Study Guide for Air Pollution Test: Chapter 18

Note: it is a good idea to check out the figures in this chapter

  • Review layers of atmosphere, especially the roles of the troposphere and stratosphere
  • Know factors that affect air pollution levels: climate (temperature and rainfall), and thermal inversions. Be able to explain conditions that increase the likelihood of thermal inversions.
  • Be able to define primary pollution and know the following examples: CO, CO2, SO2, NO, NO2, Volatile Organic Compounds (VOCs), and Particulate Matter (PM). Know the major sources (natural and anthropogenic) of these pollutants.
  • Be able to define volatile organic compound (VOC) and know a few examples.
  • Know that particulate matter is described in terms of size in micrometers (also known as microns which is represented by µm). PM 2.5 is particulate matter that is smaller than 2.5 µm. Know how the size of the particulate matter relates to its harmfulness to human health. (Smaller = worse, since we can’t keep them out)
  • Be able to define secondary pollution, photolysis and photochemical smog. Know the following examples of secondary pollutants: SO3, HNO3, H2SO4, H2CO3, O3, PAN’s. Be able to explain how temperature and time of day can affect levels of the secondary pollutants that are formed by photochemical reactions.
  • Know the difference between gray-air (industrial) and brown-air (photochemical/NO2) smog.
  • Know that at the high temperatures during combustion in automobiles, power plants and industrial plants can cause atmospheric nitrogen (N2) to react with O2 to produce nitric oxide: N2 + O2 2NO
  • Also understand that the primary pollutant NO can result in these secondary pollutants: NO2 (in brown-air smog), O3 (ground-level ozone pollution resulting from O released by photolysis if NO2 combining with O2), HNO3 (nitric acid – a cause of acid deposition) and PAN’s (peroxyacyl nitrates- from reactions with unburned hydrocarbons in the atmosphere). (Figure 18-9)
  • Understand the pH scale including the fact that it is logarithmic (base 10) so that each step on the pH scale is a 10 fold change in strength. Be able to define buffer and give examples of how acids can be buffered. Be able to define neutralization and name a substance that can be used to neutralize acidic lakes.
  • Know the definition of acid deposition, including the pH to be defined as acid deposition. Know the chemicals found in acid deposition:HNO3, H2SO4and H2CO3. Know the primary sources of these chemicals.
  • Know some of the effects of acid deposition:

Ecosystems: Effects of organisms with CaCO3. In addition to damaging organisms directly, acids can leach essential plant nutrients from the soil. Acid can mobilize toxic Al +3 ions. Effects on lakes/aquatic life.

Building materials: Can damage building materials that contain calcium carbonate such as limestone and marble and can corrode metals.

  • Be able to explain factors that make regions more vulnerable to acid deposition (Geography, soils)
  • Know strategies for preventing and cleaning-up acid rain.
  • Know the effects of the following air pollutants: ozone (O3), carbon monoxide (CO), lead (Pb), particulate matter (PM), nitrogen dioxide (NO2) and sulfur dioxide (SO2). (See link and handout for fact sheet Be able to explain why carbon monoxide is poisonous.
  • Know what the body’s natural defense mechanisms are for air pollution.
  • Know the basics of the Clean Air Act including the six pollutants that have criteria standards: NO2, SO2, carbon monoxide, lead, ozone and particulates.
  • Know the four most common/dangerous indoor air pollutants and common sources: formaldehyde, Radon-222, asbestos, and smoke.
  • Know factors that affect levels of indoor air pollutants (i.e. ventilation). Know methods of preventing or cleaning-up/diluting indoor air pollutants.
  • Be able to define the sick building syndrome (when at least 20% of a building’s occupants suffer persistent symptom that disappear when they go outside.)
  • Know methods to reduce air pollution:
  • Best approach is to reduce causes (for example, by improved energy efficiency).
  • Catalytic converters use catalysts that remove up to 90% of hydrocarbons, NOx and CO.
  • Low sulfur coal techniques to clean coal (results in hazardous wastes that must be disposed)
  • Unleaded gasoline

Study Guide: Ozone Depletion (19.4)

  • Know the natural process that creates ozone in the stratosphere. How and why does the season affect the creation of ozone? How do air circulation patterns affect the distribution of ozone?
  • Be able to compare the three types of UV radiation (UV-A, UV-B and UV-C) in terms of wavelength, frequency, energy and ability to damage tissue. Which type of UV radiation is most effectively blocked by the ozone layer?
  • Know the most important ozone depleting chemicals and their uses: CFC’s (trade name= Freon), halons and HBFC’s . Also know the approximate residence time of CFC’s. Know that in addition to these ozone depleting chemicals that supersonic jets (SST’s) that travel in the stratosphere can contribute of ozone depletion.
  • Be able to explain the overall series of reactions in which chlorine can catalyze the breakdown of ozone molecules (noting that the chlorine itself is not changed in the overall reaction and can continue to catalyzing the breakdown of more ozone molecules.) See Figure 19-D on p. 525.
  • Understand seasonal thinning of ozone over the poles. Be able to define polar vortex. Know the events that occur in winter and spring that cause the polar thinning,/ Know during which season has greatest thinning and why this occurs. Know why the ozone hole disappears each summer. Also know which hemisphere is more affected by seasonal polar thinning and why.
  • Know human health effects of UV radiation. Be able to compare the general types of skin cancer: squamous cell carcinoma, basal cell carcinoma, and melanoma. See Figure 19-E on p. 526. In addition to skin cancer, UV radiation can increased cataracts and suppress the immune system (leading to increased susceptibility to infectious disease).
  • Know that increased UV radiation can cause an increase in photochemical smog. Therefore, ironically ozone layer depletion in the stratosphere can lead to increased tropospheric ozone (ground-level ozone which is an extremely harmful air pollutant.
  • Know how ecosystems can be impacted by UV radiation: damage to plants, etc. See Fig. 19-20 on p. 524.
  • Global warming connections: CFC’s are greenhouse gases, increased radiation reaching earth due to ozone depletion can increase warming of earth, and damage to ocean autotrophs.
  • Know the history of scientific knowledge of ozone depletion and the ozone hole.
  • Know the basics of the Montreal Protocol. What were the goals and what was the international response to the goals? Why was global cooperation to cut emissions of CFC’s so successful?
  • What are projections for the ozone hole being fixed? Why will it take so long?