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OZONE and the ENVIRONMENT

OZONE and the ENVIRONMENT. Just what is Ozone?. Ozone is a form of oxygen with a different chemical property Ozone differs from oxygen: Has a distinctive odor Contains 3 oxygen atoms Absorbs damaging ultraviolet (UV) radiation In large concentrations ozone is hazardous. Earth’s Atmosphere.

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OZONE and the ENVIRONMENT

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  1. OZONE and the ENVIRONMENT

  2. Just what is Ozone? • Ozone is a form of oxygen with a different chemical property • Ozone differs from oxygen: • Has a distinctive odor • Contains 3 oxygen atoms • Absorbs damaging ultraviolet (UV) radiation • In large concentrations ozone is hazardous

  3. Earth’s Atmosphere • Troposphere start on the surface and extends 5 – 9 miles • Air most dense • All weather occurs is this region • Stratosphereextends for 31 miles • Contains the Ozone layer

  4. Composition of the Atmosphere • Nitrogen 78% • Oxygen 21% • Argon 1% • Water Vapor 0 – 7% • Ozone 0.01% • Carbon Dioxide 0.01 – 0.1%

  5. Ozone’s Primary Function • Block or absorb most of the suns ultraviolet rays • Approx. 3,000 million tons of ozone in atmosphere • If concentrated at sea level, would measure only 3 mm thick • Depletion of this protective shield allows too much UV radiation to strike earth

  6. Measuring the Ozone Layer • In 1920 Gordon Dobson began researching the ozone layer and its effects • Dobson Unit – Measures intensity of light passing through ozone layer thus measuring it’s density – 300DU is highest level of protection

  7. Destruction of the Ozone Layer • Ozone is both created and destroyed by the action of UV rays on oxygen molecules • Chlorine has been found to be major cause of ozone depletion. • UV rays react with chlorine and cause a chain reaction. One chlorine molecule can destroy 100,000 ozone molecules

  8. Satellite image of ozone hole (pink area) over Antarctica, 9-25-95

  9. Chlorofluorocarbons (CFC) • CFCs invented by Dupont, trade name Freon in 1928 • Nonflammable, nontoxic, stable, non corrosive, odorless, low boiling point • Used as refrigerants, in manufacturing processes, as cleaning solvents, as propellants in aerosol cans

  10. Chlorofluorocarbons (CFC) • Throughout the 60’s & 70’s scientists learned that CFCs can stay airborne for decades. Taking as much as 8 – 10 years to reach the stratosphere • In the stratosphere CFCs are broken down by UV rays. Chlorine & fluorine molecules are released. • Millions of tons of CFCs are currently aloft in our atmosphere, it will take several hundred years for it all to be depleted.

  11. The Ban Begins • In the late 70’s the U.S. Canada, Norway & Sweden banned CFCs in aerosol sprays • 1987 Montreal Protocol signed by 150 nations, phased reduction of annual CFC releases • CFC production totally banned as of Jan. 1996 • If ban not in place, ozone depletion estimated to grow by .5% annually • Currently hole of the size of the U.S. Size and depletion percentage varies with seasonal changes

  12. What does this mean for me? • Refrigerants used in Automobiles have changed, and may change again • Strict service procedures must be followed • Strict penalties for law breakers • Certification programs for technicians handling refrigerants

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