Air Pollution


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Air Pollution

  1. 1. Unit 7 Air pollution global warming and ozone loss By: Stephanie Barnes, German Kang, Ben Stratman, and Joshua Khankhanian
  2. 2. Chapter 18 Air pollution
  3. 3. Air Pollution Indicators <ul><li>Lichens serve as indicators to the amount of air pollution in a given area </li></ul><ul><li>Lichens will only grow in areas with little or no air pollution </li></ul>
  4. 4. The Troposphere <ul><li>The lowest layer of the Atmosphere </li></ul><ul><li>Where all weather occurs and contains about 75% of the mass of earth’s air </li></ul><ul><li>It is made up of 78% oxygen, 21% nitrogen and trace amounts of Argon and Carbon Dioxide </li></ul><ul><li>When found in the Troposphere, Ozone is considered a greenhouse gas </li></ul>
  5. 5. The Intermediary Zones <ul><li>Occur between the four major atmospheric layers </li></ul><ul><li>Each Zone marks a change in temperature which keeps the layers separated </li></ul><ul><li>These layers are called the Tropopause, the Stratopause, the Mesopause, and the Thermopause </li></ul>
  6. 6. Layers of the Atmosphere
  7. 7. The Stratosphere <ul><li>Extends from about 17-48 km from the surface of the earth </li></ul><ul><li>The composition is very similar to the troposphere but with much less water vapor and much more ozone </li></ul><ul><li>This is where the ozone layer is </li></ul>
  8. 8. Major Types of Air Pollution <ul><li>Primary Pollutants are picked up directly from the earth Examples include SO2, CO2, NO2, particulate matter, and Most Hydro carbons </li></ul><ul><li>Secondary pollutants form from mixing primary pollutants Examples Include SO3, HNO3, PANs, many salts, and NO-/3 and So2-/4 </li></ul>
  9. 9. Major Sources of Air Pollution <ul><li>Stationary sources include Factories and power plants </li></ul><ul><li>Mobile sources are fossil fuel powered vehicles </li></ul><ul><li>Natural Sources include volcanoes and dust storms </li></ul>
  10. 10. Sources of major types of air pollution
  11. 11. Brown Air Smog <ul><li>Is a mix of primary and secondary air pollutants under the influence of sunlight </li></ul><ul><li>It forms when Nitrogen and oxygen react under high temperatures within engines or power plants </li></ul><ul><li>From there it may form NO2 or Brown air smog </li></ul><ul><li>The Brown air smog can then form Nitric oxide or tropospheric ozone when it is separated by UV rays. </li></ul><ul><li>NO2 can also react to form PANs </li></ul><ul><li>NO2, O3, and PANs ar known as Photochemical oxidants </li></ul><ul><li>These processes are more productive on hot days </li></ul>
  12. 12. Industrial Smog <ul><li>Also known as gray air smog consists of mostly Sulfur Dioxides released from factories which burn coal </li></ul><ul><li>The Sulfur and Carbon Dioxide and Monoxide molecules which are released reacts with water vapor in the troposphere to form Sulfuric and ammonium sulfate. </li></ul><ul><li>This is rarely a problem today because factories that burn coal now use more sophisticated cleaning devices </li></ul>
  13. 13. Acid Deposition <ul><li>Occurs as a result of acid rain </li></ul><ul><li>Rain is naturally slightly acidic (pH 5-5.6) however due to acid deposition, rain in the eastern U.S. is typically 100 time more acidic with a pH of 3 </li></ul><ul><li>It effects terrestrial organisms when it drops below pH 5.1 and aquatic organisms when it drops below 5.5 </li></ul><ul><li>Acid deposition is becoming a serious problem to humans as well as to the natural environment </li></ul>
  14. 14. Thermal Inversion <ul><li>Occurs when a layer of cool air is trapped underneath a layer of hot air </li></ul><ul><li>This is often found in cities located at the bottom of valleys </li></ul><ul><li>This usually only occurs for a few hours, however if it lasts for more than a day, air pollutants can become trapped and become very hazardous to health </li></ul>
  15. 15. Indoor Air Pollution <ul><li>Indoor air pollution is often more harmful than outdoor </li></ul><ul><li>Common indoor air pollutants include asbestos, nitrogen oxides, carbon monoxide, Radon, and smoke from cigarettes or other sources </li></ul>
  16. 17. Radon Gas <ul><li>Radon-222 is a colorless, odorless, tasteless, radioactive gas produced by the radioactive decay of uranium-238. </li></ul><ul><li>Uranium-238 are found underground, and when radon gas seeps upward through the soil and is released, it disperses in the atmosphere and decays to harmless levels. </li></ul>
  17. 18. Radon Gas continued <ul><li>However, when the gas is drawn into buildings through cracks, drains, and hollow concrete blocks, it can build up to high levels. </li></ul><ul><li>Sources can be radioactive soil and rock surrounding foundation, and water supply. </li></ul><ul><li>Its biggest threat is lung cancer. </li></ul>
  18. 19. Effects of Air Pollution <ul><li>Exposure to air pollutants can break down natural defenses of the respiratory system, causing respiratory diseases: lung cancer, asthma, chronic bronchitis, and emphysema. </li></ul><ul><li>Elderly people, infants, pregnant women, and people with heart disease, asthma, or other respiratory diseases are specially vulnerable to air pollution. </li></ul>
  19. 20. Air Pollution <ul><li>The lungs become small and firm after exposed to air pollutants for years. </li></ul>
  20. 21. Carbon Monoxide <ul><li>Cigarette smoking is responsible for the largest human exposure to CO, but it’s also released by motor vehicles, kerosene heaters, woodstoves, fireplaces, and faulty heating systems. </li></ul><ul><li>CO can impair perception and thinking, slows reflexes, and causes headaches, drowsiness, dizziness, and nausea. </li></ul><ul><li>It can also trigger heart attacks, and angina attacks in people with heart disease. </li></ul>
  21. 22. Effects of CO <ul><li>CO can also damage the development of fetuses and young children aggravate chronic bronchitis, emphysema, and anemia. </li></ul><ul><li>Exposure to high levels of CO causes collapse, coma, irreversible damage to brain cells, and even death. </li></ul>
  22. 23. Plants <ul><li>Some gaseous pollutants damage leaves of crop plants and trees directly when they enter leaf pores. </li></ul><ul><li>Air pollutants can break down the waxy coating that helps prevent water loss and damage from diseases, pests, frosts, and droughts. </li></ul><ul><li>This phenomenon is reducing U.S. food production by 5-10%. The economic losses to agriculture range from 1.9 to 5.4 billion per year. </li></ul>
  23. 24. Aquatic Life <ul><li>High acidity can severely harm the aquatic life in freshwaters lakes. </li></ul><ul><li>Acidity can disrupt food chains which causes a decline in net primary productivity. </li></ul><ul><li>In the United States, about 9,000 lakes are threatened with excess acidity, one-third of them seriously. </li></ul><ul><li>Most of these lakes are concentrated in the Northeast and the upper Midwest- Minnesota, Wisconsin, and the upper Great Lakes. </li></ul>
  24. 25. Results of water pollution <ul><li>Aquatic diseases can cause deformities in fishes and other aquatic animals. </li></ul>
  25. 26. Preventing and Reducing Air Pollution <ul><li>The U.S. Congress passed Clean Air Acts in 1970, 1977, and 1990, providing federal air-pollution regulations that are enforced by each state. </li></ul><ul><li>These laws required the EPA to establish national ambient air quality standards (NAAQS) for seven outdoor pollutants: suspended particulate matter, sulfur oxides, carbon monoxide, nitrogen oxides, ozone, volatile organic compounds, and lead. </li></ul>
  26. 27. How to Reduce Outdoor Air Pollution <ul><li>Until recently, emphasis has been primarily on dispersing and diluting the pollutants by using tall smokestacks or adding equipment that removes some of the particulate pollutants after they are produced. </li></ul><ul><li>However, more utilities are switching to low-sulfur coal to reduce SO2 emissions. </li></ul><ul><li>Environmentalists call for taxes on air pollutant emissions and greater emphasis on prevention methods. </li></ul>
  27. 28. A Smokestack in Muscle Shoals, AL                                                                             
  28. 29. The Kaiser Aluminum Plant smokestack, behind the Catholic church, belches fumes over the residential area in the Chalmette section.
  29. 30. How to Reduce Indoor Air Pollution <ul><li>In the United States indoor air pollution poses a greater threat to health for many people than outdoor air pollution. </li></ul><ul><li>Yet the EPA spends about 500 million dollars per year fighting outdoor air pollution and only 13 million dollars a year on indoor air pollution. </li></ul>
  30. 31. How to Reduce Indoor Air Pollution <ul><li>Canadian researchers are developing an air-filtering system called a breathing wall that in effect absorbs indoor dirty air and exhales clean air. </li></ul><ul><li>In developing countries, indoor air pollution could be reduced if governments: (1) gave people simple stoves that burn biofuels more efficiently, and that are vented outside, or (2) provided them with simple solar cookers. </li></ul>
  31. 32. Chapter 19 Global warming and ozone loss
  32. 33. The greenhouse effect <ul><li>In the greenhouse effect, Certain gases in the atmosphere trap heat in the troposphere </li></ul><ul><li>The amount of heat trapped in the troposphere depends on the concentrations of greenhouse gases and how long they stay in the atmosphere </li></ul><ul><li>The most common greenhouse gases are h20, co2, 03, ch4, n20, and cfc’s </li></ul><ul><li>water vapor (1-5%) and carbon dioxide (.036%) are the major greenhouse gases </li></ul>
  33. 34. Greenhouse gases <ul><li>Carbon dioxide: responsible for 50-60% of global warming from greenhouse gases produced by humans </li></ul><ul><li>Cfc’s: add to global warming in troposphere and deplete ozone in the stratosphere </li></ul><ul><li>Methane: accounts for about 20% of overall warming effect </li></ul><ul><li>Nitrous oxide: traps heat in the troposphere and can also deplete ozone in the stratosphere </li></ul>
  34. 35. What is global warming <ul><li>Global warming is how measured atmospheric levels of certain greenhouse gases have risen over the past few decades, thus worsening the greenhouse effect </li></ul><ul><li>This is caused by human activities such as burning fossil fuels, agriculture, deforestation, and the use of CFC’s. </li></ul><ul><li>Developed countries account for 60% of co2 emissions </li></ul>
  35. 36. Global warming continued <ul><li>The united states alone accounts for about 23% of the world’s co2 emissions followed by china (14%), Russia (7%), and Japan (5%) </li></ul><ul><li>Emissions of greenhouse gases by the United States rose about 20% between 1990 and 1996 </li></ul><ul><li>Changing amounts of greenhouse gases in the atmosphere can affect the climate for centuries to come </li></ul>
  36. 37. Earth’s past climates <ul><li>During the past 800,000 years several ice ages have occurred; each glacial period lasted about 100,000 years and was followed by an interglacial period of 10,000-12,500 years </li></ul>For the past 10,000 years we have been in an interglacial period, which explains why we experience such warm climates
  37. 38. Facts about the past <ul><li>Over the past 160,000 years water vapor levels have remained steady while co2 levels have been between 190 and 290 ppm </li></ul><ul><li>Between 1946 and 1997 the temperature rose .3 degrees Celsius and since 1860, the 13 warmest years occurred </li></ul><ul><li>Although this could be a result of natural occurrences, the ipcc says it is due to human activities </li></ul>
  38. 39. Will the earth get warmer? <ul><li>Many of the measurements and estimates of the earth’s past average temperatures are not precise, therefore the past 100 years are the only accurate data we possess </li></ul><ul><li>Scientists have identified many factors (both positive and negative) regarding a rise in the average temperature </li></ul>
  39. 40. How do oceans affect climate? <ul><li>Oceans may increase global warming by releasing more co2 (positive feedback) </li></ul><ul><li>If oceans are warm enough, some of the dissolved co2 will bubble out into the atmosphere </li></ul><ul><li>Oceans may also decrease global warming by absorbing heat (negative feedback) </li></ul><ul><li>Oceans absorb 29% of the excess co2 that we put into the atmosphere </li></ul>
  40. 41. How does water vapor affect the climate? <ul><li>Warmer conditions increase the amount of evaporation, which then leads to the vast amount of clouds forming </li></ul><ul><li>Some clouds trap heat (positive feedback) or they may reflect the sunlight and cool the air (negative feedback) </li></ul>
  41. 42. Air pollution’s affect on climate <ul><li>Aerosols attract enough water molecules to form condensation nuclei, which leads to increased cloud formation </li></ul><ul><li>These clouds have a high albedo, causing the temperature to decrease </li></ul><ul><li>During the night, the clouds trap the heat </li></ul><ul><li>Aerosols are major components of acid rain, which slows forest growth and weakens or kills many trees, thus reducing the ability of the trees to absorb co2 </li></ul>
  42. 43. Co2 and photosynthesis <ul><li>The more co2 there is in the atmosphere, the more production of plants, which means that more co2 will be absorbed (negative feedback) </li></ul>
  43. 44. Human responses to climate changes <ul><li>When temperatures rise, many people in urban areas use air conditioning. Burning the coal releases more co2 and lead, leading to more global warming </li></ul><ul><li>Climate changes are unpredictable. anything can happen in the future </li></ul>
  44. 45. The warmer world’s affect on food production <ul><li>With a warmer world some regions may experience benefits in crop production, while others will be less prosperous </li></ul><ul><li>Drops of crop yields of even 10% would cause large increases in hunger and starvation and also cause economic and social turmoil </li></ul><ul><li>An increase of 1-2 degrees Celsius can cause corals to become bleached; 3-4 degrees will kill coral animals </li></ul>
  45. 46. How are water supplies affected? <ul><li>Water sources for large cities could shrink or even dry up </li></ul><ul><li>People would have to migrate to where there is an adequate water source </li></ul><ul><li>Summer runoff from snowmelt of glaciers provides 20-50% of the total streamflow in the surrounding drainage basins. The removal of such glaciers will reduce the area exposed to summer melting thus reducing the availability of water to lowland areas </li></ul>
  46. 47. Weather extremes <ul><li>When more heat is held in the climate system, more air will move across the surface, causing higher wind speeds, more clashing warm and cold fronts, and more violent weather </li></ul><ul><li>Tornadoes, hurricanes, typhoons, and violent storms will be more intense as well as an increase in the number of these disasters </li></ul>
  47. 48. Human health <ul><li>Increased rates of heat waves means that there will be more death among the elderly and people with heart disease, while also increasing suffering from respiratory problems such as asthma and bronchitis </li></ul><ul><li>Warm weather means more disease (yellow fever, malaria, and others) </li></ul><ul><li>Bacteria and molds on stored foods will also increase, meaning more spoilage of foods and food poisoning </li></ul>