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