Study Guide for Air Pollution and Ozone Depletion Test: Chapter 18 and 19.4
Review layers of atmosphere especially the roles of the troposphere and stratosphere
Know factors that affect air pollution levels: topography, climate (temperature and rainfall) , 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.
Be able to understand the nomenclature for particulate matter. PM 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.
Be able to define secondary pollution, photolysis and photochemical smog. Know the following
examples of secondary pollutants: SO3, HNO3, H2SO4, 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 automobile engines, coal-burning power
plants and industrial plants can cause atmospheric nitrogen (N2) to react with O2 to produce nitric oxide
N2 + O2  2NO
Also understand the series of reactions of NO that can result in NO2 (in brown-air smog), O3 (groundlevel 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).
Know that sulfur from burning of coal (and oil) or the smelting of metal sulfide ores (such as lead sulfide
PbS) can undergo a series of reaction with O2 and then water vapor to produce sulfuric acid (H2SO4), a
key contributor to acid deposition.
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. For example: a substance with a pH of 3 has 100 x greater H+
concentration and is 100 x more acidic than a substance with a pH of 5). 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 that
normal rainfall has a pH of approximately 5.6 due to formation of carbonic acid when some of the
carbon dioxide reacts with water vapor. Know the chemicals found in acid deposition: HNO3, H2SO4 and
H2CO3- (carbonic acid). Know the primary sources of these chemicals.
Know some of the effects of acid deposition:
Ecosystems: In addition to damaging organisms directly, acids can leach essential plant nutrients
from the soil. Acid can mobilize toxic Al +3 ions. Acid conditions can cause moderately toxic
inorganic mercury compounds to become highly toxic methylmercury.
Building materials: Can damage building materials (especially materials that contain calcium
carbonate such as limestone and marble). Acids can corrode metals.
Be able to explain factors that make regions more vulnerable to acid deposition.
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 notes and attached
sheet). Be able to explain why carbon monoxide is poisonous.
Know the basics of the human respiratory system, and what the body’s natural defense mechanisms are.
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 most common indoor air pollutants and some sources.
The four most dangerous are 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 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
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? Be able to explain why.
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 reaction in which chlorine (and other halogens such as bromine)
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 page 525.
Understand seasonal thinning of ozone over the poles. Be able to define polar vortex, be able to define
events that occur in each season to lead up to polar thinning, know during which season has greater
thinning and why this occurs. Also know which hemisphere is more affected by seasonal polar thinning
and why.
Know human health effects of UV radiation. Be able to define malignant and metastasis. Be able to
compare the general types of skin cancer: squamous cell carcinoma, basal cell carcinoma, and
melanoma. See Figure 19-E on page 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 (review air pollution
and the role of sunlight in the creation of secondary pollutants). Therefore, ironically ozone layer
depletion in the stratosphere can lead to increased tropospheric ozone (ground-level ozone which is an
extremely harmful air pollutant. Additionally, ozone layer depletion could lead to an increase in acid
deposition. (Synergistic relationship between ozone depletion and acid deposition.)
Know how ecosystems can be impacted by UV radiation: damage to plants, etc.
Know the basics of the Montreal Protocol.