1. Air and Air Pollution

2. The Atmosphere Stratosphere Stratosphere – 11-30 miles – Little water vapor – Ozone layer UV filter UV filter Troposphere Troposphere – 11 mile at equator; 8 miles at poles – weather breeder – 78% N, 21% O – Natural heating Solar radiation Solar radiation Greenhouse effect Greenhouse effect

3. The Atmosphere Exosphere Exosphere Thermosphere Thermosphere – ionosphere – aurorea borialis – hottest layer 1000 C 1000 C Mesosphere Mesosphere – very little atmosphere – coldest layer

4. Atmospheric pressure (millibars) 02004006008001,000 120 110 100 90 80 70 60 50 40 30 20 10 0 (SeaLevel) –80–4004080120 Pressure = 1,000 millibars at ground level Temperature (˚C) Altitude (kilometers) Altitude (miles) 75 65 55 45 35 25 15 5 Thermosphere Heating via ozone Mesosphere Stratosphere Ozone “layer” Heating from the earth TroposphereTemperature Pressure Mesopause Stratopause Tropopause

5. Altitude (kilometers) Ozone concentration (ppm) Altitude (miles) Stratospheric ozone Stratosphere Troposphere 40 35 30 25 20 15 10 5 0 05 1520 0 5 10 15 20 25 Photochemical ozone Benefical Ozone Harmful Ozone

6. Air Pollution introduction of chemicals, particulate matter, or microorganisms into the atmosphere at concentrations high enough to harm plants, animals, and materials such as buildings, or to alter ecosystems. the presence of one or more chemicals in the atmosphere in sufficient quantities and duration to (1) cause harm to us, other forms of life, and materials, or (2) alter climate.

7. Major Classes of Air Pollutants Carbon oxides Carbon oxides – Carbon monoxide and carbon dioxide Sulfur oxides Sulfur oxides – Sulfur dioxide and sulfur trioxide Nitrogen Oxides Nitrogen Oxides – Nitric oxide, nitrogen dioxide, nitrous oxide Volatile Organic Compounds Volatile Organic Compounds – Methane, propane, CFCs Photochemical Oxidants Photochemical Oxidants – Ozone, peroxyacal nitrates (PAN), hydrogen peroxide (H 2 O 2 ) Suspended particulate matter (SPM) Suspended particulate matter (SPM) – Dust, soot, asbestos, lead, nitrate, and sulfate salts – Sulfuric acid, PCBs, dioxins, pesticides Radioactive substances Radioactive substances – Radon-222, iodine-131, strontium-90, plutonium-239 Hazardous Air Pollutants (HAPS) Hazardous Air Pollutants (HAPS)

8. Criteria Air Pollutants Identified by the Clean Air Act 1970 EPA uses six "criteria pollutants" as indicators of air quality 1.Nitrogen Dioxide: NO 2 2.Ozone: ground level O 3 3.Carbon monoxide: CO 4.Lead: Pb 5.Particulate Matter: PM 10 (PM 2.5) 6.Sulfur Dioxide: SO 2 Volatile Organic Compounds: (VOCs) EPA established for each concentrations above which adverse effects on health may occur

9. Clean Air Act http://www.epa.gov/air/oaq_caa.html http://www.epa.gov/air/oaq_caa.html Title I - Air Pollution Prevention and Control – Part A - Air Quality and Emission Limitations – Part B - Ozone Protection (replaced by Title VI) – Part C - Prevention of Significant Deterioration of Air Quality – Part D - Plan Requirements for Nonattainment Areas Title II - Emission Standards for Moving Sources – Part A - Motor Vehicle Emission and Fuel Standards – Part B - Aircraft Emission Standards – Part C - Clean Fuel Vehicles Title III - General Title IV - Acid Deposition Control Title V - Permits Title VI - Stratospheric Ozone Protection

10. 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

11. Mobile Source Emissions: Nitrogen Oxides

12. Tropospheric Ozone (O 3 ) Properties: colorless, unpleasant odor, major part of photochemical smog Effects: lung irritant, damages plants, rubber, fabric, eyes, Sources: Created by sunlight acting on NO x and VOC, photocopiers, cars, industry, gas vapors, chemical solvents, incomplete fuel combustion products Class: photochemical oxidants

13. Ozone (O 3 ) 10,000 to 15,000 people in US admitted to hospitals each year due to ozone-related illness Children more susceptible – Airways narrower – More time spent outdoors

14. Mobile Source Emissions: Hydrocarbons – Precursors to Ozone

15. Carbon Monoxide (CO) Properties: colorless, odorless, heavier than air, 0.0036% of atmosphere Effects: binds tighter to Hb than O 2, mental functions and vision, even at low levels 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

16. Mobile Source Emissions - CO

17. Lead (Pb) Properties: grayish metal Effects: accumulates in tissue; affects kidneys, liver and nervous system (children most susceptible); mental incapacitation; possible carcinogen Sources: particulates, smelters, batteries Class: toxic or heavy metals EPA Standard: 1.5 ug/m 3 2 million tons enter atmosphere/year

18. 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)

19. Mobile Source Emissions: Fine Particulate Matter (PM 2.5 )

20. 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

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

22. Types of Pollutants Primary pollutants- polluting compounds that come directly out of the smoke-stack, exhaust pipe, or natural emission source. Examples: CO, CO 2, SO 2, NO x, and most suspended particulate matter. Secondary Pollutants - pollutants that have undergone transformation in the presence of sunlight, water, oxygen, or other compounds. Examples: ozone, sulfate and nitrate

23. Photochemical Reaction any chemical reaction activated by light any chemical reaction activated by light Photochemical Smog – a mixture of primary and secondary pollutants formed under the influence of sunlight Brown Air Smog ( N 2 + O 2 ---> 2NO) high temps (2NO + O 2 ---> 2NO 2 ) NO 2 (yellowish brown gas) NO 2 (yellowish brown gas)

24. Photochemical Smog

25. Industrial Smog Gray Smog Gray Smog – Comes from burning coal  Sulfur Dioxide  Sulfuric Acid +Particulates Unburned Carbon Unburned Carbon Fig. 17-8 p. 426

26. Thermal Inversions Thermal Inversion- when a relatively warm layer of air at mid- altitude covers a layer of cold, dense air below. The warm inversion layer traps emissions that then accumulate beneath it.

28. Temperature Inversions  Subsidence inversion Fig. 17-9 p. 427

29. Temperature Inversions  Radiation inversion Inversion layer Mountain range Sea breeze Descending warm air mass Decreasing temperature Increasing altitude

30. Acid Deposition Acid deposition- occurs when nitrogen oxides and sulfur oxides are released into the atmosphere and combine with atmospheric oxygen and water. These form the secondary pollutants nitric acid and sulfuric acid. Secondary pollutants further break down into nitrate and sulfate which cause the acid in acid deposition.

31. Acid Deposition

32. Effects of Acid Deposition Lowering the pH of lake water Decreasing species diversity of aquatic organisms Mobilizing metals that are found in soils and releasing these into surface waters Damaging statues, monuments, and buildings

34. Ways to Prevent Air Pollution Removing sulfur dioxide from coal by fluidized bed combustion Catalytic converters on cars Scrubbers on smoke stacks Baghouse filters Electrostatic precipitators

38. Stratospheric Ozone The stratospheric ozone layer exists roughly 45-60 kilometers above the Earth. Ozone has the ability to absorb ultraviolet radiation and protect life on Earth.

39. Formation and Breakdown of Ozone First, UV-C radiation breaks the bonds holding together the oxygen molecule )2, leaving two free oxygen atoms: O 2 + UV-C -> 2O Sometimes the free oxygen atoms result in ozone: O 2 + O -> O 3 Ozone is broken down into O2 and free oxygen atoms when it absorbs both UV-C and UV-B ultraviolet light: O 3 + UV-B or UV-C -> O 2 + O

40. Depletion of the Ozone Layer Global Ozone concentrations had decreased by more than 10%. Depletion was greatest at the poles Decreased stratospheric ozone has increased the amount of UV-B radiation that reaches the surface of Earth. Montreal Protocol- international agreement to reduce CFC’s.

41. Indoor Air Pollution Sick Building Syndrome Fig. 17-17 p. 434

42. Sick Building Syndrome A persistent set of symptoms in > 20% population Causes(s) not known or recognizable Complaints/Symptoms relieved after exiting building

43. Complaints/Symptoms Headaches Fatigue Reduced Mentation Irritability Eye, nose or throat irritation Dry Skin Nasal Congestion Difficulty Breathing Nose Bleeds Nausea

44. Building Related Illness Clinically Recognized Disease Exposure to indoor air pollutants Recognizable Causes

45. Clinically Recognized Diseases – Pontiac Fever – Legionella spp. – Legionnaire's Disease – Hypersensitivity Pneumonitis – Humidifier Fever – Asthma – Allergy – Respiratory Disease Chronic Obstructive Pulmonary Disease

46. Sources of Indoor Air Pollutants Building materials Furniture Furnishings and fabrics Glues Cleaning products Other consumer products Combustion appliances (cookers and heaters) Open fires Tobacco smoking Cooking House dust mites, bacteria and moulds Outdoor air

47. Important Indoor Air pollutants Nitrogen dioxide Carbon monoxide Formaldehyde Volatile Organic Compounds (VOCs) House dust mites (and other allergens, e.g. from pets) Environmental tobacco smoke Fine particles Chlorinated organic compounds (e.g. pesticides) Asbestos and man-made mineral fibres Radon

48. Most dangerous indoor pollutants 1.Cigarette smoke 2.Formaldehyde 3.Radon-222 gas

49. Radon Radon-222 Radon-222 Associated with uranium (U-238) and organic material in rocks Associated with uranium (U-238) and organic material in rocks 2 nd leading cause of lung cancer 2 nd leading cause of lung cancer 4 picocuries 4 picocuries – EPA proposed standard Fig. 17-18 p. 436

50. Effects of Air Pollution on Living Organisms and Materials Damage to mucous membranes Respiratory diseases Lung cancer Asthma – allergic reaction Chronic bronchitis – persistent inflammation Emphysema – irreversible damage Respiratory diseases Lung cancer Asthma – allergic reaction Chronic bronchitis – persistent inflammation Emphysema – irreversible damage

51. Nasal cavity Oral cavity Pharynx (throat) Trachea (windpipe) Bronchus Right lung Bronchioles (see figure 17.18b) (see figure 17.18c)

52. Epithelial cell Cilia Mucus

53. Bronchiole Alveolar duct Alveoli Alveolar sac (sectioned)

54. Reducing Indoor Air Pollution