Air Pollution Overview

1. Air Pollution Overview Chapter 15 Topics: 1) Major Air Pollutants 2) Smog & Acid Deposition

2. Our Atmosphere IS a Resource Atmospheric Composition N278.08% O220.95% Argon 0.93% Carbon dioxide 0.04% (400 ppm) Ecosystem services 1.Blocks UV radiation 2.Moderates the climate 3.Redistributes water in the hydrologic cycle

3. Air Pollution  Air pollution- the 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.  Global problem… air has no boundaries  Atmosphere is a global commons Tragedy of the commons

4. Defenses against Air Pollution • Your body has natural defenses against air pollution: – Nose hairs – Eyelashes and eye brows – Mucus in your nose and throat – Liquid in your eyes • The smaller the particles, the more likely they are to get deeper into your lungs • most dangerous for the very young, the very old and people with compromised immune systems – with existing respiratory issues (asthma, emphysema, bronchitis) are at more risk from air pollution

5. Natural Sources of Air Pollution  Volcanoes  Lightning  Forest fires  Plants

6. Anthropogenic Sources of Air Pollution  On-road vehicles  Power plants  Industrial processes  Waste disposal (incineration)

8. There are six Criteria Pollutants that are regulated by the Clean Air Act under National Ambient Air Quality Standards (NAAQS) • SO2 • NOx • CO • PM • O3 • Pb (Sulfur Dioxide) (Nitrogen Oxides) (Carbon Monoxide) (Particulate Matter) (Ozone) (Lead) Primary Primary Primary Primary Secondary Primary

9. Other air pollutants not on the NAAQS Six Criteria list, but also monitored: • Hg • VOC’s (Volatile Organic Chemicals) • CO2 (Carbon Dioxide) – 2007 – Supreme Court ruled pollutant under Clean Air Act – 2009 – EPA said they would implement in future – 2014 – in June Clean Power Plan 1stproposed to regulate green houses gases – especially from power plants – 2015 – in August, Clean Power Plan finalized by EPA – 2016 – in Feb, Supreme Court stayed implementation (Mercury)

11. National Ambient Air Quality Standards (NAAQS)

13. Major Air Pollutants • Sulfur dioxide (SO2) and sulfuric acid: – About 1/3 of SO2occurs naturally • volcanoes & fires – About 2/3 from human sources • mostly combustion of fossil fuels - coal and oil & metal production • S + O2 = SO2(Primary Air Pollutant) Respiratory irritant • SO2+ H2O = H2SO4 (Sulfuric Acid – Acid Rain) • SO2and soot contribute to industrial, gray smog

14. Major Air Pollutants • Carbon oxides: – Carbon monoxide (CO) is a highly toxic gas that forms during the incomplete combustion of carbon-containing materials. • Tail pipes of cars – Carbon dioxide (CO2) forms from complete combustion of most matter. • As of 2013, burning fossil fuels has increased its concentration 43% above pre-industrial levels

15. Major Air Pollutants • Suspended particulate matter (PM): – Consists of a variety of solid particles and liquid droplets – Natural sources: Volcanoes, fires, pollen, dust – Anthropogenic sources: FF combustion, agriculture – The most harmful forms of PM are fine particles (“PM- 10”, with an average diameter < 10 micrometers) and ultrafine particles (“PM-2.5”). – PM causes ~60,000 premature US deaths per year

16. Particulates • Solid or liquid particles that are suspended in the air Sources are varied and include: burning, fossil fuels, road dust, dust storms, pollen, fires,and volcanoes Human Health Impacts: – The smaller the PM, the more dangerous (deeper into your lungs) – Impacts vary depending on the particle, but PM increases asthma, irritates the respiratory system and can cause cancer Environmental impacts: – Scatters and absorbs sunlight, reducing visibility and photosynthesis – High levels can cause global cooling • • PM > 10 – filtered out by body PM10– not filtered by body – deposited in lungs PM2.5– not filtered by body – high toxic and deposited in lungs • • • •

18. Major Air Pollutants • Nitrogen oxides and nitric acid: – Nitrogen oxide (NO) forms when nitrogen and oxygen gas in air react – at the high-temperature combustion in automobile engines and coal-burning plants. – NO can also form from lightening and certain soil bacteria. • NO reacts with air to form NO2. • NO2 reacts with water vapor in the air to form nitric acid (HNO3) and nitrate salts (NO3-) which are components of acid deposition. • NOx + VOCs + sunlight → photochemical smog (ozone)

19. Major Air Pollutants • Ozone (O3): – Is a highly reactive gas that is a major component of photochemical smog. – It is a secondary air pollutant – It can • Cause and aggravate respiratory illness (soft tissues). • Aggravate heart disease. • Damage plants, rubber in tires, fabrics, and paints.

20. Major Air Pollutants • Lead – Is a powerful neurotoxin. – Removed from gasoline over three decades ago – Concentrations in the air have declined precipitously (yay!!!!) – Mercury from coal fired power plants is now of greater concern than lead – Sources include: old pipes and paint

21. Major Air Pollutants • Volatile organic compounds (VOCs): – Vaporize at room temp – strong odors – Hydrocarbons – emitted by the leaves of many plants – Contribute to formation of Photochemical Smog – Methane • 1/3 natural sources: plants, wetlands, termites, anaerobic respiration • 2/3 from human sources: landfills, oil & natural gas wells, cattle belching & flatulence, and rice paddies – Other VOCs: industrial solvents (trichlorethylene, benzene, vinyl chloride) and components of gasoline plastics, drugs, synthetic rubber. • Long-term exposure to benzene can cause cancer, blood disorders, and immune system damage.

22. Common VOCs Compound Methane Sources Cows, leaky pipelines, landfills Impacts Global climate change, suffocation at very high concentrations Skin and eye irritant, increase in asthma, carcinogen: nasal and leukemia Carcinogen (leukemia), neurological damage, organ damage Formaldehyde Preservative found in paneling, particle board, furniture, carpeting, etc Benzene tobacco smoke, service stations, exhaust from motor vehicles, and industrial emissions Tobacco smoke, magic markers, fossil fuels, paint thinners Dry cleaning fluid and paint strippers Xylene/Toluene Neurological damage, skin and eye irritation, organ damage Central nervous system depressant, carcinogen, skin irritant Perc

23. Smog • “Smog” = smoke + fog – coined in 1905 to describe sulfur dioxide emissions • A mixture of oxidants and particulate matter that caused haze, reduced sunlight and health effects. • Can come from natural and anthropogenic sources Photochemical smog (L.A. smog, Denver smog, brown smog) London smog (New York smog, gray smog) Name: Weather : cool, damp sunny particulates, sulfur oxides NOx, ozone, hydrocarbons. Content: gasoline, combustion. Sources: coal, etc.

24. Industrial Smog • Gray smog or London smog • Smog from industrial fossil-fuel combustion • Contains: soot, SO2, SO42-, CO, CO2 • Chemistry: – Burning sulfur-rich oil or coal creates SO2, SO3, sulfuric acid, ammonium sulfate. – Burning fossil fuels leads to CO2,CO, and Carbon particles (soot). • In London in 1952, severe pollution killed over 4000 people Mostly from POINT SOURCES like coal power plants and industry

25. Photochemical Smog • Brown smog or LA type smog • Smog from reaction of sunlight with pollutants • Builds during daylight, less at night • Hot sunny days in urban areas create perfect conditions. • Trapped by inversion layers and mountains • NOx + VOCs + sunlight → photochemical smog (mainly O3) Mostly caused by car exhaust

26. South Asia’s Massive Brown Cloud • A huge dark brown cloud of industrial smog, caused by coal- burning in countries such as China and India, stretches over much of southeastern Asia. – Respiratory ailments & deaths – photosynthesis is reduced interfering with crop development. – Fine particles and droplets in the cloud appear to be changing regional climates (including rainfall). – Acid rain on US west coast https://www.youtube.com/watch?v=qYYK-2sDN4U

27. Chemistry of Photochemical Smog • Concentration of NOx and VOCs buildup from cars in the AM • Midday UV rays increase catalyzation of photochemical reactions creating ozone and PANs • Levels stay high through the afternoon decreasing after sun set • Ozone - Formation

28. Thermal Inversions make smog worse by trapping it under a layer of cold air Areas with sunny climate, light winds, mountains on one side and an ocean on the other are susceptible to inversions

29. a valley surrounded by mountains can trap air pollutants

30. How Acid Deposition Develops

31. ACID DEPOSITION Figure 19-8

32. ACID DEPOSITION • pH measurements in relation to major coal- burning and industrial plants. Figure 19-7

33. • Acid deposition Effects – contributes to chronic respiratory disease – can leach toxic metals (such as lead and mercury) from soils and rocks – Damages statues, monuments, buildings – Kills fish – Declining Aquatic Animal Populations – Harms crops & trees – Forest decline – Ex: Black forest in Germany (50% is destroyed) – Is a regional problem downwind from coal-burning facilities. – Thin-shelled eggs – Because calcium is unavailable in acidic soil

35. Range of Tolerance

36. Acid Deposition Sources Formation Effects Solutions NOx – cars, industrial plants SO2– coal power plants, fossil fuels, cars, industrial plants NOxand SOxreact with water in the air to form H2SO4and HNO3. Humans - respiratory diseases - increases leaching of toxic metals into water Structures -Dissolves marble, limestone, sandstone, metals and plastics Ecosystems -acidic soil  nutrient loss (P, N, Ca, Mg), plant loss, release of toxic metals -acidic water  destroys all life - Direct damage  reduced photosynthesis and growth Prevention - use low-sulfur coal, use less coal -Use pollution control devices to reduce emissions -Increase use of alternate energy -Tax SO2 emissions Clean-up - Add buffers to neutralize - Add phosphate fertilizer Acid is transported regionally Dry deposition of sulfate and nitrate salts and SO2 Wet deposition of H2SO4 and HNO3.

37. Air Pollution – Part II Topics: 1) Air Pollution Control Technology 2) Indoor Air Pollution 3) Ozone Layer Destruction & Recovery

38. Air Pollution Around the World Air quality is deteriorating rapidly in developing countries China has an especially bad problem with Particulate Matter & smog Developing countries have older cars Still use leaded gasoline 5 worst cities in world Beijing, China; Mexico City, Mexico; Shanghai, China; Tehran, Iran; and Calcutta, India

40. Controlling Air Pollution • How successful has the Clean Air Act been?

41. The Clean Air Act is Working!

42. Air Quality is better in US; EPA estimates since 1970 • • • • • • • Air quality is worse in developing countries: Mexico City & Beijing: air exceeds WHO standards 350 days/year Particulate Matter (PM) – down 78% Carbon Monoxide (CO) – down 56% Nitrogen Oxides (NOx) – down 30% Lead (Pb) – down 98% Sulfur Dioxide (SO2) – down 32% Ground level Ozone (O3) – down 14% VOCs – down 55%

43. • Environmental scientists point out several deficiencies in the Clean Air Act: – U.S. rely on cleanup rather than prevention. – The U.S. Congress has delayed/failed to significantly increase fuel-efficiency (CAFE) standards for automobiles. – Regulation of motorcycles and two-cycle engines inadequate. – little or no regulation of oceangoing ships in American ports. – Airports are exempt. – does not regulate CO2. – failed to deal with indoor air pollution. – Need better enforcement of the Clean Air Act. – Executives claim correcting these deficiencies would cost too much, harm economic growth, and cost jobs.

44. Controlling Air Pollution • What are some specific technologies to reduce emissions from cars, power plants, etc?

45. Catalytic Converters reduce NOXfrom tailpipes of cars

46. “Fluidized Bed Combustion” technology • Mix coal with limestone before burning to neutralize SO2before it is emitted

47. Removing Sulfur from Coal via “gasification” technology •Convert coal to Methane gas before burning to reduce SO2emissions

48. Controlling Particulate Matter Without Electrostatic precipitator With Electrostatic precipitator

49. Scrubbers • Capture PM in a “mist” after combustion

50. Permits for Pollution Control • Cap and trade – SO2 • Turns the right to pollute into a commodity • Set a number of allowances and buy and sell them in a free- market system • SO2permit auction/trading: • 23.5 million tonnes  10.3 million tonnes from 1982 to 2008