1. AIR POLLUTION STATUS IN DELHI AND
DETAILED COMPARISON WITH DIFFERENT
CITIES OF THE WORLD.
SUBMITTED BY :
AMIT KUMAR BHOJVIA (2K13/EN/006)
SUHAANI KATARIA (2K13/EN/054)
2. CERTIFICATE
This is to certify that the report submitted by AMIT KUMAR BHOJVIA and
SUHAANI KATARIA, in partial fulfillment of the requirements of
INDUSTRIAL TRAINING at CENTRALPOLLTUION CONTROLBOARD
as a part of degree of BACHELOR OF TECHNOLOGY(ENVIRONMENTAL
ENGINEERING) of DELHI TECHNOLOGICALUNIVERSITY, NEW
DELHI ,session2015-2016 is a record of bonafide work and has submitted
anywhere for any other purpose.
AMIT KUMAR BHOJVIA
SUHAANI KATARIA
(V SEM)
3. ACKNOWLEDGEMENT
We have taken efforts in this project. However, it would not have been possible
without the kind supportand help of many individuals of STP officers and staff.
We would like to extend my sincere thanks to all of them.
We are highly indebted to Mr. J.S.Kamyotra and S.K.Tyagi for his guidance and
constant supervision as well as for providing necessary information regarding the
project and also for their support in completing the project. We are also thankful to
all lab staff for giving me training as well as guidance,
We would like to express my gratitude towards my parents and also towards
teachers of Environmental Engineering Department, DTU, for their kind co-
operation and encouragement which help me in completion of this project.
4. CONTENTS
AIR POLLUTION AS A CONCERN IN DELHI
MAJOR AND MINOR AIR POLLUTANTS PRODUCED IN DELHI
SOURCES OF AIR POLLUTION
PRESENT SCENARIO OF AIR POLLUTION IN DELHI
HEALTH EFFECTS OF AIR POLLUTION
OTHER FACTORS WHICH CAUSES AIR POLLUTION
RECENT TRENDS IN AIR QUALITY IN DELHI
CLIMATIC CONDITION OF DELHI
DELHI METRO HELPS IN REDUCTION OF AIR POLLUTION
HOW CAN CITIZENS OF DELHI HELPS IN REDUCING AIR POLLUTION
ODD EVEN SCHEME: A STEP TOWARDS REDUCTION OF AIR POLLUTION
RESULTS OF ODD EVEN SCHEME
HOW CURRENT ODD EVEN SCHEME HAS CHANGED THE MINDSET OF DELHI
PEOPLE
HOW CAN WE IMPROVISE
COMPARISON OF DELHI’S AIR POLLUTION STATUS WITH DIFFERENT CITIES
OF THE WORLD
PARIS
MEXICO
ATHENS
COMPARISON ON THE BASIS OF
Climatic condition
Air Quality
5. Concentration of air pollutants
Sources of Air pollution
Preventive measures
AIR POLLUTION AS A CONCERN IN DELHI
Air pollution is the introduction of particulates, biological molecules, or other harmful materials into Earth's
atmosphere, causing diseases,death to humans, and damage to other living organisms such as animals and food
crops, or the natural or built environment. Air pollution may come from anthropogenic or natural sources.
The atmosphere is a complex natural gaseous systemthat is essentialto support life on
planet Earth. Stratospheric ozone depletion due to air pollution has 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 toxic pollution problems in the
2008 Blacksmith Institute World's Worst Polluted Places report. According to the 2014 WHO report, air pollution in
2012 caused the deaths of around 7 million people worldwide.
An air pollutant is a substance in the air that can have adverse effects on humans and the ecosystem.The substance
can be solid particles, liquid droplets, or gases.A pollutant can be of natural origin or man-made. Pollutants are
classified as primary or secondary.Primary pollutants are usually produced from a process,such as ash from a
volcanic eruption. Other examples include carbon monoxide gas from motor vehicle exhaust, or the sulfur
dioxide released from factories. Secondary pollutants are not emitted directly. Rather, they form in the air when
primary pollutants react or interact. Ground level ozone is a prominent example of a secondary pollutant. Some
pollutants may be both primary and secondary: they are both emitted directly and formed from otherprimary
pollutants.
6. Fig. Carbon dioxide in Earth’s atmosphere during half of the global warming emissions.
Fig. Nitrogen dioxide global Air Quality levels
Source images : Cole,Steve; Gray, Ellen (14 December 2015). "New NASA Satellite Maps Show Human
Fingerprint on Global Air Quality". NASA. Retrieved 14 December 2015.
7. Fig.3. Before flue-gas desulfurization was installed, the emissions from this power plant in New Mexico contained
excessive amounts of sulfur dioxide.
Fig. Schematic drawing, causes and effects of air pollution: (1) greenhouse effect, (2) particulate contamination, (3)
increased UV radiation, (4) acid rain, (5) increased ground level ozone concentration, (6) increased levels of
nitrogen oxides.
Source images: "Indoor air pollutionand household energy". WHO and UNEP. 2011.
8. Major pollutants produced by human activity include:
Primary pollutant
Sulfur oxides (SOx) - particularly sulfur dioxide, a chemical compound with the formula SO2. SO2 is produced
by volcanoes and in various industrial processes.Coal and petroleum often contain sulfur compounds,and 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. This is one of the causes for concern over the environmental impact of
the use of these fuels as power sources.
Nitrogen oxides (NOx) - Nitrogen oxides, particularly nitrogen dioxide, are expelled from high temperature
combustion, and are also produced during thunderstorms by electric discharge. They can be seen as a
brown haze dome above or a plume downwind of cities. Nitrogen dioxide is a chemical compound with the
formula NO2. It is one of several nitrogen oxides. One of the most prominent air pollutants, this reddish-brown
toxic gas has a characteristic sharp,biting odor.
Carbon monoxide (CO) - CO is a colorless, odorless, toxic yet non-irritating 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.
Volatile organic compounds (VOC) - VOCs are a well-known outdoorair pollutant. They are categorized as
either methane (CH4) or non-methane (NMVOCs). Methane is an extremely efficient greenhouse gas which
contributes to enhance global warming. Other hydrocarbon VOCs are also significant greenhouse gases because
of their role in creating ozone and prolonging the life of methane in the atmosphere. This effect varies
depending on local air quality. The aromatic NMVOCs benzene, toluene and xylene are suspected carcinogens
and may lead to leukemia with prolonged exposure. 1, 3-butadiene is anotherdangerous compound often
associated with industrial use.
Particulates, alternatively referred to as particulate matter (PM), atmospheric particulate matter, or fine
particles, are tiny particles of solid or liquid suspended in a gas.In contrast,aerosol refers to combined particles
and gas.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 aerosols. Averaged worldwide,
anthropogenic aerosols—those made by human activities—currently account for approximately 10 percent of
our atmosphere. Increased levels of fine particles in the air are linked to health hazards such as heart
disease,altered lung function and lung cancer. Fig.
9. Fig. Size of Particulate Matter
Fig. Pollution Sources contributes to Total PM 2.5
Persistent free radicals connected to airborne fine particles are linked to cardiopulmonary disease.
Toxic metals, such as lead and mercury, especially their compounds.
Chlorofluorocarbons (CFCs) - harmful to the ozone layer; emitted from products are currently banned from
use.These are gases which are released from air conditioners,refrigerators, aerosol sprays,etc. CFC's on being
released into the air rises to stratosphere.Here they come in contact with other gases and damage the ozone
10. layer. This allows harmful ultraviolet rays to reach the earth's surface. This can lead to skin cancer, disease to
eye and can even cause damage to plants.
Ammonia (NH3) - emitted from agricultural processes.Ammonia is a compound with the formula NH3. It is
normally encountered as a gas with a characteristic pungent odor.Ammonia contributes significantly to the
nutritional needs of terrestrial organisms by serving as a precursorto foodstuffs and fertilizers. Ammonia, either
directly or indirectly, is also a building block for the synthesis ofmany pharmaceuticals. Although in wide use,
ammonia is both caustic and hazardous. In the atmosphere, ammonia reacts with oxides of nitrogen and sulfur
to form secondary particles.
Odors — such as from garbage, sewage, and industrial processes
Radioactive pollutants - produced by nuclear explosions, nuclear events,war explosives, and natural processes
such as the radioactive decay of radon.
Secondary pollutants:
Particulates created from gaseous primary pollutants and compounds in photochemical smog. Smog is a kind of
air pollution. 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 ofthe troposphere.It is
also an important constituent ofcertain regions of the stratosphere commonly known as the Ozone layer.
Photochemical and chemical reactions involving it drive many of the chemical processes that occurin 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 ofsmog.
Peroxyacetyl nitrate (PAN) - similarly formed from NOx and VOCs.
Minor air pollutants include:
A large number of minor hazardous air pollutants.Some of these are regulated in USA under the Clean Air
Act and in Europe underthe Air Framework Directive
A variety of persistent organic pollutants,which can attach to particulates
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,bioaccumulation in human and animal tissue,biomagnification
in food chains, and to have potentially significant impacts on human health and the environment.
11. SOURCES OF AIR POLLUTION
TRAFFIC CONGESTION
Areas with the largest number of cars on the road see higher levels of air pollution on average. Motor vehicles are
one of the largest sources ofpollution worldwide. You may be surprised to learn, however, that slower moving
traffic emits more pollution than when cars move at freeway speeds.Traffic jams are bad for our air. It’s when you
find yourself in a sea of orange traffic cones — stuckin what looks more like a parking lot than a highway — that
your car really starts eating up gas. The constant acceleration and braking of stop-and-go traffic burns more gas,
and therefore pumps more pollutants into the air.
The relationship between driving speed and pollution isn’t perfectly linear, though.One study suggests that
emissions start to go up when average freeway speed dips below 45 miles per hour (mph). They also start to go up
dramatically as the average speed goes above 65 mph. So, the “golden zone” for fuel-consumption and emissions
from your vehicle may be somewhere between 45 and 65 mph.
This leads to a dilemma for urban planners trying to develop roadways that will reduce congestion with an eye to
reducing the pollution that it causes.
PETROL DIESEL POLLUTION
The combustion of gasoline and other hydrocarbon fuels in automobiles, trucks, and jet airplanes produces several
primary pollutants:nitrogen oxides, gaseous hydrocarbons,and carbon monoxide, as well as large quantities of
particulates, chiefly lead. In the presence of sunlight, nitrogen oxides combine with hydrocarbons to form a
secondary class of pollutants,the photochemical oxidants, among them ozone and the eye-stinging
peroxyacetylnitrate (PAN). Nitrogen oxides also react with oxygen in the air to form nitrogen dioxide, a foul-
smelling brown gas.In urban areas like Los Angeles where transportation is the main cause of air pollution, nitrogen
dioxide tints the air, blending with other contaminants and the atmospheric water vapor to produce brown smog.
Although the use of catalytic converters has reduced smog-producing compounds in motor vehicle exhaust
emissions, studies have shown that in so doing the converters produce nitrous oxide, which contributes substantially
to global warming.
BURNING OF FUELS
In cities, air may be severely polluted not only by transportation but also by the burning of fossil fuels (oil and coal)
in generating stations,factories, office buildings, and homes and by the incineration of garbage. The massive
combustion produces tons ofash, soot,and other particulates responsible for the gray smog of cities like New York
and Chicago, along with enormous quantities of sulfur oxides (which also may be result from burning coal and oil).
These oxides rust iron, damage building stone,decompose nylon, tarnish silver, and kill plants. Air pollution from
cities also affects rural areas for many miles downwind.
INDUSTRIAL REASONS
Every industrial process exhibits its own pattern of air pollution. Petroleum refineries are responsible for extensive
hydrocarbon and particulate pollution. Iron and steel mills, metal smelters, pulp and paper mills, chemical plants,
cement and asphalt plants—all discharge vast amounts of various particulates. Uninsulated high-voltage power lines
ionize the adjacent air, forming ozone and other hazardous pollutants. Airborne pollutants from other sources
12. include insecticides,herbicides, radioactive fallout, and dust from fertilizers, mining operations, and livestock
feedlots.
DOMESTIC REASONS
The burning of the following substances is prohibited under the Environment Protection Regulation 2005:
Synthetic plastics or othersynthetic polymers.
Wood that is painted,chemically treated or contaminated with chemicals.
Chemicals otherthan those recommended by the manufacturer as a fuel.
Unseasoned wood.Wood which is burnt as a fuel should be properly seasoned (less than 20% moisture content)to
minimize smoke emissions.
Use of generators in marriages for about hours creates huge amount of air pollution, specially in marriage season.
No one seems to know how many of these generators are under contract,and how many of them are running rather
than simply being made available in the case of an emergency. But if small diesel generators are replacing other
sources of electricity at times of peak demand, it could present a conundrumto EPA, which has spent decades
working to clean up these engines but also wants to encourage the fast-growing demand-response market. Diesel
generators,which are meant for emergencies, pose a potent health risk. Diesel exhaust contains a mix of toxic
chemicals, and last month, the World Health Organization concluded that it causes cancer in humans. New diesel
generators are equipped with air filters and catalysts to clean up their emissions, but the older models can release
200 to 400 times as much smog-forming nitrogen oxides per megawatt as a new natural gas plant, and 10 times as
much as a coal plant
There are variouslocations,activitiesorfactors which are responsible for releasing pollutants into the atmosphere.
These sources can be classified into two major categories.
ANTHROPOGENIC SOURCES:
These are mostly related to the burning of multiple types of fuel.
Stationary sources include smoke stacks of power plants,manufacturing facilities (factories) and waste
incinerators, as well as furnaces and other types of fuel-burning heating devices. In developing and poor
countries, traditional biomass burning is the major source of air pollutants; traditional biomass includes wood,
crop waste and dung.
Mobile sources include motor vehicles, marine vessels,and aircraft.
Controlled burn practices in agriculture and forest management. Controlled or prescribed burning is a
technique sometimes used in forest management, farming, prairie restoration or greenhouse gas abatement. Fire
is a natural part of both forest and grassland ecology and controlled fire can be a tool for foresters.Controlled
burning stimulates the germination of some desirable forest trees, thus renewing the forest.
Fumes from paint, hair spray,varnish, aerosol sprays and other solvents
Waste deposition in landfills, which generate methane. Methane is highly flammable and may form explosive
mixtures with air. Methane may displace oxygen in an enclosed space. Asphyxia or suffocation may result if
the oxygen concentration is reduced to below 19.5% by displacement.
Military resources,such as nuclear weapons, toxic gases,germ warfare and rocketry
13. NATURAL SOURCES:
Dust from natural sources,usually large areas of land with little or no vegetation
Methane,emitted by the digestion of food by animals, for example cattle
Radon gas from radioactive decay within the Earth's crust. Radon is a colorless, odorless,naturally occurring,
radioactive noble gas that is formed from the decay of radium. It is considered to be a health hazard. Radon gas
from natural sources can accumulate in buildings, especially in confined areas such as the basement and it is the
second most frequent cause of lung cancer, after cigarette smoking.
Smoke and carbon monoxide from wildfires
Vegetation, in some regions, emits environmentally significant amounts of Volatile organic compounds (VOCs)
on warmer days.These VOCs react with primary anthropogenic pollutants —specifically, NOx, SO2, and
anthropogenic organic carbon compounds — to produce a seasonalhaze of secondary pollutants. Black gum,
poplar, oak and willow are some examples of vegetation that can produce abundant VOCs. The VOC
production from these species results in ozone levels up to eight times higher than the low-impact tree species.
Volcanic activity, which produces sulfur, chlorine, and ash particulates
PRESENT SCENARIO OF AIR POLLUTION IN DELHI
Air pollution in Delhi’s National Capital Region (NCR) is comprised of a complex mix of pollution from human
activities (vehicle emissions, industry, construction and residential fuel burning) as well as natural sources like dust
and sea salt. The heavy concentration of particulate matter is greatly affected by meteorological conditions –in the
winter, cool air causes “inversions” that stagnant the air and trap pollution close to the ground. Air flow patterns
from Afghanistan and Pakistan pick up emissions as they move over the densely urbanized regions of Punjab and
Haryana where farmers burn the straw in their fields and pull this pollution into Delhi. Pre-monsoon dust storms
also contribute to air pollution in the region.
City activities also contribute to the air pollution. The NCR generates 10,000 tons per day of municipal solid waste,
much of which is eventually burned, adding particulate pollution to the air (Guttikunda 2015) and galloping
urbanization brings massive construction projects to the area. In adddition, Delhi has more than 7.4 million vehicles
14. on it’s roads, with an additional 1,200 added each day and the result is a pollution “hotspot.”
Fig. Increase in Pollution Level
On the other hand, the Environment Pollution (Prevention & Control) Authority investigated the issue and reported
to the Supreme Court the significant role of vehicles and vehicle emissions to rising air pollution in Delhi, stating
that rapid motorization based on poor quality fuel and vehicle technology will make the air pollution trend
irreversible. The report focuses on government standards and policies that have contributed to the current pollution
problem and ends with recommended priority actions on the policy level.
From 2002 to 2012, vehicle numbers have increased by as much as 97%, contributing enormously to the
pollution load and direct exposure to toxic fumes.
The Price of Compressed Natural Gas (CNG): In 2002-03, CNG was cheaper than diesel by about
46.71%. But in December 2013, the price differential plummeted to 7.35%. Only after the most recent
intervention to reduce CNG prices by Rs 15 per kg in February 2014 has helped to increase the differential
again to about 35%. High CNG costs hurt public transport and undermine the clean fuel program.
The gap between diesel fuel and petrol prices, which are skewed towards making diesel relatively cheaper,
is leading to dieselization of cars. From just 4% of new car sales in 2000, diesel cars are now half of new
car sales.The WHO has formally reclassified diesel emissions as class I carcinogen for its strong link with
lung cancer –putting it in the same class as tobacco smoking.
Emissions standards: only 38 cities and towns have the high-level Bharat IV standards in place for fuel
and vehicles emissions. The rest of India has the much more polluting Bharat Stage III standards in place.
Equivalent to Euro IV standards,Bharat IV particulate standards are 50% cleaner than Bharat Stage III
standards for cars and 81% cleaner for trucks and diesel buses.Though Delhi follows Bharat IV standards,
significant cross-through traffic from otherlocals means that the city is greatly affected by high polluting
vehicles. You can read more on emissions standards in India here.
15. Non-polluting modes of public transportation are jeopardized. Currently it is too dangerous to walk and
cycle safely in the city. Road accident data for 2012 shows every hour a person is injured or killed in a road
accident in Delhi.
Buses are taxed more highly than cars adding to bus operation costs
Car growth is explosive due to hidden subsidies for example the low cost of parking in Delhi when
compared to parking in other international cities.
What part do emissions from India’s coal-fired power plants play in the pollution problem?
NASA satellite data from December 2013 revealed that sulfur dioxide emissions in India increased more than 60%
from 2005-2012. According to a press release from NASA, this data corroborated other research concluding that as
of 2010 India is the world’s second largest emitter of sulfur dioxide after China. That research also found that, at the
time, half of India’s emissions came from the coal-fired power sector. Head of the research team responsible for the
study added “long-lifetime, sulfur-containing air pollutants such as sulfate can be transported long distances to affect
public health and the environment at a regional scale.”
HEALTH EFFECTS OF AIR POLLUTION
Air pollution is a significant risk factor for a number of health conditions including respiratory infections, heart
disease, stroke and lung cancer. The health effects caused by air pollution may include difficulty in breathing,
wheezing, coughing, asthma and worsening of existing respiratory and cardiac conditions. These effects can result in
increased medication use, increased doctor or emergency room visits, more hospital admissions and premature
death. The human health effects of poor air quality are far reaching, but principally affect the body's resp iratory
systemand the cardiovascular system. Individual reactions to air pollutants depend on the type of pollutant a person
is exposed to, the degree of exposure, and the individual's health status and genetics. The most common sources of
air pollution include particulates, ozone, nitrogen dioxide, and sulfur dioxide. Children aged less than five years that
live in developing countries are the most vulnerable population in terms of total deaths attributable to indoor and
outdoor air pollution.
MORTALITY
It is estimated that some 7 million premature deaths may be attributed to air pollution. India has the highest death
rate due to air pollution. India also has more deaths from asthma than any other nation according to the World
Health Organization. In December 2013 air pollution was estimated to kill 500,000 people in China each year. There
is a correlation between pneumonia-related deaths and air pollution from motor vehicles.
Air pollution is estimated to reduce life expectancy by almost nine months acros s the European Union. Causes of
deaths include strokes,heart disease, COPD, lung cancer, and lung infections.
The US EPA estimates that a proposed set ofchanges in diesel engine technology 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.
The US EPA estimates allowing a ground-level ozone concentration of 65 parts per billion, would avert 1,700 to
5,100 premature deaths nationwide in 2020 compared with the current 75-ppb standard.The agency projects the
stricter standard would also prevent an additional 26,000 cases of aggravated asthma, and more than a million cases
of missed work or school.
16. A new economic study ofthe health impacts and associated costs ofair pollution in the Los Angeles Basin and San
Joaquin Valley of Southern California shows that more than 3,800 people die prematurely (approximately 14 years
earlier than normal) each year because air pollution levels violate federal standards.The number of annual
premature deaths is considerably higher than the fatalities related to auto collisions in the same area, which average
fewer than 2,000 per year.
Diesel exhaust (DE) is a major contributor to combustion-derived particulate matter air pollution. In several human
experimental studies,using a well-validated exposure chamber setup,DE has been linked to acute vascular
dysfunction and increased thrombus formation. This serves as a plausible mechanistic link between the previously
described association between particulates air pollution and increased cardiovascular morbidity and mortality.
CARDIOVASCULAR DISEASE
A 2007 review of evidence found ambient air pollution exposure is a risk factor correlating with increased total
mortality from cardiovascular events (range: 12% to 14% per 10 µg/m3 increase).
Air pollution is also emerging as a risk factor for stroke, particularly in developing countries where pollutant levels
are highest.A 2007 study found that in women, air pollution is associated not with hemorrhagic but with ischemic
stroke. Air pollution was also found to be associated with increased incidence and mortality from coronary stroke in
a cohort study in 2011. Associations are believed to be causal and effects may be mediated by vasoconstriction,low-
grade inflammation and atherosclerosis.Other mechanisms such as autonomic nervous systemimbalance have also
been suggested.
LUNG DISEASE
Chronic obstructive pulmonary disease (COPD) includes diseases such as chronic bronchitis and emphysema.
Research has demonstrated increased risk of developing asthma and COPD from increased exposure to traffic
related air pollution. Additionally, air pollution has been associated with increased hospitalization and mortality
from asthma and COPD.
A study conducted in 1960-1961 in the wake of the Great Smog of 1952 compared 293 London residents with 477
residents of Gloucester, Peterborough,and Norwich, three towns with low reported death rates from chronic
bronchitis. All subjects were male postaltruck drivers aged 40 to 59. Compared to the subjects from the outlying
towns, the London subjects exhibited more severe respiratory symptoms (including cough,phlegm, and dyspnea),
reduced lung function and increased sputumproduction and purulence. The differences were more pronounced for
subjects aged 50 to 59. The study controlled for age and smoking habits,so concluded that air pollution was the
most likely cause of the observed differences.
It is believed that much like cystic fibrosis, by living in a more urban environment serious health hazards become
more apparent.Studies have shown that in urban areas patients suffer mucus hypersecretion,lower levels of lung
function, and more self-diagnosis of chronic bronchitis and emphysema.
A Report by TIMES OF INDIA on Reduced Lung Capacity:
More than a third of schoolchildren in four big cities of India suffer from reduced lung capacity, with Delhi
showing the worst results, claims a new study whose results could be pointing to how air pollution is
impacting the health of kids in urban India.
17. In the survey,2,373 kids in Delhi, Mumbai, Bengaluru and Kolkata underwent a lung health screening test
(LHST). Of the 735 students who took the test in Delhi, 21% were found to have 'poor' lung capacity while
another19% had 'bad' capacity.
This means four out of every 10 children screened in the capital failed the test.Delhi has the worst air
quality among 1,600 cities around the world, according to the World Health Organization.
The students were asked to inhale and then exhale forcefully into a testing device to check their lung
capacity. Dr Preetaish Kaul, representative of Heal Foundation which conducted the survey, said they were
shocked to find so many children not being able to exhale properly.
Children in the three other cities surveyed were only marginally betteroff.
"The survey was observational and we did not look into the cause of poor lung health in children. However,
given the fact that most children were otherwise healthy, it will not be wrong completely to infer that poor
air quality has a role to play in causing the reduced lung capacity," said Dr Preetaish Kaul, representative of
Heal Foundation.
In Bengaluru, 36% (14% 'poor' and 22% 'bad') were found to have reduced lung capacity, followed by 35%
in Kolkata (9% 'poor' and 26% 'bad') and 27% in Mumbai (13% 'poor' and 14% 'bad').
LHST determines how much air the lungs can hold, how quickly one can move air in and out of the lungs,
and how well the lungs take oxygen in and remove carbon dioxide out from the body."The test can detect
lung diseases and measure the severity of lung problems. Poor results in LHST mean compromised lung
function and high possibilities of contracting pulmonary diseases," said a doctor.
Dr Raj Kumar, who heads the respiratory allergy and applied immunology department at Vallabhbhai Patel
Chest Institute,said more scientific studies were needed to determine the impact of air pollution on
children.
"Although I did not participate in the study,there can be no denying that air pollution is affecting us badly.
Children are worst impacted as they are yet in their growth years with vital organs of the body
physiologically not mature enough to deal with it," he said.
Anothersurvey conducted by Heal foundation suggested that a majority of people think it is the whole and
sole responsibility of the government to clean the air.
18. Source: Central Pollution Control Board. 2008b.“Study on Ambient Air Quality, Respiratory Symptoms
and Lung Function of Children in Delhi.” Environmental Health Series 2.
The survey indicated that only 15%, 24%, 27% and 9% people in Delhi, Mumbai, Bangalore and Kolkata,
respectively, thought they as individuals were also responsible for the poor quality of air in their city.
Said environmental activist Kamal Meattle, "Reckless cutting of trees,rapid urbanization and above all, a dearth of
environment-friendly laws, is the cause of many illnesses. Poor lung health is one of them. It's high time we take up
the issue on priority and figure out ways to control pollution."
CANCER
A review of evidence regarding whether ambient air pollution exposure is a risk factor for cancer in 2007 found
solid data to conclude that long-term exposure to PM2.5 (fine particulates) increases the overall risk of non-
accidental mortality by 6% per a 10 µg/m3 increase. Exposure to PM2.5 was also associated with an increased risk
of mortality from lung cancer (range: 15% to 21% per 10 µg/m3 increase) and total cardiovascular mortality (range:
12% to 14% per a 10 µg/m3 increase). The review further noted that living close to busy traffic appears to be
associated with elevated risks of these three outcomes --- increase in lung cancer deaths,cardiovascular deaths,and
overall non-accidental deaths.The reviewers also found suggestive evidence that exposure to PM2.5 is positively
associated with mortality from coronary heart diseases and exposure to SO2 increases mortality from lung cancer,
but the data was insufficient to provide solid conclusions. Anotherinvestigation showed that higheractivity level
increases deposition fraction of aerosol particles in human lung and recommended avoiding heavy activities like
running in outdoorspace at polluted areas.
In 2011, a large Danish epidemiological study found an increased risk of lung cancer for patients who lived in areas
with high nitrogen oxide concentrations.In this study,the association was higher for non-smokers than smokers.An
additional Danish study,also in 2011, likewise noted evidence of possible associations between air pollution and
other forms of cancer, including cervical cancer and brain cancer.
In December 2015, medical scientists reported that cancer is overwhelmingly a result of environmental factors, and
not largely down to bad luck. Maintaining a healthy weight, eating a healthy diet, minimizing alcohol and
eliminating smoking reduces the risk of developing the disease,according to the researchers.
19. CHILDREN’S HEALTH AT RISK
In the United States,despite the passage ofthe Clean Air Act in 1970, 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.These dangerous pollutants are known as the criteria pollutants,and include ozone, particulate matter,
sulfur dioxide, nitrogen dioxide, carbon monoxide, and lead. Protective measures to ensure children's health are
being taken in cities such as New Delhi, India where buses nowuse compressed natural gas to help eliminate the
"pea-soup" smog.A recent study in Europe has found that exposure to ultrafine particles can increase blood
pressure in children.
A Study on Blood Pressure among children:
The clinical significance of particulate-induced increases in blood pressure could be considerable. Childhood blood
pressure is an important predictor of hypertension and cardiovascular disease later in life. Although blood pressure is
believed to be a complex trait, determined by numerous genetic, biological, behavioral, social, and environmental
factors, avoiding or removing potentially irreversible adverse factors as early as possible seems reasonable.
Indeed, repeated particle-induced elevations in blood pressure also lead to repeated increases in arterial wall stress
and may result in long-term chronically elevated pressures.Epidemiological evidence exists for a chronic increase in
arterial stiffness in children due to traffic-related air pollution, as exemplified by residential traffic-related
indicators.
Our current epidemiological observations in children are in line with human exposure studies.In a crossoverstudy,
where participants were exposed 2 hr to diesel exhaust, increases in systolic blood pressure were reported until 24 hr
post exposure. No effects on diastolic blood pressure were reported. Further, a controlled experiment in healthy
adults (18–35 years of age) inhaling UFP for 2 hr showed changes in heart rate variability and loss of sympathovagal
balance. Existing evidence suggeststhat air pollution is able to trigger an acute autonomic imbalance, favoring
sympathetic nerve activity causing smooth muscle contraction and thus vasoconstriction.In a crossoverexperiment,
systolic blood pressure was significantly lower during a 2 hr walk in Beijing, China, in participants wearing a
particulate-filter face mask than in participants who were not protected by a face mask. Wearing the face mask was
also associated with increased heart rate variability, which suggests that the rapid increase in blood pressure due to
particle inhalation can be mediated through the autonomic nervous system.In other controlled studies,ultrafine
carbon particles did not change blood pressure or heart rate variability but altered endothelial dysfunction or caused
retinal vasoconstriction.
Experimental evidence of intratracheally instilled UFP in hamsters showed that UFP can pass from the lungs into the
blood circulation within minutes. Due to specific characteristics (high surface area, particle number, metal and
organic carbon content)of UFP, they may be transferred directly into the circulation and cause systemic
inflammation and peripheral vascular oxidative stress resulting in reductions of nitric oxide, enhancing
vasoconstriction and as such change blood pressure. Further, excess production of endothelin-1, a potent
vasoconstrictor,after exposure to air pollution, can cause changes in blood pressure.In animal models, plasma
endothelin was up-regulated after exposure to diesel exhaust and concentrated air particles. These results were
confirmed in an epidemiological setting where patients with metabolic syndrome and healthy volunteers showed an
increase in plasma endothelin-1 concentrations 3 hr after diesel exhaust exposure.
Study has both strengths and limitations.
Study was limited in number of repeated measurements and participants because it was part of a larger
biomonitoring program with a fixed design. The UFP concentrations did not differ significantly between
the two periods consequently,adaptation toward the blood pressure measurements cannot explain our
20. findings, because variation in exposure was random and independent of the first or second blood pressure
reading. To account for diurnal variation in blood pressure, all children were examined at the same
moment of the day. To reduce the effect of remaining variability, at least five blood pressure readings were
taken after 5 min of rest in the sitting position and the first blood pressure measurement was excluded
reported that parental smoking is an independent risk factor for children’s blood pressure. In this regard,
indoor smoking was an exclusion criteria, although this does not account for exposure to passive smoke
elsewhere. Noise exposure might be a confounding factor in the association between air pollution and
blood pressure.Because we used a repeated-measure design and the child was examined at the same
location in both sampling periods and living at the same residential address at the different examinations,
noise exposure is unlikely to be a time-varying factor and therefore unlikely to bias our estimates of acute
exposure. Additional adjustment for residential proximity to a major road, as a proxy for nighttime noise
exposure, did not alter our association between systolic blood pressure and acute UFP exposure.
The major strength ofthe current study is the measurement of the different-sized UFP and PM fractions in
schoolplaygrounds to reflect exposure as accurately as possible.
Conclusion :
Children attending schoolon days with higher ultrafine particulate concentrations (diameter < 100 nm) had higher
systolic blood pressure.This association was largely dependent on particle size and was not confounded by the
PM2.5 mass concentration.
"Clean" areas:
Even in the areas with relatively low levels of air pollution, public health effects can be significant and costly,since
a large number of people breathe in such pollutants.A 2005 scientific study for the British Columbia Lung
Association showed that a small improvement in air quality (1% reduction of ambient PM2.5 and ozone
concentrations)would produce $29 million in annual savings in the Metro Vancouver region in 2010. This finding is
based on health valuation of lethal (death) and sub-lethal (illness) affects.
Central nervous system:
Data is accumulating that air pollution exposure also affects the central nervous system.
In a June 2014 study conducted by researchers at the University of Rochester Medical Center, published in the
journal Environmental Health Perspectives,it was discovered that early exposure to air pollution causes the same
damaging changes in the brain as autism and schizophrenia. The study also shows that air pollution also affected
short-term memory, learning ability, and impulsivity. Lead researcher Professor Deborah Cory-Slechta said that
"When we looked closely at the ventricles, we could see that the white matter that normally surrounds themhadn't
fully developed.It appears that inflammation had damaged those brain cells and prevented that region of the brain
from developing, and the ventricles simply expanded to fill the space.Our findings add to the growing body of
evidence that air pollution may play a role in autism, as well as in other neuro developmental disorders." Air
pollution has a more significant negative effect of males than on females.
In 2015, experimental studies reported the detection of significant episodic (situational) cognitive impairment from
impurities in indoor air breathed by test subjects who were not informed about changes in the air quality.
Researchers at the Harvard University and SUNY Upstate Medical University and Syracuse University measured
the cognitive performance of 24 participants in three different controlled laboratory atmospheres that simulated
those found in "conventional" and "green" buildings, as well as green buildings with enhanced ventilation.
21. Performance was evaluated objectively using the widely used Strategic Management Simulation software simulation
tool, which is a well-validated assessment test for executive decision-making in an unconstrained situation allowing
initiative and improvisation. Significant deficits were observed in the performance scores achieved in increasing
concentrations of either volatile organic compounds (VOCs) or carbon dioxide, while keeping otherfactors constant.
The highest impurity levels reached are not uncommon in some classroomor office environments.
OTHER FACTORS WHICH CAUSES AIR POLLUTION
Fuel wood and biomass burning
Fuel wood and biomass burning is the primary reason for near-permanent haze and smoke observed above rural and
urban India, and in satellite pictures of the country.Fuel wood and biomass cakes are used for cooking and general
heating needs.These are burnt in cook stoves known as chullah piece in some parts of India. These cook stoves are
present in over 100 million Indian households,and are used two to three times a day, daily. As of 2009, majority of
Indians still use traditional fuels such as dried cow dung,agricultural waste, and firewood as cooking fuel.
This form of fuel is inefficient source of energy, its burning releases high levels of smoke, PM10 particulate
matter, NOx , SOx , PAHs, poly aromatics, formaldehyde, carbon monoxide and other air pollutants. Some reports,
including one by the World Health Organization, claim 300,000 to 400,000 people die of indoor air pollution and
carbon monoxide poisoning in India because of biomass burning and use of chullahs . The air pollution is also the
main cause of the Asian brown cloud which is delaying the start of the monsoon. Burning of biomass and firewood
will not stop,unless electricity or clean burning fuel and combustion technologies become reliably available and
widely adopted in rural and urban India.
India is the world's largest consumer of fuel wood, agricultural waste and biomass for energy purposes.From the
most recent available nationwide study,India used 148.7 million tonnes coalreplacement worth of fuel wood and
biomass annually for domestic energy use. India's national average annual per capita consumption of fuel wood, agri
waste and biomass cakes was 206 kilogram coal equivalent.
In 2010 terms, with India's population increased to about 1.2 billion, the country burns over 200 million tonnes of
coal replacement worth of fuel wood and biomass every year to meet its energy need for cooking and other domestic
use.The study found that the households consumed around 95 million tonnes of fuelwood, one-third of which was
logs and the rest was twigs. Twigs were mostly consumed in the villages, and logs were more popular in cities of
India.
The overall contribution of fuel wood, including sawdust and wood waste, was about 46% of the total, the rest being
agri waste and biomass dung cakes. Traditional fuel (fuel wood, crop residue and dung cake) dominates domestic
energy use in rural India and accounts for about 90% of the total. In urban areas, this traditional fuel constitutes
about 24% of the total.
Fuel wood, agricultural waste and biomass cake burning releases over 165 million tonnes of combustion products
into India's indoor and outdoorair every year. To place this volume of emission in context, the Environmental
Protection Agency (EPA) of the United States estimates that fire wood smoke contributes over420,000 tonnes of
fine particles throughout the United States – mostly during the winter months. United States consumes about one-
tenth of fuelwood consumed by India, and mostly for fireplace and home heating purposes.EPA estimates that
residential wood combustion in the USA accounts for 44 percent of total organic matter emissions and 62 percent of
22. the PAH, which are probable human carcinogens and are of great concern to EPA. The fuel wood sourced
residential wood smoke makes up over 50 percent of the wintertime particle pollution problem in California. In
2010, the state of California had about the same number of vehicles as all of India.
India burns tenfold more fuel wood every year than the United States, the fuel wood quality in India is different than
the dry firewood of the United States,and the Indian stoves in use are less efficient thereby producing more smoke
and air pollutants per kilogram equivalent. India has less land area and less emission air space than the United
States. In summary, the impact on indoor and outdoorair pollution by fuel wood and biomass cake burning is far
worse in India.
A United Nations study finds firewood and biomass stoves can be made more efficient in India. Animal dung, now
used in inefficient stoves,could be used to produce biogas, a cleaner fuel with higher utilization efficiency. In
addition, an excellent fertilizer can be produced from the slurry from biogas plants.Switching to gaseous fuels
would bring the greatest gains in terms of both thermal efficiency and reduction in air pollution, but would require
more investment. A combination of technologies may be the best way forward.
Between 2001 and 2010, India has made progress in adding electrical power generation capacity, bringing electricity
to rural areas, and reforming market to improve availability and distribution of liquified cleaner burning fuels in
urban and rural area. Over the same period, scientific data collection and analysis show improvement in India's air
quality, with some regions witnessing 30 to 65% reduction in NOx, SOx and suspended particulate matter. Even at
these lower levels, the emissions are higher than those recommended by the World Health Organization. Continued
progress is necessary.
Scientific studies conclude biomass combustion in India is the country's dominant source of carbonaceous aerosols,
emitting 0.25 teragram per year of black carbon into air, 0.94 teragram per year of organic matter, and 2.04 teragram
per year of small particulates with diameter less than 2.5 µm. Biomass burning, as domestic fuel in India, accounts
for about 3 times as much black carbon air pollution as all other sources combined, including vehicles and industrial
sources.
Fuel adulteration
Some Indian taxis and auto-rickshaws run on adulterated fuel blends. Adulteration of gasoline and diesel with lower-
priced fuels is common in South Asia, including India. Some adulterants increase emissions of harmful pollutants
from vehicles, worsening urban air pollution. Financial incentives arising from differential taxes are generally the
primary cause of fuel adulteration. In India and other developing countries,gasoline carries a much higher tax than
diesel, which in turn is taxed more than kerosene meant as a cooking fuel, while some solvents and lubricants carry
little or no tax.
As fuel prices rise, the public transport driver cuts costs by blending the cheaper hydrocarbon into highly taxed
hydrocarbon.The blending may be as much as 20-30 percent. For a low wage driver, the adulteration can yield short
term savings that are significant over the month. The consequences to long term air pollution, quality of life and
effect on health are simply ignored. Also ignored are the reduced life of vehicle engine and higher maintenance
costs,particularly if the taxi, auto-rickshaw or truck is being rented for a daily fee.
Adulterated fuel increases tailpipe emissions of hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen
(NOx) and particulate matter (PM). Air toxin emissions — which fall into the category of unregulated emissions —
of primary concern are benzene and polyaromatic hydrocarbons (PAHs), both well known carcinogens.Kerosene is
23. more difficult to burn than gasoline; its addition results in higher levels of HC, CO and PM emissions even from
catalyst-equipped cars. The higher sulfur level of kerosene is another issue.
The permissible level of fuel sulfur in India, in 2002, was 0.25 percent by weight as against 0.10 percent for
gasoline. The higher levels of sulfur can deactivate the catalyst.Once the catalyst becomes deactivated, the amount
of pollution from the vehicle dramatically increases.Fuel adulteration is essentially an unintended consequence of
tax policies and the attempt to control fuel prices, in the name of fairness. Air pollution is the ultimate result. This
problem is not unique to India, but prevalent in many developing countries including those outside of south Asia.
This problem is largely absent in economies that do not regulate the ability of fuel producers to innovate or price
based on market demand.
Fig. Smoke blanket over Delhi from satellite image due to burning of crops in Haryana and Punjab.
Source images:"Environmental Pollution". Theenvironmentalblog.org. 2011-12-16.Retrieved2012-12-11.
Traffic congestion
Traffic congestion is severe in India's cities and towns. Traffic congestion is caused for several reasons,some of
which are: increase in number of vehicles per kilometer of available road, a lack of intra-city divided-lane highways
and intra-city expressways networks, lack of inter-city expressways, traffic accidents and chaos due to poor
enforcement of traffic laws.
Traffic congestion reduces average traffic speed.At low speeds,scientific studies reveal, vehicles burn fuel
inefficiently and pollute more per trip. For example, a study in the United States found that for the same trip, cars
consumed more fuel and polluted more if the traffic was congested,than when traffic flowed freely. At average trip
speeds between 20 to 40 kilometers per hour, the cars pollutant emission was twice as much as when the average
speed was 55 to 75 kilometers per hour. At average trip speeds between 5 to 20 kilometers per hour, the cars
24. pollutant emissions were 4 to 8 times as much as when the average speed was 55 to 70 kilometers per hour. Fuel
efficiencies similarly were much worse with traffic congestion.
Traffic gridlock in Delhi and other Indian cities is extreme. The average trip speed on many Indian city roads is less
than 20 kilometers per hour; a 10 kilometer trip can take 30 minutes, or more. At such speeds,vehicles in India emit
air pollutants 4 to 8 times more than they would with less traffic congestion; Indian vehicles also consume a lot
more carbon footprint fuel per trip, than they would if the traffic congestion was less.Emissions of particles and
heavy metals increase over time because the growth of the fleet and mileage outpaces the efforts to curb emissions .
In cities like Bangalore, around 50% of children suffer from asthma.
Greenhouse gas emission:
India was the third largest emitter of carbon dioxide in 2009 at 1.65 Gt per year, after China (6.9 Gt per year) and
the United States (5.2 Gt per year). With 17 percent of world population, India contributed some 5 percent of
human-sourced carbon dioxide emission; compared to China's 24 percent share. On per capita basis,India emitted
about 1.4 tons of carbon dioxide per person, in comparison to the United States'17 tons per person,and a world
average of 5.3 tons per person.
About 65 percent of India's carbon dioxide emissions in 2009 was from heating, domestic uses and power sector.
About 9 percent of India's emissions were from transportation (cars, trains, two wheelers, airplanes, others). India's
coal-fired, oil-fired and natural gas-fired thermal power plants are inefficient and offer significant potential for
CO2 emission reduction through bettertechnology.Compared to the average emissions from coal-fired, oil-fired and
natural gas-fired thermal power plants in European Union (EU-27) countries,India's thermal power plants emit 50 to
120 percent more CO2 per kWh produced. This is in significant part to inefficient thermal power plants installed in
India prior to its economic liberalization in the 1990s.
Between 1990 and 2009, India's carbon dioxide emissions per GDP purchasing power parity basis have decreased
by over 10 percent, a trend similar to China. Meanwhile, between 1990 and 2009, Russia's carbon dioxide emissions
per GDP purchasing power parity basis have increased by 40 percent. India has one of the better records in the
world, of an economy that is growing efficiently on CO2 emissions basis.In otherwords, over the last 20 years,
India has reduced CO2 emissions with each unit of GDP increase Per Copenhagen Accord, India aims to further
reduce emissions intensity of its growing GDP by 20 to 25 percent before 2020, with technology transfer and
international cooperation.Nevertheless, it is expected, that like China, India's absolute carbon dioxide emissions will
rise in years ahead, even as International Energy Agency's AnnexI countries expect their absolute CO2 emissions to
drop.
A significant source of greenhouse gas emissions from India is from black carbon, NOx, methane and other air
pollutants.These pollutants are emitted in large quantities in India every day from incomplete and inefficient
combustion of biomass (fuel wood, crop waste and cattle dung). A majority of Indian population lacks access to
clean burning fuels, and uses biomass combustion as cooking fuel. India's poorly managed solid wastes,inadequate
sewage treatment plants, water pollution and agriculture are othersources of greenhouse gas emissions.
NASA's Lau has proposed that as the aerosol particles rise on the warm, convecting air, they produce more rain over
northern India and the Himalayan foothill, which further warms the atmosphere and fuels a "heat pump" that draws
yet more warm air to the region. This phenomenon,Lau believes, changes the timing and intensity of the monsoon,
effectively transferring heat from the low-lying lands over the subcontinent to the atmosphere over the Tibetan
25. Plateau, which in turn warms the high-altitude land surface and hastens glacial retreat. His modeling shows that
aerosols—particularly black carbon and dust—likely cause as much of the glacial retreat in the region as greenhouse
gases via this "heat pump" effect.
Health costs ofair pollution
Exposure to particulate matter for a long time can lead to respiratory and cardiovascular diseases such as asthma,
bronchitis, lung cancer and heart attacks. The Global burden of disease study for 2010, published in 2013, had found
that outdoorair pollution was the fifth-largest killer in India and around 620,000 early deaths occurred from air
pollution-related diseases in 2010.According to a WHO study,13 of the 20 most-polluted cities in the world are in
India; however, the accuracy and methodology of the WHO study was questioned by the Government of India led
by Manmohan Singh.
RECENT TRENDS IN AIR QUALITY IN DELHI
26. Monsoons scrub India's air, bringing its natural diversity in better view.
Himalayan peaks in eastern India on a day without haze.
With the last 15 years of economic development and regulatory reforms, India has made progress in improving its
air quality. The table presents the average emissions sampled at many locations,over time, and data analyzed by
scientific methods, by multiple agencies,including The World Bank. For context and comparison, the table also
includes average values for Sweden in 2008, observed and analyzed by same methods. Over 1995-2008, average
nation wide levels of major air pollutants have dropped by between 25-45 percent in India.
Pollutant 1995 2005 2008 2008
Pollutant, PM10 (micrograms per cubic meter) 109 67 59 11
Pollutant, CO2 emissions (kg per 2005 PPP$ of GDP) 0.7 0.6 0.5 0.2
Health, mortality rate (under 5, per 1000) 100 73 67 3
Pollutant, methane, Agriculture emissions (% total) 68.8 64.4 n.a. 28.1
Pollutant, nitrous oxide, Agriculture emissions (% total) 75.2 73.4 n.a. 60.2
27. India's Central Pollution Control Board now routinely monitors four air pollutants namely sulphur dioxide (SO2),
oxides of nitrogen (NOx), suspended particulate matter (SPM) and respirable particulate matter (PM10). These are
target air pollutants for regular monitoring at 308 operating stations in 115 cities/towns in 25 states and 4 Union
Territories of India. The monitoring of meteorological parameters such as wind speed and direction, relative
humidity and temperature has also been integrated with the monitoring of air quality. The monitoring of these
pollutants is carried out for 24 hours (4-hourly sampling for gaseous pollutants and 8-hourly sampling for particulate
matter) with a frequency of twice a week, to yield 104 observations in a year.
For 2010, the key findings of India's central pollution control board are:
Most Indian cities continue to violate India's and world air quality PM10 targets. Respirable particulate matter
pollution remains a key challenge for India. Despite the general non-attainment, some cities showed far more
improvement than others.A decreasing trend has been observed in PM10 levels in cities like Solapur and
Ahmedabad over the last few years.This improvement may be due to local measures taken to reduce sulfur in
diesel and stringent enforcement by Gujarat government.
A decreasing trend has been observed in sulfur dioxide levels in residential areas of many cities such as Delhi,
Mumbai, Lucknow, Bhopal during last few years. The decreasing trend in sulfur dioxide levels may be due to
recently introduced clean fuel standards,and the increasing use of LPG as domestic fuel instead of coal or
fuelwood, and the use of LPG instead of diesel in certain vehicles.
A decreasing trend has been observed in nitrogen dioxide levels in residential areas of some cities such as
Bhopal and Solapur during last few years.The decreasing trend in sulfur dioxide levels may be due to recently
28. introduced vehicle emission standards,and the increasing use of LPG as domestic fuel instead of coal or
fuelwood.
Most Indian cities greatly exceed acceptable levels of suspended particulate matter. This may be because of
refuse and biomass burning, vehicles, power plant emissions, industrial sources.
The Indian air quality monitoring stations reported lower levels of PM10 and suspended particulate matter
during monsoon months possibly due to wet deposition and air scrubbing by rainfall. Higher levels of
particulates were observed during winter months possibly due to lower mixing heights and more calm
conditions.In otherwords, India's air quality worsens in winter months, and improves with the onset of
monsoon season.
The average annual SOx and NOx emissions level and periodic violations in industrial areas of India were
significantly and surprisingly lower than the emission and violations in residential areas of India
Of the four major Indian cities, air pollution was consistently worst in Delhi, every year over 5 year period
(2004–2008). Kolkata was a close second,followed by Mumbai Chennai air pollution was least of the four.
Recent reports have found problems with pollution increasing, especially because of increasing use of vehicle
transport.
In May 2014 the World Health Organisation announced New Delhi is the most polluted city in the world.
CLIMATIC CONDITION OF DELHI
The climate of Delhi is monsoon-influenced humid subtropical bordering semi-arid, with high variation between
summer and winter temperatures and precipitation. Delhi's version of a humid subtropicalclimate is markedly
different from many other humid subtropicalcities such as Sao Paulo, Tokyo and Brisbane in that the city
features dust storms(something more commonly seen in a desert climate), has relatively dry winters and has a
prolonged spell of very hot weather, causing it to be also classified as semi-arid region.Summers start in early April
and peak in May, with average temperatures near 32 °C, although occasional heat waves can result in highs close to
45 °C on some days and therefore higher apparent temperature. The monsoon starts in late June and lasts until mid-
September, with about 797.3 mm of rain. The average temperatures are around 29 °C although they can vary from
around 25 °C on rainy days to 32 °C during dry spells. The monsoons recede in late September, and the post-
monsoon season continues till late October, with average temperatures sliding from 29 °C to 21 °C.Winter starts in
November and peaks in January, with average temperatures around 12–13 °C. Although winters are generally mild,
Delhi's proximity to the Himalayas results in cold waves leading to lower apparent temperature due to wind chill.
Delhi is notorious for its heavy fogs during the winter season.In December, reduced visibility leads to disruption of
road, air and rail traffic. They end in early February, and are followed by a short spring until the onset of the
summer. Extreme temperatures have ranged from −2.2 °C to 48.4 °C.
29. OverviewofSeasonal Distribution
Summer: April, May, June; Hot to very hot; Very low to moderate humidity; Low precipitation
Monsoon (Rainy): July, August,September; Hot, Pleasant during rains; High to very high humidity; Heavy
precipitation
Autumn: October, November; Warm days, Cool nights,Pleasant; Low humidity; Low precipitation
Winter: December, January; Cool to Cold; Moderate humidity; Low precipitation
Spring: February, March; Warm days,Cool nights, Pleasant; Low to moderate humidity; Moderate precipitation
Climate Data
Temperature records for Delhi exist for a period of a little over 100 years. The lowest ever temperature reading
during this period is -2.2 °C, recorded on January 11, 1967 at Delhi Palam. And,the highest ever temperature
reading during the same period is 48.4 °C recorded on May 26, 1998, again at Delhi Palam.
30. Climate data for Delhi (Safdarjung) 1990-2006
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °C (°F)
30.0
(86)
34.1
(93.4)
40.6
(105.1)
45.6
(114.1)
47.2
(117)
46.7
(116.1)
45.0
(113)
42.0
(107.6)
40.6
(105.1)
39.4
(102.9)
36.1
(97)
29.3
(84.7)
47.2
(117)
Average high °C (°F)
21.0
(69.8)
23.5
(74.3)
29.2
(84.6)
36.0
(96.8)
39.2
(102.6)
38.8
(101.8)
34.7
(94.5)
33.6
(92.5)
34.2
(93.6)
33.0
(91.4)
28.3
(82.9)
22.9
(73.2)
31.2
(88.2)
Daily mean °C (°F)
14.3
(57.7)
16.8
(62.2)
22.3
(72.1)
28.8
(83.8)
32.5
(90.5)
33.4
(92.1)
30.8
(87.4)
30.0
(86)
29.5
(85.1)
26.3
(79.3)
20.8
(69.4)
15.7
(60.3)
25.1
(77.2)
Average low °C (°F)
7.6
(45.7)
10.1
(50.2)
15.3
(59.5)
21.6
(70.9)
25.9
(78.6)
27.8
(82)
26.8
(80.2)
26.3
(79.3)
24.7
(76.5)
19.6
(67.3)
13.2
(55.8)
8.5
(47.3)
19.0
(66.2)
Record low °C (°F)
−0.6
(30.9)
1.6
(34.9)
4.4
(39.9)
10.7
(51.3)
15.2
(59.4)
18.9
(66)
20.3
(68.5)
20.7
(69.3)
17.3
(63.1)
9.4
(48.9)
3.9
(39)
1.1
(34)
−0.6
(30.9)
Average precipitation mm (inches)
19
(0.75)
20
(0.79)
15
(0.59)
21
(0.83)
25
(0.98)
70
(2.76)
237
(9.33)
235
(9.25)
113
(4.45)
17
(0.67)
9
(0.35)
9
(0.35)
790
(31.1)
verage precipitation days (≥ 1.0 mm) 1.7 2.5 2.5 2.0 2.8 5.5 13.0 12.1 5.7 1.7 0.6 1.6 51.7
Average relative humidity (%) 63 55 47 34 33 46 70 73 62 52 55 62 54
Mean monthly sunshine hours 214.6 216.1 239.1 261.0 263.1 196.5 165.9 177.0 219.0 269.3 247.2 215.8 2,684.6
Source 1) NOAAS
Source 2) Indian Meteorological Department (record high and low up to 2010)
Climate data for Delhi (Palam)
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °C (°F)
31.0
(87.8)
35.7
(96.3)
41.3
(106.3)
45.3
(113.5)
48.4
(119.1)
47.6
(117.7)
45.7
(114.3)
43.2
(109.8)
40.8
(105.4)
39.6
(103.3)
36.4
(97.5)
30.0
(86)
48.4
(119.1)
Average high °C (°F)
20.8
(69.4)
23.9
(75)
30.0
(86)
36.9
(98.4)
40.5
(104.9)
40.3
(104.5)
35.4
(95.7)
33.7
(92.7)
34.2
(93.6)
33.3
(91.9)
28.3
(82.9)
22.7
(72.9)
31.7
(89.1)
Average low °C (°F)
6.7
(44.1)
9.1
(48.4)
14.1
(57.4)
20.5
(68.9)
25.1
(77.2)
27.6
(81.7)
26.4
(79.5)
25.6
(78.1)
23.8
(74.8)
18.8
(65.8)
12.7
(54.9)
7.8
(46)
18.2
(64.8)
Record low °C (°F)
−2.2
(28)
−1.6
(29.1)
3.4
(38.1)
8.6
(47.5)
14.6
(58.3)
19.8
(67.6)
17.8
(64)
20.2
(68.4)
13.6
(56.5)
9.9
(49.8)
2.1
(35.8)
−1.3
(29.7)
−2.2
(28)
32. NO2 LEVEL IN NATIONAL AMBIENT AIR QUALITY STATIONS IN 2012
Source images: CPCB; NAAQS TRENDS-REPORT
33. National Mean Concentration of three regularly monitored
pollutants
National mean concentration with 90th percentile and 10th percentile for SO2, NO2 and PM10 is depicted in
National mean of SO2 concentration has decreased over the years indicating that there has been a decline in SO2
levels. Decreasing trend may be due to various interventions that have taken place in recent years such as reduction
in sulphurin diesel, use of cleaner fuel such as CNG in metro cities, change in domestic fuel from coal to LPG etc.
National mean of NO2 concentration has remained stable over the years with a slight decrease in last three years
despite increase in sources like vehicles . The reason for this may be various intervention measures that have taken
place such as improvement in vehicle technology and other vehicular pollution control measures like alternate
fuel etc. National mean of PM10 concentration shows fluctuating trend exceeding the NAAQS. The reasons being
emission from gensets,small scale industries, biomass incineration, suspension oftraffic dust,natural dust,
commercial and domestic use of fuel and vehicular emission etc. Furthermore, the increasing trend for PM10 may be
attributed to the increasing number of vehicles and re-suspension ofnatural dust.
Source images: CPCB; NAAQS TRENDS-REPORT
34. YEARLY TRENDS OF LOW,MODERATE , HIGH LEVELS OF SO2, NO2 AND PM10
36. DELHI METRO HELPS IN REDUCTION OF AIR
POLLUTION
Fig. Delhi Metro
The Delhi Metro (DM), an intra-city electric rail systemserving the National Capital Region (NCR) of India, has
been operational since December 2002. By March 2012, the DM had an operational route length of 167 km.
While a key motivation behind building a mass transit systemin Delhi was to ease traffic congestion in the city, it is
not hard to imagine that it may have a considerable impact on air quality as well. An improvement in air quality
would presumably occur mainly due to the ‘traffic diversion effect’. This refers to the possibility that commuters
who were earlier using private modes of transport such as cars and two-wheelers switch to the DM leading to net
reduction in the level of vehicular emissions.
Investigating whether this actually happened becomes particularly important for Delhi because the city is infamous
for its high levels of air pollution. On most days between 2004 and 2006, the average levels of nitrogen dioxide and
carbon monoxide exceeded the permissible standards set by the Central Pollution Control Board (CPCB). Such high
levels of pollution raise health concerns for the city's inhabitants.The adverse effects of air pollution on health
outcomes such as damage to the central nervous system, worsening of asthma and an increase in infant mortality
rates, are well document. Studies conducted by the CPCB find that high pollution levels in Delhi are positively
associated with lung function deficits and with respiratory ailments (CPCB 2008). Guttikunda and Apte (2009)
found that about 10,900 premature deaths every year in Delhi occurdue to ambient particulate matter pollution. In
light of these facts, it is important to examine whether there has been any significant impact on air pollution in Delhi
due to the operation of the metro.
Traffic diversion versus traffic creation
Based on transport economics theories, it is not possible to predict whether the net effect of the DM on air quality
will be positive or negative. The main argument is that along with the traffic diversion effect, there could be a traffic
creation effect due to introduction of a new mode of transportation.The latter refers to new demand for travel
generated by a faster and arguably more comfortable mode of transport such as the DM. For example, new demand
for travel could arise if, facilitated by the DM, people decide to relocate to the outskirts of the city to possibly
benefit from cheaperreal estate prices, and then commute longer distances to work. If part of the increased distance
is covered using pollution intensive modes of transport (such as private cars), then this could negate any traffic
diversion effect and could lead to an increase in overall level of pollution.
37. An added dimension that needs to be considered while studying the net effect is the presence of two coal-based
power plants within the city limits that were operational during our study period (2004-2006). If operation of the
DM resulted in increased capacity utilisation of these plants in order to supply electricity for running it, then this
could also contribute to higher overall emissions in the city.
Analyzing the link betweenthe metro and air quality
In our study,we examine the effect of the DM on air quality using data obtained from the CPCB on four pollutants –
nitrogen dioxide, carbon monoxide, ozone and sulfur dioxide, between 2004 and 2006. This data is collected at two
locations in Delhi - ITO, a major traffic intersection in central Delhi, and Siri Fort, a residential locality in South
Delhi. We obtained hourly data on temperature, rainfall, wind speed and relative humidity for Delhi.
In order to establish a causal link between the DM and air quality it is important to compare pollution actually
observed in the period after the DM became operational with its correct ‘counterfactual’. This counterfactual refers
to the level of pollution in the hypotheticalscenario where all otherfactors that affect pollution remain the same as
in the post-metro period, and the only difference is that the metro does not exist in the counterfactual. Any
difference between the observed pollution in the post-metro period and the pollution in the counterfactualcan then
be attributed to the DM. To do this, we estimate the trend (pattern over time) in pollution using hourly pollution data
over a reasonably long time period which includes the date of extension of the DM. If we detect a sudden change in
the level of pollution at the date of extension of the DM, then we attribute this change to the extension of the DM.
Between 2004 and 2006 there were six extensions of the DM rail network. At each extension, we examine the time
trend for each pollutant separately. We identify the localized, short term effect on pollution that can be attributed to
each extension of the DM by conducting this analysis separately for pollution data from ITO and Siri Fort. Our
preliminary analysis shows a reduction in the levels of nitrogen dioxide and carbon monoxide at both locations. This
reduction varies between 24 to 29% for nitrogen dioxide and between 26 to 69% for carbon monoxide. For sulfur
dioxide, we find an increase of 90% at ITO, and a decrease ranging between 35 to 89% for Siri Fort. For ozone, we
do not find a uni-directional effect even across extensions at a particular location.
Conclusions and caveats
To summarize, preliminary evidence points toward a reduction in the levels of nitrogen dioxide and carbon
monoxide. Given that both nitrogen dioxide and carbon monoxide are important vehicular emissions, our initial
findings suggest that the DM has encouraged people to switch from private to public mode of travel resulting in
positive effects on air quality in the city. In the light of our findings and given the existing evidence on the adverse
health effects of air pollution, these indirect health benefits should be taken into account when urban policy makers
contemplate setting up large scale intra-city transportation systems.We provide a rationale for subsidizing these
mass transit systems,such as the metro or dedicated bus routes,even when the direct costs do not show a net profit.
These public transport systems should be considered seriously for othercities that face similar challenges in terms of
vehicular congestion and health costs due to pollution.
Two caveats should be kept in mind while interpreting and understanding these results.First, the large number of
missing observations in the pollution data makes this analysis particularly challenging. Further examination is
needed to ensure that our results are not being driven by the pattern of missing observations.Second,for a few
extensions, the magnitudes of change in carbon monoxide and sulfur dioxide are very large to be driven solely by a
traffic diversion effect. Also, ozone is created in the presence of sunlight and nitrogen dioxide through a complicated
non-linear process.The results for ozone do not show a consistent pattern in our analysis.In the light of these facts,
further investigation is needed to rule out the possibility that our findings are not being driven by chance or poorly
measured pollution data.
How can citizens of Delhi help in reducing pollution?
Pollution in Delhi is a perpetual problem which need to be looked upon as a serious issue not only by the
Government but also by the citizens of the city.
38. One of the easiest ways is that there should be an efficient involvement of Resident Welfare Associations in
various localities in collection, segregation of garbage from houses and the societies.
Citizens can take steps to covert the garbage into compost in their localities.
More and more trees must be planted in every locality.
Every individual should keep a proper check on the pollution level of their vehicles.
Making more use of CNG.
One of the best ways to control pollution is to manage wastes of all types in a proper manner.
Each and every citizen should abide by the 3Rs: Recycle, Reuse, Reduce.
More and more people should use bus and metro instead of cars and scooters, as they can carry a lot more people
in one journey. Car pool is also a good option.
Controlling the use of energy and making use of electricity in an efficient manner.
One can also reduce water pollution by reducing the use of chemicals, cleaning agents, pesticides, herbicides,
fertilizers etc.
HOW TO CONTROL AIR POLLUTION IN DELHI
CONTROL MEASURES
The atmosphere has several built-in self cleaning processes such as dispersion,gravitational settling, flocculation,
absorption,rain-washout, etc to cleanse the atmosphere. However, control of contaminants at their source level is a
desirable and effective method through preventive or control technologies.
Source control: Some measures that can be adopted in this direction are:
1. Using unleaded petrol
2. Using fuels with low sulphurand ash content
3. Encouraging people to use public transport,walk or use a cycle as opposed to private vehicles
4. Ensure that houses,schools, restaurants and playgrounds are not located on busy streets
5. Plant trees along busy streets as they remove particulates, carbon dioxide and absorb noise
6. Industries and waste disposalsites should be situated outsdide the city preferably on the
downwind of the city.
7. Catalytic converters should be used to help control emissions of carbon monoxide and
hydrocarbons
Control measures in industrial centers
1. Emission rates should be restricted to permissible levels by each and every industry
2. Incorporation of air pollution control equipment in design of plant layout must be made mandatory
3. Continuous monitoring of the atmosphere for pollutants should be carried out to know the
emission levels.
39. EQUIPMENT USED TO CONTROL AIRPOLLUTION
Air pollution can be reduced by adopting the following approaches.
1. Ensuring sufficient supply of oxygen to the combustion chamber and adequate temperature so that
the combustion is complete thereby eliminating much of the smoke consisting of partly burnt ashes and
dust.
2. To use mechanical devices such as scrubbers,cyclones,bag houses and electro-static precipitators
in manufacturing processes.The equipment used to remove particulates from the exhaust gases of electric
power and industrial plants are shown below. All methods retain hazardous materials that must be disposed
safely. Wet scrubbercan additionally reduce sulphurdioxide emissions.
3. The air pollutants collected must be carefully disposed.The factory fumes are dealt with chemical
treatment.
Pollution Control Equipment:
Sometimes pollution control at source is not possible by preventing the emis sion of pollutants.Then it becomes
necessary to install pollution control equipment to remove the gaseous pollutants from the main gas stream.
The pollutants are present in high concentration at the source and as their distance from the source increases they
become diluted by diffusing with environmental air.
Pollution control equipment’s are generally classifiedinto two types:
(a) Control devices for particulate contaminants.
(b) Control devices for gaseous contaminants.
40. In the present book only the control devices for particulate contaminants are dealt with.
Control Devices forParticulate Contaminants:
(1) Gravitational Settling Chamber:
For removal of particles exceeding 50 µm in size from polluted gas streams, gravitational settling chambers (Fig
5.1) are put to use.
This device consists ofhuge rectangular chambers. The gas stream polluted with particulates is allowed to enter
from one end. The horizontal velocity of the gas stream is kept low (less than 0.3 m/s) in order to give sufficient
time for the particles to settle by gravity.
The particulates having higher density obey Stoke’s law and settle at the bottomof the chamber from where they are
removed ultimately. The several horizontal shelves or trays improve the collection efficiency by shortening the
settling path of the particles.
(2) Cyclone Separators (Reverse flow Cyclone):
Instead of gravitational force, centrifugal force is utilized by cyclone separators,to separate the particulate matter
from the polluted gas.Centrifugal force, several times greater than gravitational force, can be generated by a
spinning gas stream and this quality makes cyclone separators more effective in removing much smaller particulates
than can possibly be removed by gravitational settling chambers.
A simple cyclone separator(Fig 5.2) consists ofa cylinder with a conical base. A tangential inlet discharging near
the top and an outlet for discharging the particulates is present at the base of the cone.
41. Mechanism of Action:
The dust laden gas enters tangentially, receives a rotating motion and generates a centrifugal force due to which the
particulates are thrown to the cyclone walls as the gas spirals upwards inside the cone (i.e. flow reverses to form an
inner vortex which leaves flow through the outlet). The particulates slide down the .walls of the cone and are
discharged from the outlet.
(3) Fabric Filters (Baghouse Filters):
In a fabric filter system, a stream of the polluted gas is made to pass through a fabric that filters out the particulate
pollutant and allows the clear gas to pass through.The particulate matter is left in the form of a thin dust mat on the
insides of the bag. This dust mat acts as a filtering medium for further removal of particulates increasing the
efficiency of the filter bag to sieve more sub micron particles (0.5 µm).
A typical filter (Fig 5.3) is a tubular bag which is closed at the upper end and has a hopperattached at the lower end
to collect the particles when they are dislodged from the fabric. Many such bags are hung in a baghouse.For
42. efficient filtration and a longer life the filter bags must be cleaned occasionally by a mechanical shaker to prevent
too many particulate layers from building up on the inside surfaces of the bag.
(4) Electrostatic Precipitators:
The electrostatic precipitator (Fig. 5.4) works on the principle of electrostatic precipitation i.e. electrically charged
particulates present in the polluted gas are separated from the gas streamunder the influence of the electrical field.
A typical wire and pipe precipitator consists of:
(a) A positively charged collecting surface (grounded).
(b) A high voltage (50 KV) discharge electrode wire.
(c) Insulator to suspend the electrode wire from the top.
(d) A weight at the bottomof the electrode wire to keep the wire in position.
43. Mechanism of Action:
The polluted gas enters from the bottom, flows upwards (i.e. between the high voltage wire and grounded collecting
surface). The high voltage in the wire ionises the gas.The negative ions migrate towards the grounded surface and
pass on their negative charge to the dust particles also. Then these negatively charged dust particles are
electrostatically drawn towards the positively charged collector surface, where they finally get deposited.
The collecting surface is rapped or vibrated to periodically remove the collected dust-particles so that the thickness
of the dust layer deposited does not exceed 6 mm, otherwise the electrical attraction becomes weak and efficiency of
the electrostatic precipitator gets reduced.
As the electrostatic precipitation has 99 + percent efficiency and can be operated at high temperatures (600°C) and
pressure at less power requirement, therefore, it is economical and simple to operate compared to other devices.
(5) Wet Collectors (Scrubbers):
In wet collectors or scrubbers,the particulate contaminants are removed from the polluted gas stream by
incorporating the particulates into liquid droplets.
Common wet scrubbers are:
(i) Spray Tower
(ii) Venturi Scrubber
(iii) Cyclone Scrubber
44. (i) Spray Tower:
Water is introduced into a spray tower (Fig. 5.5.) by means of a spray nozzle (i.e. there is downward flow of water).
As the polluted gas flows upwards, the particulates (size exceeding 10 µm) present collide with the water droplets
being sprayed downward from the spray nozzles. Under the influence of gravitational force, the liquid droplets
containing the particulates settle to the bottomof the spray tower.
(ii) Venturi Scrubber:
Submicron particulates (size 0.5 to 5 µn) associated with smoke and fumes are very effectively removed by the
highly efficient Venturi Scrubbers. As shown in Fig 5.6 a Venturi Scrubber has a Venturi shaped throat section.The
polluted gas passes downwards through the throat at the velocity of 60 to 180 m/sec.
A coarse water stream is injected upwards into the throat where it gets atomised (i.e. breaks the water into droplets)
due to the impact of high velocity of the gas. The liquid droplets collide with the particulates in the polluted gas
stream.
The particles get entrained in the droplets and fall down to be removed later on. Venturi Scrubbers can also remove
soluble gaseous contaminants.Due to the atomisation of water there is proper contact between the liquid and the gas
increasing the efficiency of the Venturi Scrubber (their power cost is high because of the high inlet gas velocity).
45. To separate the droplets carrying the particulate matter from the gas stream, this gas -liquid mixture in the Venturi
Scrubber is then directed into a separation device such as a cyclone separator.
(iii) Cyclone Scrubber:
The dry cyclone chamber can be converted into a wet cyclone scrubberby inserting high pressure spray nozzles at
various places within the dry chamber (Fig. 5.7).
46. The high pressure spray nozzles generate a fine spray that intercepts the small particles in the polluted gas.The
centrifugal force throws these particles towards the wall from where they are drained downwards to the bottomof
the scrubber.
(c) Diffusion of Pollutants in Air:
Dilution of the contaminants in the atmosphere is anotherapproach to the control of air pollution. If the pollution
source releases only a small quantity of the contaminants then pollution is not noticeable as these pollutants easily
diffuse into the atmosphere but if the quantity of air contaminants is beyond the limited capacity of the environment
to absorb the contaminants then pollution is caused.
However, dilution of the contaminants in the atmosphere can be accomplished through the use of tall stacks which
penetrate the upper atmospheric layers and disperse the contaminants so that the ground level pollution is greatly re-
duced. The height of the stacks is usually kept 2 to 21/2 times the height of nearby structures.
Dilution of pollutants in air depend on atmospheric temperature, speed and direction of the wind. The disadvantage
of the method is that it is a short term contact measure which in reality brings about highly undesirable long range
effects.
This is so because dilution only dilutes the contaminants to levels at which their harmful effects are less noticeable
near their original source whereas at a considerable distance from the source these very contaminants eventually
come down in some form or another.
(d) Vegetation:
Plants contribute towards controlling air-pollution by utilizing carbon dioxide and releasing oxygen in the process of
photosynthesis.This purifies the air (removal of gaseous pollutant—CO2) for the respiration of men and animals.
Gaseous pollutants like carbon monoxide are fixed by some plants,namely, Coleus Blumeri, Ficus variegata and
Phascolus Vulgaris. Species of Pinus, Quercus, Pyrus, Juniperus and Vitis depollute the air by metabolising nitrogen
oxides. Plenty of trees should be planted especially around those areas which are declared as high-risk areas of
pollution.
(e) Zoning:
This method of controlling air pollution can be adopted at the planning stages ofthe city. Zoning advocates setting
aside of separate areas for industries so that they are far removed from the residential areas. The heavy industries
should not be located too close to each other.
47. New industries,as far as possible,should be established away from larger cities (this will also keep a check on
increasing concentration of urban population in a few larger cities only) and the locational decisions of large
industries should be guided by regional planning. The industrial estate of Bangalore is divided into three zones
namely light, medium and large industries. In Bangalore and Delhi very large industries are not permitted.
ODD EVEN SCHEME :
A step towards reduction in air pollution
The Delhi government released a detailed blueprint for its ambitious road-rationing plan to check pollution in the
national capital through odd even scheme.The plan to curb the number of vehicles plying in the city, however, has a
host of exemptions, including two-wheelers, women drivers and top politicians. The restrictions will also not apply
to CNG and electric vehicles.The odd-even scheme, to be run on a trial basis from 1 January to 15 January, will
limit four-wheelers to alternate days.Cars with licence plates ending in an odd number can ply on odd dates and
those ending in an even number can run on even dates between 8am and 8pm, except on Sunday, when no
restrictions apply.The penalty in case of a violation is Rs.2,000.The numerous exemptions, experts say,will reduce
the effectiveness of the plan that seeks to curb vehicle emissions in the world’s most polluted city.The city has been
engulfed by a blanket of smog in recent days,triggering respiratory problems among its residents.“There are no
justifications for some of the exemptions that have been included,” said Debolina Kundu, associate professorat the
National Institute of Urban Affairs. “In the long run, I don’t think it is very viable. It is just a token effort.”
The right way to approach the problem of pollution is to strengthen public transport and last-mile connectivity,But
these steps will take a long time to implement in a city that’s already choking with a noxious combination of vehicle
exhaust, dust and smoke from burning of waste levels at 295 micrograms/m3 and PM10 levels at 470
micrograms/m3. On Wednesday,the city saw the highest level of air pollution this year with particulate matter
(PM) 2.5 (tiny particles that cause respiratory problems)
Announcing the blueprint, Delhi chief minister Arvind Kejriwal said: “Pollution has become a very serious
problem.”
“We will do an assessment at the end of 15 days. If the people accept this plan, we will think about having a
permanent solution.Other countries have also taken such steps to tackle high pollution levels,” he said.
According to the Delhi statistical handbookfor 2015, the total number of registered vehicles in the city in 2014-15
was 8.83 million. Delhi added 534,000 vehicles in the year ended 31 March.Given the staggering pace of addition of
new vehicles, the odd-even plan appears to be a bold measure to curb pollution.
“It may not work the first time around, but it is a bold step that shows the changing trend in urban transpo rtation in
the country,” said Sudhakar Yedla, professorat the Indira Gandhi Institute of Development Research, Mumbai. He
48. focuses on urban transportation policy.“If you wait for public transport to improve, it will never happen.It may be a
knee-jerk reaction from the government, but (such an initiative) needs a champion,” he said.
The Delhi government has taken all approvals including that of the lieutenant governor, and will issue a formal
notification for the scheme on Monday.The list of 20-plus exemptions from the restrictions include VIPs, emergency
vehicles, ambulances, fire engines,hospitals,prisons, hearses,enforcement vehicles and defence ministry
vehicles.Among VIPs, leaders of the opposition in the Rajya Sabha and Lok Sabha, chief ministers of states,judges
of the Supreme Court and high court and Lokayukta are exempt.The Delhi chief minister and the state’s cabinet
ministers have been left out of the exemptions.
RESULTS OF ODD EVEN SCHEME
Council on Energy, Environment and Water (CEEW), an independent think-tank in Delhi, in collaboration with the
Energy Policy Institute at the University of Chicago(EPIC), independently measured air quality and traffic volumes
at five important locations (viz. Connaught Place, GTB Nagar, IIT Delhi, Mathura Road, and Shadipur) across New
Delhi, over the last three weeks. The data collected using low-cost pollution monitors showed a mixed result:
The average air pollution levels increased in the first week of January in comparison to the previous week.
However, in the second week of January, air quality was marginally better, but still poorer than the last week
of December.
Average PM 2.5 level of 306 µg/m3 was observed during the first two weeks of January 2016, similar to
average PM 2.5 level of 330 µg/m3 observed during the first fortnight of January 2014. However, the first two
weeks of 2015 had a lower average PM 2.5 level of 226 µg/m3due to unseasonalrains and winds. In other
words, meteorological variables such as temperature, wind speed and precipitation have a significant impact in
the short-term. What that means is it’s hard to provide conclusive evidence on the impact of the odd-even
policy on air quality.
The daily average number of vehicles increased by 10% in these five locations during the first two weeks of
January, as compared to the last week of December. This increase was primarily driven by an increase in 2-
wheelers (17%), 3-wheelers (12%), taxis (22%) and private buses (138%).
49. HOW CURRENT ODD EVEN SCHEME HAS CHANGED
THE MINDSET OF DELHI PEOPLE
The cut in vehicular emission due to rolling out of the odd-even scheme has resulted "definitive decline" in levels of
PM2.5 pollutants, Delhi Government said today while claiming success ofthe restrictions unveiled on January 1.
The Government said data of pollutants collected from over 55 locations showed a clear trend of improving air
quality in several areas across the city and that there has been a "positive impact" of the odd-even scheme.
"According to the scientists of the Delhi Pollution Control Committee (DPCC), 80 per cent of PM2.5 air pollution is
caused by vehicular traffic and reduction in its levels, even in outer areas of Delhi shows that reduction of four
wheeled vehicles on roads since the New Year Day is having a positive impact," the government said in a statement.
However, a report by IIT Kanpur had said vehicular pollutions contribute to around 25 per cent of PM2.5
concentrations during winters which comes down to 9 per cent during summers.
It said the ambient air data collected by DPCC through mobile dust samplers using Light Scattering Technique at 20
locations in peripheral areas of Delhi on January 4 showed a clear declining trend in the levels of PM2.5.
The major source of PM2.5 pollutant is vehicular pollution.
"In 13 of these 20 locations, the PM2.5 level has been recorded at less than 300, which proves reduction in
comparison to previous years at the same time by at least 100 units," it said.
Transport Minister Gopal Rai had asked for data collection from peripheral areas of Delhi to ascertain the impact of
NCR towns on air pollution of Delhi.
Government said since January 1, the DPCC mobile teams have recorded ambient air data from 55 locations, and the
trend is that air quality is improving in central parts and other areas which are not on the borders of the national
capital.
"The PM10 data for the latest 20 locations from peripheral areas of Delhi shows an adverse impact of NCR towns.
PM10, the major cause of which is dust arising from construction waste and wind blown dust,is on the higher side
in bordering areas. Everyone is contributing, car pooling has come in trend nd people are accepting it
HOW CAN WE IMPROVISE?
In India the public transport system is still inadequate, as per the current population status more number of
public transports should come forward to reduce air pollution and provide better public transport
connectivity.
The small roads and traffic congestion problemcould be solved by more availability of public transport and
less usage of private vehicles and supporting car pooling.
Some measures could also be opt as per the different schemes in several countries of the world, like in Paris
free public transport is provided by government during higher air pollution emergence in their city.
And in Estonia the public transport is totally free and strict laws are there to reduce air pollution and
people are convinced to follow them.
There should be a common pass for all the public transport like metro, bus, cycles etc.
Government should emphasis on providing different lanes for cycle riders for reduction in road accidents
and air pollution.
The ecofriendly vehicles including cycles and electric vehicles, must be subsidized for those who needs to
travel nearby proximity
There should a reduction in constructional activities.
50. COMPARISON OF DELHI’S AIR POLLUTON STATUS
WITH DIFFERENT CITIES OF THE WORLD
Pollution in Paris
Climate in Paris
Seasons in Paris
A melody of colors and atmospheres, a symphony of contrasting skies and light. Every season pays tribute to Paris
and highlights its charms, be it the sun caressing its pale façades, or the rain reflecting the night’s gleam. To the
sweet music of romance or a festive beat, compose your own score for your trip to the city, depending on the time of
year and the whims of the weather.
Spring (21 March-21 June)
This is the season where Paris seems to reawaken, with its avenues fringed with new green shoots and its trees in
flower. The days are getting longer, as are the opening times of museums, and the high season is just around the
corner. There’s a holiday feeling in the air and the sweet smell of candy floss pervades the pathways of the Foire du
Trône funfair. People venture out and about in the parks and gardens and along the river banks, strolling, cycling or
skating.
Average temperatures and rainfall: Minimum Maximum Rain in mm
March 4°C 12°C 35
April 6°C 16°C 42
May 10°C 20°C 57
51. Summer (21 june-21 september)
ZOOM
When the summer season is at its height, rest and relaxation and “joie de vivre” bask in the sun,on the café terraces,
in the parks and on the “beaches” by the Seine. Picnics abound and gourmets melt for the best ice cream in Paris. On
the Champs-Elysées, the 14 July parades and the cyclists triumph. Cinema and music celebrate: free films and
concerts thrill the la capital, which takes on its summer scenes.
Average temperatures and rainfall: Minimum Maximum Rain in mm
June 13°C 23°C 59
July 15°C 25°C 59
August 14°C 24°C 64
Autumn (21 September-21 December)
ZOOM
When you see the avenues and parks take on their autumn reflections, and the soft light of the street lamps sets
aglow the carpet of fallen leaves, it’s an inspiring sight.The days may be getting shorter, but the colours are
blooming. This is not only the time to return to school,but also a renewal of culture. Autumn has its own festival
52. and the major trade fairs draw the crowds. Towards the end of November, Paris already sparkles with Christmas
decorations.
Average temperatures and rainfall: Minimum Maximum Rain in mm
September 12°C 21°C 55
October 8°C 16°C 50
December 5°C 10°C 51
Winter (21 December-21 march)
ZOOM
Snow occasionally covers the rooftops of Paris with its mantle, reminiscent of the Impressionist paintings by
Caillebotte. Christmas dresses up the main avenues with its sparkle, markets and appealing window displays spring
up around the city. It is a pleasure to dive into the cosy warmth of its restaurants and cafés. Take a tasty break for
hot chocolate between two museums or after a few pirouettes on the open-air ice rinks. From January to March, this
is the charm of off-season Paris.
Average temperatures and rainfall Minimum Maximum Rain in mm
January 2°C 7°C 50
February 1°C 6°C 56
March 1°C 7°C 46
