc.

15. B. Non-degradable pollutants
•These are the substances that either do not degrade or
degrade very slowly in the natural environment.
•These include radioactive materials, heavy metals, plastics,
mercury salts, long chain phenolic chemicals, DDT etc.

16. On the basis of nature, pollutants are
of following three types :
Physical Pollutants : Heat, Noise, Radioactive substances etc.
Chemical Pollutants : Oxides of carbon, oxides of sulphur,
oxides Of nitrogen, halogen gas etc.
Biological Pollutants : Microorganisms such as bacteria, virus
and fungi etc.

17. On the basis of their source of origin
A. Point source pollutants
Those sources which can be originated from a single location
are called as point source.
•When the emission or origin source is point. i.e. the area
are very less as compare to the environment.
• It includes emission from stack, industries, municipal
sewage treatment plants, combined sewer outflow, raw
water sewage discharge etc.
•These types of discharge can be controlled by giving
necessary treatment.

18. B Line source pollutants
These are such type of sources whose location can not be
easily identified.
•When the emission is in the form of line or curve e.g.
transportation of material by conveyor belts, road rollers
and run–off from agricultural land, mining, construction
etc.
• It can not be easily controlled. Water pollution caused by
diffused source like agricultural can be controlled by
changing crop pattern and advance farm management
practices.

19. C. Area source pollutants
When the emission or origin source is an area i.e. the
area is large e.g. crushing, grinding and blasting in mines
etc.

20. SOURCES OF POLLUTION:
There are mainly two sources
a) Natural sources,
b) Man made or anthropogenic sources.

21. a) Natural sources of Pollution

22. Volcanic
eruptions
release gases
and volcanic ash

23. Forest fires produce smoke and
trace gases

24. Other sources are
•Dust storms increase the wind blown dust into the
environment,
•Bacteria, spores, cysts and pollens are all natural
pollutants.
•Decay of organic matter in marshy places releases marsh
gas which is a light colorless inflammable hydrocarbon.

25. b) Man made or anthropogenic
sources.

27. Invention of automobiles

28. Over population

29. Deforestation : Destruction of natural habitant

30. Nuclear explosions

31. Over – exploitation of natural sources

32. Construction of buildings, roads and dams

34. Explosives used in wars

35. Use of fertilizers and pesticides

36. Mining and
quarrying

37. TYPES OF ENVIRONMENTAL
POLLUTION:
Main types of pollution are
1) Water Pollution
2) Air Pollution
3) Marine Pollution
4) Noise Pollution
5) Thermal Pollution
6) Land Pollution