1. Air Pollution Outdoor Air Pollution

2. Stationary and Mobile Sources of Air Pollution Two Sources of Air Pollution 1. Stationary Sources: have a relatively fixed location Point Sources: Fugitive Sources: Area Sources: 2. Mobile Sources: move from place to place while emitting pollutants Ex) Airplanes

3. General Effects of Air Pollution Visual quality of the environment Vegetation, Animals, Soil Water Quality Natural and Artificial Structures Human Health

4. Primary and Secondary Pollutants, Natural and Human Primary Pollutants –Those emitted directly into the air –Hydrocarbons, particulates, etc. Secondary Pollutants –Produced through reactions between primary pollutants and normal atmospheric compounds –Ozone

5. Major Air Pollutants 1.Sulfur Dioxide (acid rain) 2.Nitrogen Dioxide / Nitrogen Oxide 3.Carbon Monoxide 4.Ozone and Other Photochemical Oxidants 5.Volatile Organic Compounds 6.Particulate Matter 7.Hydrogen Sulfide 8.Hydrogen Fluoride 9.Hazardous Gases 10.Lead

6. Outdoor Air Pollutants – 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

7. Outdoor Air Pollutants – 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, power plants, forest fires, volcanoes, bacteria in soil Class: Nitrogen oxides (NO x ) EPA Standard: 0.053 ppm

8. Outdoor Air Pollutants – Carbon Monoxide (CO) Properties: colorless, odorless, heavier than air, 0.0036% of atmosphere Effects: binds tighter to Hb than O 2 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

9. Outdoor Air Pollutants – Ozone (O 3 ) Properties: colorless, unpleasant odor, major part of photochemical smog Effects: lung irritant, damages plants, rubber, fabric, eyes, 0.1 ppm is unhealthy Sources: Created by sunlight acting on NO x and VOC, cars, industry, gas vapors, chemical solvents, fuel combustion products Class: photochemical oxidants

10. Outdoor Air Pollutants – 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)

11. Size of Selected Particulates

12. Total Suspended Particulates (TSP) for several large countries

13. Outdoor Air Pollutants – VOCs (Volatile Organic Compounds) Properties: organic compounds that evaporate easily, usually aromatic Effects: eye and respiratory irritants; carcinogenic; decreased visibility due to brown haze; liver, CNS, or kidney damage; damages plants Sources: evaporation of solvents or fuels, fossil fuels, plants (largest source), aerosols, paint thinners, dry cleaning Class: HAPs (Hazardous Air Pollutants) Concentrations indoors up to 1000x outdoors 600 million tons of CFCs

14. Outdoor Air Pollutants – 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

15. US Emissions of Six Major Air Pollutants Note that there have been significant reductions.

16. Urban Air Pollution Potential for Air Pollution Determined by: –Rate of emission –Downwind distance –Average wind speed –Elevation Atmospheric Inversion: –Occurs when warmer air is found above cooler air and it poses a particular problem when there is a stagnant air mass

17. Factors that influence Air Pollution formation and intensity Topography (hills and mountains) Local climate (inversions, air pressure, temperature, humidity) Population density Amount of industry Fuels used by population and industry for heating, manufacturing, transportation, power Weather: rain, snow,wind Buildings (slow wind speed) Mass transit used Economics

18. Smog –A mixture between smoke and fog that produces unhealthy urban air Two Types –Sulfurous Smog / Industrial Smog / Fossil Fuels –Photochemical Smog / Sunlight & Pollutants

19. Formation of Industrial Smog

20. ProcedureChemical Reaction 1. Carbon in coal or oil burned C + O 2 − CO 2 2C + O 2 − CO 2. Unburned carbon − sootC 3. Sulfur in oil and coal reacts with O 2 S + O 2 − SO 2

21. Formation of Industrial Smog ProcedureChemical Reaction 4. Sulfur dioxide reacts with O 2 to form sulfur trioxide 2SO 2 + O 2 − 2SO 3 5. Sulfur trioxide reacts with H 2 O SO 3 + H 2 O − H 2 SO 4 6. Sulfuric acid reacts with atmospheric ammonia to form brown, solid ammonium sulfate H 2 SO 4 + 2NH 3 − (NH 4 ) 2 SO 4

22. Formation of Photochemical Smog

23. TimeDescription 6 - 9 A.M.Morning commute increases NO x and VOCs N 2 + O 2 − 2 NO NO + VOC − ΝΟ 2 ΝΟ 2 − UV − ΝΟ + Ο 9 - 11 A.MAs traffic decreases NO x and VOCs react 2NO + O 2 − 2ΝΟ 2

24. TimeDescription 11 A.M. – 4 P.M. As sunlight becomes intense, NO 2 breaks down and Ozone increases ΝΟ 2 − UV − ΝΟ + Ο Ο 2 + Ο − Ο 3 Nitrogen dioxide also forms nitric acid 3ΝΟ 2 + Η 2 Ο − 2 Η 2 ΝΟ 3 + ΝΟ 11 A.M. – 4 P.M. Nitrogen dioxide also reacts with VOCs released by autos, industry, etc. ΝΟ 2 + VOCs − 2 PANs Peroyacyl nitrates (toxic) 4 P.M. - sunset As sun goes down the production of ozone halts Net Result: NO + VOC + O 2 + UV − O 3 + PAN

25. Pollution Control Particulates Automobiles Sulfur Dioxide –Coal Gasification: converts coal to gas to remove sulfur –Scrubbing: gas desulfurization

26. Air Pollution: Legislation and Standards Clean Air Act Amendments of 1990 –Comprehensive regulations enacted by U.S congress that address acid rain, toxic emissions, ozone depletion and automobile exhaust Air Quality Standards –Attempt to control air pollution Tougher Standards for PM 2.5 and Ozone Air Quality Index

27. Specific Air Pollution Treatment Technology Traditional –Move factory to remote location –Build taller smokestack so wind blows pollution elsewhere New –Biofiltration : vapors pumped through soil where microbes degrade –High-energy destruction: high-voltage electricity –Membrane separation: diffusion of organic vapors through membrane –Oxidation: High temperature combustor

28. New continued … –Vapor phase carbon absorption: gases pumped through series of carbon filled canisters which absorb contaminants –Electrostatic precipitators: Electrostatically charged surfaces attracts particles –Sulfur removal: mix crushed limestone with fuel –Nitrogen oxide control: staged burners or catalytic converters –Hydrocarbon control: closed system to prevent release before treatment with afterburners –Hybrid, electric and hydrogen powered vehicles Specific Air Pollution Treatment Technology Continued…

29. Air Pollution Indoor Air Pollution

30. Pathways, Processes and Driving Forces Chimney Effect (Stack Effect) –Process whereby warmer air rises in buildings to upper levels and is replaced in the lower portion of the building by outdoor air drawn through a variety of openings, such as windows doors or cracks in the foundation or walls

31. Sick Building Syndrome A condition associated with an indoor environment that appears to be unhealthy The symptoms people report cannot be traced to any one particular cause

32. Environmental Tobacco Smoke Secondhand smoke 2 sources –Smoke exhaled by smokers –Smoke emitted from burning tobacco The most hazardous indoor pollutant

33. Radon Gas Radon –Naturally occurring radioactive gas –Colorless, odorless, tasteless –Only identified through proper testing Health hazard when leaked into homes Exposure is associated with lung cancer

34. How Radon Enters Houses

35. Major Indoor Pollutants 1, 1, 1- Trichloroethane Aerosol spraysDizziness, breathing irregularities AsbestosPipe insulation, ceilings, floor tiles, oven mitts Lung Cancer and asbestosis Benzo −α− pyreneTobacco smoke, woodstoves Lung Cancer Carbon MonoxideFaulty furnaces, cigarette smoke Headache, heartbeat irregularities, death, CO has 250x affinity for Hb than O 2

36. ChloroformPulp and paper mills, water and wastewater plants Cancer FormaldehydePaneling, particle board, furniture, carpeting, adhesives Nausea, dizziness, irritation of throat, eyes, and lungs Methylene chloridePaint strippers and thinner – persistent Nerve disorders, diabetes Nitrogen oxidesFurnaces, stoves, fireplaces and vents Headaches, irritated lungs Para- dichlorobenzene Air fresheners, mothballsCancer Major Indoor Pollutants Continued…

37. http://www.metricmind.com/ac_honda/main.htm Radon – 22Soil and rock near house foundation, concrete Lung cancer StyreneCarpets, plastics,Kidney and liver damage Tetrachlor- ethylene Dry-cleaning fluidNerve disorders, damage to liver and kidneys, cancer Tobacco SmokeCigarettes and other smoking sources Lung cancer and heart disease Organic MaterialDust mites, fungal and algal spores, dust (human skin), animal dander, hair, carpet fibers, fur Allergies, coughs, sneezing, eye irritation, sore throats, difficulty breathing Major Indoor Pollutants Continued …