3. WHAT IS AIR
POLLUTION
Air pollution is the introduction of
chemicals , particulate matter , or
biological materials that cause
harm or discomfort to humans or
other living organisms, or cause
damage to the natural environment
or built environment , into the
atmosphere .
4. AIR POLLUTION
• The atmosphere is a complex dynamic
natural gaseous system that is essential to
support life on planet Earth. Stratospheric
ozone depletion due to air pollution has
long been recognized as a threat to
human health as well as to the Earth's
ecosystems.
• Indoor air pollution and urban air quality
are listed as two of the world's worst
pollution problems in the 2008
Blacksmith Institute World's Worst
Polluted Places report.
5. POLLUTANTS
A substance in the air that can cause harm to humans and the
environment is known as an air pollutant. Pollutants can be in
the form of solid particles, liquid droplets, or gases. In
addition, they may be natural or man-made.2
Pollutants can be classified as primary or secondary. Usually,
primary pollutants are directly emitted from a process, such as
ash from a volcanic eruption, the carbon monoxide gas from a
motor vehicle exhaust or sulfur dioxide released from
factories. Secondary pollutants are not emitted directly.
Rather, they form in the air when primary pollutants react or
interact. An important example of a secondary pollutant is
ground level ozone — one of the many secondary pollutants
that make up photochemical smog. Some pollutants may be
both primary and secondary: that is, they are both emitted
directly and formed from other primary pollutants.
7. PRIMARY POLLUTANTS
Major primary pollutants produced by human activity include:
Sulfur oxides (SOx) - especially sulphur dioxide, a chemical
compound with the formula SO2. SO2 is produced by
volcanoes and in various industrial processes. Since coal and
petroleum often contain sulphur compounds, their combustion
generates sulfur dioxide. Further oxidation of SO2, usually in
the presence of a catalyst such as NO2, forms H2SO4, and
thus acid rain.[2] This is one of the causes for concern over
the environmental impact of the use of these fuels as power
sources.
Nitrogen oxides (NOx) - especially nitrogen dioxide are
emitted from high temperature combustion. Can be seen as
the brown haze dome above or plume downwind of cities.
Nitrogen dioxide is the chemical compound with the formula
NO2. It is one of the several nitrogen oxides. This reddish-
brown toxic gas has a characteristic sharp, biting odor. NO2 is
one of the most prominent air pollutants.
8. Contd…
Carbon monoxide - is a colourless, odorless, non-irritating but very
poisonous gas. It is a product by incomplete combustion of fuel such
as natural gas, coal or wood. Vehicular exhaust is a major source of
carbon monoxide.
Carbon dioxide (CO2) - a colourless, odorless, non-toxic
greenhouse gas associated with ocean acidification, emitted from
sources such as combustion, cement production, and respiration
Volatile organic compounds - VOCs are an important outdoor air
pollutant. In this field they are often divided into the separate
categories of methane (CH4) and non-methane (NMVOCs).
Methane is an extremely efficient greenhouse gas which contributes
to enhanced global warming. Other hydrocarbon VOCs are also
significant greenhouse gases via their role in creating ozone and in
prolonging the life of methane in the atmosphere, although the effect
varies depending on local air quality. Within the NMVOCs, the
aromatic compounds benzene, toluene and xylene are suspected
carcinogens and may lead to leukemia through prolonged exposure.
1,3-butadiene is another dangerous compound which is often
associated with industrial uses.
9. Contd…
Volatile organic compounds (VOCs) are
organic chemicals that have a high vapor pressure at
ordinary, room-temperature conditions. Their high vapor
pressure results from a low boiling point, which causes
large numbers of molecules to evaporate or sublimate from
the liquid or solid form of the compound and enter the
surrounding air. An example is formaldehyde, with a boiling
point of –19 °C (–2 °F), slowly exiting paint and getting
into the air.
Many VOCs are dangerous to human health or cause harm
to the environment. VOCs are numerous, varied, and
ubiquitous. They include both man-made and naturally
occurring chemical compounds. VOCs play an important
role in communication between plants. 1 Anthropogenic
VOCs are regulated by law, especially indoors, where
concentrations are the highest. VOCs are typically not
acutely toxic, but instead have compounding long-term
health effects. Because the concentrations are usually low
and the symptoms slow to develop, research into VOCs and
their effects is difficult.
10. Contd…
Particulates – also known as particulate matter (PM), suspended
particulate matter (SPM), fine particles, and soot – are tiny
subdivisions of solid matter suspended in a gas or liquid. In contrast,
aerosol refers to particles and/or liquid droplets and the gas together.
Sources of particulate matter can be man made or natural. Air pollution
and water pollution can take the form of solid particulate matter, or be
dissolved.1 Salt is an example of a dissolved contaminant in water, while
sand is generally a solid particulate.
To improve water quality, solid particulates can be removed by
water filters or settling, and is referred to as insoluble particulate matter.
Dissolved contaminants in water are often collected by distilling, allowing
the water to evaporate and the contaminants to return to particle form
and precipitate.
Some particulates occur naturally, originating from volcanoes,
dust storms, forest and grassland fires, living vegetation, and sea spray.
Human activities, such as the burning of fossil fuels in vehicles,
power plants and various industrial processes also generate significant
amounts of particulates. Coal combustion in developing countries is the
primary method for heating homes and supplying energy. Averaged over
the globe, anthropogenic aerosols—those made by human activities—
currently account for about 10 percent of the total amount of aerosols in
our atmosphere.2 Increased levels of fine particles in the air are linked
to health hazards such as heart disease, altered lung function and
lung cancer.
12. Persistent free Radicals
Radicals (often referred to as free radicals) are atoms,
molecules, or ions with unpaired electrons on an open shell
configuration. Free radicals may have positive, negative, or
zero charge. With some exceptions, the unpaired electrons
cause radicals to be highly chemically reactive.
Radicals, if allowed to run free in the body, are believed to
be involved in degenerative diseases, senescence (the
aging process), and cancers.
Free radicals play an important role in combustion,
atmospheric chemistry, polymerization, plasma chemistry,
biochemistry, and many other chemical processes. In
chemical biology, superoxide and nitric oxide regulate many
processes, such as controlling vascular tone. Such radicals
can even be messengers in a phenomenon dubbed
redox signaling. A radical may be trapped within a
solvent cage or be otherwise bound.
13. Secondary pollutants include :
Particulate matter formed from gaseous primary pollutants and
compounds in photochemical smog. Smog is a kind of air
pollution; the word "smog" is a portmanteau of smoke and fog.
Classic smog results from large amounts of coal burning in an
area caused by a mixture of smoke and sulfur dioxide. Modern
smog does not usually come from coal but from vehicular and
industrial emissions that are acted on in the atmosphere by
ultraviolet light from the sun to form secondary pollutants that
also combine with the primary emissions to form
photochemical smog.
Ground level ozone (O3) formed from NOx and VOCs. Ozone
(O3) is a key constituent of the troposphere. It is also an
important constituent of certain regions of the stratosphere
commonly known as the Ozone layer. Photochemical and
chemical reactions involving it drive many of the chemical
processes that occur in the atmosphere by day and by night.
At abnormally high concentrations brought about by human
activities (largely the combustion of fossil fuel), it is a
pollutant, and a constituent of smog.
Peroxyacetyl nitrate (PAN) - similarly formed from NOx and
VOCs.
14. Minor air pollutants include:
Persistent organic pollutants (POPs) are
organic compounds that are resistant to
environmental degradation through
chemical, biological, and photolytic
processes. Because of this, they have been
observed to persist in the environment, to
be capable of long-range transport,
bioaccumulate in human and animal tissue,
biomagnify in food chains, and to have
potential significant impacts on human
health and the environment.
15. Sources
Sources of air pollution refer to the various
locations, activities or factors which are
responsible for the releasing of pollutants
into the atmosphere. These sources can
be classified into two major categories
which are:
Anthropogenic sources (human
activity) mostly related to burning
different kinds of fuel
17. Power Station
A power station (also referred to as a
generating station, power plant, or
powerhouse) is an industrial facility for the
generation of electric energy.123
At the center of nearly all power stations is a
generator, a rotating machine that converts
mechanical energy into electrical energy by
creating relative motion between a magnetic field
and a conductor. The energy source harnessed to
turn the generator varies widely. It depends
chiefly on which fuels are easily available and on
the types of technology that the power company
has access to.
18. Contd…
The world's first
power station was
built by Sigmund
Schuckert in the
Bavaria town of
Ettal and went into
operation in 18784.
The station
consisted of 24
dynamo electric
generators which
were driven by a
steam engine. It
was used to
illuminate a grotto
in the gardens of
Linderhof Palace.
19. Indore Air Quality (IAQ)
A lack of ventilation indoors concentrates air pollution where
people often spend the majority of their time. Radon (Rn) gas, a
carcinogen, is exuded from the Earth in certain locations and
trapped inside houses. Building materials including carpeting and
plywood emit formaldehyde (H2CO) gas. Paint and solvents give
off volatile organic compounds (VOCs) as they dry. Lead paint can
degenerate into dust and be inhaled. Intentional air pollution is
introduced with the use of air fresheners, incense, and other
scented items. Controlled wood fires in stoves and fireplaces can
add significant amounts of smoke particulates into the air, inside
and out.13 Indoor pollution fatalities may be caused by using
pesticides and other chemical sprays indoors without proper
ventilation.
Carbon monoxide (CO) poisoning and fatalities are often caused
by faulty vents and chimneys, or by the burning of charcoal
indoors. Chronic carbon monoxide poisoning can result even from
poorly adjusted pilot lights. Traps are built into all domestic
plumbing to keep sewer gas, hydrogen sulfide, out of interiors.
Clothing emits tetrachloroethylene, or other dry cleaning fluids,
for days after dry cleaning.
20. Contd…
Though its use has now been banned in many countries, the extensive use
of asbestos in industrial and domestic environments in the past has left a
potentially very dangerous material in many localities. Asbestosis is a
chronic inflammatory medical condition affecting the tissue of the lungs. It
occurs after long-term, heavy exposure to asbestos from asbestos-
containing materials in structures. Sufferers have severe dyspnea
(shortness of breath) and are at an increased risk regarding several
different types of lung cancer. As clear explanations are not always
stressed in non-technical literature, care should be taken to distinguish
between several forms of relevant diseases. According to the
World Health Organisation (WHO), these may defined as; asbestosis, lung
cancer, and Peritoneal Mesothelioma (generally a very rare form of cancer,
when more widespread it is almost always associated with prolonged
exposure to asbestos).
Biological sources of air pollution are also found indoors, as gases and
airborne particulates. Pets produce dander, people produce dust from
minute skin flakes and decomposed hair, dust mites in bedding, carpeting
and furniture produce enzymes and micrometre-sized fecal droppings,
inhabitants emit methane, mold forms in walls and generates mycotoxins
and spores, air conditioning systems can incubate Legionnaires' disease
and mold, and houseplants, soil and surrounding gardens can produce
pollen, dust, and mold. Indoors, the lack of air circulation allows these
airborne pollutants to accumulate more than they would otherwise occur in
nature.
21. Health effects
The World Health Organization states that 2.4 million people die
each year from causes directly attributable to air pollution, with
1.5 million of these deaths attributable to indoor air pollution. 14 "
Epidemiological studies suggest that more than 500,000
Americans die each year from cardiopulmonary disease linked to
breathing fine particle air pollution. . ."15 A study by the
University of Birmingham has shown a strong correlation between
pneumonia related deaths and air pollution from motor vehicles.
16 Worldwide more deaths per year are linked to air pollution than
to automobile accidents.[] Published in 2005 suggests that
310,000 Europeans die from air pollution annually.[] Causes of
deaths include aggravated asthma, emphysema, lung and heart
diseases, and respiratory allergies.[] The US EPA estimates that a
proposed set of changes in diesel engine technology (Tier 2) could
result in 12,000 fewer premature mortalities, 15,000 fewer
heart attacks, 6,000 fewer emergency room visits by children with
asthma, and 8,900 fewer respiratory-related hospital admissions
each year in the United States.[] Air pollution is also emerging as
a risk factor for stroke, particularly in developing countries where
pollutant levels are highest.17
22. Effect of cystic fibrosis
A study from around the years of 1999 to 2000, by the
University of Washington, showed that patients near and
around particulate matter air pollution had an increased risk of
pulmonary exacerbations and decrease in lung function.23
Patients were examined before the study for amounts of
specific pollutants like Pseudomonas aeruginosa or
Burkholderia cenocepacia as well as their socioeconomic
standing. Participants involved in the study were located in the
United States in close proximity to an
Environmental Protection Agency.[] During the time of the
study 117 deaths were associated with air pollution. Many
patients in the study lived in or near large metropolitan areas
in order to be close to medical help. These same patients had
higher level of pollutants found in their system because of
more emissions in larger cities. As cystic fibrosis patients
already suffer from decreased lung function, everyday
pollutants such as smoke, emissions from automobiles,
tobacco smoke and improper use of indoor heating devices
could further compromise lung function.24
23. EFFECTS OF COPD
Chronic obstructive pulmonary disease (COPD), also known
as chronic obstructive lung disease (COLD), chronic
obstructive airway disease (COAD), chronic airflow
limitation (CAL) and chronic obstructive respiratory disease
(CORD), is the co-occurrence of chronic bronchitis and
emphysema, a pair of commonly co-existing diseases of the lungs
in which the airways become narrowed.1 This leads to a limitation
of the flow of air to and from the lungs, causing
shortness of breath (dyspnea). In clinical practice, COPD is
defined by its characteristically low airflow on lung function tests.2
In contrast to asthma, this limitation is poorly reversible and
usually gets progressively worse over time. In England, an
estimated 842,100 of 50 million people have a diagnosis of COPD.
3
COPD is caused by noxious particles or gas, most commonly from
tobacco smoking, which triggers an abnormal
inflammatory response in the lung.4
The diagnosis of COPD requires lung function tests. Important
management strategies are smoking cessation, vaccinations,
rehabilitation, and drug therapy (often using inhalers). Some
patients go on to require long-term oxygen therapy or
lung transplantation.
24. Air Pollution
Studies in many countries have found people who
live in large cities have a higher rate of COPD
compared to people who live in rural areas.27
Urban air pollution may be a contributing factor for
COPD, as it is thought to slow the normal growth of
the lungs, although the long-term research needed
to confirm the link has not been done. Studies of
the industrial waste gas and COPD/asthma-
aggravating compound, sulfur dioxide, and the
inverse relation to the presence of the blue lichen
Xanthoria (usually found abundantly in the
countryside, but never in towns or cities) have been
seen to suggest combustive industrial processes do
not aid COPD sufferers. In many
developing countries, indoor air pollution from
cooking fire smoke (often using biomass fuels such
as wood and animal dung) is a common cause of
COPD, especially in women.
25. Genetics
Some factor in addition to heavy smoke exposure is
required for a person to develop COPD. This factor
is probably a genetic susceptibility. COPD is more
common among relatives of COPD patients who
smoke than unrelated smokers.29 The genetic
differences that make some peoples' lungs
susceptible to the effects of tobacco smoke are
mostly unknown. Alpha 1-antitrypsin deficiency is a
genetic condition that is responsible for about 2%
of cases of COPD. In this condition, the body does
not make enough of a protein, alpha 1-antitrypsin.
Alpha 1-antitrypsin protects the lungs from damage
caused by protease enzymes, such as elastase and
trypsin, that can be released as a result of an
inflammatory response to tobacco smoke.
26. Effect of children
Cities around the world with high exposure to air pollutants
have the possibility of children living within them to develop
asthma, pneumonia and other lower respiratory infections as
well as a low initial birth rate. Protective measures to ensure
the youths' health are being taken in cities such as New Delhi,
India where buses now use compressed natural gas to help
eliminate the “pea-soup” smog.28 Research by the
World Health Organization shows there is the greatest
concentration of particulate matter particles in countries with
low economic world power and high poverty and population
rates. Examples of these countries include Egypt, Sudan,
Mongolia, and Indonesia. In the United States, the
Clean Air Act was passed in 1970, however in 2002 at least 146
million Americans were living in non-attainment areas—regions
in which the concentration of certain air pollutants exceeded
federal standards.29 Those pollutants are known as the
criteria pollutants, and include ozone, particulate matter, sulfur
dioxide, nitrogen dioxide, carbon monoxide, and lead. Because
children are outdoors more and have higher minute ventilation
they are more susceptible to the dangers of air pollution.
27. Control Devices
The following items are commonly used as
pollution control devices by industry or
transportation devices. They can either destroy
contaminants or remove them from an exhaust
stream before it is emitted into the atmosphere.
Particulate scrubbersWet scrubber is a form of
pollution control technology. The term describes a
variety of devices that use pollutants from a
furnace flue gas or from other gas streams. In a
wet scrubber, the polluted gas stream is brought
into contact with the scrubbing liquid, by spraying
it with the liquid, by forcing it through a pool of
liquid, or by some other contact method, so as to
remove the pollutants.
28. Legal Regulations
In general, there are two types of
air quality standards. The first class
of standards (such as the U.S.
National Ambient Air Quality
Standards and E.U. Air Quality
Directive) set maximum
atmospheric concentrations for
specific pollutants. Environmental
agencies enact regulations which
are intended to result in attainment
of these target levels. The second
class (such as the North American
Air Quality Index) take the form of
a scale with various thresholds,
which is used to communicate to
the public the relative risk of
outdoor activity. The scale may or
may not distinguish between
different pollutants.
29. Governing Urban Air Pollution
In Europe, Council Directive 96/62/EC on ambient air
quality assessment and management provides a common
strategy against which member states can “set objectives
for ambient air quality in order to avoid, prevent or reduce
harmful effects on human health and the environment . . .
and improve air quality where it is unsatisfactory”.35
On 25 July 2008 in the case Dieter Janecek v Freistaat
Bayern CURIA, the European Court of Justice ruled that
under this directive35 citizens have the right to require
national authorities to implement a short term action plan
that aims to maintain or achieve compliance to air quality
limit values.36
This important case law appears to confirm the role of the
EC as centralised regulator to European nation-states as
regards air pollution control. It places a supranational legal
obligation on the UK to protect its citizens from dangerous
levels of air pollution, furthermore superseding national
interests with those of the citizen.