CE 11 Midterm 2 Review
HO #13-15: Air Pollution
Primary pollutants: Emitted directly to the atmosphere by combustion (power plants burning
fossil fuels), evaporation (gasoline, paint), and grinding/abrasion (asbestos, dust)
Secondary pollutants: Created by chemical reaction in atmosphere (e.g. ozone)
Combustion is never 100% efficient, so other compounds are formed and released.
U.S. Clean Air Act: 6 criteria pollutants (CO, NO
, Pb, PM). Also identifies 189
other hazardous air pollutants (e.g. benzene).
National Ambient Air Quality Standards: apply to outdoor air; primary standards are to
protect public health, esp. most sensitive populations. Secondary standards are to protect
public "welfare" (buildings, crops, visibility, domestic animals).
): particulate matter is aerosol, dust, smoke, soot found in the air. The
smaller it is, the worse it is for chronic health. Cause of respiratory infections, cardiac
disorders, and asthma. The subscript number indicates the avg. diameter in micrometers.
: Found in coal and petroleum (diesel), which are used for electricity generation and
metal processing. It oxidizes in the air: SO
acid rain and secondary
PM. Acid rain "washes" tree trunks and plants, acidifies lakes with no buffer capacity
(threatens aquatic life), degrades buildings (fiscal impact). A decreasing problem in North
America due to the success of the cap-and-trade program over the past decade. An
increasing problem in industrializing countries, such as China. Reduction in the industry is
less elastic than in electricity generation.
: Includes NO and NO
and released as heat from combustion of fossil fuels
(+transportation). It oxidizes with the air: NO
acid rain and secondary
PM. Health and environmental effects include: a major smog precursor, visibility
impairment, creates nitrates (
PM), and acid deposition.
CO: Comes from combustion of transport fuels and incomplete, fuel-rich combustion.
Health and environmental effects include: asphyxiation, smog precursor, central nervous
system effects, affects people with heart conditions.
O3: Good in the stratosphere (block UV rays), bad in the troposphere (for our health). A
product of photochemical smog: VOC + NOx + sunlight + O2 = O3. Health and
environmental effects: Inflammation of mucus membranes, asthma, reduced respiratory
capacity, reduces ability of plants to produce and store food. Formation NOT linear with