1. Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings Atomosphere & Air Pollution& Solid Waste Miller Chapters 18 & 19 & 21 Many Slides from Mark Ewoldsen, Ph.D. La Canada HS

2. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Take a minute to view our majestic planet

3. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Natural sources of air pollution dust storms fires volcanoes

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7. The atmosphere is composed of nitrogen (N 2 ) 78%, oxygen (O 2 ) 21%, argon (Ar) 93%, water vapor(H 2 O), and a number of trace gases

8. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 2 H 2 + O 2 --> 2 H 2 O Write the equations for photosynthesis and respiration

9. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings PollutantChemical Reaction Carbon Monoxide (CO)2 C + O 2 ------2 CO Carbon Dioxide (CO 2) C + O 2 ------ 2 CO 2 Nitric Oxide (NO)N 2 + O 2 -------- 2NO Nitrogen dioxide (NO 2 )2NO + O 2 ----------- 2NO 2 Sulfur dioxide (SO 2 )S + O 2 ---------------- SO 2

10. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Artificial sources of air pollution Human-caused air pollution includes: Point sources = specific spots where large amounts of pollution are discharged (factory smokestacks) Non-point sources = diffuse, often made up of many small sources (charcoal fires from thousands of homes)

11. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Artificial sources of air pollution Human-caused air pollution includes: Primary pollutants = emitted into troposphere in a directly harmful form (soot, carbon monoxide) Secondary pollutants = produced when primary pollutants and chemicals already present in the atmosphere to form new harmful chemicals (ozone in troposphere)

12. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Criteria Air Pollutants EPA uses six "criteria pollutants" as indicators of air quality 1. Nitrogen Dioxide: NO 2 2. Ozone: ground level O 3 3. Carbon monoxide: CO 4. Lead: Pb 5. Particulate Matter: PM 10 (PM 2.5) 6. Sulfur Dioxide: SO 2 Volatile Organic Compounds: (VOCs) EPA established for each concentrations above which adverse effects on health may occur

13. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Primary Pollutants Secondary Pollutants Sources Natural Stationary CO CO 2 SO 2 NO NO 2 Most hydrocarbons Most suspended particles SO 3 HNO 3 H 2 SO 4 H2O2H2O2H2O2H2O2 O3O3O3O3PANs Most andsalts NO 3 – Mobile SO 4 2–

14. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Human Impact on Atmosphere Burning Fossil Fuels Using Nitrogen fertilizers and burning fossil fuels Refining petroleum and burning fossil fuels Manufacturing  Adds CO 2 and O 3 to troposphere  Global Warming  Altering Climates  Produces Acid Rain  Releases NO, NO 2, N 2 O, and NH 3 into troposphere  Produces acid rain  Releases SO 2 into troposphere  Releases toxic heavy metals (Pb, Cd, and As) into troposphere www.dr4.cnrs.fr/gif-2000/ air/products.html

15. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nitrogen Dioxide (NO 2 ) Properties : reddish brown gas, formed as fuel burnt in car, strong oxidizing agent, forms Nitric acid in air Effects : acid rain, lung and heart problems, decreased visibility (yellow haze), suppresses plant growth Sources : fossil fuels combustion @ higher temperatures, power plants, forest fires, volcanoes, bacteria in soil Class : Nitrogen oxides (NO x ) EPA Standard : 0.053 ppm

16. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Air Pollution over China-The Asian Black Cloud

17. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Ozone (O 3 ) Properties : colorless, unpleasant odor, major part of photochemical smog Effects : lung irritant, damages plants, rubber, fabric, eyes, 0.1 ppm can lower PSN by 50%, Sources : Created by sunlight acting on NO x and VOC, photocopiers, cars, industry, gas vapors, chemical solvents, incomplete fuel combustion products Class : photochemical oxidants

18. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Ozone (O 3 ) 10,000 to 15,000 people in US admitted to hospitals each year due to ozone-related illness Children more susceptible -Airways narrower -More time spent outdoors

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20. Carbon Monoxide (CO) Properties : colorless, odorless, heavier than air, 0.0036% of atmosphere Effects : binds tighter to Hb than O 2, mental functions and visual acuity, even at low levels Sources: incomplete combustion of fossil fuels 60 - 95% from auto exhaust Class : carbon oxides (CO 2, CO) EPA Standard : 9 ppm 5.5 billion tons enter atmosphere/year

21. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Lead (Pb) Properties : grayish metal Effects : accumulates in tissue; affects kidneys, liver and nervous system (children most susceptible); mental retardation; possible carcinogen; 20% of inner city kids have [high] Sources : particulates, smelters, batteries Class : toxic or heavy metals EPA Standard : 1.5 ug/m 3 2 million tons enter atmosphere/year

22. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Suspended Particulate Matter (PM 10 ) Properties : particles suspended in air (<10 um) Effects : lung damage, mutagenic, carcinogenic, teratogenic Sources: burning coal or diesel, volcanoes, factories, unpaved roads, plowing, lint, pollen, spores, burning fields Class : SPM: dust, soot, asbestos, lead, PCBs, dioxins, pesticides EPA Standard : 50 ug/m 3 (annual mean)

23. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Sulfur Dioxide (SO 2 ) Properties : colorless gas with irritating odor Effects : produces acid rain (H 2 SO 4 ), breathing difficulties, eutrophication due to sulfate formation, lichen and moss are indicators Sources : burning high sulfur coal or oil, smelting or metals, paper manufacture Class : sulfur oxides EPA Standard : 0.3 ppm (annual mean) Combines with water and NH 4 to increase soil fertility

24. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings VOCs (Volatile Organic Compounds) Properties : organic compounds (hydrocarbons) that evaporate easily, usually aromatic Effects : eye and respiratory irritants; carcinogenic; liver, CNS, or kidney damage; damages plants; lowered visibility due to brown haze; global warming Sources: vehicles (largest source), evaporation of solvents or fossil fuels, aerosols, paint thinners, dry cleaning Class : HAPs (Hazardous Air Pollutants) -Methane -Benzene -Chlorofluorocarbons (CFCs), etc. Concentrations indoors up to 1000x outdoors 600 million tons of CFCs

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26. Other Air Pollutants Carbon dioxideCarbon dioxide ChloroFluoroCarbonsChloroFluoroCarbons FormaldehydeFormaldehyde BenzeneBenzene AsbestosAsbestos ManganeseManganese DioxinsDioxins CadmiumCadmium Others not yet fully characterizedOthers not yet fully characterized

27. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Formation & Intensity Factors Local climate (inversions, air pressure, temperature, humidity)Local climate (inversions, air pressure, temperature, humidity) Topography (hills and mountains)Topography (hills and mountains) Population densityPopulation density Amount of industryAmount of industry Fuels used by population and industry for heating, manufacturing, transportation, powerFuels used by population and industry for heating, manufacturing, transportation, power Weather: rain, snow,windWeather: rain, snow,wind Buildings (slow wind speed)Buildings (slow wind speed) Mass transit usedMass transit used EconomicsEconomics

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29. ...when polluted air is stagnant (weather conditions, geographic location) Los Angeles, CA Smog Forms

30. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Primary Pollutants Secondary Pollutants Sources Natural Stationary CO CO 2 SO 2 NO NO 2 Most hydrocarbons Most suspended particles SO 3 HNO 3 H 2 SO 4 H2O2H2O2H2O2H2O2 O3O3O3O3PANs Most andsalts NO 3 – Mobile SO 4 2–

31. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Photochemical Smog Primary Pollutants NO 2 + Hydrocarbons Auto Emissions UV radiation H 2 O + O 2 Secondary Pollutants HNO 3 O 3 nitric acidozone Photochemical Smog

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33. Air Pollution Results

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36. Six “criteria pollutants” Emissions of all of these, especially lead and carbon monoxide, have substantially declined since 1970.

37. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Volatile organic compounds “VOCs” are regulated by many governments. Large group of potentially harmful carbon- containing chemicals used in industrial processes. Hydrocarbons are one example. About half are human-made, half natural. VOCs contribute to smog, produce secondary pollutants.

38. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Toxic air pollutants Toxic air pollutants = chemicals known to cause serious health or environmental problems Include substances known to cause cancer and reproductive defects, and substantial ecological harm Most produced by human activities 188 toxic air pollutants are regulated under the 1990 Clean Air Act.

39. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Industrial smog Smog from industrial pollution, fossil-fuel combustion The kind that blanketed London in 1952 “Gray air smog” Contains soot, sulfur, CO, CO 2 …

40. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Industrial smog The U.S. had its own “killer smog” from industrial pollution. Shown is Donora, Pennsylvania, in 1948, at mid-day. Subsequent demand for legislation against pollution made U.S. air much cleaner.

41. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Industrial smog Chemistry of industrial smog: Burning sulfur-rich oil or coal creates SO 2, SO 3, sulfuric acid, ammonium sulfate. Carbon leads to CO 2 and CO.

42. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings The star pollutants mentioned are sulfur dioxide, nitrogen dioxide and particulates caused by an assortment of methods such as burning fossil fuels, bi products of power plants or even particles that include lead, dust ammonia and other harmful substances

43. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Photochemical smog Smog from reaction of sunlight with pollutants The kind that blankets so many American cities today “Brown air smog” Contains tropospheric ozone, NO 2, VOCs, 100 more… Hot sunny days in urban areas create perfect conditions.

44. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Photochemical smog Mexico City and many of the world’s cities suffer from the brownish haze of photochemical smog. Inversion layers and mountains can trap smog over certain cities.

45. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Chemistry of photochemical smog: Nitric oxide starts a chain reaction. Reaction with sunlight, water vapor, hydrocarbon, results in over 100 secondary pollutants. Photochemical smog

46. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stratospheric ozone depletion Ozone at low altitudes = beneficial layer protecting us from UV radiation Ozone layer— ~ 12 parts per million in lower stratosphere—is enough to absorb UV and protect us. But in the 1960s scientists noticed ozone concentrations were dropping. NASA Video on Ozone Hole

47. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stratospheric ozone depletion In 1974, Sherwood Rowland and Mario Molina pegged the blame on chlorofluorocarbons (CFCs). They won the Nobel Prize for this scientific detective work. CFCs = human-made molecules in which hydrogens of hydrocarbons are replaced by chlorine and fluorine atoms Mass-produced by industry, in refrigerants and consumer products like aerosol sprays

48. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stratospheric ozone depletion 1 Cl atom can split many O 3 molecules CFCs persist in the stratosphere. They split oxygen atoms off ozone (O 3 ) to form oxygen (O 2 ).

49. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stratospheric ozone depletion In 1985, the “ozone hole” was detected over Antarctica. Ozone levels had declined 40–60% over the previous decade.

50. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stratospheric ozone depletion Scientists worried about the effects of extra cancer-causing UV on people, organisms, ecosystems. The ozone hole (blue) reached its greatest extent in September 2000 (satellite imagery).

51. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stratospheric ozone depletion The Dobson spectrophotometer, invented in 1924, can infer ozone concentrations from the ground, and helped scientists detect ozone depletion.

52. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stratospheric ozone depletion In 1987, over 180 nations signed the Montreal Protocol, which restricted CFC production globally. Follow-up agreements strengthened the pact. Today CFC levels are down, and stratospheric ozone is starting to recover. The Montreal Protocol is one of the biggest environmental success stories of our time. We have apparently avoided a major environmental problem.

53. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stratospheric ozone depletion Reasons for success of the Montreal Protocol: Government and industry cooperated on finding solutions (cheap replacement technologies for CFCs), so battles typical to environmental debates were minimized. Protocol was implemented with “adaptive management”—ability to fine-tune actions as time goes on, in response to new data or conditions.

54. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Clean Air Act legislation Major air pollution legislation: Clean Air Act of 1970: Set stricter standards than previous laws Imposed emissions limits Provided research funds Enabled citizens to sue violating parties Clean Air Act of 1990: Strengthened previous regulations Introduced emissions trading for sulfur dioxide

55. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings