This document discusses different types of environmental pollution including air, water, and land pollution. It defines pollution as undesirable changes that harm living things and ecosystems. The main causes of pollution are pollutants, which are substances produced by human activity that are present in greater than natural amounts and have detrimental effects. Pollutants are classified as degradable, slowly degradable, and non-degradable. Air pollution occurs when gases contaminate the air from sources like vehicles, industries, and power plants. Water pollution happens when harmful substances like sewage and chemicals pollute water bodies. Land becomes polluted when chemical and industrial wastes are discharged onto the surface.
3. Definition of pollution
• Pollution is the effect of undesirable changes in our surroundings
that have adverse effects on human beings, animals, birds, forests,
plants, and all the biotic components of ecosystem.
• Pollution is harmful for all the living units.
4. Pollutants
• The substances which are the major cause of pollution is known as
the pollutant.
• Pollutants includes solid, liquid or gaseous substances present in
greater than natural abundance produced due to human activity,
which have detrimental effect on our environment.
• From the ecological perspective pollutants can be classified as
follows:
1. Degradable pollutants
2. Slowly degradable pollutants
3. Non-Degradable pollutants
5. 1. Degradable pollutants
• These can be rapidly broken down by natural process.
• E.g: Domestic sewage, discarded vegetables etc.
2. Slowly degradable pollutants
• Pollutants that remain in the environment for many years in
unchanged condition and takes decades or longer to degrade.
• E.g: DDT and most plastics.
3. Non- Degradable pollutants
• These cannot be degrade by the natural process. Once they are
released into the environment they are difficult to eradicate and
continue to acculumate.
• E.g: Toxic elements like lead and mercury.
6. Air Pollution
• When clean air is contaminated by the gases like carbon dioxide, carbon
monoxide, Sulphur dioxide, nitrogen oxide, clay, sand partricles etc. The air is
said to be polluted.
• The atmospheric air in the cities is polluted by the smokes emitted from the
industries, exhaust gases coming out of the vehicles like car, trucks, two
wheelers etc.
• When we breath contaminated air containing gases like carbon dioxide and
sulphur dioxide instead of clean air, these toxic gases enter our respiratory
system causing various types of diseases like asthma, cough, bronchitis and
pneumonia.
• Atmospheric pollution has been increased due to industrialization and
increasing number of automobiles.
• Pollution level in metro cities like Kolkata, Chennai, Delhi and Mumbai has
been crossed to dangerous level.
7. Types of air
pollutants and their
classification
Natural and Man-
made Pollutants
Primary Pollutants
and Secondary
Pollutants
Gases Aerosoles
Types of air pollutants and their classification
8. 1. Natural and Man-made Pollutants
• Natural pollutants are naturally generated in the atmosphere.
• They includes pollen grains, bacteria, viruses and volcanic ashes etc.
• Man-made pollutants include exhaust gases from vehicles, power
plants and industries.
• Carbon dioxide emitted from respiratory system is also man-made
pollution.
9. 2. Primary Pollutants and Secondary Pollutants
• Primary pollutants directly contaminate the air by mixing with it.
• E.g: Carbon dioxide and Sulphur dioxide gases is a primary pollutant.
• Secondary pollutants mix with the air and react chemically with other
constituents of air producing another harmful pollutions.
• E.g: Moisture in the air mixes with sulphur dioxide producing
sulphuric acid which is secondary pollutant.
10. 3. Gases
• All the gases like CO2, CO, SO2, chlorine are dangerous pollutants.
• They contaminate the air.
• Generally these gases are generated as product of combustions and
chemical reaction.
11. 4. Aerosols
• Microscopic particles of solid liquid and gases are called aerosols.
These aerosols are of the size 0.01 micron to 100 micron.
• Different kinds of aerosols
1. Dust particles
2. Smoke
3. Fog
4. Mist
5. Fumes
12. Sources of Air Pollution
• The atmospheric air is polluted in following manners:
a) Various types of gases produced in chemicals and other types of
industries.
b) Carbon dioxides, sulphur dioxides and carbon monoxide generated
during the combustion of fuels in the boiler of power plants.
c) Different types of particulate matters such as dust, sand, pollen grains,
salts and aerosols.
d) Due to combustion of petrol, diesel and CNG in automobiles.
e) Oxidation and reduction processes of carbonic substances.
f) Aerobic reaction and purification of municipal waste materials and
garbage generate toxic gases which pollute the air.
g) Fire in the forest and volcanic ashes.
13. Water Pollution
• When the quality or composition of water
changes directly or indirectly as a result of
man’s activities such that it becomes unfit for
any purpose it is said to be polluted.
• Whenever harmful substances such as sewage,
toxic chemicals, silt, etc., get mixed with water,
the water becomes polluted. The substances
that pollute water are called water pollutants.
• As for example, when toxic chemicals are
discharged into the rivers, lakes and ponds the
water gets polluted.
14. Point Sources And Non-point Sources of Pollution
• Point sources of pollution: When the sources of pollution
can be readily identified because it has a definite source and
place where it enters the water it is said to be a point
sources.
• Eg: Municipal and industrial discharge pipes.
• Non-point sources of pollution: When the sources of
pollution cannot be readily identified such as agricultural
runoff, acid rain etc, it is said to be a non-point sources.
15. Main pollutants of water
Inorganic and insoluble pollutants Fine sand and clay
Soluble pollutant Different types of organic and inorganic
soluble chemicals.
Municipal wastes Human excreta, waste food materials.
Liquid waste from industries Chemicals, greases, oil etc.
Heavy metals Cu, Fe, Hg etc
Insecticides and pesticides Insecticides and pesticides used for
crops and vegetables
Biological pollution Bacteria and micro-organism
Organic matters Left of food, spoiled vegetables
16. • Water pollution is extremely harmful for animals, human beings and
agriculture.
• Polluted water causes water borne diseases like
1. Cholera
2. Jaundice
3. gastroenteritis.
4. Etc.
17. Prevention of water pollution
1. Discharge of waste- chemicals, dyes and other compounds into
river, lakes and oceans must be immediately stopped by enforcing
strict regulation.
2. Scientific methods should be adopted for disposing the municipal
wastes and garbage.
3. Insecticides and pesticides must not be used in agriculture.
4. Drinking water must be supplied through water filtration and
treatment plants to general public.
18. Land Pollution
• Land is getting polluted if solid and liquid chemical and industrial
wastes are discharged on the surface of land.
• Liquid toxic chemicals on the surface of land percolates in to the soil.
It spreads down into the earth and pollutes the underground water
table. If this polluted water is used for farming or drinking purpose
the toxic chemical like mercury, arsenic traces find their way to
humans and animals affecting their health and life.
• In this way pollution due to solid and liquid wastes is very harmful
and dangerous.
19. Land Pollution
• Insecticides and pesticides also causes the land pollution. Insecticide
like DDT are non biodegradable. This means it cannot be destroyed
but gets transmitted from land to food material which we eat.
• Due to land pollution, land becomes non-fertile and useless for
agricultural purpose.