Criteria Air Pollutants EPA uses six criteria pollutants

Criteria Air Pollutants EPA uses six "criteria pollutants" as indicators of air quality 1. 2. 3. 4. 5. 6. Nitrogen Dioxide: NO 2 Ozone: ground level O 3 Carbon monoxide: CO Lead: Pb Particulate Matter: PM 10 (PM 2. 5) Sulfur Dioxide: SO 2

Nitrogen Dioxide (NO 2) 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

Tropospheric Ozone (O 3) 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)

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

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

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

Sulfur Dioxide (SO 2) Properties: colorless gas with irritating odor Effects: produces acid rain (H 2 SO 4), breathing difficulties, lichen and moss are indicators Sources: burning high sulfur coal or oil, smelting or metals, paper manufacture • Combines with water and NH 4 to increase soil fertility

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

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 -350, 000 US citizens die annually from indoor and outdoor air pollution

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

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