AIR POLLUTION Dr. Wesam Al Madhoun

1. AIR POLLUTIONDr. Wesam Al Madhoun

2. What is air pollution? • The presence of any substances in the atmosphere in quantities which are or may be harmful or injurious to human health, welfare, animal or plant life, or property or unreasonably interfere with the enjoyment of life or property.

3. Outdoor Air Pollution

4. Primary Pollutants CO CO2 Secondary Pollutants SO2 NO NO2 SO3 Most hydrocarbons HNO3 H2SO4 Most suspended particles H2O2 O3 PANs 2 – NO3 and salts SO4 Most – Natural Sources Stationary Mobile

5. Primary vs. Secondary Pollutants • Primary- put directly into air from polluting source. • Secondary- when primary combines with other substances in air and creates something more hazardous (acid rain, smog) • Sun often provides energy.

6. Major Sources of Primary Pollutants Stationary Sources • Combustion of fuels for power and heat – Power Plants • Other burning such as wood & crop burning or forest fires • Industrial/ commercial processes • Solvents and aerosols Mobile Sources • Highway: cars, trucks, buses and motorcycles • Off-highway: aircraft, boats, farm equipment, and construction machinery.

7. Natural Sources • Forest fires- ash, particulates, carbon dioxide • Volcanoes- ash, acid mist, hydrogen sulfide • Decaying vegetation- sulfur cmpds • Trees & bushes- Volatile Organic Cmpds (VOC’s) • Pollen • Viruses • Bacteria • Dust- from storms in arid regions • Gut bacteria- methane gas

8. Anthropogenic Sources of Air Pollution

9. Criteria Air Pollutants EPA uses seven "criteria pollutants" as indicators of air quality • Sulfur Dioxide: SO2 • Nitrogen Dioxide: NO2 • Carbon monoxide: CO • Lead: Pb • Particulate Matter: PM10 (PM 2.5) • Volatile Organic Compounds: (VOCs) • Ozone: ground level O3

10. Sulfur Dioxide (SO2) • Properties: colorless gas with irritating odor • Effects: produces acid rain (H2SO4), breathing difficulties, eutrophication due to sulfate formation. • Sources:burning high sulfur coal or oil in power plants, smelting or metals, paper manufacture • Class: sulfur oxides • EPA Standard: 0.3 ppm (annual mean) • 2nd largest cause of air pollution-related health damage. (1st is smoking) • Sulfate particles reduce visibility in the U.S. as much as 80% • Reflects sunlight so may have cooling effect

11. Sulfur Dioxide Emissions

12. Nitrogen Dioxide (NO2) • Properties: reddish brown gas, formed as fuel burned in car, strong oxidizing agent, forms Nitric acid (HNO3) 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, fertilizers • Class: Nitrogen oxides (NOx) • EPAStandard: 0.053 ppm • Excess nitrogen is causing fertilization & eutrophication of inland waters & seas

13. Mobile Source Emissions: Nitrogen Oxides

14. Carbon Monoxide (CO) • Properties:colorless, odorless, heavier than air, 0.0036% of atmosphere • Effects:binds tighter to Hemoglobin (Hb) than O2, so organs do not get O2 needed, makes you sleepy, impairs mental functions and visual acuity, even at low levels • Sources:incomplete combustion of fossil fuels 60 - 95% from auto exhaust • Class:carbon oxides (CO2, CO) • EPAStandard:9 ppm • 1 billion tons enter atmosphere/year

15. Mobile Source Emissions – CO

16. 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 levels • Sources: particulates from fuel combustion, smelters, batteries • Class:toxic or heavy metals • EPAStandard: 1.5 ug/m3 • 2 million tons enter atmosphere/year • Mercury- neurotoxin from coal power plants • Both mercury & lead travel on air currents and fall into aquatic ecosystems causing bioaccumulation & biomagnification in food webs.

17. Suspended Particulate Matter (PM10) • 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 (polychlorinated biphenyls), dioxins, pesticides • EPA Standard: 50 ug/m3 (annual mean) • PM2.5 is worse because small enough to be inhaled more deeply • Asbestos fibers & cigarette smoke are most dangerous respirable particles because they are carcinogenic

18. Mobile Source Emissions: Fine Particulate Matter (PM2.5)

19. 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, wetlands, rice paddies, bacteria, plants. • Class: HAPs (Hazardous Air Pollutants- cause cancer, birth defects, mutation, neutroxins) • Methane • Benzene • Chlorofluorocarbons (CFCs), etc. • Concentrations indoors up to 1000x outdoors • 600 million tons of CFCs

20. Ozone (O3) • Properties: colorless, unpleasant odor, major part of photochemical smog • Effects: lung irritant, damages plants, rubber, fabric, eyes • Sources: Created by sunlight acting on NOx and VOC , photocopiers, cars, industry, gas vapors, chemical solvents, incomplete fuel combustion products • Class: photochemical oxidants • Good ozone vs. bad ozone- good is in stratosphere and bad is at ground level (from cars) • Figure 18.10 shows secondary production of urban smog by photochemical rxns in atmosphere

22. Other Air Pollutants • Carbon dioxide- natural source from photosynthesis & respiration; human caused from fossil fuels & deforestation • ChloroFluoroCarbons (CFC’s)- from refrigerants, aerosols, Styrofoam • Formaldehyde- building materials & household products • Benzene- paint • Asbestos- car brakes, building materials • Dioxins- pesticides • Cadmium- batteries, plastics industry

23. Formation & Intensity of Pollutant is influenced by… • Local climate (inversions, air pressure, temperature, humidity) • Topography (hills and mountains) • 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

24. cool air Pollutants cool air warm air (inversion layer) warm air • surface heated by sun • warm air rises (incl. pollutants) • cools off, mixes with air of equal density & disperses • surface cools rapidly (night) • a layer of warm air overlays surface • polluted surface air rises but cannot disperse  remains trapped Thermal Inversion- occur in valleys-pollutant effects are intensified when air cannot move upward due to cold upper air layer

25. Smog Forms ...when polluted air is stagnant (weather conditions, geographic location) Los Angeles, CA

26. Solar radiation Photochemical Smog Ultraviolet radiation NO Nitric oxide O Atomic oxygen O2 Molecular oxygen NO2 Nitrogen dioxide H2O Water Hydrocarbons PANs Peroxyacyl nitrates Aldehydes (e.g., formaldehyde) O3 Ozone HNO3 Nitric acid P h o t o c h e m i c a l S m o g

27. Urban Heat Islands • Cities are generally 3-5ºC warmer than rural areas • Caused by: • Lack of vegetation to absorb heat • Dark buildings & roads trap heat • Buildings create windbreaks • Dust Dome- trapping of dirt & particulates over city

28. INDOOR AIR POLLUTION

29. What are some sources of indoor air pollution? • Cigarette smoke • Deadliest indoor air pollutant • Contain formaldehyde, carbon monoxide • Causes lung cancer, emphysema • Second hand smoke may be worse due to particulates that come from tip.

30. What are some sources of indoor air pollution? • Mold • Moisture in carpets • Allergy symptoms, breathing problems, headache, fatigue

31. What are some sources of indoor air pollution? • Carbon monoxide • Malfunctioning furnace, gas appliances, cars • Blood cannot carry oxygen • Feel sleepy, nausea, dizzy, cause death.

32. What are some sources of indoor air pollution? • Radon • Colorless, odorless, radioactive gas • Comes from soil under basements • Long term exposure can cause lung cancer • Fix cracks in floor or walls to prevent influx of radon • Install ventilation fan in basement to blow radon out. Zone 1 (purple) high levels of radon Zone 3 (yellow) low levels of radon

33. What are some sources of indoor air pollution? • Asbestos • Roofing, flooring, insulation, brakes • OK… unless disturbed or deteriorates • Can cause asbestosis (scarring of lungs) and mesothelioma (type of lung cancer) Plaque build up (scarring) in lung w/asbestosis

34. What are some sources of indoor air pollution? • Lead • Old homes, toys, lead crystal dishes • Causes behavior & learning problems, slow growth, hearing problems, headaches

35. What are some sources of indoor air pollution? • Formaldehyde • Pressed wood, paneling, particle board, glue. • Respiratory irritation, fatigue, skin rash, known to cause cancer

36. What are some sources of indoor air pollution? 8. VOC’s • Paradichlorobenzene- mothballs, insecticides • (perchloroethylene))- dry cleaned clothes • Benzene- paints, cigarettes • Causes respiratory problems, headaches, loss of coordination, nausea, organ damage, cancer

37. Effects of Air Pollution on… 1. Human Health 2. Plant Health 3. Acid Deposition

38. 1. Human Health • Depends on intensity & duration of exposure, age & prior health status • At-risk groups: young, old, or already suffering from respiratory/cardiovascular disease. Also, more active & outside vs. sedentary inside lifestyle • Most susceptible- less-developed countries use smoky fires for cooking & heating

39. Exposure • Time spent in various environments in US and less-developed countries

40. How is it introduced to body? • Inhalation • Absorption thru skin • Contamination of food & water

41. How does air pollution affect people? • Chronic bronchitis- coughing, trouble breathing • Asthma- not caused by air pollution, but aggravated by it. • Emphysema- lungs lose elasticity, hard to breathe • Lung Cancer- caused by cigarettes, car exhaust, particulates, asbestos, arsenic, radon

42. How does air pollution affect people? • Sick building syndrome- • Buildings closed up to save energy- no circulation • Effects of fumes intensified • Symptoms: headache, eye or throat irritation, cough, itchy skin, dizziness, nausea, fatigue • Feel better when you get fresh air outside. • ≥20% of workers must be afflicted to be classified as SBS

43. 2. Plant Health • Two Methods of Damage • Directly toxic • Irritate cell membranes • First few days- discoloration due to chlorosis (bleaching) of leaf • Later- necrotic (dead) lesions develop leading to death • Disruption of plant hormones • Ethylene from fossil fuels, chemical plants is a major culprit • Synergistic effects (when combined two are worse than each individually) unpredictable • White pine seedlings exposed to low levels of O3 & SO2 individually are fine. When combined cause death • In alfalfa, O3 and SO2 together are less harmful than individually. • Air pollutant effects on plants are sometimes confused with insect damage or other diseases.

44. Necrosis of watermelon leaf Necrotic lesions on lower surface of potato leaves

45. 3. Acid Deposition

46. Measuring Acid Rain • Normal rain is slightly acidic and has a pH of about 5.0-5.6 • Any rainfall with a pH value less than 5.0 is defined as acid rain

47. Wet Refers to acid rain, fog, sleet, cloud vapor and snow. Dry Refers to acidic gases and particles. Two Forms…

48. Increased Acidity • Dry deposited gases and particles can also be washed from trees and other surfaces by rainstorms. • The runoff water adds those acids to the acid rain, making the combination more acidic than the falling rain alone.

49. Compounds Two main contributers to acid deposition: • Sulfur Dioxide (SO2) • Nitrogen Oxides (NOx) • NO- nitric oxide (or nitrogen monoxide) • NO2- nitrogen dioxide • N2O- nitrous oxide • 66% of all sulfur dioxides and 25% of all nitrogen oxides comes from coal or oil electric power plants. Most nitrogen oxides come from cars

50. When gas pollutants e.g. sulfur dioxide, nitrogen dioxidedissolve in rain water, various acids are formed. • CO2 + H2O  H2CO3 (carbonic acid) • SO2 + H2O  H2SO4 (sulfuric acid) • NO2 + H2O  HNO2 (nitrous acid) + HNO3 (nitric acid)