Air Pollution

1. Air Pollution Chapter 16

2. In an average year, a typical coal plant generates • 3,700,000 tons of carbon dioxide (CO2) • 10,000 tons of sulfur dioxide (SO2) • 500 tons of small airborne particles • 10,200 tons of nitrogen oxide (Nox) • 720 tons of carbon monoxide (CO) • 220 tons of hydrocarbons, volatile organic compounds (VOC) • 170 pounds of mercury, 225 pounds of arsenic, 114 pounds of lead, 4 pounds of cadmium, other toxic heavy metals, and trace amounts of uranium.

3. Natural Sources • Sand and dust storms • Pollen and spores • Volcanic eruptions • Forest fires

4. Volcanoes • Particulates • Sulfur dioxide • Carbon dioxide • Hydrogen sulfide

5. Forests • VOCs that form Ozone Sea Spray • Sulfur compounds Natural decomposition • Methane • Decaying vegetation – sulfur compounds

6. When did Air pollution begin? • 2,000 years ago a Roman philosopher complained about the foul air in Rome • 1273 – England’s King Edward I decreed that burn a particular type of dirty coal was illegal • Industrial Revolution of the 1800s • Problem is worse today because modern societies burn large amounts of fossils fuels mostly from vehicles and industries

7. Primary Pollutants • Harmful chemicals that are direct products of combustion, evaporation, and friction that enter the atmosphere • Ex. VOCs (volatile organic compounds), Carbon Monoxide, Nitrogen oxides, Sulfur dioxide, lead, and particulate matter

8. Secondary Pollutants • Harmful chemicals that form from primary pollutants • chemical reactions with usually sunlight or water occurring in the atmosphere that produce additional pollutants • Ex. Ozone = photochemical reaction between VOCs/NOxwith sunlight providing the energy • SO3 reacts with water vapor to produce sulfuric acid

9. Thermal Inversion • Typically occur in a valley • Concentrated pollutants are trapped by overlying colder air • Examples: L.A., Mexico City Heat Islands • cities due to lack of cooling green vegetation and increased run-off (more impermeable surfaces)

10. http://www.learn.londonmet.ac.uk/packages/euleb/data/glossary/images/image_0.pnghttp://www.learn.londonmet.ac.uk/packages/euleb/data/glossary/images/image_0.png http://dnr.wi.gov/air/images/Air_Matters/AM200802B.jpg

11. Indoor Air pollution • Radon – radioactive gas seeps into basements from surrounding bedrock • Second leading cause of lung cancer • Formaldehyde – plywood, pressboard, furniture stuffing, carpeting • Asbestos – fire retardant fiber; once used in insulation, ceiling tiles; causes lung cancer, mesothelioma (rare cancer)

12. Sick Building Syndrome • A building where health effects are linked to the building • Headache, eye and throat irritation, cough, dizziness, fatigue, nausea • Symptoms improved when personleaves the building • Defined as “sick” if 20% of occupants experience symptoms • Have inadequate ventilation

13. How do we improve Air Quality? • Catalytic converter use platinum-palladium & rhodium catalysts to remove 90% of NOx, hydrocarbons & carbon monoxide. • Raprenox (rapid removal of nitrogen oxides) that uses nonpoisonous cyanuric acid which reacts with NOx to produce CO2, CO, H2O. This removes 99% of the NOx. • Electrostatic precipitators use charged electrodes to attract & then collect pollutants such as heavy metals. • Limestone reacts with sulfur to clean coal.

14. Solutions for Global Warming:

15. Clean Air Act - 1963, 1970, 1990 & 1997 • 1963: A pool of money to be used by the states to set limits & regulate air pollution. • 1970: Set specific standards for the criteria pollutants (Also the EPA was established to not only set standards but also enforce them.) • 1990: Added acid rain, HAP’s, ozone protection, marketing pollution rights, VOC’s • 1997: Proposed lowering troposheric ozone from 0.12 ppm to 0.08 ppm. Lowering soot & dust from 10 microns to 2.5 microns & therefore requiring factories & powerplants to clean up emissions.

16. Acid Rain • A mixture of wet and dry deposited material from the atmosphere containing higher than normal amounts of nitric and sulfuric acids. • result from natural sources, such as volcanoes and decaying vegetation, • and man-made sources, primarily emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) resulting from fossil fuel combustion. • In the United States, roughly 2/3 of all SO2 and 1/4 of all NOx come from electric power generation that relies on burning fossil fuels, like coal.  • Acid rain occurs when these gases react in the atmosphere with water, oxygen, and other chemicals to form various acidic compounds. The result is a mild solution of sulfuric acid and nitric acid. • prevailing winds blow these compounds across state and national borders, sometimes over hundreds of miles.

17. http://www.epa.gov/acidrain/what/index.html

18. Acid Deposition • Wet Deposition • acid chemicals in the air are blown into areas where the weather is wet, acids fall to the ground in the form of rain, snow, fog, or mist. • The strength of the effects depends on several factors, including how acidic the water is; the chemistry and buffering capacity of the soils involved; and the types of fish, trees, and other living things that rely on the water. • Dry Deposition • where the weather is dry, the acid chemicals may become incorporated into dust or smoke and fall to the ground through dry deposition, sticking to the ground, buildings, homes, cars, and trees. • Dry deposited gases and particles can be washed from these surfaces by rainstorms. This runoff water makes the resulting mixture more acidic. • About half of the acidity in the atmosphere falls back to earth through dry deposition.

19. Effects of Acid Deposition • In areas where buffering capacity is low, acid rain releases aluminum from soils into lakes and streams; aluminum is highly toxic to many species of aquatic organisms. • low pH and increased aluminum levels cause chronic stress that may not kill individual fish, but leads to lower body weight and smaller size and makes fish less able to compete for food and habitat

20. GOOD OZONE • Stratospheric ozone blocks out harmful Ultraviolet rays • Ozone layer in the stratosphere is thinning over Antarctica • Chemical compounds responsible are • CFCs – Chloroflourocarbons • Halocarbons/Halons

21. CFCs • Manufactured to be used as • coolant/refrigerant in air conditioners and refrigerators • Aerosols/propellants • Foam blowing insulation (Styrofoam) • Solvents/cleaners • Greenhouse gas with the highest heat trapping capability per molecule

22. Halocarbons/Halons • Manufactured to be used as a • Fire retardant (fire extinguishers) • Soil fumigant/pesticide • Solvents • Foam-blowing insulation

23. DESTROY the Ozone Layer • CFCs are broken down by UV rays and release halogen atoms (chlorine/bromine/fluorine) • Halogen atoms sequester atomic oxygen forming Halogen oxides • Chlorine can split Ozone • CFCs are very stable and since there are no reservoirs for them in nature, they reach the stratosphere

24. Human health effects Sunburn/ skin cancer Eye damage/ cataracts Reduction of human immune system Effects on Ecosystem Reduction of primary productivity in oceans Disruption of food chain Decreased plant productivity Effects on major food crops Direct damage to mammals, fish, amphibians DESTROY the Ozone Layer

25. BAD OZONE • Pollutant at ground level • Human: throat/lung/eye irritation; aggravation of asthma/bronchitis/ emphysema; impaired development of lungs in young children; chest discomfort; suppression of immune system • Ecosystem:; crop damage; stresses plants; decreased photosynthesis; kills leaf tissue, indirect contribution to global warming