Air Pollution

1. 16 Air Pollution Coal-burning power plants produce about two-thirds of the sulfur oxides, one-third of all nitrogen oxides, and half of the mercury emitted in the U.S. each year.

2. Ambient Air • Improving in cities • Air pollution is everywhere • 147 billion tons of pollution each year in U.S. • 2 billion tons world wide per year • Becoming worse in developing countries

3. Natural Sources of Air Pollution • Volcanic ash • Sulfur from decaying plants and sea spray • V.O.C’sfrom trees and bushes

4. Natural Sources of Pollution Blue Ridge Mountains

5. Difference between natural forest fires and human-started forest fires? • Technically none. HOWEVER... We don’t help.

6. Human Caused Air-Pollution • Primary Pollutants – directly released • Secondary Pollutants – modified to hazardous after contact with the air • Fugitive Emissions – don’t go through a smoke stack • U.S. Clean Air Act (1970) – created maximum levels for the Conventional/Criteria pollutants

7. Sulfur Compounds • Naturally created in sea spray and volcanoes • 114 million TPY • Humans cause 90% of emissions • Created through combustion of coal and oil • Colorless, corrosive • Component of acid rain

8. Nitrogen Compounds • Highly reactive • Common Forms: NO, NO2, and HNO3 • 230 million tons released annually

9. Carbon Oxides • Common as CO2 • Usually nontoxic • Common cause of global warming • Carbon Monoxide very dangerous

10. Particulate Material • “Aerosol” • Dust, ash, or other particles in the air • Dangerous to human lungs and hearts

11. CASE STUDY: The Black Blizzard • Dust Bowl • Massive cloud of particulate material • Reached NYC from the Mid-west • Forced hundreds of thousands of farmers to leave their homes and travel to cities to find work in factories

12. Metals and Halogens • Released in metal fumes • Metabolic poison and neurotoxin • Lead very dangerous • Banned in 1986 from gasoline

13. VOC’s • Volatile Organic Compounds • Mostly released by respiration of plants • 28 million tons released each year

14. Photochemical Oxidants • Products of atmospheric reactions through solar energy • OZONE • Shield against the sun

15. Air Toxins • HAPS – hazardous air pollutants • Carcinogens, neurotoxins • Monitored by the EPA • Stored in Toxic Release Inventory (TRI) • Released 4 billion pounds in 2005 • Mercury and Dioxin rising

16. Unconventional Pollutants • Light, Odor, Noise?

17. Indoor v. Outdoor Air STAY OUTSIDE…

18. Climate and Topography

19. Climate and Topography • Cities much hotter • Wind currents can carry pollutants across continents

20. Stratospheric Ozone Is Declining • 1985: stratospheric ozone levels over the South Pole were declining during Sept. and Oct. • Principal agents of ozone depletion: • Chlorine-based aerosols (chlorofluorocarbons or CFCs) • Halon gases • Ozone is critical to the Earth

21. Progress In Controlling Pollution • Starting with the Montreal Protocol in 1987, the use of CFCs has been phased out • Hydrochlorofluorocarbons (HCFCs) are an effective alternative • It is predicted that stratospheric ozone levels will be back to normal in 40 years due to the bans • The UH-OH of ozone restoration

22. Polluted Air and You • World Health Organization estimates between 5 and 6 million people die from illnesses stemming from air pollution each year • The risk of heart attacks, respiratory diseases, and lung cancer are much higher in polluted areas • Intensity of health issues from air pollution are dependent on: • Level of air pollution • Duration of exposure • Age (very young or very old have higher risk) • Prior health status • Genetics • Lifestyle (physical work, exercise, and smoking can increase risk) • Soot and fine particulates are the biggest threat to industrialized countries • Producers of fine particulates: power plants, diesel engines, smoke from fires • Solutions: bans in general, filters, precipitators

23. Air Pollution and Plants • Plants are susceptible to air pollution • A smelter in Ontario caused the destruction of all plant life within a 30 km radius due to sulfur dioxide emissions • Extremely tall smokestacks were added along with sulfur scrubbers, reducing emissions by 90%, allowing the ecosystem to begin recovery • Pollution can directly damage plant cells • Starts with mottling (discoloration) due to the chlorosis (bleaching of chlorophyll) • Followed by necrotic (dead) spots on the leaves, reducing the plants ability to photosynthesize • Synergistic effects can occur when a plant is exposed to two pollutants at the same time and the effect is worse than the effect of each pollutant individually

24. Acid Deposition • pH: lower is more acidic, higher is more basic, 7 is neutral • Unpolluted rain has a pH of 5.6 due to naturally present carbon dioxide in the atmosphere • Lowers pH: volcanic emissions, biological decomposition, chlorine/sulfates from ocean spray • Raises pH: alkaline dust • H2SO4 and HNO3 are carried by prevailing winds from NW Europe to Scandinavia

25. CASE STUDY! • CO2 is absorbed into oceans and converted to carbonic acid • A study in The Proceedings of the National Academy of Sciences focused on the effects of increased CO2 in the atmosphere on the Humboldt squid • Scientists at URI used a flow-through respirometer to test the metabolism of the squids while the concentrations of gases were changed within the tank • The researchers found that the squids became lethargic and the metabolism dropped • Scientists say that the entire make-up of the ocean will shift in the near future due to lack of oxygen- the squids’ resting zone of low oxygen will be shallower, encroaching on the area of the ocean where they are able to hunt

26. Back To Acid Deposition… • Sulfates: 2/3 of acidic pollution, nitrates are the other third • Seedling production, tree density, and viability of forests declines in acidic environments • Smoke/soot: coats buildings, paintings, textiles • Acids: destroys limestone and marble (Parthenon, TajMahal, Colosseum, Washington Monument) • If all human-made sources of air pollution were shut down, the air would clear in a few days and visibility would improve ten times over

27. Minimizing Production: Industrial • Particulate removal: filtering emissions • Mesh of cotton cloth, spun glass fibers, or asbestos-cellulose are used as filters • Industrial filters are like vacuum cleaner bags or can utilize electricity to charge dust particles and cause them to stick to an oppositely charged plate (efficient collecting but consumes large amounts of energy) • Sulfur removal: sulfur is most damaging to living beings • Switch fuels • Clean fuels • Sulfur is a resource • Nitrogen oxides: NOx • Controlling flow of air and fuel can reduce production in internal combustion engines and industrial boilers • Staged burners control burning temperatures and oxygen flow to prevent formation • Catalytic converters removes 90% of NOx • Hydrocarbon controls: complete combustion or evaporation • Produced by: incomplete combustion, solvent evaporation from chemical factories, paints, dry cleaning, plastic manufacturing, printing, etc. • Closed systems reduce emissions • Afterburners are useful in industrial exhaust stacks

28. Minimizing Production: Domestic • Conserve fuel (carpool, bike, walk, use public transport) • Use renewable energy • Keep your car in good shape (have your car tuned every 10,000 miles) • Avoid using oil-based paint • Do not use spray cans • Refrain from using dry-cleaners

29. Clean Air Legislation • The Clean Air Act of 1963 • First national legislation in U.S. dealing with air pollution control • Included federal grants to states so that each state could set and enforce air quality regulations • Amendments to the Clean Air Act in 1970 • Established primary and secondary standards for ambient air quality • “Clear Skies” plan • President Bush’s aggressive plan to reduce emissions • Wanted the removal of “new source review”- allowed old factories to not install features to cut pollution until they replaced their equipment • Too costly and time-consuming to define new and old factories • Instead, voluntary controls and a trading program for air pollution allowances • Cap-and-trade= sets max amounts of pollutants, lets facilities pay others to reduce emissions on their behalf, causes dirty hot spots of factories that pay others • Never passed Congress • Clean Air Interstate Rule (CAIR) • Set new limits • Allows flexibility/discretion for eastern states that are victim to pollution drifting into their territory from other areas • Carbon dioxide is not included as a pollutant

30. Current and Future Conditions • We are improving! • Lead, SO2, CO all dropped • NOx has not significantly declined

31. Developing Countries • Especially problematic areas: • Mexico City • China • Eastern Europe

32. There’s Still Hope! • Sweden, West Germany, Austria, and Switzerland have made great strides • The Global Environmental Monitoring System (GEMS) reports declines in particulates • Cubatao, Brazil