Ch. 17 Continued

1. Ch. 17 Continued Acid Deposition Indoor Air Pollution Ozone Depletion

2. Acid Deposition • Deposition of acidic pollutants on earth’s surface (rain, snow, snow, particulates) • Origin: SO2 and NOx from fossil fuel combustion

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7. Ozone Layer • Stratosphere - maximum concentration at ~25 km altitude • Effectively blocks dangerous UV radiation • 1985 researchers reported ozone levels over Antarctica down by 40-60% - thinning called “ozone hole” • Causation: CFCs (chlorofluorocarbons) • Production increasing since 1928 • Inexpensive refrigerants, fire extinguishers, and aerosol propellants • 1 molecule removes as many as 100,000 O3 molecules • Montreal Protocol 1987 – 180 countries agree to reduce production to ½

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10. 1987 Montreal Protocol on Substances that Deplete the Ozone Layer • Landmark international agreement • Effective January 1, 1989 • Five revisions • 1990 (London), 1992 (Copenhagen), 1995 (Vienna), 1997 (Montreal), 1999 (Beijing) • 36 nations to cut emissions of CFC’s (eventually 180) • Currently 95% reduction in ozone depleting compounds • Based on success of treaty ozone levels expected to return to normal around 2050

11. Ozone Depletion

13. Natural Capital Degradation Effects of Ozone Depletion Human Health • Worse sunburn • More eye cataracts • More skin cancers • Immune system suppression Food and Forests • Reduced yields for some crops • Reduced seafood supplies from reduced phytoplankton • Decreased forest productivity for UV-sensitive tree species Wildlife • Increased eye cataracts in some species • Decreased population of aquatic species sensitive to UV radiation • Reduced population of surface phytoplankton • Disrupted aquatic food webs from reduced phytoplankton Air Pollution and Materials • Increased acid deposition • Increased photochemical smog • Degradation of outdoor paints and plastics Fig. 20-21, p. 488 Global Warming • Accelerated warming because of decreased ocean uptake of CO2 from atmosphere by phytoplankton and CFCs acting as greenhouse gases

14. Indoor Air Pollution • U.S. citizens spend 90% of their time indoors • How did energy crisis worsen indoor air pollution? • Most dangerous: • Tobacco smoke (4000+ toxins/carcinogens) • Radon (15% of global lung cancer says WHO) • VOCs (Hunting VOCs in the Home)

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17. Connecticut Radon MapEPA