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-Paracelsus, 1493-1541

All substances are poisons; there is none which is not a poison. The right dose distinguishes a poison and a remedy. -Paracelsus, 1493-1541. Chapter 9—air pollution.

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-Paracelsus, 1493-1541

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  1. All substances are poisons; there is none which is not a poison. The right dose distinguishes a poison and a remedy. -Paracelsus, 1493-1541

  2. Chapter 9—air pollution Meaning– immediate and local hazards to health and materials, not climate change. Regulated by the EPA for the public , OSHA in the work place. Lead SO2 NOX=nitrogen oxides Mercury Hydrocarbons Ozone (also Ch. 10)

  3. Acceptable levels (mg/kg=ppm, by weight)(in soil/dust) • Mercury 2 • Cadmium 3 • Selenium 3 • Arsenic 20 • Boron 25 • Copper 50 • Lead 100 • Titanium 500 (1 ppm=1 gram in one ton)

  4. In air (over 8 hour day) • Lead 50 mg/m3 (Table 9.3  1.5 mg/m3 over a quarter) • Arsenic 10 mg/m3 • Mercury 0.1 mg/m3 = 100 mg/m3 OSHA for the workplace, EPA for the public

  5. Fossil fuel emissions Gas Oil Coal CO2 117,000 164,000 208,000 CO 40 33 208 NOx 92 448 457 SO2 1 1122 2591 Particulates 7 84 2744 Mercury 0.000 0.007 0.016 (in pounds per billion Btu)

  6. CO2- a pollutant? Recent US Supreme Court decision- yes, and therefore under the responsibility of the EPA. Chapter 10.

  7. TetraEthyl Lead ‘antiknock’ additive to gasoline, 1:1260 mixture • >30 mg/liter of air7 point drop in IQ • 10 mg/liter 4 point drop in IQ • Clogs catalytic converters (Monday) Phased out as of 1972 in US

  8. Sulfur, SO2,sulfuric acid Sulfur can be 3-10% of coal, <1% for some western coal. Wash the coal at the mine—coal dust floats, sulfur minerals sink. S burns to SO2sulfuric acid in the air. ‘Scrub’ the exhaust gas—CaO with water CaSO4, gypsum

  9. SSO2 Reaction S + O2SO2 Relative weights Carbon =12 Oxygen =16, O2=32 Sulfur (S)=32 32 grams of S 32+2x16= 64 grams of SO2 32 tons of S64 tons of SO2 1 ton of S64 / 32 = 2 tons of SO2

  10. Acid rain • Sulfur sulfuric acid in the air, rain • NOx  nitric acid

  11. Sulfur Cap and Trade 1990 Clean Air Act set a national cap on SO2 from power plants, 9.5 million tons in 2000, 8.95 Mt in 2010. Was 17.3 Mt in 1980. Permits based on existing emissions. Can be bought and sold. Monitored by on-site equipment, reported to EPA. www.epa.gov/airmarkets

  12. NOx=nitrogen oxides Made with oxygen and nitrogen in air when heated. Power plants and cars. Part of acid rain. Overfertilizes RMNP.

  13. Mercury 40% of mercury in environment comes from power plants. Can concentrate in the food chain as methyl mercury. National average in coal 0.17 ppm (USGS) 109 tons/year x 0.17x10-6 = 170 t of mercury each year. Actual emissions about 50 t/year. EPA national cap of 38 tons in 2010

  14. Dental mercury • Old fillings can total 2.5 grams of mercury, vaporized at cremation. • Air from cremation can get to 200 mg/m3 !! • Globally 65 kg per year.

  15. Ozone=O3 • Chapter 10 for global effects • Autos– air+heatNO2 (the brown cloud) • NO2 + sunshineNO + O • O + O2O3 0zone Ozone and NO2 are strong oxidizers, eat tissue, plastic, rubber.

  16. Hydrocarbons Unburned fuel

  17. Result • Cleaner air resulting from the Clean Air Act of 1970 and others have added 5 months to US life spans. • Some cities/areas, 10 months.

  18. 1. (8)The US burns one billion (109) tons of coal each year, and 1% of this by weight is sulfur. How many tons of SO2 would we dump into the air each year if nothing were done about this? You will need a chemical reaction to compute the ratio of weights of sulfur (S, atomic weight 32) and SO2. 2. (4)In fact, ‘washing’ the coal removes 40% of the sulfur, and ‘scrubbing’ the power plant gas removes another 80%. By what factor do these combine to lower the answer to Problem 1? 3. (8)What is acid rain? Name three bad things it does.

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