1. 19
Air Pollution

2. Overview of Chapter 19 Atmosphere as a Resource
Types and Sources of Air Pollution
Effects of Air Pollution
Controlling Air Pollution in the US
Ozone Depletion in the Stratosphere
Acid Deposition
Air Pollution Around the World
Indoor Air Pollution
© 2012 John Wiley & Sons, Inc. All rights reserved.

3. Atmospheric pressure (millibars) Altitude (kilometers)
200
400
600
800
1,000
120 75
Temperature
110
Pressure 65
Layers of the Atmosphere
Highlights:
Pressure decreases with altitude until it reaches zero
Troposphere is the layer we live in; mostly N and O; weather; colder as you go up
Stratosphere: has the ozone layer; warmer as you go up
Environmental science focuses mostly on those two layers
100
Thermosphere 90 55 80
Heating via ozone
Mesosphere 45 70
Altitude (kilometers) 60
Altitude (miles) 35 50
Stratosphere 40 25 30 15
Ozone “layer” 20
Heating from the earth
Troposphere 10 5
Pressure = 1,000
millibars at
ground level
(Sea
Level)
–80
–40 40 80
120
Temperature (˚C)

4. Atmosphere as a Resource
Atmospheric Composition
Nitrogen 78.08%
Oxygen %
Argon 0.93%
Carbon dioxide 0.04%
Ecosystem services
( what it does for the ecosystem)
Blocks UV radiation
Moderates the climate
Redistributes water in the hydrologic cycle
© 2012 John Wiley & Sons, Inc. All rights reserved.

5. Air Pollution - Terminology
Chemicals added to the atmosphere by natural events or human activities in high enough concentrations to be harmful
Two categories
Primary Air Pollutant
Harmful substance emitted directly into the atmosphere
Secondary Air Pollutant
Harmful substance formed in the atmosphere when a primary air pollutant reacts with substances normally found in the atmosphere or with other air pollutants
© 2012 John Wiley & Sons, Inc. All rights reserved.

6. Major Air Pollutants
© 2012 John Wiley & Sons, Inc. All rights reserved.

7. © 2012 John Wiley & Sons, Inc. All rights reserved.

8. Major Classes of Air Pollutants
Particulate Material
Nitrogen Oxides
Sulfur Oxides
Carbon Oxides
Hydrocarbons
Ozone
© 2012 John Wiley & Sons, Inc. All rights reserved.

9. Particulate Material
Thousands of different solid or liquid particles suspended in air. Small and light enough to remain suspended in atmosphere for short periods to long periods
Includes: soil particles, soot, lead, asbestos, sea salt, and sulfuric acid droplets
Major human sources: Burning coal in power and industrial plants (40%), burning diesel and other fuels in vehicles (17%), agriculture (plowing, burning off fields), unpaved roads, construction.
Health effects: Nose and throat irritation, lung damage, and bronchitis; aggravates bronchitis and asthma; shortens life; toxic particulates (such as lead, cadmium, PCBs, and dioxins) can cause mutations, reproductive problems, cancer. May contain materials with toxic/carcinogenic effects. Small particles can become lodged in lungs.
Environmental effects: Reduces visibility; acid deposition of H2SO4 droplets can damage trees, soils, and aquatic life in lakes.
Property damage: Corrodes metal; soils and discolors buildings, clothes, fabrics, and paints
© 2012 John Wiley & Sons, Inc. All rights reserved.

10. Nitrogen Oxides Nitrogen Oxides
Description: Reddish-brown irritating gas that gives photochemical smog its brownish color; in the atmosphere can be converted to nitric acid (HNO3), a major component of acid deposition. Gases produced by the chemical interactions between atmospheric nitrogen and oxygen at high temperature
Major human sources: Fossil fuel burning in motor vehicles (49%) and power and industrial plants (49%).
Health effects: Lung irritation and damage; aggravates asthma and chronic bronchitis; increases susceptibility to respiratory infections such as the flu and common colds (especially in young children and older adults).
Environmental effects: Reduces visibility; acid deposition of HNO3 can damage trees, soils, and aquatic life in lakes.
Property damage: HNO3 can corrode metals and eat away stone on buildings, statues, and monuments; NO2 can damage fabrics.
© 2012 John Wiley & Sons, Inc. All rights reserved.

11. Sulfur Oxides SULFUR DIOXIDE (SO2)
Description: Colorless, irritating; forms mostly from the combustion of sulfur containing fossil fuels such as coal and oil (S + O2 SO2); in the atmosphere can be converted to sulfuric acid (H2SO4), a major component of acid deposition. Gases produced by the chemical interactions between sulfur and oxygen.
Major human sources: Coal burning in power plants (88%) and industrial processes (10%). Causes acid precipitation
Health effects: Breathing problems for healthy people; restriction of airways in people with asthma; chronic exposure can cause a permanent condition similar to bronchitis. According to the WHO, at least 625 million people are exposed to unsafe levels of sulfur dioxide from fossil fuel burning.
Environmental effects: Reduces visibility; acid deposition of H2SO4 can damage trees, soils, and aquatic life in lakes.
Property damage: SO2 and H2SO4 can corrode metals and eat away stone on buildings, statues, and monuments; SO2 can damage paint, paper, and leather.
Gases produced by the chemical interactions between sulfur and oxygen
© 2012 John Wiley & Sons, Inc. All rights reserved.

12. Carbon Oxides and Hydrocarbons
Description: Colorless, odorless gas that is poisonous to air-breathing animals; forms during the incomplete combustion of carbon-containing fuels (2 C + O2 2 CO).
Major human sources: Cigarette smoking (p. 409), incomplete
burning of fossil fuels. About 77% (95% in cities)comes from motor vehicle exhaust.
Health effects: Reacts with hemoglobin in red blood cells and reduces the ability of blood to bring oxygen to body cells and tissues. This impairs perception and thinking; slows reflexes; causes headaches, drowsiness, dizziness, and nausea; can trigger heart attacks and angina; damages the development of fetuses and young children; and aggravates chronic bronchitis, emphysema, and anemia. At high levels it causes collapse, coma, irreversible brain cell damage, and death.
Carbon Oxides
Gases carbon monoxide (CO) and carbon dioxide (CO2)
Greenhouse gases
Hydrocarbons
Diverse group of organic compounds that contain only hydrogen and carbon (ex: CH4 - methane)
Some are related to photochemical smog and greenhouse gases
© 2012 John Wiley & Sons, Inc. All rights reserved.

13. Ozone
OZONE (O3)
Description: Highly reactive, irritating gas with an unpleasant odor that forms in the troposphere as a major component of photochemical smog
Major human sources: Chemical reaction with volatile organic compounds (VOCs, emitted mostly by cars and industries) and nitrogen oxides to form photochemical smog).
Health effects: Breathing problems; coughing; eye, nose, and throat irritation; aggravates chronic diseases such as asthma, bronchitis, emphysema, and heart disease; reduces resistance to colds and pneumonia; may speed up lung tissue aging.
Environmental effects: Ozone can damage plants and trees; smog can reduce visibility.
Property damage: Damages rubber, fabrics, and paints
Troposphere Ozone
Man-made pollutant in the lower atmosphere
Secondary air pollutant
Component of photochemical smog
Stratospheric Ozone
Essential component that screens out UV radiation in the upper atmosphere
Man- made pollutants (ex: CFCs) can destroy it
© 2012 John Wiley & Sons, Inc. All rights reserved.

14. Ozone Damage to Grape Leaves
© 2012 John Wiley & Sons, Inc. All rights reserved.

15. Sources of Outdoor Air Pollution
Two main sources
Transportation
Industry
Intentional forest fires is also high
© 2012 John Wiley & Sons, Inc. All rights reserved.

16. Urban Air Pollution Photochemical Smog (ex: Los Angeles below)
Brownish-orange haze formed by chemical reactions involving sunlight, nitrogen oxide, and hydrocarbons. Found in modern cities, especially in warm, sunny areas.
© 2012 John Wiley & Sons, Inc. All rights reserved.

17. Industrial smog (AKA London-type smog or gray smog) Smoke pollution
Worst is during the winter months when combustion of household fuel is high.
Serious problem in developing countries.
© 2012 John Wiley & Sons, Inc. All rights reserved.

18. Environmental Science 5e
Botkin and Keller
Environmental Science 5e

19. Environmental Science 5e
Botkin and Keller
Environmental Science 5e

20. Formation of Photochemical Smog
© 2012 John Wiley & Sons, Inc. All rights reserved.

21. Initial reaction of nitrogen dioxide with sunlight

22. Urban Air Pollution Atmospheric Inversion or aka temp. inversion:
Occurs when warmer air is found above cooler air and it poses a particular problem when there is a stagnant air mass.

23. Environmental Science 5e
Botkin and Keller
Environmental Science 5e

24. Factors in smog formation
Decrease smog
Increase smog
Urban buildings
Hills and mountains
High temperatures
“Grasshopper Effect”
Precipitation
Salty sea spray
Wind
Reduce factory/car emissions

25. Sources of Smog in Los Angeles
© 2012 John Wiley & Sons, Inc. All rights reserved.

26. Effects of Air Pollution
Low level exposure
Irritates eyes
Causes inflammation of respiratory tract
Can develop into chronic respiratory diseases
© 2012 John Wiley & Sons, Inc. All rights reserved.

27. Children and Air Pollution
Greater health threat to children than adults
Air pollution can restrict lung development
Children breath more often than adults
Children who live in high ozone areas are more likely to develop asthma
© 2012 John Wiley & Sons, Inc. All rights reserved.

28. Controlling Air Pollution
Smokestacks with electrostatic precipitator (right)
Electrode imparts negative charge on the air pollutants
Negatively charged pollutants are then attracted to positively charged walls- fall into collector
© 2012 John Wiley & Sons, Inc. All rights reserved.

29. Controlling Air Pollution
Smokestacks with scrubbers (right)
Particulate material can also be controlled by proper excavating techniques
© 2012 John Wiley & Sons, Inc. All rights reserved.

30. Scrubbers Emissions not controlled- heavily polluted
Emissions controlled with scrubbers-only steam expelled
© 2012 John Wiley & Sons, Inc. All rights reserved.

31. Controlling Air Pollution
Phase I Vapor Recovery System for gasoline
© 2012 John Wiley & Sons, Inc. All rights reserved.

32. The Clean Air Act
Authorizes EPA to set limits on amount of specific air pollutants permitted
Focuses on 6 pollutants:
lead, particulate matter, sulfur dioxide, carbon monoxide, nitrogen oxides, and ozone
Act has led to decreases in air pollutants
Most dramatic is lead - decreased by 98% since (due to switch to unleaded gasoline)
© 2012 John Wiley & Sons, Inc. All rights reserved.

33. The Clean Air Act
© 2012 John Wiley & Sons, Inc. All rights reserved.

34. Urban Air Quality
© 2012 John Wiley & Sons, Inc. All rights reserved.

35. Ozone Depletion in Stratosphere
Ozone Protects earth from UV radiation
© 2012 John Wiley & Sons, Inc. All rights reserved.

36. Ozone Depletion in Stratosphere
Ozone thinning/hole
First identified in over Antarctica
Occurs annually between Sept and Nov because:
Caused by human- produced bromine and chlorine containing chemicals (Ex: CFCs)
© 2012 John Wiley & Sons, Inc. All rights reserved.

37. Ozone Depletion in Stratosphere
Hole over Antarctica requires two conditions:
Sunlight just returning to polar region
Circumpolar vortex- a mass of cold air that circulates around the southern polar region
Polar stratospheric clouds form
Enable chemical reactions that cause Cl and Br to destroy ozone
© 2012 John Wiley & Sons, Inc. All rights reserved.

38. Effects of Ozone Depletion
Higher levels of UV- radiation hitting the earth
Eye cataracts
Skin cancer (right)
Weakened immunity
May disrupt ecosystems
May damage crops and forests
© 2012 John Wiley & Sons, Inc. All rights reserved.

39. Recovery of Ozone Layer
Montreal Protocol (1987)
Reduction of CFCs
Started using HCFCs (greenhouse gas)
Phase out of all ozone destroying chemicals is underway globally
Satellite pictures in 2000 indicated that ozone layer was recovering
Full recovery will not occur until 2050
© 2012 John Wiley & Sons, Inc. All rights reserved.

40. Acid Deposition (AKA Acid Rain)
Sulfur dioxide and nitrogen dioxide emissions react with water vapor in the atmosphere and form acids that return to the surface as either dry or wet deposition
pH scale
© 2012 John Wiley & Sons, Inc. All rights reserved.

41. Chemistry and Acid Rain
The pH of rainwater is normally slightly acidic, at about 5.6, due mainly to reaction of carbon dioxide with water to form carbonic acid.

42. Gases from natural events
Volcanic eruptions, forest fires, and lightning produce sulfur dioxide, sulfur trioxide, and nitrogen dioxide.
These gases can react with atmospheric water in much the same way that carbon dioxide does to produce sulfurous acid, sulfuric acid, nitric acid and nitrous acid.
Refer to “Chemistry is indeed relevant to APES.”

43. How Acid Deposition Develops
© 2012 John Wiley & Sons, Inc. All rights reserved.

44. Effects of Acid Deposition
Declining Aquatic Animal Populations
Thin-shelled eggs prevent bird reproduction
Calcium is unavailable in acidic soil
Forest decline
(right) Black Forest in Germany
© 2012 John Wiley & Sons, Inc. All rights reserved.

45. Acid Deposition and Forest Decline
© 2012 John Wiley & Sons, Inc. All rights reserved.

46. pH levels of US soil

47. Air Pollution Around the World
Air quality is deteriorating rapidly in developing countries
Developing countries have older cars
Shenyang, China
Residents only see sunlight a few weeks each year
5 worst cities in world
Beijing, China; Mexico City, Mexico; Shanghai, China; Tehran, Iran; and Calcutta, India
© 2012 John Wiley & Sons, Inc. All rights reserved.

48. Case-In-Point Air Pollution in Beijing and Mexico City
Beijing (left)
Mexico City (right)
© 2012 John Wiley & Sons, Inc. All rights reserved.

49. Long Distance Transport of Air Pollutants
Global Distillation Effect
© 2012 John Wiley & Sons, Inc. All rights reserved.

50. Acid Rain Prevention and Solution
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
Acid Rain Prevention and Solution
Burn low-sulfur coal
Remove SO2 particulates, and Nox from smokestack gases
Remove Nox from motor vehicular exhaust
Tax emissions of SO2

51. Indoor Air Pollution Pollutants can be 5– 100x greater than outdoors
Radon, cigarette smoke, carbon monoxide, nitrogen dioxide, formaldehyde pesticides, lead, cleaning solvents, ozone, and asbestos
© 2012 John Wiley & Sons, Inc. All rights reserved.

52. Formaldehyde
Found in: plywood, furniture, upholstery, floor adhesives, dry cleaning chemicals.
Causes: breathing problems, headache, sore throat, dizziness, eye irritation in those sensitive to low levels.
Chronic exposure to higher levels can lead to cancer.
Radon
Naturally occurring from radioactive decay of U-238.
Occurs in soils, bedrock and can get into homes through cracks.
Can’t get out and builds up
Can lead to lung cancer

53. 1, 1, 1- Nitrogen Oxides: Tobacco Smoke Carbon Monoxide
Para-dichlorobenzene: air fresheners, moth balls; cancers
Tetrachloroethylene: dry cleaning residue; nerve, liver, kidney problems
Chloroform: chlorine-treated hot water; cancers
Formaldehyde: from processed wood; eye, nose, throat, lung irritant
1, 1, 1-
Trichloroethane: aerosals; dizziness, irregular breathing
Benzo-a-pyrene: from smoke; lung cancer
Nitrogen Oxides:
Gas ovens, kerosene heaters, un-vented gas burning; lung irritation, headaches
Styrene: from carpet/plastic. Kidney/liver problems
Tobacco Smoke
Asbestos: old floor tile,
Pipe insulation;
lung problems, cancer
Radon-222: from soils, lung disease
Carbon Monoxide
Methylene Chloride: paint stripper, thinner; nerve, diabetes

54. Indoor Air Pollution - Radon
© 2012 John Wiley & Sons, Inc. All rights reserved.

55. VI. Pollution (25-30%) Air pollution Sources-primary and secondary
major air pollutants (pollutant chart)
measurement units
smog
acid deposition-causes and effects
indoor air pollution
remediation and reduction strategies trading article, emissions trading game)
Clean Air Act and other relevant laws