1. Criteria Air Pollutants
EPA uses six "criteria pollutants" as indicators of air quality
Nitrogen Dioxide: NO2
Ozone: ground level O3
Carbon monoxide: CO
Lead: Pb
Particulate Matter: PM10 (PM 2.5)
Sulfur Dioxide: SO2

2. Nitrogen Dioxide (NO2) Properties: reddish brown gas
Effects: acid rain, lung and heart problems, decreased visibility (yellow haze), suppresses plant growth
Sources: fossil fuels combustion, power plants, forest fires, volcanoes, bacteria in soil

3. Tropospheric Ozone (O3)
Properties: colorless, unpleasant odor, major part of photochemical smog
Effects: lung irritant, damages plants, rubber, fabric, eyes, reduce resistance to colds
Sources: Results from interactions of sunlight, nitrogen oxides, and volatile carbons
(photocopiers, cars, industry, gas vapors, chemical solvents, incomplete fuel combustion products)

4. Carbon Monoxide (CO) Properties: colorless, odorless, heavier than air
Effects: reacts with hemoglobin – reduces ability of blood to transport oxygen
Sources: incomplete combustion of fossil fuels 77% from auto exhaust, cigarettes
5.5 billion tons enter atmosphere/year

5. Lead (Pb) Properties: solid, toxic, metal
Effects: accumulates in tissue; affects kidneys, liver and nervous system (children most susceptible); possible carcinogen
Sources: particulates, smelters, batteries, paint, leaded gasoline (banned in developed countries)
2 million tons enter atmosphere/year

6. Suspended Particulate Matter
Properties: particles suspended in air (<10 um)
Effects: lung damage, mutagenic, carcinogenic, teratogenic, shortens life
Sources: burning coal or diesel, volcanoes, factories, unpaved roads, plowing, lint, pollen, spores, burning fields

7. Sulfur Dioxide (SO2) Properties: colorless gas with irritating odor
Effects: produces acid rain (H2SO4), breathing difficulties, lichen and moss are indicators
Sources: burning high sulfur coal or oil, smelting or metals, paper manufacture
Combines with water and NH4 to increase soil fertility

8. Effects of Air Pollution
Mechanisms to protect respiratory system from pollutants
Hairs in nose that filter large particles
Sticky mucus in lining of upper respiratory tract
Sneezing & coughing
Cilia lining upper respiratory
tract

9. Effects of Air Pollution
Exposure to pollutants causes
Lung cancer
Ashtma—allergic reaction causing sudden episodes of muscle spasms in bronchial walls resulting in shortness of breath
Chronic bronchitis—persistent inflammation & damage to cells lining the bronchi causing mucus buildup, coughing, & shortness of breath
Emphysema—irreversible damage to air sacs leading to abnormal dilation of air spaces, loss of lung elasticity, & acute shortness of breath
Estimated 150, ,000 US citizens die annually from indoor and outdoor air pollution

10. Temperature Inversions
Subsidence Temperature Inversion
Large mass of warm air moves into a region at high altitude and floats over a mass of colder air near the ground
Radiation Temperature Inversion
Occurs at night as the air near the ground cools faster than the air above
As the sun rises & warms earth’s surface, radiation inversion disappears by noon dispersing pollutant build-up
Prolonged temperature inversions
City located in a valley surrounded by mountains that experiences cloudy & cold weather during part of the year
Surrounding mountains block sun needed to reverse nightly radiation inversions
City with several million people & motor vehicles in an area with sunny climate, light winds, mountains on three sides, & ocean on the other
Los Angeles basin

11. Kyoto Protocol
1997: signed by some 160 nations at the third United Nation Framework Convention on Climate Change conference (UNFCCC).
The protocol calls for the first ever legally binding commitments to reduce carbon dioxide and 5 other greenhouse gas emissions to 5.2 % below 1990 levels by 2012
2005: Kyoto Protocol goes into effect. Signed by major industrial nations except US.
Different levels of emissions restrictions were placed on MEDCs and LEDCs
Al Gore signed but Senate never ratified so protocol is not legally binding in U.S.
US did not sign because of the lack of restrictions on LEDCs and b/c it may harm economy of U.S.
GWB did not sign because of uncertainty in global warming predictions and costs of controlling emissions would unfairly disadvantage businesses while China and India had no restrictions
2007: Supreme Courts ruled that EPA had authority to regulate greenhouse gases under Clean Air Act
2010: Under Obama – EPA proposed fuel efficiency standards that would reduce greenhouse gases 30% by 2016