Air

Pollution
 Learning Objectives

✓ Determine different sources and factors of Air Pollution

✓ Evaluate on how air pollution affects in micro, meso, and global scales
✓ Analyze some practices to mitigate air pollution
 Air Pollution
The release of pollutants such as gases, particles, biological
molecules, etc. into the air that is harmful to human health
and the environment.
 Air Pollution
Contamination of the indoor or outdoor environment by any
chemical, physical or biological agent that modifies the natural
characteristics of the atmosphere.
 Air Pollution
Household combustion devices, motor vehicles, industrial
facilities and forest fires are common sources of air pollution.
 Types and Sources Of Air
Pollutants

Primary Air Pollutants Secondary Air Pollutants

Types Air
Pollutants Primary Air Pollutants

A primary pollutant is an air pollutant

emitted directly from a source.

Secondary Air Pollutant

A secondary pollutant is not directly
emitted as such, but forms when other
pollutants (primary pollutants) react in the
atmosphere.
 Primary Source of
Transportations
Air Pollutant
Combustion engines from cars and trucks
produce a number of polluting elements including
ozone, particulate matter, and other smog-
forming emissions. Nitrogen oxide and carbon
monoxide are other main components of this
exhaust, and both have had a proven negative
impact on the environment. It is estimated that in
2013, transportation contributed more than half
of the carbon monoxide and nitrogen oxides in
the atmosphere. It also contributed to almost a
quarter of the hydrocarbons emitted into our
air.
 Primary Source of
Transportations
Air Pollutant
Car exhaust also contains a number of volatile
organic compounds that react badly with nitrogen
oxides in the presence of sunlight. These
compounds form what is essentially ground-level
ozone, the main ingredient in smog. Other
dangerous chemicals in these volatile organic
compounds include toxic air pollutants such as
benzene, acetaldehyde, and 1,3-butadiene, all of
which have been linked to cancer.
 Primary Source of
Industrial Activities
Air Pollutant
Industrial air pollution is when factories, mines,
and transportation release harmful substances
into the air. These pollutants can cause health
problems such as respiratory diseases, cancers,
decreased lung function, and asthma. They can
also harm the environment, leading to things like
acid rain and climate change. Industrial facilities
emit a wide range of pollutants into the air,
including particulate matter, sulfur dioxide,
nitrogen oxides, and other toxic chemicals.
 Primary Source of
Sources of emissions in Industries Air Pollutant
Point-Source Emissions – also known as
stationary sources of emission, are released at
height or ground level, from an identifiable
source, and are dispersed in the atmosphere.
Emissions from stationary sources. It is easy to
trace the source of such emissions back to
stacks, outlets, etc.
 Primary Source of
Sources of emissions in Industries Air Pollutant
Non-Point Source – A source of emission that is
not easily identifiable. These are called mobile and
fugitive emissions, they consist of leaks of
particulate matter from transportation and
loading, for example, are not identifiable and
stationary sources. Also called diffuse or
‘fugitive emissions’ (non-point sources), are
contrary to stack emissions and originate from
an area, such as a stockpile or a road.
 How does it affect Human health?

The impact of industrial air pollution on the residents of an industrial

township can be significant. Long-term exposure to these pollutants can cause
respiratory and cardiovascular diseases, as well as cancers. It can also lead
to decreased lung function, increased frequency of asthma attacks, and
other respiratory illnesses. In addition, industrial air pollution can also
contribute to environmental degradation, such as acid rain and climate
change, which can have far-reaching impacts on human health and the
environment.
Primary Source of Air
Agriculture Practices
Pollutant
Agricultural pollution is contamination of the
environment and related surroundings as a result of
using the natural and chemical products for farming.
This contamination is actually injurious to all living
organisms that depend on the food on cultivation.

Causes of Agricultural Pollution

Chemical fertilizers
These are mostly nitrogen and phosphorus based
chemicals like ammonia and nitrates that in correct
amounts boost the fertility of the soil. But in most
cases these are used in more quantity than required
and hence tend to be retained in the soil not adding to
its goodness.
Primary Source of Air
Pollutant Heavy metals

Cadmium, fluoride, radioactive elements like uranium are

regularly found in the parent minerals from which the
fertilisers are obtained. Dangerous metals such as
Mercury, Lead, Arsenic, Chromium, and Nickel are seen
in traces in Zinc rich wastes from the steel industries
which are used as fertilizers. These are often not
removed from the because of the high cost involved.
Primary Source of Air
Pollutant
Animal management

Farms specializing in rearing cattle, sheep, goats, pigs,

and poultry must have strict regulations concerning the
disposal of manure and other associated waste
material. These must not be indiscriminately disposed in
the surrounding areas. They cause pollution of the air
as well as the water. 18 per cent of Greenhouse gases
are said to be generated by farm animals. The large
amounts of manure created, carry pathogens that are
harmful for humans too. Proper animal waste
management can reduce the huge bulk of it, making it
easier to use.
Primary Source of Air
Pollutant Kaingin

In rural and agricultural areas, the end of the dry

season often coincides with the practice of crop
burning. Farmers burn crop residue to prepare the land
for the next planting season, leading to a significant
release of pollutants. This practice, while localised, can
have a substantial impact on the air quality in
surrounding areas. The smoke from these fires contains
a high concentration of particulate matter and other
harmful pollutants, posing health risks to local
communities.
Primary Source of Air
Construction and Demolition
Pollutant Construction or demolition works deteriorate air quality
in three main ways:
Dust nuisance. The circulation of machinery,
demolition operations or the loading and unloading of
materials release suspended particles (PM10, PM2.5
and PM1) that can cause health risks when inhaled,
especially among the most vulnerable groups of
people.
Atmospheric emissions from machinery. Machinery on
a construction site generates noise, dust and gases
such as NOx or CO.
Transport of construction materials. The handling
of construction materials also contributes to higher
pollution levels, especially in the case of particulate
matter.
Primary Source of Air
Construction and Demolition
Pollutant
Air pollution from construction is a real challenge due
to the various sources and emanation of different
pollutants. In this respect, particulate matter is one of
the most harmful emissions. Their hazardous nature
derives from their size, for example, particles ranging
from 10 microns (PM10) to 1 micron (PM1). In addition
to this characteristic, sometimes the nature of the
particle must also be taken into account, since, in the
case of asbestos, silica or wood, it can represent an
added risk factor. However, detailed analyses are
necessary to ascertain this.
Secondary Source
Ozone (O3)
of Air Pollutants
Ozone (O3) is present throughout the atmosphere
although there are concentration peaks at two levels,
the stratosphere (15 - 50 km) and troposphere (0-15
km), with the largest fraction and concentrations being
in the stratospheric O3 layer ( Royal Society, 2008).
Stratospheric O3 is important as it regulates the
transmittance of ultraviolet light to the surface of the
earth. Hence reductions in stratospheric O3 in polar
regions, particularly the Antarctic "ozone hole", are of
concern regarding the health effects of exposure to
increased levels of UV-B.
Secondary Source
Ozone (O3)
of Air Pollutants
Formation and Sources

Ground-level ozone (O3) is not emitted directly from

anthropogenic sources. It is a “secondary” pollutant
formed by a complicated series of chemical reactions in
the presence of sunlight. Photochemical reactions of
NOx and VOCs (originating from largely from
combustion processes) govern the concentration of
ground-level O3 in the atmosphere. Under typical
daytime conditions with a well-mixed atmosphere, three
reactions reach equilibrium and no net chemistry occurs.
Secondary Source
Particulate Matter
of Air Pollutants When it comes to particulate matter and health, size
matters: According to the U.S. Environmental
Protection Agency, differently sized particles are
associated with different health effects. The commonly
regulated size classifications are PM10 (inhalable
particles with diameters of 10 micrometers and less)
and PM2.5 (respirable particles with diameters of 2.5
micrometers and less). Larger particles can irritate our
airways, while smaller particles can penetrate deeper
into our lungs and bloodstream and cause inflammation
that affects other organs. Scientists have associated
PM2.5 with increased risk of coronary heart disease,
heart attacks, and strokes. Other studies show people
who breathe more particulate matter are more likely to
develop lung cancer, respiratory tract infections, chronic
obstructive pulmonary disease (COPD), and problems
during pregnancy and birth, such as preterm birth and
low birth weight.
Secondary Source
Acid Rain
of Air Pollutants Acid rain results when sulfur dioxide (SO2) and nitrogen
oxides (NOX) are emitted into the atmosphere and
transported by wind and air currents. The SO2 and
NOX react with water, oxygen and other chemicals to
form sulfuric and nitric acids. These then mix with water
and other materials before falling to the ground.

While a small portion of the SO2 and NOX that cause

acid rain is from natural sources such as volcanoes, most
of it comes from the burning of fossil fuels. The major
sources of SO2 and NOX in the atmosphere are

Burning of fossil fuels to generate electricity. Two

thirds of SO2 and one fourth of NOX in the
atmosphere come from electric power generators.
Vehicles and heavy equipment.
Manufacturing, oil refineries and other industries.
Secondary Source
Smog
of Air Pollutants
Smog is air pollution that reduces visibility. The term
"smog" was first used in the early 1900s to describe a mix
of smoke and fog. The smoke usually came from burning
coal. Smog was common in industrial areas, and remains a
familiar sight in some cities today.

Today, most of the smog we see is photochemical smog.

Photochemical smog is produced when sunlight reacts with
nitrogen oxides and at least one volatile organic compound
(VOC) in the atmosphere. Nitrogen oxides come from car
exhaust, coal power plants, and factory emissions. VOCs
are released from gasoline, paints, and many cleaning
solvents. When sunlight hits these chemicals, they form
airborne particles and ground-level ozone—or smog.
Factors that Affects Air
Pollution
Air pollution is contamination of the indoor or outdoor environment by any chemical, physical or
biological agent that modifies the natural characteristics of the atmosphere.
Household combustion devices, motor vehicles, industrial facilities and forest fires are common
sources of air pollution. Pollutants of major public health concern include particulate matter, carbon
monoxide, ozone, nitrogen dioxide and sulfur dioxide. Outdoor and indoor air pollution cause
respiratory and other diseases and are important sources of morbidity and mortality.
WHO data show that almost all of the global population (99%) breathe air that exceeds WHO
guideline limits and contains high levels of pollutants, with low- and middle-income countries suffering
from the highest exposures.

Air quality is closely linked to the earth’s climate and ecosystems globally. Many of the drivers of
air pollution (i.e. combustion of fossil fuels) are also sources of greenhouse gas emissions. Policies to
reduce air pollution, therefore, offer a win-win strategy for both climate and health, lowering the
burden of disease attributable to air pollution, as well as contributing to the near- and long-term
mitigation of climate change.
Thank you