lOMoARcPSD|4454852

Air Pollution - Lecture notes 1

Information System (Minhaj University Lahore)

StuDocu is not sponsored or endorsed by any college or university

Downloaded by Omkar Rajmane (omkarrajmane09@gmail.com)
 lOMoARcPSD|4454852

Pollution
Pollution is defined as the excess discharge of any substance into the environment which
affects adversity quality of environment and causing damage to humans, plants and animals.

Pollution is explained as any substance introduced into the environment that adversely
affects the usefulness of resources

Pollution can be in the form of solid, liquid or gaseous substance. Pollution causes damage
to human, plant and animal life. The nature and concentration of pollutant determine the
severity of effect of pollution.

Classification of pollution

The pollutants that pollute the environment is divided into following types

1.Air-pollution
2.Water-pollution
3.Soil-Pollution
4.Marine-pollution
5.Noise-pollution
6.Thermal-pollution
7. Nuclear hazards

Air pollution

It is the presence of harmful foreign substances (pollutants) in the atmosphere, emitted by

both natural and anthropogenic (human activity) sources.

Air pollution is the contamination or presence of unwanted substances in the air making it
harmful and detrimental for human and animal health.

Air Pollution is the deterioration of the quality of the air to an extent that:

• it becomes difficult to breathe, often toxic or detrimental,

• it complicates the health of living beings,
• it causes the body organs to malfunction,
• it damages the habitats of animal, plants, and other living organisms,
• it poses the threat to the natural environment and its habitats.

Downloaded by Omkar Rajmane (omkarrajmane09@gmail.com)

 lOMoARcPSD|4454852

Pure air is necessary for our health. Air pollution is the leading cause of several diseases.
During the past few years, air pollution has emerged as one of the leading causes of death
worldwide.

Causes of air pollution

1. Industrialization
2. Urbanization
3. Vehicles emission
4. Deforestation
5. Population

6. installation of chemical

7. test of modern weapons

8. increase of motor vehicles

9. Greenhouse gases
Types of air pollutants
Air pollutants can broadly classified into two types-
1. Primary pollutants
2. Secondary pollutants

Downloaded by Omkar Rajmane (omkarrajmane09@gmail.com)

 lOMoARcPSD|4454852

Classification of air pollutants:

Air pollutants can also be divided into two categories: primary pollutant and secondary
pollutant.

• Primary pollutants: Primary pollutants are emitted directly from the sources. The
example of primary pollutant includes carbon dioxide (CO2), carbon monoxide (CO),
sulfur dioxide, nitric-oxide, ammonia, hydrogen sulphide, and radioactive substances.
Industrial fumes and smokes, ash, dust, mist, are other primary sources of air pollution.

• Secondary pollutants: The secondary pollutants are not emitted from the sources.
They are formed when primary pollutants interact with atmospheric constituents.
Example includes sulphur-trioxide (SO3), nitrogen-trioxide, ozone (O3), hydrocarbons,
acid rain, etc.
Major Air Pollutants
The pollutants that contribute major portion of global air pollution are:

1 Sulphur Oxides (SOx): These substances are produced by industry, particularly the
industrial combustion of fossil fuels. They are also produced naturally when volcanoes
erupt.
Sulphur dioxide (SO2) is a Colourless gas with a sharp odour that accounts for about 18%
of allair pollution.
Sources:
Chemical industries, Metals meltings, Pulp and paper mills,Oil refineries

Effects of Sulphur dioxide:

Sulphur dioxide reacts with moisture in eyes, lungs and mucous membranes to form
strongirritating acid. It can trigger allergic reaction and asthama.
If moisture is present in the atmosphere, sulphur dioxides is converted into sulphuric
acid or ifconditions are dry, into sulphate particulates. The tiny- only 0.1 to 1 mm in
diameter-sulphuricacid and sulphate particulates form aerosols. The aerosols
contribute to the adverse healthseffects of smog and haze and also play a serious role in
haze. Sulphuric acid and sulphate arelikewise directly involved in three serious global
global change problems.
Acidic deposition isone of those.
The stratospheric ozone depletion, where by sulphate particles in the stratosphere
providesurfaces on which ozone-destroying reactions occur. A third major effect is the
antiwarminginfluence they exert in global climate change
2 Nitrous oxides(N2O):

Downloaded by Omkar Rajmane (omkarrajmane09@gmail.com)

 lOMoARcPSD|4454852

These oxides are released into the atmosphere when industrial combustion occurs at
high temperatures.

3 Carban Monoxide (CO)

It is a colourless, odourless, flammable gas, which is a product of incomplete
combustion. Ifcarbon were completely oxidized during burning, complete combustion to
carbon dioxide wouldoccur and carbon monoxide would not be a problem.
It is important not to confuse carbonmonoxide with carbon dioxide. Carbon monoxide
(CO) is an incomplete combustion product andcan be toxic even at low concentrations,
whereas carbon dioxide (CO2) is a complete oxidationproduct.

Sources of Carbon monoxide:

Carbon monoxide is formed whenever a carbon material is burned e.g. automobile
exhausts,cigarettes etc. In addition to motor vehicles, sources of carbon monoxide
include burning coal,natural gas or biomass. Biomass combustion can be a significant
source of exposure in rural
areas or in underdeveloped countries where it is burned for cooking,heating and even
light.Atmospheric oxidation of methane gas and other hydrocarbons and even light.
Atmosphericoxidation of methane gas and other hydrocarbons also produces carbon
monoxide.

Effects of CO:
Carbon monoxide accounts for more than 50% of air pollution nationwide and
worldwide. It is apervasive pollutant. Worldwide, hundreds of millions monoxide-
related illness, which include
headaches, dizziness and drowsiness. Reports show that about 11% heart failure caused
byexcess carbon monoxide.
In the normal situation, the iron atom in the blood protein haemoglobin, picks up
oxygen fromthe lung and transports in to the body’s cells. There the haemoglobin
releases oxygen and picksup the waste gas carbon dioxide, which it transports back to
the lungs and releases. After
releasing carbon dioxide, it picks up more oxygen. Carbon monoxide has 200 items
greateraffinity for the iron in haemoglobin than does oxygen and interrupts this cycle
by displacingoxygen. The result is a lowered amount of oxygen reaching the heart which
can lead to heartfailure in sensitive people.
Carbon monoxide also has other adverse effects in the body. For
example, it interferes with the oxygen-carrying proteins in muscles.
When humans are exposed to CO, it forms carboxyhaemoglobin at the expense
ofoxyhaemoglobin. Tissues are thus deprived of oxygen and asphyxiation occurs.
If the victimcontinues to receive a high dosage of CO, then permanent brain damage
and even death willresult. Initial symptoms include dizziness, headache, nausea and
faintness.

Downloaded by Omkar Rajmane (omkarrajmane09@gmail.com)

 lOMoARcPSD|4454852

Chronic exposure at 25 mg m-3 of CO in air causes cardiovascular problems which can

beparticularly dangerous to a person who already suffers from such problems. The
inhalation of 35ppm for eight hours causes a loss in ability to learn and do complicated
tasks, reduces
awareness, decreases manual dexterity, and disturb sleep activity
4 Carbon dioxide (CO2):
This noxious gas is another pollutant released when fossil fuels are burnt.
5 Particulates:
Small particles can be released into the air by aerosol use and by the combustion of
fossil fuels (for example, soot is released when coal is burned).
Besides above, nitrogen oxide (NOx) and hydrocarbons (H.C.) are major pollutants.
Further, organic and inorganic acids, bacteria, viruses, insecticides, etc. pollutes the air.

Sources of air pollutants:

Major sources of air pollution includes both natural sources and man-made source
(anthropogenic).

A. Natural sources:
The natural sources of air pollutants includes volcanic eruptions, forest fires, deflation of
sands and dusts, storms, etc.

• Volcanic pollutants :
Are produced as a result of volcanic activities. Examples: ashes, smokes, carbon dioxide,
chlorine, sulfur, dust and other gases.

• Land surface pollutants:

It often get mixed with earth’s atmosphere. The dust, sand, soil particles, salt, etc. are
the examples of land pollutants.
• The cosmic particles:
And rays, comets, etc. are the natural sources of air pollution.
• Green plants and vegetation:
That produces Volatile organic compounds (VOC) in large quantity are indirect
pollutants.
B. Anthropogenic (Man-made sources)

Downloaded by Omkar Rajmane (omkarrajmane09@gmail.com)

 lOMoARcPSD|4454852

Industries, automobiles, agriculture, power plants, domestic sources, etc. are the man-made or
anthropogenic sources of air pollution.

• Industrial air pollutants:

Are the harmful substances that are released into the air during the manufacturing,
production and other industrial process. The smokes, fumes, etc. emitted from large
industries and power plants are the examples of industrial air pollutants. The dust and
particulate matters also gets mixed with air to worsen the situation.
• Domestic air pollutants:
Are the contaminated chemicals and substances that released into the air as a result of
household activities. The domestic sources of air pollutant includes gases from kitchen,
burning of coal gas, fuel wood, etc.
• Vehicular pollutants:
Are emitted by various automobiles. The mixes and polluted the air. For example, the
smoke, gases, fumes, emissions from surface, water and air transport vehicles causes
pollution.

• Agricultural activities:
Also involves the introduction of pollutants into the environment. When insecticides,
pesticides and herbicides are sprayed on agricultural fields, they also get mixed with air.
This results to an increase in air pollution of the surrounding environment.
• Pollutants from fossil-fuel based power plants:
The heavy dependence on fossil fuels for meeting the power requirement has done much
damage to our environment. When fossil fuels are burnt, the produces several harmful
gases including CO2. The heat generated from the power plants negatively affects the
environment. The smokes and fly ash that is discharged get mixed with air.

Downloaded by Omkar Rajmane (omkarrajmane09@gmail.com)

 lOMoARcPSD|4454852

The impact of air pollution:

Air pollution have a negative impact on the environment andthe ecosystems within the
environment. They are discussed below in points:

• Smog:

Particulates can cause thick, gloomy clouds in the air. This can severely limit visibility,
and is a particular problem in big cities where vehicle use is very heavy.

• Respiratory problems in humans:

Sulfides, nitrous oxides and carbon monoxide can all cause respiratory illness in
humans In high quantities or over long periods of time, these pollutants can also be
fatal.

Downloaded by Omkar Rajmane (omkarrajmane09@gmail.com)

 lOMoARcPSD|4454852

• The acidification of the oceans:

If the air is polluted, these pollutants can dissolve into the oceans and saturate them
with carbon, particulates, sulfides and nitrates. In this way, air pollution turns into
water pollution as well, spoiling the habitats of marine and freshwater life.

• Freak weather:

Global warming does not just cause global temperatures of earth and sea to rise. It
also causes freak weather events such as huge blizzards, forest fires, tsunamis and so
on. This disrupts agriculture, destroys animals’ habitats and causes poverty, drought
and the displacement of vast numbers of human beings across the face of the earth.

How to Control Air Pollution?

Much of the air pollution is caused due to human activity. The following remedial measures
can be taken to control air pollution:

Downloaded by Omkar Rajmane (omkarrajmane09@gmail.com)

 lOMoARcPSD|4454852

• Plant more trees. Trees absorb greenhouses gases such as CO2 and releases O2 into the
air.
• Use fewer vehicles. Vehicles releases much of the pollutants into the air. An alternative
way to save air polluting is to start using e-vehicles.
• Use less fossil fuels. Fossil fuels such as coal, when burned, releases massive quantity of
polluting gases into the environment.
• Make use of Renewable energy. Unlike thermal power plants, that pollutes the air,
renewable sources of power such as hydro power, wind power, solar power, etc., are
comparatively less polluting.
• Use green technologies. Unlike traditional factories, that releases a lot of polluting
fumes in the air, modern green plants releases a minimal of polluting gases.

What are greenhouse gases?

A greenhouse gas is a gaseous compound present in the atmosphere that is able to trap heat.

Greenhouse gases are gases that contribute to the greenhouse effect. This is the name for the
warming of the earth when certain gases trap the sun’s rays in the atmosphere.

Greenhouse gases are gases such as carbon dioxide (CO2), carbon monoxide, water-vapor,
ozone, nitrous oxide, and sulfides, sulfurous compounds, CFC (chlorofluorocarbons), methane
and some substances found in aerosols.

Why are they called greenhouse gases?

These are called greenhouse gases because they trap heat within the earth’s atmosphere and
cause the greenhouse effect.

Such gases absorb infrared radiation resulting in a surge in earth’s temperature. The
greenhouse effect is the name for the warming up of the earth due to changes in its
atmosphere.

Are greenhouse gases harmful?

Greenhouse gases lead to environmental pollution and global warming. This is all part of the
wide phenomenon of climate change. Such gases are harmful gases in the atmosphere. The
adverse effects that they have on climate and the planet in general includes, rising sea levels,
melting ice caps and climate change.

Downloaded by Omkar Rajmane (omkarrajmane09@gmail.com)

 lOMoARcPSD|4454852

A greenhouse gas gives out radiation within the range of thermal infrared. The common term
for infrared energy is heat, and thus the warming effect.

The greenhouse effect must be combated by using less greenhouse gases as it poses a
substantial threat to the survival of all species on earth including humans.

Where do greenhouse gases come from?

The main source of greenhouse gases is fossil fuel combustion. A large amount of the harmful
levels of greenhouse gases in our atmosphere come from human industrial activity. This is
demonstrated by the levels of these gases in the atmosphere increased drastically during and
after the Industrial Revolution in the 1900s.

Causes:

Key causes of greenhouse gases include burning fossil fuels (which produces CO2 and other
chemicals), agriculture (nitrous oxide is released when fertilizers are sprayed onto crops and
the use of coolants and refrigerants (which contain high levels of CFCs).

Solution:

The reduction of the emission of greenhouse gases can be achieved by:

• Burn fewer fossil fuels.

• Using clean and green energy.
• Driving fuel-efficient vehicles.
• Planting trees.
• Using environment-friendly farming methods.
Greenhouse gases:

It lead to environmental pollution and global warming. They are the cause of the greenhouse
effect which has led to increased global temperatures.

The major sources of greenhouse gas are:

• Power Plants: Burning fossil fuel to generate electricity releases greenhouse gas.
2. Motor emissions: Vehicles emit greenhouse gas into the atmosphere as they burn-

Downloaded by Omkar Rajmane (omkarrajmane09@gmail.com)

 lOMoARcPSD|4454852

fuel.
3. Deforestation: Trees store nitrous oxide and methane which are released into the
atmosphere when they are cut down.
4. Factories: Manufacturing plants are a source of carbon dioxide and other
greenhouse gases.
5. Agriculture: Farming can also release greenhouse gases into the atmosphere.

Global Warming:

The rise in earth’s surface temperature as a consequence of greenhouse effect is called Global
Warming.

What is the meaning Global warming?

According to Wikipedia, “Global warming, also referred to as climate change, is the observed
century-scale rise in the average temperature of the Earth’s climate system and its related
effects.”

What causes Global Warming?

Downloaded by Omkar Rajmane (omkarrajmane09@gmail.com)

 lOMoARcPSD|4454852

1. Deforestation and industrial emissions result to an increase greenhouse gases (such as

carbon-dioxide) around earth’s atmosphere.

2. These greenhouse gases traps and absorbs atmospheric heat and ultimately causes
Global warming (an increase earth’s surface temperature).

Effects / Impact of Global Warming

If Global warming continues the world would be in danger. The major effects and impacts of
Global Warming are:

1. Climate Change: Global warming is causing climate change. The world’s is becoming
warmer and warmer. There is also prediction of regional climate changes along the
ecosystem.

2. Sea Level Change: One major consequence of global warming arising out of greenhouse
effect is the rise in sea level. Four major changes take place prior to this. They are: thermal
expansion, mountain glacier melting, greenland ice sheet melting and Polar (Arctic and
Antarctic) ice sheet melting. Thus, the coastal cities and ports may be submerged under sea-
water. Many islands may vanish from the earth surface as well as from the world map.

3. Water Balance: Although changes in sea-level have received much publicity, problems of
water availability are likely to be more serious and perhaps more expensive to solve. In future,
warmer world will face water crisis in some parts while in other regions it will be wetter than
it is now.

There is uncertainty regarding regional forecasts of future precipitation as warming of globe

makes it difficult to predict. Also, pattern of agricultural changes, or effects on ecosystems in
general are fairly unpredictable. This also puts threat on the rich biodiversity of the
ecosystem.

4. Human Health: The human health is put at risk because of Global warming. In recent
years, there have been newer reports of spread of major tropical diseases with changing
climate. As the earth becomes warmer, more and more people are likely to be affected by
tropical diseases.

How to prevent Global Warming?

Downloaded by Omkar Rajmane (omkarrajmane09@gmail.com)

 lOMoARcPSD|4454852

The problem of Global Warming can be controlled by minimizing the emission of greenhouse
gases into the environment. The following preventive steps would help save the earth from the
harmful effects of Global Warming.

• Laws. The Laws that governs pollution and greenhouse gases should be followed.
• Reduction in thermal power generating stations. Reduced dependence on thermal
power for our electricity need would help towards reducing the quantity if carbon
dioxide in the environment. The use of fossil fuels for generating conventional energy is
a major of greenhouse gases. Instead, we can rely on various forms of renewable
energies.
• We should not waste paper. We can save paper by keeping documents in electronic
format and by not printing emails.
• Planting Trees. Trees absorb carbon dioxide and releases oxygen. Trees are helpful in
reducing the problem of global warming.
• Sharing our car. We can share our car while going to office or performing other
scheduled activities. On one hand, we will save money, and on the other, we will emit
less greenhouse gases.
• We should minimize waste at our home. Instead of throwing the excess food stuff in
the garbage, we can use them in feeding the animals. Old and discarded clothes can be
donated to poor people.
• Use less electricity. We can put off the fans, heaters, and air-conditioners when not in
use. We can also install solar panels at our rooftops.
How to control global warming?
• Stop deforestation (cutting of trees).
• Start and adopt afforestation (establishment of new forests), reforestation
(reestablishment of old forests) and other forest conservation methods,Reduce the use
of fossil fuels in power and electricity generation.

Referrence:
• World Health Organization.Basic Environmental Health.WHO.
• Oxford University ,2001
• Gilbert “Introduction to Enginering & Science” 2nd edition 1996.
• UNEP, UNDP, World Bank(1998).
• Oxford University Press.

Downloaded by Omkar Rajmane (omkarrajmane09@gmail.com)