History of significant air pollution events

• many of the worst air pollution episodes occurred in the last two centuries in London
  • key ingredients - calm winds, fog, smoke from coal burning
  • 1873 - 700 deaths
  • 1911- 1150 deaths
  • 1952 - over 4000 deaths
    • this last event prompted the parliament to pass a Clean Air Act in 1956
• other events around the world:
  • 1930 - Meuse Valley
    • pollution became trapped in a narrow valley - 600 people became ill, 63 were killed.

• In the U.S., air quality degraded quickly shortly after the industrial revolution
• again, the problem was coal burning in the central and mid western U.S.
  • 1948 - Donora, PA in the Monongahela River Valley
  • five-day episode - 1000's became ill, 20 were killed
• 1960s - NYC experience several dangerous episodes
• 1960s-70s - Los Angeles - increase in industry and automobile usage led to many pollution episodes

• The above events led to passing the Clean Air Act of 1970 (updated in 1977 and again in 1990)
  • empowered the federal government to set emission standards that each state would have to meet

Even the most remote areas are affected by air pollution..... like the grand canyon....