NGR302I Air Pollution. NGR302I Outdoor Air Pollution

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Transcript of NGR302I Air Pollution. NGR302I Outdoor Air Pollution

  • Air Pollution

  • Outdoor Air Pollution

  • Air PollutionSourcesTransportationStationary sourcesIndustrialIssuesGlobal warmingOzone depletionAcid rainPoisonsRemediesPreventionRemovalLegislative Issues

  • Air Pollution Index

  • Major Air Pollutants

  • Cars, Planes, TrainsAre 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.

  • Acid Rain

  • pH

  • Effect of pH on Fish PopulationsOnly a few marine species can survive when pH is smaller than 5.

  • Global warming

  • The Greenhouse Effect

  • 1995 UN ReportInternational Panel on Climate Change consisted of 2500 scientists reported: Unless there is a reduction in greenhouse emission, the Earths average temperature will increase by 2-6.5o F and the sea level will rise by 6 to 38 inches by the year 2100

  • SourcesCarbon dioxide (solid waste, fossil fuels) Methane (organic wastes, livestock)Nitrous oxide (agricultural and industrial activities, fossil fuels combustion)OzoneHydrofluorocarbons (HFCs), and sulfur hexafluoride (SF6) (industrial processes)

  • EffectivenessHFCs 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.

  • CO2 ProductionRate of CO2 production is acceleratingNote the seasonal variations

  • Vehicle Trend

  • Top Ten Producers of Greenhouse Gases

  • Effects of Global WarmingNo doubt that greenhouse gases are warming the planet, scientists might only agree on its degreeSulfur from volcanic eruptionsParticles from forest firesWarming effects are stronger than cooling effectsDoubling of CO2 emission will cause 4-9o F increase in the global temperature

  • Worst Case ScenarioPositive Feedback MechanismAs temperature goes up, oceans dissolve less carbon dioxideLess nutrient biomass (plankton)faster ozone depletion (more UV, less plankton)More wetlands releasing methaneHigher temperature

  • What can you doPurchase a more economy carInsulate your homeCarpoolRecycleUse more efficient appliancesPlant treesEducate others

  • Ozone Depletion

  • The ProblemIn 1990s ozone concentration in the upper atmosphere has been decreased by 4-5% over the previous three decadesSatellite 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.

  • OzoneWhat is Ozone?Molecules consist of 3 atoms of oxygen (O3) It is a secondary pollutantIt 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.

  • ConsequencesOne chlorine or bromine molecule can destroy 100,000 ozone molecules, causing ozone to disappear much faster than nature can replace it.

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

  • SourcesChlorofluorocarbons (CFCs), halons, and other ozone depleting substances CoolantsAerosolsFoaming agentsFire extinguishersSolvents

  • Ozone Destroying Chemicals

  • History1930 CFC First utilized1974 - US production increased to 800,000 tons per year1978 - US banned use of CFC 1982 Volcanic ash from eruption of El Chichon in Mexico depleted ozone concentration in mid latitude1985 - A team of British scientist discovered the ozone hole over Antarctica and Arctic1995 Crutzen, Molina, Rowland shared the Nobel Prize in Chemistry for understanding how ozone is formed and decomposed in the atmosphere

  • FormationKineticsCl + O3 Cl-O +O2Cl-O + O3 Cl + 2O2Repeat step a.Net reaction2O3 3O2

  • ConsequenceIncrease UV exposureUV-B causes aging of the skin, cancer and cataractsEstimated additional 12 million skin cancers within the next 50 years in the US aloneImpairs human immune systemsDamages UV sensitive crops (soybeans) Food ShortageDecreases 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

  • MythsSince 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)

  • Internet ResourcesState of Environments in Different Countries (http://www.unep.org/unep/soe.htm)

  • 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

  • Sources of Indoor Air Pollution

  • Sick Building SyndromeSBS 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 responsibleProblem more severe after 1970 Arab oil embargoBuilding codes require sufficient ventilation for large buildings. Similar codes do not exist for smaller commercial buildings and homes.

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

  • Safety LimitEPA 0.3 pCi/l (pico curie per liter)Compare with .2 pCi/l for average outdoor levels and 1 pCi/l for average indoor levelsImmediate action if above 200 rangeAction within years if between 4-20 rangeCould be considerably higher if there is a Radon problemRadon 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 USVery high correlation among smokers

  • Smoking2 million die of smoking related illnesses (cancer, emphysema, bronchitis, heart ailment) worldwide325,000 annual death toll in the US5000 die from second hand smokingIncreased health and insurance cost of 40-100 million dollarsFine particles, odor, and other carcinogenic materials are the main cause

  • AsbestosNaturally occurring minerals that can be separated into small-diameter fibersIt is chemically stable, and excellent thermal and electrical insulator3,000-12,000 persons die (in US) every year from mesothelomia (a form of lung cancer)

  • Asbestos safety1986 Asbestos Hazard and Emergency ActMandated the removal of asbestos-containing materials from schoolsThere are still in some old buildings in form of asbestos-filled vinyl floor tile, insulation on pipes and boilers, asphalt roofing shingles

  • Chemicals and SolventsChlorinated CompoundsTetrachloroethylene in dry cleaners, damage to liver and kidney1,1,1 Trichloroethane aerosol spray cans and propellant, nerve disorder and asthmaMethylene chloride Paint removers, softners, nerve disorder and diabetesChloroforms Hot shower water (from chlorine added to water), carcinogenicBenzene Ring-containing CompoundsStyrene and vinyl chloride plastics and carpets, kidney and liver damageBenzo-a-pyrene Wood and tobacco smoke, carcinogenic

  • Chemicals (Continued)FormaldehydesPlastics, adhesive resins, ENT irritant, nausea and dizzinessMicroorganismsVOC - Molds, bacteriasCO, NOx, and O3 (Usually associated with outdoor air pollutionsCO and NOx - Kerosene heaters, stovesOzone Copy machines

  • ControlVentilationExclusion and removalProduct SelectionMaintenance

  • ControlReference: Dubeck et al, A world View of environmental Issues, Saunders College Publishing, 2nd Ed. , 1998

  • RegulationsPractically nonexistentExcept 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)

  • RemedyMost common is litigation under Common LawOut of court settlementsState Workman Compensation

    NEED FEDERAL LEGISLATION

  • Internet ResourcesEPA (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)

    Magellan and Amelia Earhart were the famous circumnavigators of their day. Today every man is Magellan, every woman Amelia.Sulfur Volcanic eruptions produce a large amount of sulfur that will eventually reach the stratosphere1930s - Nontoxic,CFC was used instead of ammonia, because it was non explosive, nontoxic and inexpensive 1960s - CFC became major source of