Climate: Air Quality


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An overview of airpollution, the two cities you need as case studies (London and Mexico) and the key pollutants and acts you need to know about.

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Climate: Air Quality

  1. 1. Air Quality An overview of urban pollution
  2. 2. Why is air quality an issue <ul><li>Over 1.6 billion people affected each year - 50% of total global urban popn </li></ul><ul><li>UK - one child in 7 has asthma </li></ul><ul><li>LEDC’s - 700m at risk from indoor air pollution (cooking and heating) </li></ul><ul><li>Air quality is closely linked to levels of development - graph page 28 in module </li></ul>
  3. 3. LEDC’s <ul><li>Cities - very densely populated (Cairo - 24 000 per km2, Calcutta - 88 000) </li></ul><ul><li>Cars/vehicles - fewer env controls in LEDC’s, rapidly expanding rate of car ownership </li></ul><ul><li>Cars are lower quality and less efficient, roads are in poorer conditions which damages the cars and decreases efficiency </li></ul><ul><li>Lack of service - more pollution </li></ul><ul><li>BUT - car industries are an important factor in development (esp.. China and India) </li></ul>
  4. 4. Air quality and health <ul><li>Asthma - death rate has increased from 40% to 60% in recent decades - June 1994 - significant outbreak associated with high pressure systems which favour high levels of ozone </li></ul><ul><li>USA - costs estimated at $16bill for healthcare and $24 bill in absenteeism and lost productivity </li></ul>
  5. 5. Who is at risk <ul><li>Young and elderly, asthmatics, people with lung diseases, pregnant women </li></ul><ul><li>This list accounts for 20% of the developed worlds population and higher in LEDC’s </li></ul>
  6. 6. Legislation UK <ul><li>1956 and 1968 - clean air acts </li></ul><ul><li>Controls on emissions of smoke, grit and dust, certain industrial sources, controls on chimney heights and designated smoke control areas </li></ul>
  7. 7. Legislation - WHO <ul><li>World Health organization </li></ul><ul><li>1987 </li></ul><ul><li>Published guidelines on concentrations of various pollutants </li></ul><ul><li>Levels are set below the minimum at which adverse effects have been observed </li></ul>
  8. 8. Main Pollutants <ul><li>Using the module, Waugh and the textbook, draw up a table to summaries </li></ul><ul><li>This should take 15 minutes </li></ul>Lead Volatile Organic Compounds (VOC’s) Nitrogen Oxide Carbon Monoxide Respirable particulates Impacts on human activity Physical conditions which make it worse Source Sulphur Dioxide and smoke
  9. 9. Air pollution categories <ul><li>Air pollution episodes classified into three categories </li></ul><ul><li>Summer smog - ozone (o3), Respirable particulates and nitrogen dioxide </li></ul><ul><li>Vehicle smog - nitrogen dioxide and Respirable particulates </li></ul><ul><li>Winter smog - high levels of SO2 during high pressure systems </li></ul>
  10. 10. Impact of climate <ul><li>Winter smog's - associated with cold, high pressure, temperature inversions and higher rates of Sulphur Dioxide emissions associated with increased heating and energy use </li></ul><ul><li>Urban areas at risk if surrounded by high ground - cold air surrounding sinks down and traps pollutants </li></ul><ul><li>Persists throughout the high pressure system </li></ul>
  11. 11. <ul><li>Summer smog </li></ul><ul><li>AKA Photochemical smog </li></ul><ul><li>Calm sunny days when photochemical activity leads to ground level ozone formation </li></ul><ul><li>OZONE is formed when reactions take place between nitrogen oxides and VOC’s in sunlight </li></ul><ul><li>Causes stinging eyes, coughing, headaches, chest pains, nausea, severe breathing problems in asthmatics </li></ul>
  12. 12. City Centers and Ozone <ul><li>In city centers - more likely to find nitrogen dioxide as main pollutant through vehicle emissions, vehicles emit nitric oxide as well as nitrogen dioxide. </li></ul><ul><li>Nitrogen oxide converts into nitric oxide by reactions with oxygen and ozone - can reduce the ozone content in cities </li></ul>
  13. 13. Homework <ul><li>For both London and Mexico city </li></ul><ul><li>Make a detailed list of the causes, effects and the solutions </li></ul><ul><li>For the solutions - evaluate the proposed solutions for both cities - which will be more effective? </li></ul>