1. BHARATI VIDYAPEETH COLLEGE OF
ENGINEERING
EVS PROJECT
ON PHOTOCHEMICAL SMOG
SUBMITTED BY-
Sr.No. NAME ROLL NO.
1 PARMAR JASPAL SINGH 3707
2 PRAVEEN KUMAR YADAV 3716
3 SANDEEP PAVASKAR 3714
4 JITESH SARODE 3722
5 PRANAY PATIL 3711
Subject Incharge H.O.D

2. ACKNOWLEDGEMENT
We take this opportunity to express my profound sincere
gratitude to all those who helped me to carry out this project
successfully.
We owe our sincere gratitude to our Principal Dr. M.Z.Shaikh
and also to our college committee members for giving the
encouragement that helped us to complete the project successfully.
Our sincere thanks to Mrs S.D.Jadhav, Head of the Department of
Mechanical engineering, Bharati Vidyapeeth college of engineering,
who inspired us with his valuable suggestions and advice throughout
our lectures. We also express our sincere thanks to all other staff
members.
We express our sincere gratitude to our External guide Mrs.
Reshma Ahmed (Mam) Technologies for sparing his valuable time in
giving the valuable information and suggestions all through, for the
successful completion of the project.
At the very outset we convey our gratitude to our Internal Guide
Mrs. Reshma Ahmed (Mam), Lecturer for Mechanical Department,
for allowing us to do project and enabling us to complete the same
successfully. We express our profound gratitude for his valuable
guidance and support.
We extend our thanks to our Class Teacher, Mr.Pramod Kothmire
for his valuable suggestions during the project work.
We here by thank one and all who extended their helping hand in the
accomplishment of the project.

3. INDEX
Sr.no Titles Pg.no
1 Definition 1
2 Description 2
3 Development/Formation 3
4 Chemical Reaction Occurence 5
5 Health Effects 6
6 Natural Causes 6
7 Areas Affected 7
8 Pollution Index 11
9 Prevention/Solutions 11
10 Bibliography 12

4. DEFINITION OF PHOTOCHEMICAL SMOG
A combination of fog and chemicals that come from
automobile and factory emissions and is acted upon by
the action of the sun. Nitrogen dioxide, in the presence
of the sun and some hydrocarbons, is turned into nitric
oxide and atomic oxygen. The atomic oxygen reacts
with the oxygen molecules and other constituents of
automobile exhaust fumes to form a variety of products
including ozone. The ozone is harmful in itself and is
also implicated in a highly complex series of continuing
reactions. Is completely being photochemical smog

5. DESCRIPTION:-
Definition
o Carbon monoxide and sulfur oxide are considered primary pollutants. These
pollutants undergo chemical changes and cause secondary effects such as
smog. Air pollution is defined by the existence and integration of toxic
compounds in the atmosphere in concentrations high enough to cause harm to
humans, animals and the Earth's environment.
Cause
o Burning fossil fuels emits carbon monoxide and sulfur oxide. Automobiles, buses,
planes and any form of gas-fueled transportation emit carbon monoxide gases
through exhaust systems. Sulfur dioxide is created through the burning of coal,
and is associated with industrial waste. Manufacturing processes use coal for
fuel, releasing sulfur dioxide into the air through the factory exhaust systems.
Effects
o Air pollution is the source of smog, acid rain and possibly global warming. Smog
is classified as either photochemical smog or industrial smog. Photochemical
smog, often evidenced by the brown cloud hanging over densely populated
cities, is created by the interaction of sunlight with molecules of primary
pollutants. The resulting chemical reaction is toxic to humans and animals.
Industrial smog is characterized by the gray-brown fog that hangs over industrial
areas and is attributed to the interaction of sunlight, air molecules and sulfur
dioxide. The result is, again, toxic air.
Considerations
o Individuals and businesses alike have taken steps to reduce their contributions to
air pollution. Manufacturing and purchasing vehicles that use gas more efficiently
and driving less, recycling to reduce landfills that emit toxic gases and
patronizing those businesses that reduce their industrial waste all aid in
controlling air pollution. These actions, while laudable, act as a preventative only
in reducing the amount of toxins spewed into the Earth's atmosphere.

6. SMOG
Smog is a type of air pollution; the word "smog" was coined in the early 20th
century as a portmanteau of the words smoke and fog to refer to smoky fog. The
word was then intended to refer to what was sometimes known as pea soup fog,
a familiar and serious problem in London from the 19th century to the mid
20th century. This kind of smog is caused by the burning of large amounts of
coal within a city; this smog contains soot particulates from smoke, sulfur dioxide
and other components. Modern smog, as found for example in Los Angeles, is a
type of air pollution derived from vehicular emission from internal combustion
engines and industrial fumes that react in the atmosphere with sunlight to form
secondary pollutants that Photochemical smog.
Photochemical smog was first described in the 1950s. It is the chemical reaction of sunlight,
nitrogen oxides and volatile organic compounds in the atmosphere, which leaves airborne
particles and ground-level ozone. This noxious mixture of air pollutants can include the
following:
Nitrogen oxides, such as nitrogen dioxide
PeroAldehydes
xyacyl nitrates
Tropospheric ozone
Volatile organic compounds
All of these chemicals are usually highly reactive and oxidizing. Photochemical smog is
therefore considered to be a problem of modern industrialization. It is present in all modern
cities, but it is more common in cities with sunny, warm, dry climates and a large number of
motor vehicles. Because it travels with the wind, it can affect sparsely populated areas as well.

7. Development of Photochemical Smog
Certain conditions are required for the formation of photochemical smog. These conditions
include:
1. A source of nitrogen oxides and volatile organic compounds. High concentrations of these
two substances are associated with industrialization and transportation. Industrialization and
transportation create these pollutants through fossil fuel combustion.
2. The time of day is a very important factor in the amount of photochemical smog present. The
following illustrates the daily variation in the key chemical players. The diagram suggests:
Early morning traffic increases the emissions of both nitrogen oxides and VOCs as
people drive to work.
Later in the morning, traffic dies down and the nitrogen oxides and volatile organic
compounds begin to be react forming nitrogen dioxide, increasing its concentration.
As the sunlight becomes more intense later in the day, nitrogen dioxide is broken down
and its by-products form increasing concentrations of ozone.
At the same time, some of the nitrogen dioxide can react with the volatile organic
compounds to produce toxic chemicals such as PAN.
As the sun goes down, the production of ozone is halted. The ozone that remains in the
atmosphere is then consumed by several different reactions.
3. Several meteorological factors can influence the formation of photochemical smog. These
conditions include:
Precipitation can alleviate photochemical smog as the pollutants are washed out of the
atmosphere with the rainfall.
Winds can blow photochemical smog away replacing it with fresh air. However,
problems may arise in distant areas that receive the pollution.
Temperature inversions can enhance the severity of a photochemical smog episode.
Normally, during the day the air near the surface is heated and as it warms it rises,
carrying the pollutants with it to higher elevations. However, if a temperature inversion
develops pollutants can be trapped near the Earth's surface. Temperature inversions cause
the reduction of atmospheric mixing and therefore reduce the vertical dispersion of
pollutants. Inversions can last from a few days to several weeks.
4. Topography is another important factor influencing how severe a smog event can become.
Communities situated in valleys are more susceptible to photochemical smog because hills and
mountains surrounding them tend to reduce the air flow, allowing for pollutant concentrations
to rise. In addition, valleys are sensitive to photochemical smog because relatively strong
temperature inversions can frequently develop in these areas

8. FORMATION DIAGRAM
OF PHOTOCHEMICAL SMOG

9. Chemistry of Photochemical Smog
The previous section suggested that the development of photochemical smog is primarily
determined by an abundance of nitrogen oxides and volatile organic compounds in the
atmosphere and the presence of particular environmental conditions. To begin the chemical
process of photochemical smog development the following conditions must occur:
Sunlight.
The production of oxides of nitrogen (NOx).
The production of volatile organic compounds (VOCs).
Temperatures greater than 18 degrees Celsius.
If the above criteria are met, several reactions will occur producing the toxic chemical
constituents of photochemical smog. The following discussion outlines the processes required
for the formation of two most dominant toxic components: ozone (O3) and peroxyacetyl
nitrate (PAN). Note the symbol R represents a hydrocarbon (a molecule composed of carbon,
hydrogen and other atoms) which is primarily created from volatile organic compounds.
Nitrogen dioxide can be formed by one of the following reactions. Notice that the nitrogen
oxide (NO) acts to remove ozone (O3) from the atmosphere and this mechanism occurs
naturally in an unpolluted atmosphere.
O3 + NO »»» NO2 + O2
NO + RO2 »»» NO2 + other products
Sunlight can break down nitrogen dioxide (NO2) back into nitrogen oxide (NO).
NO2 + sunlight »»» NO + O
The atomic oxygen (O) formed in the above reaction then reacts with one of the abundant
oxygen molecules (which makes up 20.94 % of the atmosphere) producing ozone (O3).
O + O2 »»» O3
Nitrogen dioxide (NO2) can also react with radicals produced from volatile organic
compounds in a series of reactions to form toxic products such as peroxyacetyl nitrates (PAN).
NO2 + R »»» products such as PAN
It should be noted that ozone can be produced naturally in an unpolluted atmosphere. However,
it is consumed by nitrogen oxide as illustrated in the first reaction. The introduction of volatile
organic compounds results in an alternative pathway for the nitrogen oxide, still forming
nitrogen dioxide but not consuming the ozone, and therefore ozone concentrations can be
elevated to toxic levels.

10. Health effects
Highland Park Optimist Club wearing smog-gas masks at banquet, Los Angeles, circa 1954
The Ontario Medical Association announced that smog is responsible for an estimated 9,500
premature deaths in the province each year.
A 20-year American Cancer Society study found that cumulative exposure also increases the
likelihood of premature death from a respiratory disease, implying the 8-hour standard may be
insufficient.
Natural causes
An erupting volcano can also emit high levels of sulphur dioxide along with a large quantity of
particulate matter; two key components to the creation of smog. However, the smog created as a
result of a volcanic eruption is often known as "vog"[citation needed] to distinguish it as a natural
occurrence.
The radiocarbon content of some plant life has been linked to the distribution of smog in some
areas. For example; presence of Creosote bush in the Los Angeles area has been shown to have
an effect on smog distribution that is more than fossil fuel combustion alone.
Areas affected
Beijing air on a day after rain (left) and a smoggy day (right)
Smog can form in almost any climate where industries or cities release large amounts of air
pollution, such as smoke or gases. However, it is worse during periods of warmer, sunnier
weather when the upper air is warm enough to inhibit vertical circulation. It is especially
prevalent in geologic basins encircled by hills or mountains. It often stays for an extended
period of time over densely populated cities or urban areas, and can build up to dangerous
levels.

11. 1).London, United Kingdom
Victorian London was notorious for its thick smogs, or "pea-soupers", a fact that is often
recreated (as here) to add an air of mystery to a period costume drama
2).Mexico City, Mexico
Due to its location in a highland "bowl", cold air sinks down onto the urban area of Mexico
City, trapping industrial and vehicle pollution underneath, and turning it into the most
infamously smog-plagued city of Latin America. Within one generation, the city has changed
from being known for some of the cleanest air of the world into one with some of the worst
pollution, with pollutants like nitrogen dioxide being double or even triple international
standards.
Photochemical Smog Over Mexico City December 2010.
3).Santiago, Chile
Similar to Mexico City, the air pollution of Santiago valley located between the Andes and
Chilean Coast Range turning it into the most infamously smog-plagued city of South America.
Other aggravant of the situation resides in its high latitude (31 degrees South) and dry weather
at most part of the year.

12. 4).Tehran, Iran
In December 2005, schools and public offices had to close in Tehran, Iran and 1600 people
were taken to hospital, in a severe smog blamed largely on unfiltered car exhaust.
5).United States
A NASA astronaut photograph of a smog layer over central New
York.
Counties in the United States where one or more National Ambient Air Quality Standards are
not met, as of June 2007.
Smog was brought to the attention of the general US public in 1933 with the publication of the
book "Stop That Smoke", by Henry Obermeyer, a New York public utility official, in which he
pointed out the effect on human life and even the destruction of 3,000 acres (12 km2) of a
farmer's spinach crop. Since then, the United States Environmental Protection Agency has
designated over 300 U.S. counties to be non-attainment areas for one or more pollutants tracked
as part of the National Ambient Air Quality Standards. These areas are largely clustered around
large metropolitan areas, with the largest contiguous non-attainment zones in California and the
Northeast. Various U.S. and Canadian government agencies collaborate to produce real-time air
quality maps and forecasts.

13. Los Angeles and the San Joaquin Valley
Being in low basins surrounded by mountains, Los Angeles and the San Joaquin Valley are
notorious for their smog. The millions of vehicles in these basins plus the added effects of the
San Francisco Bay and Los Angeles/Long Beach port complexes contribute to further air
pollution. While strict regulations by the multiple California government agencies overseeing
this problem have reduced the number of Stage 1 smog alerts from several hundred annually to
just a few, these geologically predisposed entrapment zones collect pollution levels from cars,
trucks and fixed sources which still exceeds health standards and is a pressing issue for the
more than 25 million people who live there.
Major incidents in the US
1948, October 30–31, Donora, PA: 20 died, 600 hospitalized, thousands more stricken.
Lawsuits were not settled until 1951.
1953, November, New York: Smog kills between 170 and 260 people.
1954, October, Los Angeles: heavy smog shuts down schools and industry for most of the
month.
1963, New York: blamed for 200 deaths
6).Ulaanbaatar, Mongolia
In late 1990s to early 2000 a massive immigration to Ulaanbaatar from countryside begun,
causing air pollution in Ulaanbaatar. Estimated 150,000 households mainly living in traditional
Mongolian gers in outskirts of Ulaanbaatar burn wood and coal (some poor families burn even
car tires & trash) to heat themselves during harsh winter that lasts from October to April since
these outskirts are not connected to the city's central heating system. A temporary solution to
decrease smog is proposed in forms of stoves with improved efficiency although with no visible
results.
7).Southeast Asia
Singapore's Downtown Core on 7 October 2006, when it was affected by forest fires in
Sumatra, IndonesiaSmog is a regular problem in Southeast Asia caused by land and forest fires
in Indonesia, especially Sumatra and Kalimantan, although the term haze is preferred in
describing the problem

14. Pollution index
The severity of smog is often measured using automated optical
instruments such as Nephelometers, as haze is associated with
visibility and traffic control in ports. Haze however can also be
an indication of poor air quality though this is often better
reflected using accurate purpose built air indexes such as the
American Air Quality Index, the Malaysian API (Air Pollution
Index) and the Singaporean Pollutant Standards Index.
In hazy conditions, it is likely that the index will report the
suspended particulate level. The disclosure of the responsible pollutant is mandated in some
jurisdictions.
Prevention / Solution
o Air pollution may be prevented only if individuals and businesses stop
using toxic substances that cause air pollution in the first place. This would
require the cessation of all fossil fuel-burning processes, from industrial
manufacturing to home use of air conditioners. This is an unlikely scenario at this
time. However, as of June 2010, the Environmental Protection Agency (EPA) put
forth a proposal for a Federal Transport Rule, which sets stringent regulations on
industrial and power supply manufacturing and handling. The regulations are
designed to further reduce harmful emissions into the Earth's atmosphere.
o Reducing vehicle exhaust emissions NO and another important source
of hydrocarbons is vehicle exhaust emissions. When the fuel during combustion
in the engine cylinder, owing to internal combustion engines with fuel containing
impurities other than carbon, hydrogen, oxygen, incomplete combustion of
internal combustion engines, tail gas containing a certain amount of emissions of
CO, hydrocarbons, NO, particulate matter and ozone (formaldehyde, Acrolein,
and so on.
o If oxide. Such a catalyst can be a combination of platinum or rhodium or just
platinum. Since platinum catalyses un-burnt hydrocarbon and oxygen reaction,
resulting in production of carbon-dioxide and water vapor, the formation of ozone
is nullified. Similarly, rhodium can also help by oxidizing all the carbon monoxide
to carbon dioxide. If automobiles use unleaded petrol, the catalytic converters
can automobiles are provided with catalytic converters, it can reduce the
emissions of carbon monoxide and nitrogen be used.

15. BIBLIOGRAPHY
o
o http://hk.geocities.com/xavier114fch/03/03b.htm
http://www.wisegeek.com/what-is-photochemical-smog.htm
http://www.wisegeek.com/is-ozone-depletion-reversible.htm
http://www.wisegeek.com/what-are-cfcs.htm
http://www.windows.ucar.edu/tour/link=/earth/Atmosphere/smog.htm
l
http://www.ausetute.com.au/photsmog.html
http://en.wikipedia.org/wiki/Air_pollution
http://www.greenfacts.org/glossary/pqrs/primary-pollutant-secondary-
pollutant.htm
http://hk.geocities.com/xavier114fch/03/03b.htm
http://www.shodor.org/master/environmental/air/photochem/smogapp
lication.html
http://discovermagazine.com/1992/sep/canwerepairtheai120
http://www.physics.uoguelph.ca/summer/scor/articles/scor205.htm
http://en.wikipedia.org/wiki/Smog.