1. Air Pollution
Chapter 18

2. Core Case Study: South Asia’s Massive Brown Cloud
Asian Brown Cloud
Causes
Chemical composition
Areas impacted
Air pollution connects the world
Steps taken in China and India to reduce air pollution
Asia’s Brown Cloud
Shanghai China 2004

3. 18-1 What Is the Nature of the Atmosphere?
1) Atmospheric layers
a) Layers and temperatures Page 470
b) Density: decreases with altitude
c) Air pressure: Decreases with altitude
2) Air movements
a) Troposphere: 75-80% of the air mass, consists of N-78%, O-21% (page 470 other gases)
b) This layer is responsible for weather & climate

4. Figure 18.3: Natural capital.
The earth’s atmosphere is a dynamic system that includes four layers. The average temperature of the atmosphere varies with altitude (red line) and with differences in the absorption of incoming solar energy. Note how the atmosphere’s temperature falls and rises again twice as we move from lower to upper layers. Because the troposphere receives most of its heat from the earth’s surface, it cools as its air gets further from the surface. Most ultraviolet radiation from the sun is absorbed by ozone, found primarily in the stratosphere’s ozone layer, 17–26 kilometers (11–16 miles) above sea level. This ozone absorption causes the temperature to rise in the stratosphere. Question: Why do you think most of the planet’s air is in the troposphere?
Fig. 18-3, p. 467

5. 18-1 What Is the Nature of the Atmosphere?
3) Stratosphere:
a) Upper layer
b) Has less water vapor and more ozone
c) Ozone: 2O2 + UV  2 O3
d) Ozone layer: blocks about 95% harmful UV radiation 5

6. 18-2 What Are the Major Outdoor Pollution Problems?
1) Air pollution
a) Concentration of chemicals that causes harm
b) Natural sources: dust, wildfires, volcanoes, plant chemicals
c) Human: released by cars and industry, mostly from fossil fuels
2) Combining pollutants
a) Primary: directly released into the air
b) Secondary: formed by combining primary particles or with air molecules

7. Figure 18.5: Human inputs of air pollutants come from mobile sources (such as cars) and stationary sources (such as industrial, power, and cement plants). Some primary air pollutants react with one another and with other chemicals in the air to form secondary air pollutants.
Fig. 18-5, p. 469

8. Case Study: Air Pollution in the Past: The Bad Old Days (pg 471)
Discovery of fire
Middle Ages
Industrial Revolution
London, England
1850s
1952: yellow fog
Clean Air Act of 1956
United States
1948: Donora, PA; first U.S. air pollution disaster
1963: New York City
Global problem

9. 18-2 What Are the Major Outdoor Pollution Problems?
c) Urban areas normally have higher outdoor pollution levels, but they can spread by wind
d) Good News: the air quality in developed countries has improved
e) Bad News: WHO says more than 1.1 billion people live in areas where air is unhealthy
f) The biggest threat to poor is indoor pollution from burning material to heat, & cook 9

10. 18-2 What Are the Major Outdoor Pollution Problems?
3) What are the major outdoor pollutants
a) Carbon oxides
1. CO: colorless, odorless gas from incomplete combustion. Sources: exhaust, burning, tobacco, inefficient stoves. Inhibits ability to carry oxygen
2. CO2: colorless, odorless, contributes to global warming & climate change. Mostly from fossil fuels
b) Nitrogen oxides
1. NO: colorless, from motors & coal burning 10

11. 18-2 What Are the Major Outdoor Pollution Problems?
1. NO: colorless, from motors & coal burning
2. NO2: reddish-brown, secondary pollutant, part of smog
3. HNO3:Nitric acid forms from water reacting with NO2-acid deposition
4. N2O: greenhouse gas from fertilizers, animal wastes and fossil fuels
c) Sulfur
1. SO2: colorless, irritating odor, from burning coal containing sulfur, refining and smelting 11

12. 18-2 What Are the Major Outdoor Pollution Problems?
2. H2SO4: forms when SO2 combines with water- acid deposition 12

13. Statue damaged by acid precipitation
Figure 18.7: Acid deposition and other forms of air pollution have corroded this statue in Newport, Rhode Island (USA).

14. 18-2 What Are the Major Outdoor Pollution Problems?
d) Particulates
1. SPM (suspended) various solid & liquid particles that remain suspended in the air. 38% from coal burning, cars, plowing, road construction, unpaved roads, tobacco
2. Fine & ultrafine particles: irritate respiratory system, aggravate asthma and bronchitis & shorten life (60-70K premature deaths per year)
e) Ozone: colorless, highly reactive: cause coughing & breathing problems, aggravate heart & lung disease, damages plants, rubber, fabrics & paint 14

15. 18-2 What Are the Major Outdoor Pollution Problems?
f) VOC (volatile organic compounds): gases in atmosphere (ex page 474): Greenhouse gases, cause leukemia, blood disorders, immune system damage, dizziness, death
Science focus: detecting air pollutants (pg 475)
Lichens are good indicators of air pollution 15

16. Case Study: Lead Is a Highly Toxic Pollutant (page 474-475)
Does not break down in the environment
Sources
Human health and environmental impact
Most vulnerable
Reduction of lead (Pb)
Unleaded gasoline
Unleaded paint
Still problems
2007: toys with Pb paint recalled
Global ban on lead in gasoline and paint

17. Replace lead pipes and plumbing fixtures containing lead solder
Solutions
Lead Poisoning
Control
Prevention
Replace lead pipes and plumbing fixtures containing lead solder
Phase out leaded gasoline worldwide
Phase out waste incineration
Remove leaded paint and lead dust from older houses and apartments
Ban use of lead solder
Sharply reduce lead emissions from incinerators
Ban use of lead in computer and TV monitors
Remove lead from TV sets and computer monitors before incineration or land disposal
Ban lead glazing for ceramicware used to serve food
Figure 18.8: Individuals matter.
There are several ways to help protect children from lead poisoning. Questions: Which two of these solutions do you think are the most important? Why?
Test for lead in existing ceramicware used to serve food
Ban candles with lead cores
Test existing candles for lead
Test blood for lead by age 1
Wash fresh fruits and vegetables
Fig. 18-8, p. 472

18. 18-2 What Are the Major Outdoor Pollution Problems?
4) Burning Coal produces industrial smog
a) Consists of SO2, suspended H2SO4, & solid particles (gray smog), rare in developed countries, but still a problem in China, India, Ukraaine, and some E. European countries
b) Simple chemistry: 18

19. Figure 18.9: This is a greatly simplified model of how pollutants are formed when coal and oil are burned. The result is industrial smog.
Fig. 18-9, p. 474

20. 18-2 What Are the Major Outdoor Pollution Problems?
5) Photochemical smog
a) Mixture of primary & secondary pollutants formed under influence of UV radiation
VOCs + NO2 + Heat + Sunlight 
Ground level O3 and other photochemical oxidants
Aldehydes
Other secondary pollutants
b) NO2, O3 & PANs are photochemical oxidants 20

21. Fig. 20-5
p. 440

22. Figure 18.11: This is a greatly simplified model of how the pollutants that make up photochemical smog are formed.
Fig , p. 475

23. 18-2 What Are the Major Outdoor Pollution Problems?
c) Hotter days increase ozone & other components of smog, usually peak by late morning
d) It is more common in cities with sunny, warm & dry climates
Santiago, Chile 23

24. 18-2 What Are the Major Outdoor Pollution Problems?
6) Factors decreasing or increasing outdoor air pollution
a) Reducing
1. gravity pulls out heaver particles
2. Rain & Snow: wash out
3. Salty sea spray: wash out
4. Winds: move it away
5. Chemical reactions 24

25. 18-2 What Are the Major Outdoor Pollution Problems?
b) Increasing
1. Buildings: slow wind speed
2. Hills & mountains: reduce air flow
3. High temperatures: promote reactions
4. VOCs released from certain plants
5. Grasshopper effect: winds move pollutants to the poles
6. Temperature inversions: trap pollutants 25

26. 18-2 What Are the Major Outdoor Pollution Problems?
c) Temperature inversion: when warm air is on top of cold air, trapping the pollutants
d) Most likely to occur
1. Town located in a valley surrounded by mountains where weather turns cloud and cold during part of the year
2. City with several million vehicles in area with sunny climate, light winds, mountains on 3 sides and ocean on the other 26

27. Temperature Inversions
Subsidence inversion
Fig p. 443

28. 18-3 What Is Acid Deposition and Why Is It a Problem?
1) Acid deposition is serious regional problem
a) Tall smoke stacks reduce local pollution, but increase regional pollution downwind
b) Acidic particles descend as
1. wet deposition (snow, fog, cloud vapor or rain) with a pH less than 5.6
2. dry deposition: acidic particles
c) It is a regional problem in areas that are downwind from coal burning facilities & urban areas with large number of motor vehicles

29. Figure 18.14: Natural capital degradation.
Acid deposition, which consists of rain, snow, dust, or gas with a pH lower than 5.6, is commonly called acid rain. Soils and lakes vary in their ability to neutralize excess acidity. See an animation based on this figure at CengageNOW. Question: What are three ways in which your daily activities contribute to acid deposition?
Fig , p. 477

30. Figure 18.15: This map shows regions where acid deposition is now a problem and regions with the potential to develop this problem. Such regions have large inputs of air pollution (mostly from power plants, industrial facilities, and ore smelters) or are sensitive areas with naturally acidic soils and bedrock that cannot neutralize (buffer) additional inputs of acidic compounds. Question: Do you live in or near an area that is affected by acid deposition or an area that is likely to be affected by acid deposition in the future? (Data from World Resources Institute and U.S. Environmental Protection Agency)
Fig , p. 478

31. 18-3 What Is Acid Deposition and Why Is It a Problem?
d) Areas with basic soil can neutralize or buffer the acid inputs, but acidic soils have no natural buffer
e) Mountaintop forests in the eastern US and east of LA are bathed in acidic fog
f) The worst acid deposition is in Asia
2) Harmful effects
a) Respiratory damage
b) statues, monuments, buildings, metals and car finishes
c) Leaches toxic metals form soil into drinking water 31

32. Acid Deposition in the US
Fig p. 445

33. 18-3 What Is Acid Deposition and Why Is It a Problem?
d) harms aquatic ecosystems (fish need above 4.5 pH and Al released from soil blocks gills)
e) Harms crops, reduced productivity
f) Damages forests, usually by making them more susceptible to stresses like cold, diseases, insects and drought 33

34. Figure 18.16: Natural capital degradation.
Air pollution is one of several interacting stresses that can damage, weaken, or kill trees and pollute surface and groundwater. The photo insert shows air pollution damage to trees at a high elevation in Mount Mitchell State Park, North Carolina (USA). See an animation based on this figure at CengageNOW.
Fig a, p. 479

35. 18-3 What Is Acid Deposition and Why Is It a Problem?
g) Most of the forests & lakes are not being destroyed or seriously harmed by acid deposition
h) It has not reduced overall tree growth in the vast majority of forests in the US or Canada
i) Has hindered tree growth in some areas
3) We know how to reduce Acid deposition
Page 483-next slide) 35

36. Add lime to neutralize acidified lakes
Solutions
Acid Deposition
Prevention
Cleanup
Reduce coal use
Add lime to neutralize acidified lakes
Burn low-sulfur coal
Increase use of natural gas and renewable energy resources
Add phosphate fertilizer to neutralize acidified lakes
Figure 18.17: There are several ways to reduce acid deposition and its damage. Questions: Which two of these solutions do you think are the most important? Why?
Remove SO2 from smokestack particulates and NOx gases and remove vehicular exhaust NOx from motor
Tax emissions of SO2
Fig , p. 483

37. Science Focus: Revisiting Hubbard Brook to Study Effects of Acid Rain (pg 482)
White Mountains, NH, U.S.
Experimentation supports:
Trees do not suffer from direct contact with acid rain
Nutrients are leached out of the soil
Effect of Ca2+ on regrowth of the forest

38. 18-4 What Are the Major Indoor Air Pollution Problems?
a) Developing countries: exposes people to dangerous levels of particulate pollution
b) WHO: indoor air pollution is, for poor people, the world’s most serious air pollution problems
c) Developed countries: you may be inhaling more air pollutants inside than outside (higher health risk)
d) May causes as many as 6K premature cancer deaths per year in the US

39. Figure 18.19: Numerous indoor air pollutants are found in most modern homes (Concept 18-4). Question: To which of these pollutants are you exposed? (Data from U.S. Environmental Protection Agency)
Fig , p. 482

40. 18-4 What Are the Major Indoor Air Pollution Problems?
e) EPA findings
1. levels of 11 common pollutants are 2-5 times higher inside than outside in US
2. Levels inside cars in traffic clogged urban areas can be 18X higher than outside
3. Health risks from exposure to chemicals are magnified because most people spend 70-98% of their time indoors or in vehicles
f) Sick-building syndrome: include dizziness, headache, coughing, sneezing, shortness of breath, nausea, burning eyes, sore throats, fatigue, irritability, skin dryness,& depression 40

41. 18-4 What Are the Major Indoor Air Pollution Problems?
g) Almost one in five commercial buildings in the US is considered sick
h) 4 most dangerous pollutants in developed countries
1. tobacco smoke
2. formaldehyde
3. radioactive Radon-222 gas
4. very small particles 41

42. Case Study: Radioactive Radon Gas pg 485
Figure 18.20: Science.
There are a number of ways that radon-222 gas can enter homes and other buildings. Question: Have you tested the indoor air where you live for radon-222? (Data from U.S. Environmental Protection Agency)

43. 18-5 What Are the Health Effects of Air Pollution?
1) Read your body’s natural defenses
2) Air pollution is a big killer
a) WHO: at least 3 million people worldwide die prematurely each year
b) Cause: heart attacks, respiratory diseases & lung cancer
c) In US, 150K to 350K per year
d) Others suffer from asthma attacks & other respiratory disorders
e) EPA: 125K get lung cancer from diesel emissions

44. Figure 18.22: This map shows the distribution of premature deaths from air pollution in the United States, mostly from very small, fine, and ultra-fine particles added to the atmosphere by coal-burning power plants. Questions: Why do the highest death rates occur in the eastern half of the United States? If you live in the United States, what is the risk at your home or where you go to school? (Data from U.S. Environmental Protection Agency)
Fig , p. 485

45. 18-6 How Should We Deal with Air Pollution?
Read Laws and regulations can reduce outdoor air pollution
Case study page 489
Read we can use the marketplace to reduce outdoor pollution
There are many ways to reduce outdoor pollution
Reducing indoor pollution should be a priority
Emphasis should be on prevention

46. Stationary Source Air Pollution
Solutions
Stationary Source Air Pollution
Prevention
Reduction or Disposal
Burn low-sulfur coal or remove sulfur from coal
Disperse emissions (which can increase downwind pollution) with tall smokestacks
Convert coal to a liquid or gaseous fuel
Remove pollutants from smokestack gases
Figure 18.23: There are several ways to prevent, reduce, or disperse emissions of sulfur oxides, nitrogen oxides, and particulate matter from stationary sources such as coal-burning power plants and industrial facilities (Concept 18-6). Questions: Which two of these solutions do you think are the most important? Why?
Tax each unit of pollution produced
Phase out coal use
Fig , p. 487

47. Motor Vehicle Air Pollution
Solutions
Motor Vehicle Air Pollution
Prevention
Cleanup
Walk, bike, or use mass transit
Require emission control devices
Inspect car exhaust systems twice a year
Improve fuel efficiency
Figure 18.24: There are a number of ways to prevent and reduce emissions from motor vehicles (Concept 18-6). To find out what and how much your car emits, go to Questions: Which two of these solutions do you think are the most important? Why?
Get older, polluting cars off the road
Set strict emission standards
Fig , p. 487

48. Use adjustable fresh air vents for work spaces
Solutions
Indoor Air Pollution
Prevention
Cleanup or Dilution
Ban indoor smoking
Use adjustable fresh air vents
for work spaces
Set stricter formaldehyde emissions standards for carpet, furniture, and building materials
Circulate air more frequently
Circulate a building’s air through rooftop greenhouses
Figure 18.25: There are several ways to prevent and reduce indoor air pollution (Concept 18-6). Questions: Which two of these solutions do you think are the most important? Why?
Prevent radon infiltration
Use less polluting cleaning agents, paints, and other products
Use efficient venting systems for wood-burning stoves
Fig , p. 488

49. Figure 18.27: Individuals matter.
You can reduce your exposure to indoor air pollution. Questions: Which three of these actions do you think are the most important? Why?
Fig , p. 489