Air Pollution
By- Anup Muni Bajracharya

Air Pollution
• Defination
• Undesirable, unwanted changes in the physical,
chemical and biological characteristics of air that
have adverse effects on biotic community like
Human, plants and animals.
• “the presence of one or several substances in the
external atmosphere, introduced by man to such
an extent as to effect health and welfare of
human system and the life in the atmosphere.”

Types of Air Pollutants
• There are two types
of air pollutants:
Primary Pollutants
• The pollutants that
directly cause air
pollution are known
as primary pollutants.
Sulphur-dioxide
emitted from factories
is a primary pollutant.
Secondary Pollutants
• The pollutants formed
by the intermingling
and reaction of
primary pollutants are
known as secondary
pollutants. Smog,
formed by the
intermingling of
smoke and fog, is a
secondary pollutant.

Sources
• Air pollution mainly caused by
human activities, even though
sometimes it can result from
Natural phenomena such as
volcanic eruptions, dust storms
and wildfires
• Anthropogenic air
pollution sources are:
• 1. Combustion of fossil fuels
• 2. Emissions from industries
and factories
• 3. Domestic sources
• 4. Agricultural activities
• 5. Waste production
volcanic eruptions
Forest fires

1. Emissions from industries and factories
Fluoride, Nitric acid, Iron-steel, Chloro-
alkali, Cement, Mineral acid plant and
industries are most common sources of air
pollutants. These emits a variety of
pollutants in the atmosphere specially
oxides of carbon, nitrogen, and sulphur.
The metallurgical industry: high-
temperature processing of ores emit
aerosols rich in trace elements (Cd, Cu, Ni,
Pb, V, and Zn).
•Other industrial processes: high-
temperature processing and manufacturing
( Cr, Cu, Ni, Pb, and Zn)
•Transport: road traffic (Cd, Cu, Fe, Ni, Pb,
and Zn), erosion of brake pads (Cu, and Sb),
erosion of train rails (Cu)
•Waste treatment: incineration of
household waste (As, Cr, Cu, Ni, Pb, Sb, Se,
V, and Zn)

2. Automobiles/Vehicles
Gasoline used in automobiles
as fuel produces carbon-
monooxide, hydrocarbons,
lead compounds, carbon
particles and some carbonyl
compounds in the
atmosphere. They are the
major source of air pollution.

Automobile Pollutants
• i. Hydrocarbons:
• A class of burned or partially burned fuel, hydrocarbons are toxins
and are a major contributor to smog, which can be a major problem
in urban areas.
• ii. Carbon monoxide (CO):
• A product of incomplete combustion, carbon monoxide reduces the
blood’s ability to carry oxygen.
• iii. Nitrogen oxides (NOx):
• Generated when nitrogen in the air reacts with oxygen at the high
temperature and pressure inside the engine.
• iv. Particulate matter:
• Soot or smoke made up of particles in the micrometre size range:
• v. Sulfur oxide (SOx):
• A general term for oxides of sulphur, which are emitted from motor
vehicles burning fuel containing a high concentration of sulphur.

3. Domestic sources- Combustion of fuels
Domestic combustion of fuels result in the
emissions of CO2, CO, and NO fueled by wood,
agricultural residues, and dung.
The smell from the newly painted walls is
the smell of the chemicals present in the
paints. It not only pollutes the air but also
affects breathing.

4. Agricultural activities
A range of pollutant gases, and especially nitrogen compounds
(NO2, NO, NH3, N2O) are emitted to the atmosphere from
agricultural activities, including fertilizer use, farm machinery
and livestock waste
Burning of crop residues
Fertiliser releases ammonia which mixes with the pollution from traffic, gas burning and industry

5. Waste treatment-burning/incineration
• Open waste burning gave the following emissions to
the atmosphere:
• Carbon monoxide (CO)
• PM (soot and ash)
• Aldehydes
• Polycyclic Aromatic Hydrocarbons (PAH)

Others…
• Thermal power plants
thermal power plants of are main source of dust, carbon
oxide, aldehydes, carbon, hydrocarbon, ash etc. are the
common emission of power plants.
• Mining Activities
In the mining process, the minerals below the earth are
extracted using large pieces of equipment. The dust and
chemicals released during the process not only pollute the air,
but also deteriorate the health of the workers and people
living in the nearby areas.
• Other sources
solid wastes, radio-active natural sources, viable particles,
odour pollutants etc.

Effects of Air Pollution
• The hazardous effects of air pollution on the
environment include:
• Diseases
• Global warming
• Ozone depletion
• Acid rain

Diseases
• Diseases caused by air pollutants kill and hospitalize millions of
people every year.
• Estimates by the World Health Organization imply that one out of
every eight deaths in the world is due to conditions associated with
air pollution.
• New research has established stronger links between both outdoor
and indoor air pollution and the development of respiratory and
cardiovascular diseases.
• The most common diseases caused by air pollution include
• ischemic heart disease/coronary heart disease,
• stroke,
• chronic obstructive pulmonary disease (COPD),
• lung cancer and
• acute lower respiratory infections in children.

Ischemic heart disease, or coronary
heart disease, is linked with the buildup
of calcium or other materials like fat
within the coronary artery. This leads to
blockages which prevent blood from
reaching the heart and other areas of
the body.
COPD refers to not a single disease,
but multiple diseases which make it
difficult to breathe. These diseases
include bronchitis and emphysema,
and both conditions can be caused
by damage to the lungs from air
pollutants.
Diseases

Lung cancer is the uncontrolled division of
cells within the lungs, and it is associated
with air pollutants, especially particulate
matter pollution, and secondhand smoke.
“Particulate air pollution has been linked
with strokes, which occur when the
blood supply to the brain is cut-off.
Strokes can easily lead to brain damage
or death.
Children are especially vulnerable to
developing acute lower respiratory tract
infections because their bodies and lungs are
still developing, and emissions of soot and
other pollutants hit them harder than adults.
Diseases

Global warming
Global warming is a phenomenon of
climate change characterized by a
general increase in average
temperatures of the Earth, which
modifies the weather balances and
ecosystems for a long time. It is directly
linked to the increase of greenhouse
gases in our atmosphere, worsening
the greenhouse effect

Green house effect
Global warming occurs when carbon
dioxide (CO2) and other air pollutants
collect in the atmosphere and absorb
sunlight and solar radiation that have
bounced off the earth’s surface.
Normally this radiation would escape
into space, but these pollutants, which
can last for years to centuries in the
atmosphere, trap the heat and cause
the planet to get hotter.
These heat-trapping pollutants—
specifically carbon dioxide, methane,
nitrous oxide, water vapor, and
synthetic fluorinated gases—are known
as greenhouse gases, and their impact
is called the greenhouse effect.

Effects of Global Warming
• Disappearing glaciers, early snowmelt, and severe droughts will cause more
dramatic water shortages and continue to increase the risk of wildfires.
• Rising sea levels will lead to even more coastal flooding
A.B
A.B

Acid rain
A.B

Dead or dying trees are a common sight in
areas effected by acid rain.
Acid rain leaches aluminum from the
soil. That aluminum may be harmful to
plants as well as animals.
Acid rain also removes minerals and
nutrients from the soil that trees need to
grow.
Acid Rain Damages Buildings and Objects
damaging effect on buildings, statues,
monuments, and cars.
can cause paint to peel and stone statues
to begin to appear old and worn down,
which reduces their value and beauty.
Acid Rain Damages Lakes and Streams-pH low
Acid Rain Can Cause Health Problems
in People-asthma,bronchitis
Effects of Acid rain

Ozone depletion

How CFCs destroys Ozone

Effects of ozone depletion
A.B

Preventive measures
• Prevention methods can either come from government (laws) or by
individual action.
• Public awareness programs should be launched.
• The alternative source of energy like solar energy, wind energy,
electric energy etc. should be used in place of fossil fuels like coal,
wood, oil etc.
• In industries the air filtration technique should be used.
• Legislative actions by government.
• Population growth rate should be controlled.
• Plantation should be done.
• The use of cheap fuel with higher sulphur content should be
avoided.
• Use of public vehicles or eco-friendly vehicles.