Air pollution is caused by harmful smoke and fumes as also particulate matter from various sources such as exhausts of vehicular traffic, factories, burning of fossil fuels, burning of garbage and farm refuse, and construction sites. Air pollution is a big health hazard causing several diseases in humans. It affects the respiratory and cardiac systems of the human body, and also affects the eyes and other organs of the body. Millions of people die each year due to air pollution. We need to take stringent measures urgently to curb air pollution and improve the quality of the air we breathe.
NATURAL AIR POLLUTION:
When we think of pollution, we
tend to think it's a problem that humans cause through ignorance or
stupidity—and that's certainly true, some of the time. However, it's important
to remember that some kinds of air pollution are produced naturally. Forest
fires, erupting volcanoes, and gases released from radioactive decay of rocks
inside Earth are just three examples of natural air pollution that can have
hugely disruptive effects on people and the planet.
Forest fires (which often start
naturally) can produce huge swathes of smoke that drift for miles over
neighbouring cities, countries, or continents. Giant volcanic eruptions can
spew so much dust into the atmosphere that they block out significant amounts
of sunlight and cause the entire planet to cool down for a year or more.
Radioactive rocks can release a gas called radon when they decay, which can
build up in the basements of buildings with serious effects on people's health
(each year, around 21,000 people die of lung cancer, due to radon gas in the
United States).
AIR POLLUTION IN INDIA:
Air pollution occurs when harmful or excessive
quantities of substances including gases, particles, and biological molecules
are introduced into the Earth's atmosphere. Air pollution in India is a serious
issue, ranking higher than smoking, high blood pressure, child and maternal
malnutrition, and risk factors for diabetes. At least 140 million people
breathe air 10 times or more over the WHO safe limit and 13 of the world's 20 cities with the
highest annual levels of air pollution are in India. Air pollution contributes to the premature
deaths of 2 million Indians every year. In urban areas, most emissions come
from vehicles and industry, whereas in rural areas, much of the pollution stems
from biomass burning for cooking and keeping warm. In autumn and winter months,
large scale crop residue burning in agriculture fields – a low cost alternative
to mechanical tilling – is a major source of smoke, smog and particulate
pollution. India has a low per capita emissions of greenhouse gases but the
country as a whole is the third largest after China and the United States. A
2013 study on non-smokers has found that Indians have 30% lower lung function
compared to Europeans.
The Air (Prevention and Control
of Pollution) Act was passed in 1981 to regulate air pollution and there have
been some measurable improvements. However, the 2016 Environmental Performance
Index ranked India 141 out of 180 countries.
In 2015, Government of India,
together with IIT Kanpur launched the National Air Quality Index.[10] In 2019,
India launched 'The National Clean Air Programme' with tentative national
target of 20%-30% reduction in PM2.5 and PM10 concentrations by 2024, considering
2017 as the base year for comparison. It will be rolled out in 102 cities that
are considered to have air quality worse than the National Ambient Air Quality
Standards.
CAUSES OF AIR POLLUTION:
Different types of causes which is
responsible for air pollution.
POWERPLANTS:
Renewable energy sources such as
solar panels and wind turbines are helping us generate a bigger proportion of
our power every year, but the overwhelming majority of electricity (around 70
percent in the United States, for example) is still produced by burning fossil
fuels such as coal, gas, and oil, mostly in conventional power plants. Just
like car engines, power plants should theoretically produce nothing worse than
carbon dioxide and water; in practice, fuels are dirty and they don't burn
cleanly, so power plants produce a range of air pollutants, notably sulfur
dioxide, nitrogen oxides, and particulates. (They also release huge amounts of
carbon dioxide, a key cause of global warming and climate change when it rises
and accumulates in the atmosphere. We discuss this a bit more down below).
INDUSTRIAL PLANT AND FACTORIES:
Plants that produce the goods we
all rely on often release small but significant quantities of pollution into
the air. Industrial plants that produce metals such as aluminumand steel,
refine petroleum, produce cement, synthesize plastic, or make other chemicals
are among those that can produce harmful air pollution. Most plants that
pollute release small amounts of pollution continually over a long period of
time, though the effects can be cumulative (gradually building up). Sometimes
industrial plants release huge of amounts of air pollution accidentally in a
very short space of time. One notable case happened in Bhopal, India in
December 1984, when a large chemical plant run by the Union Carbide company
released a poisonous gas (methyl isocaynate) that hung over the local area,
killing around 3000 people and injuring thousands more.
EFFECTS:
Effects On the Environment
Like people, animals, and plants,
entire ecosystems can suffer effects from air pollution. Haze, like smog, is a
visible type of air pollution that obscures shapes and colors. Hazy air
pollution can even muffle sounds.
Air pollution particles
eventually fall back to Earth. Air pollution can directly contaminate the
surface of bodies of water and soil. This can kill crops or reduce their yield.
It can kill young trees and other plants.
Sulfur dioxide and nitrogen oxide
particles in the air, can create acid rain when they mix with water and oxygen
in the atmosphere. These air pollutants come mostly from coal-fired power
plants and motor vehicles. When acid rain falls to Earth, it damages plants by
changing soil composition; degrades water quality in rivers, lakes and streams;
damages crops; and can cause buildings and monuments to decay.
Like humans, animals can suffer
health effects from exposure to air pollution. Birth defects, diseases, and
lower reproductive rates have all been attributed to air pollution.
Effects On Humans
People experience a wide range of
health effects from being exposed to air pollution. Effects can be broken down
into short-term effects and long-term effects.
Short-term effects, which are
temporary, include illnesses such as pneumonia or bronchitis. They also include
discomfort such as irritation to the nose, throat, eyes, or skin. Air pollution
can also cause headaches, dizziness, and nausea. Bad smells made by factories,
garbage, or sewer systems are considered air pollution, too. These odors are less
serious but still unpleasant.
Long-term effects of air
pollution can last for years or for an entire lifetime. They can even lead to a
person's death. Long-term health effects from air pollution include heart
disease, lung cancer, and respiratory diseases such as emphysema. Air pollution
can also cause long-term damage to people's nerves, brain, kidneys, liver, and
other organs. Some scientists suspect air pollutants cause birth defects.
Nearly 2.5 million people die worldwide each year from the effects of outdoor
or indoor air pollution.
People react differently to
different types of air pollution. Young children and older adults, whose immune
systems tend to be weaker, are often more sensitive to pollution. Conditions
such as asthma, heart disease, and lung disease can be made worse by exposure
to air pollution. The length of exposure and amount and type of pollutants are
also factors.
Automobile
With the cultural and
technological revolution came the automobile, totalling 53 million in the
1950s, world automobiles in 2010 exceed 550 million. About 19 million vehicles
are added each year to the global total. Automobiles have come to mankind as a
mixed blessing. While they enable mankind to conquer distances they also caused
blatant destruction of the human environment, poisoned the atmosphere and made
human beings vulnerable to several diseases, road accidents and fatalities.
They are also a major consumer of oxygen.
The most affected group of people
are the urban habitants, the city-dwellers, drivers, hawkers, vendors,
shopkeepers and residents in the busy city area. But perhaps the worst
sufferers are the traffic policemen, who remain close to the fumes of vehicle
exhaust and must inhale large quantities of their toxic pollutants every day,
while on duty. Roughly, a man breathe 22,000 times and inhales 16 kg of air,
daily.
In 2005, for example, the vehicle
population in India comprised about 25 million two wheelers, 5 million cars,
jeeps and taxis and 4 million buses and goods vehicles. Of these 40% were
concentrated in Delhi, 25% in Mumbai and 15% in Kolkata. However, the overall
vehicular population distribution of major categories in metro-cities are
depicted
In years past, levels of air,
noise, and sight pollution were much lower than they are today. There are more
cars on the road today, and because of this we experience higher levels of
pollution than before. The automobile is probably the leading contributor
pollution in our cities. They release toxic emissions into our atmosphere.
Automobiles are linked particularly to carbon monoxide pollution. They are
noisy (especially if you are living near the highway), and they take up
valuable space in the form of vast parking lots that are unpleasing to the eye.
The Characteristics of Automobile Pollution:
The internal combustion engine
has made an important contribution to the air pollution.
The main pollutants released by
engines are:
1. Carbon monoxide
2. Un-burnt hydrocarbons
3. Nitrogen oxides
4. Sulphur oxides
5. Lead compounds
6. Smoke
7. Particulates
8. Odour.
Among the important constituents
of the petrol engine exhaust are carbon monoxide, un-burnt hydrocarbons,
nitrogen oxides, particulates and lead, while diesel engine emits un-burnt
hydrocarbons, nitrogen oxides, sulphur oxides, smoke and odour.
The vehicle population is growing
rapidly throughout the world and emissions from transportation will increase in
proportion, if unchecked.
Effect of Automobile Pollutants:
i. Prolonged exposure to
hydrocarbons contributes to asthma, liver disease, and cancer, overexposure of
carbon monoxide poisoning may be fatal.
ii. NOx is a precursor to smog
and acid rain. NOx is a mixture of NO
and NO2. NO2 destroys resistance to respiratory infection.
iii. Particulate matter causes
negative health effects, including but not limited to respiratory disease.
iv. Oil, petroleum products and
other toxins from automobiles kill fish, plants, aquatic life and even people.
One quart of oil will contaminate thousands of gallons of water because it does
not dissolve. These toxins as well as trace metals and degreasing agents used
on automobiles contaminate drinking water and can cause major illness. Some of
these toxins and metals are absorbed in various sea life and cause medical
problems to people when eaten.
Control of Automobile Pollution:
i. Engine efficiency has been
steadily improved with improved engine design.
ii. One of the first-developed
exhaust emission control systems is secondary air injection. Originally, this
system was used to inject air into the engine’s exhaust ports to provide oxygen
so unburned and partially-burned hydrocarbons in the exhaust would finish
burning.
Air injection is now used to
support the catalytic converters oxidation reaction, and to reduce emissions
when an engine is started from cold. After a cold start, an engine needs a
fuel-air mixture richer than what it needs at operating temperature, and the
catalytic converter does not function efficiently until it has reached its own
operating temperature.
2. Associate Professor, Deptt.of Biotechnology Swami Vivekanand Subharti University,Meerut
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