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
The winter of 2012/2013 has been bad!

3. 18-1 What Is the Nature of the Atmosphere?
Concept The atmosphere is structured in layers, including the troposphere, which supports life, and the stratosphere, which contains the protective ozone layer.

4. The Atmosphere Consists of Several Layers
Atmosphere varies in
Density
Atmospheric pressure
Temperature

5. Air Movements in the Troposphere Play a Key Role in Earth’s Weather and Climate
75–80% of the earth’s air mass
Closest to the earth's surface
Chemical composition of air
Rising and falling air currents: weather and climate
Involved in chemical cycling

6. The Stratosphere Is Our Global Sunscreen
Similar composition to the troposphere, with 2 exceptions
Much less water
O3, ozone layer, filters UV
Location

7. Trophosphere/stratosphere

8. 18-2 What Are the Major Outdoor Pollution Problems?
Concept Pollutants mix in the air to form industrial smog, mostly the result of burning coal, and photochemical smog, caused by motor vehicle, industrial, and power plant emissions.

10. Note: This sign is in Dinosaur National Monument at a beautiful overlook.

12. Air Pollution Comes from Natural and Human Sources
Natural sources
Dust blown by wind
Pollutants from wildfires and volcanoes
Volatile organics released by plants
Withdrawing groundwater
Human sources: mostly in industrialized and/or urban areas
Stationary sources
Mobile sources

13. Case Study: Air Pollution in the Past: The Bad Old Days
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
Donora Death Fog
1963: New York City
Global problem

14. Denora Death Fog

15. Some Pollutants in the Atmosphere Combine to Form Other Pollutants
Primary pollutants
Secondary pollutants
Air quality improving in developed countries
Much more needs to be done in developing countries
Indoor pollution: big threat to the poor
Discuss: How do primary pollutants become secondary pollutants? In ______ words.

17. What Are the Major Outdoor Air Pollutants? (1)
Carbon oxides
Carbon monoxide (CO)
Carbon dioxide (CO2)
Sources
Human health and environmental impact
Ozone (O3)
Human and environmental impact
Discuss: Ozone is good/ ozone is bad. In ___ words.

18. What Are the Major Outdoor Air Pollutants? (2)
Review: Draw the N cycle and the S cycle. Do not look them up.
Nitrogen oxides (NOx) and nitric acid (HNO3)
Sources
Acid deposition
Photochemical smog
Human health and environmental impact
Sulfur dioxide (SO2) and sulfuric acid (H2SO4)

19. What Are the Major Outdoor Air Pollutants? (3)
Particulates
Suspended particulate matter (SPM)
Fine
Ultrafine
Sources
Human health and environmental impact
Volatile organic compounds (VOCs)
Hydrocarbons and terpenes
Human and environmental impact

20. Science Focus: Detecting Air Pollutants
Chemical instruments
Satellites
Nanotechnology
Biological indicators
Lichens

21. Case Study: Lead Is a Highly Toxic Pollutant
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

23. Burning Coal Produces Industrial Smog
Chemical composition of industrial smog
Reduction of this smog in urban cities of the United States
China and smog
Human deaths

24. Sunlight Plus Cars Equals Photochemical Smog
Chemical composition
Sources
VOCs + NO2 + Heat + Sunlight yields
Ground level O3 and other photochemical oxidants
Aldehydes
Other secondary pollutants
Human health and environmental impact

25. Several Factors Can Decrease or Increase Outdoor Air Pollution (1)
Outdoor air pollution may be decreased by:
Settling of particles due to gravity
Rain and snow
Salty sea spray from the ocean
Winds
Chemical reactions

26. Several Factors Can Decrease or Increase Outdoor Air Pollution (2)
Outdoor air pollution may be increased by:
Urban buildings
Hills and mountains
High temperatures
Emissions of VOCs from certain trees and plants
Grasshopper effect
Temperature inversions

27. 18-3 What Is Acid Deposition and Why Is It a Problem?
Concept Acid deposition is caused mainly by coal-burning power plant and motor vehicle emissions, and in some regions, threatens human health, aquatic life and ecosystems, forests, and human-built structures.

28. Acid Disposition Is a Serious Regional Air Pollution Problem
Acid deposition, acid rain
Formation
Local versus regional problems
Effects of prevailing winds
Buffers
Where is the worst acid deposition?

30. Acid Deposition Has a Number of Harmful Effects
Human respiratory disorders
Aquatic ecosystems affected
Release of toxic metals
Leaching of soil nutrients
Loss of crops and trees
Damage to buildings, statues, and monuments

31. We Know How to Reduce Acid Deposition
Prevention approaches
Clean up
Add lime to neutralize acidified lakes and soil
Add phosphate fertilizer to neutralize acidified lakes

32. 18-4 What Are the Major Indoor Air Pollution Problems?
Concept The most threatening indoor air pollutants are smoke and soot from wood and coal cooking fires (a hazard found mostly in developing countries) and chemicals used in building materials and products.

33. Indoor Air Pollution Is a Serious Problem (1)
Developing countries
Indoor burning
Poor suffer the greatest risk
Developed countries
Indoor air pollution is greater than outdoor air pollution
Why?
11 of the common air pollutants higher inside than outside
Greater in vehicles than outside
Health risks magnified: people spend 70–98% of their time is indoors

34. Indoor Air Pollution Is a Serious Problem (2)
Who are at greatest risk from indoor air pollution?
Children under 5 and the elderly
Sick
Pregnant women
People with respiratory disorders or heart problems
Smokers
Factory workers

35. Indoor Air Pollution Is a Serious Problem (3)
Four most dangerous indoor air pollutants:
Tobacco smoke
Formaldehyde
Radioactive radon-222 gas
Very small particles
Sources of these pollutants
Human health risks

36. Indoor Air Pollution Is a Serious Problem (5)
Other possible indoor air pollutants:
Pesticide residue
Pb particles
Living organisms and their excrements
E.g., Dust mites and cockroach droppings
Airborne spores of molds and mildews
Sick-building syndrome

38. Case Study: Radioactive Radon Gas
Sources
Human health risks
Testing for radon
Correcting a radon problem

39. 18-5 What Are the Health Effects of Air Pollution?
Concept Air pollution can contribute to asthma, chronic bronchitis, emphysema, lung cancer, heart attack, and stroke.

40. Your Body’s Natural Defenses against Air Pollution Can Be Overwhelmed
Respiratory system protection from air pollutants
Role of cilia, mucus, sneezing, and coughing
Effect of smoking and prolonged air pollution exposure
Chronic bronchitis
Emphysema

41. Air Pollution Is a Big Killer
3 Million deaths per year world-wide
Mostly in Asia
Main causes
EPA: proposed stricter emission standards for diesel-powered vehicles
Link between international trade and air pollution
Cargo ships and pollution

42. Naples, Italy – 2008 Smog from burned trash

43. 18-6 How Should We Deal with Air Pollution?
Concept Legal, economic, and technological tools can help to clean up air pollution, but much greater emphasis should be focused on preventing air pollution.

44. Laws and Regulations Can Reduce Outdoor Air Pollution
United States
Clean Air Acts: 1970, 1977, and 1990
EPA
National ambient air quality standards (NAAQs) for 6 outdoor criteria pollutants
National emission standards for 188 hazardous air pollutants (HAPs)
Toxic Release Inventory (TRI)

45. Laws and Regulations Can Reduce Outdoor Air Pollution
Good news in U.S.
Decrease in emissions
Use of low-sulfur diesel fuel: cuts pollution
Developing countries: more air pollution
What does a scrubber look like?

46. Case Study: U.S. Air Pollution Can Be Improved
Rely on cleanup more than prevention of pollution
Raise fuel-efficiency for cars, SUVs, and light trucks
Better regulation of emissions of motorcycles and two-cycle gasoline engines
Regulate air pollution for oceangoing ships in American ports

47. Case Study: U.S. Air Pollution Can Be Improved
Why are airports exempt from many regulations?
Regulate greenhouse gas emissions
Ultrafine particles are not regulated
Urban O3 levels too high
What about indoor air pollution?
Better enforcement of the Clean Air Acts
Is intense pressure needed from citizens to make improvements?

48. We Can Use the Marketplace to Reduce Outdoor Air Pollution
Emission trading or cap-and-trade program
Mixed reactions to program
SO2 emissions down significantly
NO2 will be tried in the future

49. There Are Many Ways to Reduce Outdoor Air Pollution
1980 –2006
SO2 emissions from U.S. electric power plants decreased by 66%
NOx emissions by 41%
Particulate emissions by 28%
Older plants not governed by the same regulations

50. Reducing Indoor Air Pollution Should Be a Priority
Greater threat to human health than outdoor pollution
What can be done?
Prevention
Cleanup

51. We Need to Put More Emphasis on Pollution Prevention
Output approaches
New shift to preventing outdoor and indoor pollution
Pressure from citizens