1. Air Pollution
Chapter 15

2. Key Concepts Structure and composition of the atmosphere
Types and origins of major outdoor air pollutants
Two types of smog
Acid deposition and how it can be reduced
Harmful effects of air pollutants
Preventing and controlling air pollution

3. When is a Lichen Like a Canary?
Mine canaries
Lichens
Detectors of air pollution
Isle Royale in Lake Superior
Chernobyl
Fig. 15-1, p. 345

4. When is a Lichen Like a Canary?
Fig. 15-1, p. 345

5. Earth’s Atmosphere Troposphere 78% N2, 21% O2 Stratosphere Ozone layer
Fig. 15-2, p. 347

6. Atmospheric pressure (millibars) Altitude (kilometers)
Earth’s Atmosphere
Atmospheric pressure (millibars)
200
400
600
800
1,000
120 75
Temperature
110
Pressure 65
100
Thermosphere 90
Mesopause 55
Heating via ozone 80
Mesosphere 45 70 60
Stratopause
Altitude (kilometers)
Altitude (miles) 35 50
Stratosphere 40 25 30
Tropopause 15
Ozone “layer” 20
Heating from the earth 10 5
Troposphere
–80
–40 40 80
120
Pressure = 1,000
millibars at
ground level
(Sea Level)
Temperature (˚C)
Fig. 15-2, p. 347

7. Outdoor Air Pollution What is air pollution?
Stationary and mobile sources
Primary pollutants
Secondary pollutants
How air pollutants migrate
Health threats
Major air pollutants (Table 15-1, p. 349)
Volatile organic compounds (VOCs)
Carbon dioxide: a pollutant?

8. Sources and Types of Air Pollutants
Primary Pollutants CO
CO2
Secondary Pollutants
SO2 NO
NO2
SO3
Most hydrocarbons
HNO3
H2SO4
Most suspended
particles
H2O2 O3
PANs
SO4 2 –
Most
NO3 –
and
salts
Sources
Natural
Stationary
Mobile
Fig. 15-3, p. 348

9. Table 15-1, p. 349

10. Photochemical Smog Photochemical reactions Photochemical smog
Natural and human origins
Brown-air smog
Temperature effects
Urban areas

11. Photochemical Smog in Mexico City
Fig. 15-4, p. 351

12. Industrial Smog
Science Spotlight, p. 350: Air Pollution in the Past: The Bad Old Days
Composition of industrial smog (sulfur dioxide and sulfuric acid)
Gray-air smog
Situation better in developed countries
Serious problem in industrializing countries, such as China
“Black Triangle” of eastern Europe
Asian brown cloud

13. Industrial Smog in India
Fig. 15-5, p. 351

14. How Natural Eliminates Smog
Rain and snow
Salty sea spray
Winds

15. Factors Influencing the Formation of Smog
Urban buildings
Topography
High temperatures
“Grasshopper Effect”
Temperature inversions

16. Acid Deposition Sulfur dioxide and nitrogen oxides
Wet and dry acid deposition
Acid rain
Regional air pollution
Ohio Valley
Buffers
Wind transportation

17. Acid Deposition Fig. 15-6, p. 353 Wind Transformation to
sulfuric acid (H2SO4)
and nitric acid (HNO3)
Windborne ammonia gas
and particles of cultivated soil
partially neutralize acids and
form dry sulfate and nitrate salts
Wet acid deposition
(droplets of H2SO4 and
HNO3 dissolved in rain
and snow)
Nitric oxide (NO)
Dry acid
deposition
(sulfur dioxide
gas and particles
of sulfate and
nitrate salts)
Sulfur dioxide (SO2)
and NO
Acid fog
Farm
Lakes in shallow
soil low in
limestone
become
acidic
Ocean
Lakes in
deep soil
high in limestone
are buffered
Fig. 15-6, p. 353

18. pH Measurements at US Sites
Fig. 15-7, p. 354

19. Current and Potential Problems with Acid Deposition
Potential problem areas because of sensitive soils
Potential problem areas because of air pollution: emissions leading to acid deposition
Current problem areas
(including lakes and rivers)
Fig. 15-8, p. 355

20. Harmful Effects of Acid Deposition
Respiratory diseases in humans (bronchitis and asthma)
Leaches metals from water pipes
Damages statues and other property
Decreases atmospheric visibility (Grand Canyon)
Kills fish and other aquatic organisms
Leaches plant nutrients from soils
Weakens trees (mountaintop forests)

21. Impacts of Air Pollution on Trees and Water
Emission
Acid
deposition
SO2
H2O2
PANs
NOX O3
Others
Increased
Susceptibility
to drought,
extreme cold,
insects, mosses,
and disease
organisms
Direct damage
to leaves and bark
Reduced
photosynthesis
and growth
Soil acidification
Tree death
Leaching of soil nutrients
Release of toxic
metal icons
Root
damage
Reduced nutrient
and water uptake
Acid
Groundwater
Fig. 15-9, p. 356

22. Tree Damage from Acid Deposition
Fig , p. 356

23. Reducing Acid Deposition
© 2006 Brooks/Cole - Thomson
Solutions
Acid Deposition
Prevention
Cleanup
Reduce air pollution by improving energy efficiency
Add lime to neutralize
acidified lakes
Reduce coal use
Add phosphate
fertilizer to neutralize
acidified lakes
Increase natural gas use
Increase use of
renewable resources
Burn low-sulfur coal
Remove SO2 particulates, and Nox from smokestack gases
Remove Nox from motor vehicular exhaust
Tax emissions of SO2
Fig , p. 357

24. Indoor Air Pollution Pollutants often at higher concentrations indoors
Pollution inside cars
Most people spent most of their time indoors
Cancer risks
Sick-building syndrome
Mold and allergies
Serious problem in developing countries

25. Major Indoor Air Pollutants
Tobacco smoke
Formaldehyde
Radon
Very fine particles

26. Major Indoor Air Pollutants
Para-dichlorobenzene
Chloroform
Tetrachloro-ethylene
Formaldehyde
1, 1, 1-
Trichloroethane
Styrene
Nitrogen Oxides
Benzo-a-pyrene
Particulates
Tobacco Smoke
Radon-222
Asbestos
Carbon Monoxide
Methylene Chloride
Fig , p. 358

27. Radon Radioactive Rn-222 Lung cancer threat
With uranium in rocks and soils
Testing homes
Remedies
Fig , p. 359

28. Harmful Effects of Air Pollution
Human respiratory system
Asthma
Lung cancer
Chronic bronchitis
Emphysema
Health effects of major air pollutants (Table 15-1, p. 349)
Premature deaths
Serious threat of indoor air pollution
Impact of coal-fired power plants
Cancer from diesel exhausts

29. Human Respiratory System
Fig a, p. 360

30. Healthy and Diseased Human Lungs
Fig , p. 360

31. Premature US Deaths from Air Pollution
Fig , p. 361

32. Preventing and Reducing Air Pollution
U.S. Clean Air Acts
National Ambient Air Quality Standards
Criteria from risk assessments
Primary standards
Secondary standards
Hazardous air pollutants
Toxic Release Inventory
“Right to Know” laws
Emissions trading

33. Solutions: Stationary Source Air Pollution
© 2006 Brooks/Cole - Thomson
Solutions
Stationery Source Air Pollution
Prevention
Dispersion or Cleanup
Burn low-sulfur
coal
Disperse
emissions above
thermal inversion
layer with tall
smokestacks
Remove sulfur
from coal
Remove
pollutants after
combustion
Convert coal
to a liquid or
gaseous fuel
Tax each unit
of pollution
produced
Shift to less
polluting fuels
Fig , p. 363

34. Solutions: Motor Vehicles
© 2006 Brooks/Cole - Thomson
Solutions
Motor Vehicle Pollutions
Prevention
Cleanup
Mass transit
Emission control
devices
Bicycles and walking
Less polluting engines
Less polluting fuels
Car exhaust
Inspections
twice a year
Improve fuel efficiency
Get older, polluting
cars off the road
Give buyers tax write-
offs for buying low-
polluting, energy-
efficient vehicles
Stricter emission
standards
Restrict driving in polluted areas
Fig , p. 364

35. Solutions: Indoor Air Pollution
© 2006 Brooks/Cole - Thomson
Solutions
Indoor Air Pollution
Prevention
Cleanup
Cover ceiling tiles and lining of 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 building’s air through rooftop greenhouses
Prevent radon infiltration
Use exhaust hoods for stoves and appliances burning natural gas
Use office machines in well-ventilated areas
Use less polluting substitutes for harmful cleaning agents, paints, and other products
Install efficient chimneys for wood-burning stoves
Fig , p. 364

36. Solutions: Air Pollution
Prevention
Cleanup
Improve energy efficiency
to reduce fossil fuel use
Reduce poverty
Distribute cheap and efficient cookstoves 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
Develop simple and cheap test for indoor pollutants such as particulates, radon, and formaldehyde
Transfer technologies for latest energy efficiency, renewable energy, and pollution prevention to developing countries.
Fig , p. 365

37. What Can You Do?
© 2006 Brooks/Cole - Thomson
What Can You Do?
Indoor Air Pollution
Test for radon and formaldehyde inside your home and take corrective measures as needed.
Do not buy furniture and other products containing formaldehyde.
Remove your shoes before entering your house to reduce inputs of dust, lead, and pesticides.
Test your house or workplace for asbestos fiber levels and for any crumbling asbestos materials if it was built before 1980.
Don't live in a pre-1980 house without having its indoor air tested for asbestos and lead.
Do not store gasoline, solvents, or other volatile hazardous chemicals inside a home or attached garage.
If you smoke, do it outside or in a closed room vented to the outside.
Make sure that wood-burning stoves, fireplaces, and kerosene- and gas-burning heaters are properly installed, vented, and maintained.
Install carbon monoxide detectors in all sleeping areas.
Fig , p. 365