This document discusses air pollution and its causes, effects, and methods of control. It begins by describing the composition of the atmosphere and how air pollution occurs from both natural and human sources. The major classes of air pollutants are identified as particulate matter, nitrogen oxides, sulfur oxides, carbon oxides, hydrocarbons, and ozone. Transportation and industry are cited as the main sources of outdoor air pollution. The health effects of air pollution and methods to control pollution through emissions standards and regulations are also examined.

1. Air PollutionAir Pollution
*Acknowledged – Some points and pictures have been taken from internet sources as I acknowledge them.*Acknowledged – Some points and pictures have been taken from internet sources as I acknowledge them.
A.Mohanraj M.A., M.Phil., CCFE., (Ph.D)
Assistant Professor of English,
SBK College, Aruppukottai – 626 101.
A.Mohanraj M.A., M.Phil., CCFE., (Ph.D)
Assistant Professor of English,
SBK College, Aruppukottai – 626 101.

2. Overview of Air PollutionOverview of Air Pollution
o Atmosphere as a ResourceAtmosphere as a Resource
o Types and Sources of Air PollutionTypes and Sources of Air Pollution
• Major Classes of Air PollutantsMajor Classes of Air Pollutants
• Sources of Outdoor Air PollutantsSources of Outdoor Air Pollutants
• Urban Air PollutionUrban Air Pollution
o Effects of Air PollutionEffects of Air Pollution
o Controlling Air PollutionControlling Air Pollution

3. Atmosphere as a ResourceAtmosphere as a Resource
o AtmosphericAtmospheric
CompositionComposition
• Nitrogen 78.08%Nitrogen 78.08%
• Oxygen 20.95%Oxygen 20.95%
• Argon 0.93%Argon 0.93%
• Carbon dioxide 0.04%Carbon dioxide 0.04%
o Ecosystem servicesEcosystem services
• Blocks UV radiationBlocks UV radiation
• Moderates theModerates the
climateclimate
• Redistributes water inRedistributes water in
the hydrologic cyclethe hydrologic cycle

4. Types and Sources of Air PollutionTypes and Sources of Air Pollution
o Air PollutionAir Pollution
• Chemicals added to the atmosphere by naturalChemicals added to the atmosphere by natural
events or human activities in high enoughevents or human activities in high enough
concentrations to be harmfulconcentrations to be harmful
o Two categoriesTwo categories
• Primary Air PollutantPrimary Air Pollutant
•
Harmful substance that is emitted directly into theHarmful substance that is emitted directly into the
atmosphereatmosphere
• Secondary Air PollutantSecondary Air Pollutant
•
Harmful substance formed in the atmosphere when aHarmful substance formed in the atmosphere when a
primary air pollutant reacts with substancesprimary air pollutant reacts with substances
normally found in the atmosphere or with other airnormally found in the atmosphere or with other air
pollutantspollutants

5. Major Air PollutantsMajor Air Pollutants

7. Major Classes of Air PollutantsMajor Classes of Air Pollutants
o Particulate MaterialParticulate Material
o Nitrogen OxidesNitrogen Oxides
o Sulfur OxidesSulfur Oxides
o Carbon OxidesCarbon Oxides
o HydrocarbonsHydrocarbons
o OzoneOzone

8. Particulate MaterialParticulate Material
o Thousands of different solid or liquidThousands of different solid or liquid
particles suspended in airparticles suspended in air
• Includes: soil particles, soot, lead, asbestos,Includes: soil particles, soot, lead, asbestos,
sea salt, and sulfuric acid dropletssea salt, and sulfuric acid droplets
o Dangerous for 2 reasonsDangerous for 2 reasons
• May contain materials with toxic effectsMay contain materials with toxic effects
• Extremely small particles can become lodged inExtremely small particles can become lodged in
lungslungs

9. Nitrogen and Sulfur OxidesNitrogen and Sulfur Oxides
o Nitrogen OxidesNitrogen Oxides
• Gases produced by the chemical interactionsGases produced by the chemical interactions
between atmospheric nitrogen and oxygen atbetween atmospheric nitrogen and oxygen at
high temperaturehigh temperature
• ProblemsProblems
•
Greenhouse gasesGreenhouse gases
•
Cause difficulty breathingCause difficulty breathing
o Sulfur OxidesSulfur Oxides
• Gases produced by the chemical interactionsGases produced by the chemical interactions
between sulfur and oxygenbetween sulfur and oxygen
• Causes acid precipitationCauses acid precipitation

10. Carbon Oxides and HydrocarbonsCarbon Oxides and Hydrocarbons
o Carbon OxidesCarbon Oxides
• Gases carbon monoxide (CO) and carbonGases carbon monoxide (CO) and carbon
dioxide (COdioxide (CO22))
• Greenhouse gasesGreenhouse gases
o HydrocarbonsHydrocarbons
• Diverse group of organic compounds thatDiverse group of organic compounds that
contain only hydrogen and carbon (ex: CHcontain only hydrogen and carbon (ex: CH44--
methane)methane)
• Some are related to photochemical smog andSome are related to photochemical smog and
greenhouse gasesgreenhouse gases

11. OzoneOzone
o Tropospheric OzoneTropospheric Ozone
• Man- made pollutant in the lower atmosphereMan- made pollutant in the lower atmosphere
• Secondary air pollutantSecondary air pollutant
• Component of photochemical smogComponent of photochemical smog
o Stratospheric OzoneStratospheric Ozone
• Essential component that screens out UVEssential component that screens out UV
radiation in the upper atmosphereradiation in the upper atmosphere
• Man- made pollutants (ex: CFCs) can destroy itMan- made pollutants (ex: CFCs) can destroy it

12. Sources of Outdoor Air PollutionSources of Outdoor Air Pollution
o Two main sourcesTwo main sources
• TransportationTransportation
• IndustryIndustry
o Intentional forestIntentional forest
fires is also highfires is also high

13. Chemical Reactions That FormChemical Reactions That Form
Major Outdoor Air PollutantsMajor Outdoor Air Pollutants

14. Urban Air PollutionUrban Air Pollution
o Photochemical Smog (ex: Los Angeles below)Photochemical Smog (ex: Los Angeles below)
• Brownish-orange haze formed by chemical reactionsBrownish-orange haze formed by chemical reactions
involving sunlight, nitrogen oxide, and hydrocarbonsinvolving sunlight, nitrogen oxide, and hydrocarbons

15. Air Pollution in Shanghai, China, inAir Pollution in Shanghai, China, in
20042004

19. Transportation related causes of air pollutionTransportation related causes of air pollution

20. Formation of Photochemical SmogFormation of Photochemical Smog

21. Smog over Los AngelesSmog over Los Angeles

22. Smog over the Sea of JapanSmog over the Sea of Japan

23. Case-In-Point Air Pollution in BeijingCase-In-Point Air Pollution in Beijing
and Mexico Cityand Mexico City
o Beijing (left)Beijing (left)
o Mexico City (above)Mexico City (above)

24. Global Outlook: Photochemical SmogGlobal Outlook: Photochemical Smog
in Santiago, Chilein Santiago, Chile

25. Denver’s Brown CloudDenver’s Brown Cloud

26. Aerial sprayingAerial spraying

27. Natural sourcesNatural sources

28. Silent pollutersSilent polluters

29. Effects of Air PollutionEffects of Air Pollution
o Low level exposureLow level exposure
• Irritates eyesIrritates eyes
• Causes inflammation of respiratory tractCauses inflammation of respiratory tract
o Can develop into chronic respiratoryCan develop into chronic respiratory
diseasesdiseases

30. Health Effects of Air PollutionHealth Effects of Air Pollution
o Sulfur Dioxide and Particulate materialSulfur Dioxide and Particulate material
• Irritate respiratory tract and impair ability ofIrritate respiratory tract and impair ability of
lungs to exchange gaseslungs to exchange gases
o Nitrogen DioxidesNitrogen Dioxides
• Causes airway restrictionCauses airway restriction
o Carbon monoxideCarbon monoxide
• Binds with iron in blood hemoglobinBinds with iron in blood hemoglobin
• Causes headache, fatigue, drowsiness, deathCauses headache, fatigue, drowsiness, death
o OzoneOzone
• Causes burning eyes, coughing, and chestCauses burning eyes, coughing, and chest
discomfortdiscomfort

31. Major Components of the HumanMajor Components of the Human
Respiratory SystemRespiratory System

32. Normal Human Lungs and the LungsNormal Human Lungs and the Lungs
of a Person Who Died of Emphysemaof a Person Who Died of Emphysema

33. Air Pollution Is a Big KillerAir Pollution Is a Big Killer
o 3 Million deaths per year world-wide3 Million deaths per year world-wide
• Mostly in AsiaMostly in Asia
• Main causesMain causes
o EPA: proposed stricter emission standardsEPA: proposed stricter emission standards
for diesel-powered vehiclesfor diesel-powered vehicles
o Link between international trade and airLink between international trade and air
pollutionpollution
• Cargo ships and pollutionCargo ships and pollution

34. Children and Air PollutionChildren and Air Pollution
o Greater health threat to children thanGreater health threat to children than
adultsadults
• Air pollution can restrict lung developmentAir pollution can restrict lung development
• Children breath more often than adultsChildren breath more often than adults
o Children who live in high ozone areas areChildren who live in high ozone areas are
more likely to develop asthmamore likely to develop asthma

35. Controlling Air PollutionControlling Air Pollution
o Smokestacks withSmokestacks with
electrostatic precipitatorelectrostatic precipitator
(right)(right)
WithoutWithout
ElectrostaticElectrostatic
precipitatorprecipitator
With ElectrostaticWith Electrostatic
precipitatorprecipitator

36. Controlling Air PollutionControlling Air Pollution
o Smokestacks withSmokestacks with
scrubbers (right)scrubbers (right)
o Particulate material canParticulate material can
also be controlled byalso be controlled by
proper excavatingproper excavating
techniquestechniques

37. Controlling Air PollutionControlling Air Pollution
o Phase I Vapor Recovery System forPhase I Vapor Recovery System for
gasolinegasoline

38. The Clean Air ActThe Clean Air Act
o Authorizes EPA to setAuthorizes EPA to set
limits on amount oflimits on amount of
specific air pollutantsspecific air pollutants
permittedpermitted
o Focuses on 6Focuses on 6
pollutants:pollutants:
• lead, particulatelead, particulate
matter, sulfur dioxide,matter, sulfur dioxide,
carbon monoxide,carbon monoxide,
nitrogen oxides, andnitrogen oxides, and
ozoneozone
o Act has led toAct has led to
decreases!decreases!

39. Other Ways to Improve Air QualityOther Ways to Improve Air Quality
o Reduce sulfur content in gasoline from itsReduce sulfur content in gasoline from its
current average of 330 ppm to 30 ppmcurrent average of 330 ppm to 30 ppm
• Sulfur clogs catalytic convertersSulfur clogs catalytic converters
o Require federal emission standards for allRequire federal emission standards for all
passenger vehiclespassenger vehicles
• Including SUVs, trucks and minivansIncluding SUVs, trucks and minivans
o Require emission testing for all vehiclesRequire emission testing for all vehicles
• Including dieselIncluding diesel

40. Ozone Depletion in StratosphereOzone Depletion in Stratosphere
o Ozone Protects earth from UV radiationOzone Protects earth from UV radiation
• Part of the electromagnetic spectrum withPart of the electromagnetic spectrum with
wavelengths just shorter than visible lightwavelengths just shorter than visible light

41. Ozone Depletion in StratosphereOzone Depletion in Stratosphere
o Ozone thinning/holeOzone thinning/hole
• First identified in 1985First identified in 1985
over Antarcticaover Antarctica
o Caused byCaused by
• human-produced brominehuman-produced bromine
and chlorine containingand chlorine containing
chemicalschemicals
• Ex: CFCsEx: CFCs

42. Ozone Depletion in StratosphereOzone Depletion in Stratosphere
o Hole over Antarctica requires twoHole over Antarctica requires two
conditions:conditions:
• Sunlight just returning to polar regionSunlight just returning to polar region
• Circumpolar vortex- a mass of cold air thatCircumpolar vortex- a mass of cold air that
circulates around the southern polar regioncirculates around the southern polar region
•
Isolates it from the warmer air in the rest of theIsolates it from the warmer air in the rest of the
planetplanet
o Polar stratospheric clouds formPolar stratospheric clouds form
• Enables Cl and Br to destroy ozoneEnables Cl and Br to destroy ozone

43. Effects of Ozone DepletionEffects of Ozone Depletion
o Higher levels of UV-Higher levels of UV-
radiation hitting theradiation hitting the
earthearth
• Eye cataractsEye cataracts
• Skin cancer (right)Skin cancer (right)
• Weakened immunityWeakened immunity
o May disruptMay disrupt
ecosystemsecosystems
o May damage cropsMay damage crops
and forestsand forests

44. Recovery of Ozone LayerRecovery of Ozone Layer
o Montreal Protocol (1987)Montreal Protocol (1987)
• Reduction of CFCsReduction of CFCs
• Started using HCFCs (greenhouse gas)Started using HCFCs (greenhouse gas)
o Phase out of all ozone destroying chemicalsPhase out of all ozone destroying chemicals
is underway globallyis underway globally
o Satellite pictures in 2000 indicated thatSatellite pictures in 2000 indicated that
ozone layer was recoveringozone layer was recovering
o Full recovery will not occur until 2050Full recovery will not occur until 2050

45. Acid DepositionAcid Deposition
o Sulfur dioxide and nitrogen dioxideSulfur dioxide and nitrogen dioxide
emissions react with water vapor in theemissions react with water vapor in the
atmosphere and form acids that return toatmosphere and form acids that return to
the surface as either dry or wetthe surface as either dry or wet
depositiondeposition
o pH scalepH scale

46. Acid Deposition Has a Number ofAcid Deposition Has a Number of
Harmful EffectsHarmful Effects
o Leaching of soil nutrientsLeaching of soil nutrients
o Loss of crops and treesLoss of crops and trees
o Damage to buildings, statues, andDamage to buildings, statues, and
monumentsmonuments

47. How Acid Deposition DevelopsHow Acid Deposition Develops

48. Emissions
SO2
H2O2
PANs
NOx
Acid
deposition O3
Others
Direct damage to
leaves and bark
Reduced
photosynthesis
and growth
Increased
susceptibility to
drought, extreme
cold, insects,
mosses, and
disease organisms
Soil acidification Tree death
Leaching
of soil
nutrients
Release
of toxic
metal ions
Root damage
Reduced nutrient
and water uptakeAcids
Lake

49. Statue Corroded byStatue Corroded by
Acid Deposition andAcid Deposition and
Other Forms of AirOther Forms of Air
Pollution, RI, U.S.Pollution, RI, U.S.

50. Effects of Acid DepositionEffects of Acid Deposition
o Declining AquaticDeclining Aquatic
Animal PopulationsAnimal Populations
o Thin-shelled eggsThin-shelled eggs
prevent birdprevent bird
reproductionreproduction
• Because calcium isBecause calcium is
unavailable in acidic soilunavailable in acidic soil
o Forest declineForest decline
• Ex: Black forest inEx: Black forest in
Germany (50% isGermany (50% is
destroyed)destroyed)

51. Fig. 18-15, p. 483
SOLUTIONS
Acid Deposition
Prevention Cleanup
Add lime to
neutralize
acidified lakes
Reduce coal use
Burn low-sulfur coal
Add phosphate
fertilizer to
neutralize acidified
lakes
Increase natural gas use
Increase use of
renewable energy
resources
Remove SO2
particulates and NOx
from smokestack gases
Remove NOx from motor
vehicular exhaust
Tax emissions of SO2
Reduce air pollution by
improving energy
efficiency

52. Air Pollution Around the WorldAir Pollution Around the World
o Air quality is deterioratingAir quality is deteriorating
rapidly in developing countriesrapidly in developing countries
o Shenyang, ChinaShenyang, China
• Residents only see sunlight a fewResidents only see sunlight a few
weeks each yearweeks each year
o Developing countries have olderDeveloping countries have older
carscars
• Still use leaded gasolineStill use leaded gasoline
o 5 worst cities in world5 worst cities in world
• Beijing, China; Mexico City, Mexico;Beijing, China; Mexico City, Mexico;
Shanghai, China; Tehran, Iran; andShanghai, China; Tehran, Iran; and
Calcutta, IndiaCalcutta, India

53. Long Distance Transport of AirLong Distance Transport of Air
PollutantsPollutants

54. Indoor AirIndoor Air
PollutionPollution
o Pollutants can bePollutants can be
5-100X greater5-100X greater
than outdoorsthan outdoors
o Most common:Most common:
• Radon, cigaretteRadon, cigarette
smoke, carbonsmoke, carbon
monoxide,monoxide,
nitrogen dioxide,nitrogen dioxide,
formaldehydeformaldehyde
pesticides, lead,pesticides, lead,
cleaning solvents,cleaning solvents,
ozone, andozone, and
asbestosasbestos

55. Indoor Air Pollution - RadonIndoor Air Pollution - Radon

56. Fig. 18-24, p. 492
SOLUTIONS
Indoor Air Pollution
Prevention Cleanup or Dilution
Clean ceiling tiles and line
AC ducts to prevent
release of mineral fibers
Use adjustable fresh air
vents for work spaces
Ban smoking or limit it to
well-ventilated areas Increase intake of
outside air
Change air more
frequently
Set stricter formaldehyde
emissions standards for
carpet, furniture, and
building materials Circulate a building’s air
through rooftop
greenhousesPrevent radon
infiltration
Use efficient venting
systems for wood-
burning stoves
Use office machines in
well-ventilated areas
Use less polluting
substitutes for harmful
cleaning agents, paints,
and other products
Use exhaust hoods for
stoves and appliances
burning natural gas

57. Fig. 18-26, p. 493
SOLUTIOS
Air Pollution
Outdoor Indoor
Improve energy efficiency
to reduce fossil fuel use
Reduce poverty
Distribute cheap and
efficient cookstoves or
solar cookers to poor
families in developing
countries
Rely more on lower-
polluting natural gas
Rely more on renewable
energy (especially solar
cells, wind, and solar-
produced hydrogen)
Reduce or ban
indoor smoking
Transfer energy
efficiency, renewable
energy, and pollution
prevention technologies
to developing countries
Develop simple and
cheap tests for indoor
pollutants such as
particulates, radon,
and formaldehyde
*Acknowledged – Some points and pictures have been taken from internet sources as I acknowledge them.