Air Pollution
Chapter 18 AhrensMonday, 23 November
1Monday, November 23
Air pollution definition
• Air pollutants are airborne substances (either solids, liquids, or gases) that occur in concentrations high enough to threaten the health of people and animals, to harm vegetation and structures, or to toxify a given environment
Monday, November 23 2
Ways to categorize air pollutants
• There is human-induced air pollution and natural sources of air pollution
• There are fixed sources of air pollution and moving sources of air pollution (mobile sources)
• There are point sources of air pollution and area sources of air pollution
• There are primary and secondary pollutants
Monday, November 23 3
Primary and secondary pollutants
• Primary air pollutants enter the atmosphere directly from their sources– Examples are carbon monoxide and sulfur dioxide
• Secondary air pollutants form only when a chemical reaction occurs with primary air pollutants– Examples are photochemical oxidants and acid
deposition– Secondary air pollutants are more difficult to control
Monday, November 23 4
Santiago, Chile
Monday, November 23 5Fig. 18-CO, p. 500
October 23, 2003 wild fires
Monday, November 23 6Fig. 18-1, p. 503
Table 18-1, p. 5037Monday, November 23
Fig. 18-2, p. 5048Monday, November 23
Fig. 18-2, p. 5049Monday, November 23
Fig. 18-2, p. 50410Monday, November 23
Fig. 18-3a, p. 50411Monday, November 23
Fig. 18-3b, p. 50412Monday, November 23
East China Sea: pollution, smoke, and dust
Monday, November 23 13Fig. 18-4, p. 505
Thunderstorm and cumulus clouds above a layer of haze
Monday, November 23 14Fig. 18-5, p. 506
Table 18-2, p. 51315Monday, November 23
Fig. 3, p. 51616Monday, November 23
Fig. 18-10, p. 51217Monday, November 23
Stepped Art
Fig. 18-10, p. 51218Monday, November 23
Table 18-3, p. 51319Monday, November 23
Fig. 18-11, p. 51420Monday, November 23
Fig. 18-12, p. 51421Monday, November 23
A secondary pollutant: smog/photochemical oxidants/ozone• Smog originally meant smoke and fog• Now smog refers to the chemical soup created
by sunlight acting on hydrocarbons (VOCs) and oxides of nitrogen in the presence of oxygen and sunlight
• Ozone is the main constituent of smog, but there are many others, including PAN
• Smog attacks the respiratory system
Monday, November 23 22
Fig. 18-6, p. 50723Monday, November 23
Secondary air pollutant: acid deposition
• Acid deposition: can be dry or acid rain, snow, fog, dew– Oxides of sulfur, oxides of nitrogen combine with
water vapor or liquid water drops in the air– Sulfuric acid, nitric acid form– Acid attacks structures and plants– In bodies of water, acid allows heavy metals to
leach out and contaminate water supplies, toxify water for fish and other living things
Monday, November 23 24
Fig. 18-21, p. 52425Monday, November 23
Fig. 18-22, p. 52426Monday, November 23
Fig. 18-23, p. 52527Monday, November 23
Fig. 18-13, p. 51528Monday, November 23
Fig. 18-14, p. 51729Monday, November 23
Fig. 18-14a, p. 51730Monday, November 23
Fig. 18-14b, p. 51731Monday, November 23
Fig. 18-15, p. 51732Monday, November 23
Fig. 4, p. 51833Monday, November 23
Fig. 4a, p. 51834Monday, November 23
Fig. 4b, p. 51835Monday, November 23
Fig. 4c, p. 51836Monday, November 23
Fig. 4d, p. 51837Monday, November 23
Fig. 4e, p. 51838Monday, November 23
Fig. 18-16, p. 51939Monday, November 23
Fig. 18-17, p. 51940Monday, November 23
Fig. 18-18, p. 52041Monday, November 23
Stepped Art
Fig. 18-18, p. 52042Monday, November 23
Fig. 18-19, p. 52043Monday, November 23
Fig. 5, p. 52144Monday, November 23
Table 18-4, p. 52245Monday, November 23
Fig. 18-20, p. 52346Monday, November 23