Homework Discussion – ANSWERS

Clean Air Act

  1. What is the Clean Air Act?
  2. Authorized the EPA to set limits on amounts of air pollutants permitted in the US
  3. What was it a response to?
  4. Unacceptable high levels of air pollutants causing premature deaths in the US
  5. Who oversees it?
  6. EPA
  7. What was the most dramatic improvement in air quality from 1970 to 2001, and what caused this?
  8. There was a 98% decrease in the amount of lead in the atmosphere
  9. Due to US switch to unleaded gas.
  10. What are “nonattainment areas”?
  11. Areas that still contain higher levels of pollutants than are recommended.
  12. EPA estimates 90 million Americans currently live in nonattainment areas
  13. Based on Figure 2, is the Clean Air Act working?
  14. YES!
  15. What was the focus of the 1990 amendment to the Clean Air Act?
  16. Industrial airborne toxic chemicals & Motor Vehicle emissions
  17. Before 1990, airborne emissions of only 7 toxic chemicals were regulated. The amendments required a 90% reduction in the atmospheric emissions of 189 toxic chemicals by 2003
  18. What was the main change to the Clean Air Act in 1997?
  19. Limited the emission of particulate matter because of concern over health effects of microscopic particulate matter
  20. How will commuting on public transportation help clean our air quality?
  21. less fuels being used = less air pollution = better air quality
  22. In your opinion, has the Clean Air Act of 1970 been successful? Use your knowledge and the figures on this worksheet as evidence.
  23. Answers will vary
  24. Consider the increase in population since 1970 - have we improved our air quality with that in mind?
  25. Yes.
  26. Look at the cartoon (Figure 4).
  27. What does the cartoon tell you about the United States air quality in 2002?
  28. It wasn’t as good as the Clean Air Act had intended.
  29. Is this a fair representation?
  30. No –artist feels that the gov’t was ignoring the stipulations of the Clean Air Act.
  31. Is there bias? If so, what???
  32. Yes!
  33. What can we do to avoid this type of situation?
  34. Strict policy, oversight, etc.

Other ways to improve air quality…

  1. How does the sulfur content of gas damage our atmosphere?
  2. Sulfur clogs catalytic converters so they can’t effectively remove emissions from exhaust
  3. Why is it harmful to drive an SUV?
  4. They do not have the same federal emissions standards as ordinary automobiles and they produce more than twice the pollution of a car.
  5. Why is California on the cutting edge of air pollution reform?
  6. 1998 - issued strict pollution standard for SUV’s requiring they emit the same amt of pollution as cars
  7. Why are small engines so damaging to our atmosphere? (Envirobrief p. 447)
  8. They produce about 10% of US hydrocarbon emissions are attributed to mobile sources
  9. 1997: EPA set emissions standards for handheld and non-handheld equipment
  10. By 2007 the EPA will reduce hydrocarbon emissions and nitrogen oxide emissions 59% beyond 1997 standards

California’s Leading the Way!

  1. Can an individual state impose stricter pollution limits than the federal government?
  2. Yes! California’s leading the way for this.
  3. Can an individual state impose weaker pollution limits than the federal government?
  4. No! All states must comply with the minimal EPA regulations.
  5. What would happen to California’s smog if 20 of every 100 cars was a hybrid?
  6. Decrease!
  7. Discuss your opinions:
  8. Do you think that it is alright for the government to restrict car companies from producing polluting cars?
  9. Should tax incentives be given to those who purchase fuel economic vehicles?
  10. Would it be fair to impose a tax on vehicles that do not burn fuel efficiently?

Case in Point…. MEXICO CITY

  1. In general, why is there a problem with air pollution in developing countries?
  2. Developing countries are more concerned about their economy than environment. Environmental degradation can take a back seat until they can afford better technologies.
  3. What happened to the visibility in Mexico City since 1940?
  4. decreased from 7 mi to 1 mi since 1940
  5. Mexico City’s pollution problem is caused by two problems. Discuss these:
  6. population growth
  7. more people = more pollution
  8. location
  9. Mexico city is a bowl-shaped valley ringed by mountains on 3 sides
  10. When is air quality worst in Mexico City? Why?
  11. from Oct-Jan because of temp inversions caused by seasonal variations in the atm
  12. Where does the pollution come from?
  13. cars, contaminated gasoline, dried fecal matter from sewage, liquefied petroleum gas
  14. How is the government trying to fix the air pollution problem?
  15. replacing old technology (switched to unleaded vehicles, use of catalytic converters, reforested nearby hillsides, restrict driving during peak times, upgraded refineries, etc)

FIGURE 1

FIGURE 2

FIGURE 3: Emissions in the US, 1970 and 2000

FIGURE 4: Cartoon

FIGURE 5:

Sources of Smog in Los Angeles