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Chapter 19 Air Pollution

Chapter 19 Air Pollution. Overview of Chapter 19. Atmosphere as a Resource Types and Sources of Air Pollution Major Classes of Air Pollutants Sources of Outdoor Air Pollutants Urban Air Pollution Effects of Air Pollution Controlling Air Pollution in the US. Atmosphere as a Resource.

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Chapter 19 Air Pollution

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  1. Chapter 19Air Pollution

  2. Overview of Chapter 19 • Atmosphere as a Resource • Types and Sources of Air Pollution • Major Classes of Air Pollutants • Sources of Outdoor Air Pollutants • Urban Air Pollution • Effects of Air Pollution • Controlling Air Pollution in the US

  3. Atmosphere as a Resource • Atmospheric Composition • Nitrogen 78.08% • Oxygen 20.95% • Argon 0.93% • Carbon dioxide 0.04% • Ecosystem services • absorbs UV radiation • Moderates the climate • Redistributes water in the hydrologic cycle

  4. Types and Sources of Air Pollution • Air Pollution • natural events or human activities in high enough concentrations to be harmful • Two categories • Primary Air Pollutant • emitted directly into the atmosphere • Secondary Air Pollutant • formed in the atmosphere when a primary air pollutant reacts with substances normally found in the atmosphere or with other air pollutants

  5. Major Air Pollutants

  6. Major Classes of Air Pollutants • Particulate Material • Nitrogen Oxides • Sulfur Oxides • Carbon Oxides • VOCs • Ozone

  7. Particulate Material • Solid or liquid particles suspended in air (soil particles, soot, lead, asbestos, and sulfuric acid droplets) • Combustion of wood, manure, coal, oil gasoline. Agriculture. Road construction.(Black soot from diesel engines more than gasoline powered vehicles) • Natural sources: volcano/forest fires • Scatter/absorb sunlight (large forest fire/volcanic eruption)  reduced photosynthesis • Dangerous for 2 reasons • May contain materials with toxic or carcinogenic effects • Extremely small particles (PM10 and PM2.5) can become lodged in lungs (reduce lung function)

  8. Nitrogen Oxides • Nitrogen Oxides • Gases produced by the chemical interactions between atmospheric nitrogen and oxygen at high temperature; cars! • Problems • Greenhouse gas, ozone depleter, contributes to photochemical smog, leads to acid rain • Respiratory irritant, slow plant growth

  9. Sulfur Oxides • Gases produced by the chemical interactions between sulfur and oxygen; industry (chemicals, metal, paper)/power plants (coal!!!!) • Causes acid precipitation • Respiratory irritant • Slow plant growth

  10. Carbon Oxides • Carbon Oxides • carbon monoxide (CO) • Binds with hemoglobin  less oxygen • Incomplete combustion • carbon dioxide (CO2) • Greenhouse gas  global warming (global climate change)

  11. VOCs

  12. "Good up high, bad nearby!". Ozone (O3) • Tropospheric Ozone (BAD) • Secondary air pollutant (NOx + VOCs + sunlight) • Component of photochemical smog • Reduces lung function; asthma; reduce plant growth; degrade plastics/rubber • Stratospheric Ozone (GOOD; not air pollutant) • Essential component that screens out UV radiation in the upper atmosphere • Man- made pollutants (ex: CFCs) can destroy it

  13. metals • Mercury • Bioaccumulation/biomagnification • Major source: burning coal (electricity) • Harm: brain damage (neurotoxin) • Lead • Gasoline • Paints – eaten by small children • Harm: brain damage (neurotoxin)

  14. Sources of Outdoor Air Pollution • Two main sources • Transportation • Industry • Natural –lightening caused fires; volcanoes

  15. Urban Air Pollution • Photochemical Smog (ex: Los Angeles below) • Brownish-orange haze formed by chemical reactions involving sunlight, nitrogen oxide, and VOCs City surrounded by mountains; in a valley.

  16. Formation of Photochemical Smog • NOx + VOCs + sunlight  photochemical smog (includes ozone)

  17. Formation of Photochemical Smog • NO + VOCs + O2 + uv O3 + PANs • NO2 + H2O  2HNO3 + NO • NO2 + VOCs  PANs • NO2 + uv  NO + O; O2 + O  O3 Hotter = more VOCs

  18. Sources of Smog in Los Angeles

  19. Case-In-Point Air Pollution in Beijing and Mexico City • Beijing (left) • Mexico City (above) • How tied to tourism/economics?

  20. Urban air pollution • Industrial smog – “gray” smog • Photochemical smog – worse in summer • Temperature inversion(thermal inversion) • Cold air with pollutants trapped by warmer air above Valleys, coastal • Urban heat island – localized heat buildup (concrete absorbs heat, tall buildings block wind, less vegetation, more industries/cars/air conditioners that produce heat increase thunderstorms; dust domes

  21. Long Distance Transport of Air Pollutants: global distillation effect • Issues: persistent compounds found in areas not using them: worse in colder regions (higher latitudes and higher elevations) • Ex: PCBs: stored in body fat, example of biomagnification • Stockholm Convention on Persistent Organic Pollutants

  22. Long Distance Transport of Air Pollutants

  23. Acid Deposition • Sulfur dioxide and nitrogen dioxide emissions react with water vapor in the atmosphere and form acids that return to the surface as either dry or wet deposition • pH scale: 1 number = 10x change NORMAL RAIN = pH 5-6 ACID RAIN = BELOW 5

  24. How Acid Deposition Develops

  25. Effects of Acid Deposition • Adirondack Lakes, NY: no fish (reduces species diversity) • Thin-shelled eggs prevent bird reproduction • Because calcium is unavailable in acidic soil • Forest decline – increases nutrient leaching/directly harms leaves • Ex: Black forest in Germany (50% is destroyed) Erodes statues, buildings, etc

  26. Acid Deposition and Forest Decline

  27. Effects of Air Pollution • Low level exposure • Irritates eyes • Causes inflammation of respiratory tract • Can develop into chronic respiratory diseases

  28. Health Effects of Air Pollution • Sulfur Dioxide and Particulate material • Irritate respiratory tract and impair ability of lungs to exchange gases • Nitrogen Dioxides • Causes airway restriction • Carbon monoxide • Binds with iron in blood hemoglobin • Causes headache, fatigue, drowsiness, death (at prolonged exposure) • Ozone • Causes burning eyes, coughing, and chest discomfort, asthma

  29. Children and Air Pollution • Greater health threat to children than adults • Air pollution can restrict lung development • Children breath more often than adults • Children who live in high ozone(O3) areas are more likely to develop asthma

  30. Who’s still smoking?? • Most preventable cause of death • Lung cancer, heart attacks, strokes, other cancers • Increasing in China, Brazil, Pakistan; decreasing in US, Europe

  31. Controlling Air Pollution in US • Smokestacks with electrostatic precipitator (right) Without Electrostatic precipitator With Electrostatic precipitator

  32. Controlling Air Pollution in the US • Smokestacks with scrubbers

  33. Controlling Air Pollution in the US • Catalytic converters: reduce CO, NOx, and VOCs • Drive less • Mass transit • Bike lanes/wide sidewalks • Carpooling/lanes • Hybrid vehicles • Restrict evaporation of dry-cleaning fluid • Reduce # of wood burning stoves

  34. The Clean Air Act (1970) 1990 • EPA sets limits on amount of specific air pollutants permitted • Focuses on 6 pollutants: • lead, particulate matter, sulfur dioxide, carbon monoxide, nitrogen oxides, and ozone (CO2 added in 2007) • Act has led to decreases! Clean Air Act Amendment of 1990 focused on reducing acid rain

  35. Other Ways to Improve Air Quality • Reduce sulfur content in gasoline from its current average of 330 ppm to 30 ppm • Sulfur clogs catalytic converters • Require federal emission standards for all passenger vehicles • Including SUVs, trucks and minivans • Require emission testing for all vehicles • Including diesel

  36. Air Pollution Around the World • Air quality is deteriorating rapidly in developing countries • Shenyang, China • Residents only see sunlight a few weeks each year • 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

  37. Indoor Air Pollution • Worse in developing countries – wood/manure/coal indoors pneumonia/bronchitis • Most common: • Radon, cigarette smoke, carbon monoxide, nitrogen dioxide, formaldehyde (carpets) pesticides, lead (paint/plumbing), cleaning solvents, ozone (photocopiers), and asbestos

  38. Indoor air pollution – developed countries • More time inside • Better sealed/insulated for energy efficiency • More products from plastics and other petroleum-based products

  39. Indoor Air Pollution - Radon • Most serious indoor air pollutant • From radioactive decay of uranium in Earth’s crust • Increase lung cancer risks • -2nd leading cause

  40. Sick building syndrome • Highly sealed buildings  build-up of VOCs and other toxic material (glues, cleaning agents, copy machines), mold/pollen….poor ventilation • Eyes irritated, headaches, nausea, respiratory infections • Lost work time, medical bills

  41. Other strategies to reduce emissions • Cap and trade • Tax incentives for pollution control • Legislative standards for energy efficiency • Increasing research into renewable energy

  42. Unit of measurement: decibel (db) • Prolonged exposure damages hearing by hurting hair cells in the cochlea • Increases heart rate, migraines, dizziness, stress Noise pollution Possible solutions: noise barriers next to highways, limit vehicle speed, quieter jet engines, local laws/enforcement for residential power tools, loud radios, etc. Disrupts animal behavior: frogs calls  difficulty finding a mate

  43. Stratospheric Ozone (O3) • Ozone protects earth from UV radiation (UV-B, UV-C) • Part of the electromagnetic spectrum with wavelengths just shorter than visible light

  44. Stratospheric Ozone (O3) • O2 + O  O3 (catalyzed by UV of sun)

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