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Air Pollution

Air Pollution. Outdoor Air Pollution. Air Pollution. Sources Transportation Stationary sources Industrial Issues Global warming Ozone depletion Acid rain Poisons Remedies Prevention Removal Legislative Issues. Air Pollution Index. Major Air Pollutants. Cars, Planes, Trains….

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Air Pollution

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  1. Air Pollution NGR302I

  2. Outdoor Air Pollution NGR302I

  3. Air Pollution • Sources • Transportation • Stationary sources • Industrial • Issues • Global warming • Ozone depletion • Acid rain • Poisons • Remedies • Prevention • Removal • Legislative Issues ENGR302I

  4. Air Pollution Index ENGR302I

  5. Major Air Pollutants ENGR302I

  6. Cars, Planes, Trains… • Are the major source of NOx, CO, CO2, HC and particulate. • In US, car/person ratio approaches 1. • During their lives, every American will drive and fly a million miles, equal to forty trips around the globe. • Worldwide, number of cars will exceed 1 billion in 2020; About one car for every seven man, woman, or child. • Efficiency is still low; 20% for ICE, 80% for the electricity (27% if electricity comes from fossil fuel); Hybrids can give 10-20% more gas mileage. ENGR302I

  7. Acid Rain NGR302I

  8. pH ENGR302I

  9. Effect of pH on Fish Populations • Only a few marine species can survive when pH is smaller than 5. ENGR302I

  10. Global warming NGR302I

  11. The Greenhouse Effect ENGR302I

  12. 1995 UN Report • International Panel on Climate Change consisted of 2500 scientists reported: “Unless there is a reduction in greenhouse emission, the Earth’s average temperature will increase by 2-6.5o F and the sea level will rise by 6 to 38 inches by the year 2100” ENGR302I

  13. Sources • Carbon dioxide (solid waste, fossil fuels) • Methane (organic wastes, livestock) • Nitrous oxide (agricultural and industrial activities, fossil fuels combustion) • Ozone • Hydrofluorocarbons (HFCs), and sulfur hexafluoride (SF6) (industrial processes) ENGR302I

  14. Effectiveness • HFCs are the most heat-absorbent. Methane traps over 20 times more heat per molecule than carbon dioxide, and nitrous oxide absorbs 200 times more heat per molecule than carbon dioxide. ENGR302I

  15. CO2 Production • Rate of CO2 production is accelerating • Note the seasonal variations ENGR302I

  16. Vehicle Trend ENGR302I

  17. Top Ten Producers of Greenhouse Gases ENGR302I

  18. Effects of Global Warming • No doubt that greenhouse gases are warming the planet, scientists might only agree on its degree • Sulfur from volcanic eruptions • Particles from forest fires • Warming effects are stronger than cooling effects • Doubling of CO2 emission will cause 4-9o F increase in the global temperature ENGR302I

  19. Worst Case Scenario • Positive Feedback Mechanism • As temperature goes up, oceans dissolve less carbon dioxide • Less nutrient biomass (plankton) • faster ozone depletion (more UV, less plankton) • More wetlands releasing methane • Higher temperature ENGR302I

  20. What can you do… • Purchase a more economy car • Insulate your home • Carpool • Recycle • Use more efficient appliances • Plant trees • Educate others ENGR302I

  21. Ozone Depletion NGR302I

  22. The Problem • In 1990’s ozone concentration in the upper atmosphere has been decreased by 4-5% over the previous three decades • Satellite observations indicate a world-wide thinning of the protective ozone layer. The most noticeable losses occur over the North and South Poles because ozone depletion accelerates in extremely cold weather conditions. ENGR302I

  23. Ozone • What is Ozone? • Molecules consist of 3 atoms of oxygen (O3) • It is a “secondary pollutant” • It is not emitted directly into the air, but at ground level is created by a chemical reaction between oxides of nitrogen (NOx), and volatile organic compounds (VOC) in the presence of sunlight. ENGR302I

  24. One chlorine or bromine molecule can destroy 100,000 ozone molecules, causing ozone to disappear much faster than nature can replace it. Consequences ENGR302I

  25. Good in Upper Atmosphere (Blocks 99% of the Sun’ ultraviolet radiation) Bad in Lower atmosphere (health hazard to human, environment, and crops) Good Ozone and Bad Ozone ENGR302I

  26. Chlorofluorocarbons (CFCs), halons, and other ozone depleting substances Coolants Aerosols Foaming agents Fire extinguishers Solvents Sources ENGR302I

  27. Ozone Destroying Chemicals ENGR302I

  28. 1930 – CFC First utilized 1974 - US production increased to 800,000 tons per year 1978 - US banned use of CFC 1982 – Volcanic ash from eruption of El Chichon in Mexico depleted ozone concentration in mid latitude 1985 - A team of British scientist discovered the ozone hole over Antarctica and Arctic 1995 – Crutzen, Molina, Rowland shared the Nobel Prize in Chemistry for understanding how ozone is formed and decomposed in the atmosphere History ENGR302I

  29. Kinetics Cl + O3 Cl-O +O2 Cl-O + O3  Cl + 2O2 Repeat step a. Net reaction 2O33O2 Formation ENGR302I

  30. Consequence • Increase UV exposure • UV-B causes aging of the skin, cancer and cataracts • Estimated additional 12 million skin cancers within the next 50 years in the US alone • Impairs human immune systems • Damages UV sensitive crops (soybeans) • Food Shortage • Decreases the photoplankton (a plant that grows in the ocean) • Because plants "breathe in" carbon dioxide and "breathe out" oxygen, carbon dioxide levels in the air could also increase. • Floods and Drought ENGR302I

  31. Myths • Since CFCs are heavier than air, CFC will sink back to lower atmosphere. • It is because of the volcanoes (HCl) and ocean (NaCl) that ozone are depleted. • Depletion is only over Antarctica (and to a lower extent over Arctic) ENGR302I

  32. Internet Resources • State of Environments in Different Countries(http://www.unep.org/unep/soe.htm) ENGR302I

  33. Indoor Air Pollution Average person stays 90% of his time indoors Energy conservancy projects have exacerbated this problem Common sources of indoor air pollution are: Cigarette and tobacco smoke Paints, lead and other construction material Stoves, refrigerators and other appliances cleaners and chemicals Pesticides Soil Drinking Water NGR302I

  34. Sources of Indoor Air Pollution ENGR302I

  35. Sick Building Syndrome • SBS is usually referred to office or residential buildings in which occupants experience a large increase of dizziness, nausea, headaches, sore throat, etc. • EPA estimates that 20 to 30% of all US buildings are sick. • Appliances, carpeting, building materials are mostly responsible • Problem more severe after 1970 Arab oil embargo • Building codes require sufficient ventilation for large buildings. Similar codes do not exist for smaller commercial buildings and homes. ENGR302I

  36. Radon (Rn-222) • Chemically inert • Naturally occurring, radioactive material dispersed through rocks and soil In homes mostly through basements, faucet showerhead, and walls • Mostly from radioactive decay of U-238, U-235, and Th-232 Emits gamma rays, and alpha particles with eventual decay to stable lead • Once inside quickly decays (T1/2=3.8 days) to lead, bismuth and deposits on solid surfaces within the home ENGR302I

  37. Safety Limit • EPA – 0.3 pCi/l (pico curie per liter) • Compare with .2 pCi/l for average outdoor levels and 1 pCi/l for average indoor levels • Immediate action if above 200 range • Action within years if between 4-20 range • Could be considerably higher if there is a Radon problem • Radon releases alpha particle ( some will be deposited in the lung as we breathe) • 20,000 cases of lung cancer per year attributed to radon in US • Very high correlation among smokers ENGR302I

  38. Smoking • 2 million die of smoking related illnesses (cancer, emphysema, bronchitis, heart ailment) worldwide • 325,000 annual death toll in the US • 5000 die from second hand smoking • Increased health and insurance cost of 40-100 million dollars • Fine particles, odor, and other carcinogenic materials are the main cause ENGR302I

  39. Asbestos • Naturally occurring minerals that can be separated into small-diameter fibers • It is chemically stable, and excellent thermal and electrical insulator • 3,000-12,000 persons die (in US) every year from mesothelomia (a form of lung cancer) ENGR302I

  40. Asbestos safety • 1986 – Asbestos Hazard and Emergency Act • Mandated the removal of asbestos-containing materials from schools • There are still in some old buildings in form of asbestos-filled vinyl floor tile, insulation on pipes and boilers, asphalt roofing shingles ENGR302I

  41. Chemicals and Solvents • Chlorinated Compounds • Tetrachloroethylene – in dry cleaners, damage to liver and kidney • 1,1,1 Trichloroethane – aerosol spray cans and propellant, nerve disorder and asthma • Methylene chloride – Paint removers, softners, nerve disorder and diabetes • Chloroforms – Hot shower water (from chlorine added to water), carcinogenic • Benzene Ring-containing Compounds • Styrene and vinyl chloride – plastics and carpets, kidney and liver damage • Benzo-a-pyrene – Wood and tobacco smoke, carcinogenic ENGR302I

  42. Chemicals (Continued) • Formaldehydes • Plastics, adhesive resins, ENT irritant, nausea and dizziness • Microorganisms • VOC - Molds, bacterias • CO, NOx, and O3 (Usually associated with outdoor air pollutions • CO and NOx - Kerosene heaters, stoves • Ozone – Copy machines ENGR302I

  43. Control • Ventilation • Exclusion and removal • Product Selection • Maintenance ENGR302I

  44. Control Reference: Dubeck et al, “A world View of environmental Issues”, Saunders College Publishing, 2nd Ed. , 1998 ENGR302I

  45. Regulations • Practically nonexistent • Except for radon, asbestos, CFC, and tobacco smokes (state level) • 1993: Indoor Air Quality Act (passed by senate but not acted by the House) • Voluntary Standards (industry specific) • EPA (Outdoor only) • TSCA (Chemical Substances) • OSHA (Significant Risk in the Workplace) • CPSA (Consumer products) ENGR302I

  46. Remedy • Most common is litigation under Common Law • Out of court settlements • State Workman Compensation NEED FEDERAL LEGISLATION ENGR302I

  47. Internet Resources • EPA (http://www.epa.gov/iaq/pubs/targetng.html) • OSHA (www.osha.gov) • World Health Organization (WHO) (www.who.ch) • State of Environments in Different Countries(http://www.unep.org/unep/soe.htm) ENGR302I

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