Air pollution


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Air pollution

  1. 1. Air Pollution
  2. 2. Thought of the DayDo unto others as you wouldhave them do unto you…Hazrat Isa (A.S)Air Pollution 2
  3. 3. Air PollutionThe presence in the atmosphere of one or moreair contaminants in sufficient quantities and ofsuch characteristics and duration as to beinjurious to human, plant, or animal life, tohealth, or to property, or to unreasonablyinterfere with the enjoyment of life or propertyAir Pollution 3
  4. 4. The AtmosphereAir Pollution 4
  5. 5. Composition of the AtmosphereAir Pollution 5
  6. 6. Air PollutantAn air pollutant can beconsidered as a substancein the air that, in highenoughconcentrations, producesa detrimentalenvironmental effectAir Pollution 6
  7. 7. Environmental EffectAn environmental effectis defined as a measurableor perceivable detrimentalchange resulting fromcontact with an airpollutantAir Pollution 7
  8. 8. Ambient AirAmbient air is the air towhich the general publichas access, i.e. anyunconfined portion of theatmosphereAmbient concentrationThe appropriately timeaveraged concentration ofa substance at a locationto which the generalpublic has accessAir Pollution 8
  9. 9. Air PollutantsThe two basic physicalforms of air pollutants areParticulate MatterGasesCarbon Monoxide (CO)Sulfur Dioxide (SO2)Nitrogen Dioxides (NO2)Volatile Organic Compounds(VOCs)Air Pollution 9
  10. 10. Particulate Matter• A criteria air pollutant• Particulate matter includes dust, soot, andother tiny bits of solid materials that arereleased into and move around in the air• Particulates are produced by manysources• burning of diesel fuels by trucks and buses• incineration of garbage• mixing and application of fertilizers andpesticides• road construction• industrial processes such as steelmaking, mining operations• agricultural burning (field and slashburning)• fireplaces and woodstoves• Particulate pollution cancause eye, nose, andthroat initiation and otherhealth problemsAir Pollution 10
  11. 11. Particulate MatterAir Pollution 11
  12. 12. Relative Size of ParticlesAir Pollution 12
  13. 13. PM 10, 2.5, 0.1Air Pollution 13
  14. 14. Types and Sources of Air PollutionA primary pollutant is one thatis emitted into the atmospheredirectly from the source of thepollutant and retains the samechemical formA secondary pollutant is onethat is formed by atmosphericreactions of precursor orprimary emissions. Secondarypollutants undergo a chemicalchange once they reach theatmosphereAir Pollution 14
  15. 15. Natural Sources (Biogenic)VolcanoesWind StormsSand StormsForest FiresPollenNatural DecompositionNatural RadioactivityAir Pollution 15
  16. 16. Dust Storm over Southwestern Asia• The Moderate ResolutionImaging Spectroradiometer(MODIS) on NASA’s Terrasatellite captured thisnatural-color image onMarch 20, 2012Air Pollution 16
  17. 17. Man Made Sources(Anthropogenic)Mobile SourcesAutomobilesTrainsAero planesStationary Sources (NonMoving Sources)Power PlantsIndustrial FacilitiesAir Pollution 17
  18. 18. Criteria PollutantsThe criteria pollutants areCarbon Monoxide (CO)Sulfur Oxides (SOx)Nitrogen Oxides (NOx)Ozone (O3)Lead (Pb)Particulate Matter (PM)Air Pollution 18
  19. 19. Carbon Monoxide (CO)• Carbon monoxide (CO) is acolorless, odorless, poisonous gas• slightly lighter than air• produced through the incompletecombustion of carbon• operations of internal combustionengines, such as automobiles• CO enters the bloodstream andreduces the delivery of oxygen to thebody’s organs and tissues• most serious for people withcardiovascular disease• Exposures to elevated carbonmonoxide concentrations areassociated with impairment of visualperception, work capacity, manualdexterity, learning ability, andperformance of complex tasksAir Pollution 19
  20. 20. Sulfur dioxide (SO2)• Sulfur dioxide (SO2) is acorrosive, poisonous gas• produced in power plants, particularly usehigh-sulfur coal as a fuel• SO2 and oxides of nitrogen after beingreleased into the atmosphere, can bechemically converted into sulfates andnitrates• may later be deposited on the ground inthe form of so-called acid rain or snow• At high concentrations, SO2 affectsbreathing and produces respiratory illness• alterations in the defenses of the lungs• aggravation of existing respiratory andcardiovascular disease• Sulfur dioxide can also produce damageon trees and agricultural cropsAir Pollution 20
  21. 21. Nitrogen Dioxide (NO2)• Nitrogen dioxide (NO2) is produced whenfuels are burned at high temperatures• main sources are transportation vehiclesand power plants• NO and NO2 are inhaled, they can irritatethe lungs and lower resistance torespiratory infections such as influenza• continued or frequent exposure to highconcentrations causes increased incidenceof acute respiratory disease in children• Nitrogen oxides are also an importantprecursor of both ozone and acidicprecipitation• may affect both terrestrial and aquaticecosystems• limit for nitrogen dioxide is also designedto support the limit for ozoneAir Pollution 21
  22. 22. Ozone (O3)• Ozone (O3) is formed in the atmosphere asa result of chemical reactions betweenoxides of nitrogen and volatile organiccompounds, such as hydrocarbons (HCs)• If inhaled, damages lung tissue• reduces lung function• sensitizes the lungs to other irritants• Scientific evidence indicates that ambientlevels of ozone not only affect people withimpaired respiratory systems, such asasthmatics, but healthy adults andchildren• Specific effects, particularly at elevatedconcentrations, include eye and lungirritation• Ozone is also responsible for severalbillion dollars of agricultural crop loss inthe United States each year.Air Pollution 22
  23. 23. Lead (Pb)• Lead (Pb) is a heavy, comparativelysoft metal used as an additive togasoline• household paint• shotgun pellets• stained-glass windows• When taken into the body, itaccumulates in the blood, bones, andsoft tissues• Because it is not readily excreted, italso affects the kidneys, liver, nervoussystem, and blood-forming organs• Excess exposure may causeneurological impairments such asseizures, mental retardation, and/orbehavioral disorders.Air Pollution 23
  24. 24. Particulate Matter• Particulates are solids or liquidsproduced by the combustion offuel in stationary power plants• diesel-powered vehicles• various industrial processes• produced by plowing and burningof agricultural fields• If particulates are inhaled, theycan lead to respiratory symptoms• aggravate existing respiratory• cardiovascular disease• alter the defenses of the bodyagainst foreign materials, damagelung tissue, and produce latentcancers and premature mortality.Air Pollution 24
  25. 25. National Primary US Air QualityStandardsAir Pollution 25
  26. 26. Table 1: Sources, Health and Welfare Effects for Criteria Pollutants.Pollutant Description Sources Health Effects Welfare EffectsCarbon Monoxide (CO) Colorless, odorless gas Motor vehicle exhaust,indoor sources includekerosene or wood burningstoves.Headaches, reducedmental alertness, heartattack, cardiovasculardiseases, impaired fetaldevelopment, death.Contribute to theformation of smog.Sulfur Dioxide (SO2) Colorless gas thatdissolves in water vaporto form acid, and interactwith other gases andparticles in the air.Coal-fired power plants,petroleum refineries,manufacture of sulfuricacid and smelting of orescontaining sulfur.Eye irritation, wheezing,chest tightness, shortnessof breath, lung damage.Contribute to theformation of acid rain,visibility impairment,plant and water damage,aesthetic damage.Nitrogen Dioxide (NO2) Reddish brown, highlyreactive gas.Motor vehicles, electricutilities, and otherindustrial, commercial,and residential sourcesthat burn fuels.Susceptibility torespiratory infections,irritation of the lung andrespiratory symptoms(e.g., cough, chest pain,difficulty breathing).Contribute to theformation of smog, acidrain, water qualitydeterioration, globalwarming, and visibilityimpairment.Ozone (O3) Gaseous pollutant when itis formed in thetroposphere.Vehicle exhaust andcertain otherfumes. Formed fromother air pollutants in thepresence of sunlight.Eye and throat irritation,coughing, respiratorytract problems, asthma,lung damage.Plant and ecosystemdamage.Lead (Pb) Metallic element Metal refineries, leadsmelters, batterymanufacturers, iron andsteel producers.Anemia, high bloodpressure, brain and kidneydamage, neurologicaldisorders, cancer, loweredIQ.Affects animals andplants, affects aquaticecosystems.Particulate Matter (PM) Very small particles ofsoot, dust, or other matter,including tiny droplets ofliquids.Diesel engines, powerplants, industries,windblown dust, woodstoves.Eye irritation, asthma,bronchitis, lung damage,cancer, heavy metalpoisoning, cardiovasculareffects.Visibility impairment,atmospheric deposition,aesthetic damage.Air Pollution 26
  27. 27. Perfect CombustionAir Pollution 27
  28. 28. Incomplete CombustionAir Pollution 28
  29. 29. EmissionsAir Pollution 29
  30. 30. Anthropogenic Sources(Man-Made Sources)• Mobile Sources• On-Road Sources• Non-Road Sources• Stationary Sources• Point Source• Area SourceAir Pollution 30
  31. 31. Mobiles Sources• Responsible for more thanhalf of the air pollution• cars are primary source• vehicles produce 75-90% lesspollution for each mile driventhan their 1970 counterpart• no. of vehicles have increasedimmensely• Mobile Sources Pollutants• 45% VOC emissions• 50% NOx emissions• 60% CO emissions• 50% hazardous air pollutantsin urban airAir Pollution 31
  32. 32. Mobile SourcesAir Pollution 32
  33. 33. Air Quality Index• The Air Quality Index(AQI), also known as theAir Pollution Index (API)or Pollutant StandardIndex (PSI) is an indexfor reporting daily airqualityAir Pollution 33
  34. 34. How does the AQI work?• Think of the AQI as ayardstick that runs from 0 to500. The higher the AQIvalue, the greater the levelof air pollution and thegreater the health concern• An AQI value of 100generally corresponds tothe national air qualitystandard for thepollutant, which is the levelEPA has set to protect publichealthAir Pollution 34
  35. 35. Air Pollution 35Air Quality IndexLevels of Health ConcernNumericalValueMeaningGood 0-50Air quality is considered satisfactory,and air pollution poses little or no risk.Moderate 51-100Air quality is acceptable; however, forsome pollutants there may be amoderate health concern for a verysmall number of people who areunusually sensitive to air pollution.Unhealthy forSensitive Groups101-150Members of sensitive groups mayexperience health effects. The generalpublic is not likely to be affected.Unhealthy 151-200Everyone may begin to experiencehealth effects; members of sensitivegroups may experience more serioushealth effects.Very Unhealthy 201-300Health alert: everyone may experiencemore serious health effects.Hazardous > 300Health warnings of emergencyconditions. The entire population ismore likely to be affected.
  36. 36. Air Pollution 36
  37. 37. Green House GasesAir Pollution 37Carbon DioxideWater VaporsMethaneNitrous OxideChlorofloro Carbons CFCsOzone
  38. 38. Acid Rain / Acid Deposition• Acid deposition occurs whenemissions of sulfur dioxide andnitrogen oxides in the atmospherereact with water, oxygen, andoxidants to form acidic compounds• These compounds fall to the earth ineither dry form (gas and particles)known as Dry Deposition or wetform (rain, snow, and fog) known asWet DepositionDuration of the reaction• It takes days or weeks foratmospheric SOx and NOx to beconverted to acids and deposited onthe earths surface, acid depositionoccurs in a multistate scale hundredsof miles away from its sourcesAir Pollution 38
  39. 39. World Health Day 2012Air Pollution 39
  40. 40. Thank YouAir Pollution 40
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