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Urban Air Quality

Urban Air Quality. Urban Air Quality. Gaseous Composition of the Atmosphere. Urban Air Quality. Sources of Urban Air Pollutants Stationary Sources Mobile Sources Non-Point (Area). Urban Air Quality. Types of Urban Air Pollutants

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Urban Air Quality

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  1. Urban Air Quality

  2. Urban Air Quality • Gaseous Composition of the Atmosphere

  3. Urban Air Quality • Sources of Urban Air Pollutants • Stationary Sources • Mobile Sources • Non-Point (Area)

  4. Urban Air Quality • Types of Urban Air Pollutants • Primary Pollutant - a pollutant that directly enters the air as a result of natural events or human activities

  5. Urban Air Quality • Types of Urban Air Pollutants • Examples of Primary Pollutants • Carbon monoxide (CO) • Carbon dioxide (CO2) • Sulfur dioxide (SO2) • Nitric oxide (NO) • Hydrocarbons (HCs) • Suspended Particulate Matter (SPMs)

  6. Urban Air Quality • Types of Urban Air Pollutants • Secondary Pollutant - a pollutant that is formed in the air through chemical reactions between or among primary pollutants or between primary pollutants and other gases in the atmosphere

  7. Urban Air Quality • Types of Urban Air Pollutants • Examples of Secondary Pollutants • Nitrogen Dioxide (NO2) • Sulfur Trioxide (SO3) • Nitric Acid (HNO3) • Hydrogen Peroxide (H2O2) • Tropospheric Ozone (O3) • Nitrate (NO3) • Peroxyacetyl Nitrates (PANs)

  8. Urban Air Quality • Chemical Classes of Urban Air Pollutants • Carbon Oxides • CO • CO2 • Sulfur Oxides • SO • SO2

  9. Urban Air Quality • Chemical Classes of Urban Air Pollutants • Nitrogen Oxides • NO (nitric oxide) • NO2 (nitrogen dioxide) • N2O (nitrous oxide - “laughing gas!”) • Sulfur Oxides • SO2 (sulfur dioxide) • SO3 (sulfur trioxide)

  10. Urban Air Quality • Chemical Classes of Urban Air Pollutants • Volatile Organic Compounds (VOCs) • CH4 (methane) • C6H6 (benzene) • CFCs (chlorofluorohydrocarbons) • CH20 (formaldehydr)

  11. Urban Air Quality • Chemical Classes of Urban Air Pollutants • Suspended Particulate Matter (SPMs) • Dust • Soot • Asbestos • Pollen

  12. Urban Air Quality • Chemical Classes of Urban Air Pollutants • Photochemical Oxidants • O3 (tropospheric ozone) • H2O2 (hydrogen peroxide) • PANs (peroxyacetylnitrates)

  13. Urban Air Quality • Chemical Classes of Urban Air Pollutants • Radioactive Substances • Rn222 (Radon) • Toxic Metals • Pb - Lead • Cd - Cadmium • Hg - Mercury • Ar - Arsenic

  14. Urban Air Quality • Regulation of Urban Air Pollution • Clean Air Acts • Passed in 1970, 1977, 1990 • Enacted federal air pollution regulations that are enforced by each state • Established National Ambient Air Quality Standards (NAAQS)

  15. Urban Air Quality • Regulation of Urban Aair Pollution • NAAQS • 7 Criteria Pollutants • SPMs • Sulfur Oxides • Carbon Monoxide • Nitrogen Oxides • Tropospheric Ozone • VOCs • Lead

  16. Urban Air Quality • Regulation of Urban Aair Pollution • NAAQS • Primary NAAQS - standards established to protect human health • Secondary NAAQS - standards established to protect all organisms • Nonattainment Area - any area that does not meet primary or secondary NAAQS for a criteria pollutant

  17. Urban Air Quality National Ambient Air Quality Standards Carbon Monoxide 9 ppm over 8-hr period, not to be exceeded more than once a year; 35-ppm for 1-hr period Ozone 0.12 ppm for 1-hr period, not to be exceeded more than once per year

  18. Urban Air Quality National Ambient Air Quality Standards Sulfur Dioxide 0.03 ppm annual average; 0.14 ppm for 24-hr period, not to be exceeded more than once per year Nitrogen Oxides 0.05 ppm annual average

  19. Urban Air Quality • Regulation of Urban Air Pollution • Criteria Pollutants • Tropospheric Ozone • Source: Chemical reactions between VOCs, nitrogen oxides, and sunlight • Health Effects: Reduced lung function; asthma; congestion • Environmental Impacts: Reduced visibility; plant damage, reduced photosynthesis and nutrient uptake, crop destruction; forest diebacks • Property Damage: Rubber; plastics

  20. Urban Air Quality • Regulation of Urban Air Pollution • Criteria Pollutants • Carbon Monoxide • Source: Incomplete combustion of fossil fuels • Health Effects: Reduced oxygen levels; impaired visual perception; reduced lung function; asthma; congestion • Environmental Impacts: Reduced visibility; plant damage • Property Damage: Rubber; plastics

  21. Urban Air Quality • Regulation of Urban Air Pollution • Criteria Pollutants • Nitrogen and Sulfur Oxides • Source: Incomplete combustion of fossil fuels • Health Effects: Lung damage; respiratory illnesses • Environmental Impacts: Acid deposition; plant damage; photochemical smog; crop destruction • Property Damage: Enhanced chemical weathering

  22. Urban Air Quality • Regulation of Urban Air Pollution • Criteria Pollutants • SPMs • Source: Incomplete combustion of fossil fuels; agriculture; unpaved roads • Health Effects: Lung damage; respiratory illnesses • Environmental Impacts: Reduced visibility (haze • Property Damage: Discoloration of clothing and structures

  23. Urban Air Quality • Regulation of Urban Air Pollution • Criteria Pollutants • Lead • Source: Leaded gasoline; lead paint; smelters; lead-acid batteries • Health Effects: Damage to nervous system; cancer; mental retardation; digestive disorders • Environmental Impacts: Harmful to wildlife

  24. Urban Air Quality • Photochemical (Brown-Air) Smog • A mixture of primary and secondary pollutants (mostly tropospheric ozone) formed under the influence of sunlight

  25. Urban Air Quality • Photochemical (Brown Air) Smog • Factors of Formation • Topography • Local climate • Population density • Amount of industry • Industrial fuel types

  26. Urban Air Quality • Photochemical (Brown Air) Smog • Factors of Formation • Topography • Hills and mountains reduce air flow in valleys and allow pollutant levels to build up at ground level • Buildings in cities slow wind speed, reducing dilution and dispersal of pollutants

  27. Urban Air Quality • Photochemical (Brown Air) Smog • Factors of Formation • Topography • Thermal Inversion • Sunny climate • Light winds • Mountains on three sides, ocean on the other • High population density • High motor vehicle usage • High industrialization using fossil fuels

  28. Urban Air Quality • Photochemical (Brown Air) Smog • Factors of Formation • Topography • Los Angeles Basin • Hemmed in by mountains on 3 sides and ocean on the other • 14 million people; 23 million motor vehicles • Frequent thermal inversions • Air pollution capital of U.S.

  29. Urban Air Quality • Photochemical (Brown Air) Smog • Factors of Formation • Local Climate • Areas with high average annual precipitation and wind speeds have less smog due to dilution and dispersal

  30. Urban Air Quality • Industrial (Gray-Air) Smog • Mixture of sulfur dioxide, suspended droplets of sulfuric acid, and SPMs • Found mostly in LDCs where coal and heavy oils are burned • China • Ukraine • Eastern Europe

  31. Urban Air Quality • Acid Deposition • The falling of acids and acid-forming compounds from the atmosphere to the Earth’s surface

  32. Urban Air Quality • Acid Deposition • Components • Primary Pollutants • Nitrogen Oxides (NOx) • Sulfur Oxides (SOx) Secondary Pollutants • Nitric Acid (HNO3) • Sulfuric Acid (H2SO4)

  33. Urban Air Quality • Acid Deposition • Acid Sources • Coal-burning power plants • Smelters • Factors • Urban areas

  34. Urban Air Quality • Acid Deposition • Mechanisms of Acid Deposition • Dry Deposition • Precipitation

  35. Urban Air Quality • Acid Deposition • Environmental Impacts of Acid Deposition • Regional environmental problem because acids remain in atmosphere for only a few days • Environmental impacts depend on buffering capacity of soils

  36. Urban Air Quality • Acid Deposition • Environmental Impacts of Acid Deposition • Ecosystems most harmed by acid deposition are those with thin soils that lack natural buffering

  37. Urban Air Quality • Acid Deposition • Environmental Impacts of Acid Deposition • Damage to materials • Statues • Buildings • Metals • Car finishes

  38. Urban Air Quality • Acid Deposition • Environmental Impacts of Acid Deposition • Human Health • Bronchitis • Asthma

  39. Urban Air Quality • Acid Deposition • Environmental Impacts of Acid Deposition • Aquatic Ecosystems • Acid Shock • Aluminum toxicity • Stimulates excessive mucus formation leading to asphyxiation of fish by clogging their gills

  40. Urban Air Quality • Acid Deposition • Environmental Impacts of Acid Deposition • Aquatic Ecosystems • Formation of methylmercury • Highly toxic • Soluble in fatty tissue of animals • Bioaccumulation

  41. Urban Air Quality • Acid Deposition • Environmental Impacts of Acid Deposition • Aquatic Ecosystems • Fun Facts • 16,000 lakes in Norway and Sweden contain no fish • 9,000 lakes in U.S. are threatened with excess acidity (most in the Great Lakes!)

  42. Urban Air Quality • Acid Deposition • Environmental Impacts of Acid Deposition • Terrestrial Ecosystems • Most damage when pH < 5.1 • Damage to tree foliage bathed in acidic fog

  43. Urban Air Quality • Acid Deposition • Environmental Impacts of Acid Deposition • Terrestrial Ecosystems • Increased susceptibility to various stressors • Cold temperatures • Diseases • Insects • Drought • Depletion of plant nutrients

  44. Urban Air Quality • Urban Climate • Cities are generally warmer, rainier, foggier, and cloudier than suburbs or rural areas

  45. Urban Air Quality • Urban Climate • Cities generate enormous amounts of heat • Automobiles • Factories • Furnaces • Lights • Air conditioners • People

  46. Urban Air Quality • Urban Climate • Urban Heat Island - the buildup of heat in the atmosphere above an urban area

  47. Urban Air Quality • Indoor Air Pollution • Sources • Combustion • Building materials and furnishings • Household cleaning products • Personal care products • Central heating/cooling systems • Outside sources - radon gas and pesticides • Poor ventilation

  48. Urban Air Quality • Indoor Air Pollution • Most Dangerous Indoor Air Pollutants • Formaldehyde • Asbestos • Cigarette smoke • Radon-222 • Fiberglass

  49. Urban Air Quality • Indoor Air Pollution • Leading cause of cancer • High-risk health problem for humans • “Sick Building Syndrome” • Coughing • Sneezing • Nausea • Burning eyes • Flulike symptoms

  50. Urban Air Quality • Indoor Air Pollution • “Sick Building Syndrome” • 17% of all buildings in U.S. are “sick”, including the U.S. EPA headquarters in Washington, DC • Mineral fibers falling from ceiling tiles are main culprit

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