Presentation on theme: "Air pollution and the ozone hole. Ozone Review: answer these questions What is ozone? What is its chemical formula? Where is ozone found Of what importance."— Presentation transcript:
Air pollution and the ozone hole
Ozone Review: answer these questions What is ozone? What is its chemical formula? Where is ozone found Of what importance is ozone?
What harms the ozone layer? CFCs = chlorofluorocarbons Large, man-made molecules with chlorine in them. CFCs were used in many aerosols, refrigeration units, air conditioners. UV radiation knocks the chlorine out of the molecule, where it then is able to react with ozone, destroying it.
The ozone hole YouTube - The Earth's Ozone Hole from YouTube - The Earth's Ozone Hole from During the Antarctic winter, June-August, cold winds circle the Antarctic Air above Antarctica is very cold then. Chlorine split off from CFCs. Then, when sunlight returns in September-November, the suns rays split chorine molecules into chlorine atoms, which destroy ozone.
Impact of ozone hole Lower ozone allows more UV-B radiation to reach the ground. This radiation can damage DNA in humans and other organisms. UV radiation can kill phytoplankton UV radiation can interfere with photosynthesis
Protecting stratospheric ozone 1987 – nations met in Canada and agreed to limit their production of CFCs (Montreal Protocol).
Particulate pollution What is it? –Small particles in the atmosphere –Made of sulfuric and nitric acid, organic chemicals, metals, soil, and dust particles Two sizes –Larger: 2.5 – 10 micrometers called PM10 –Smaller: < 2.5 micrometers called PM2.5
Particulate matter PM10: coarse particles, near roadways and dusty places PM2.5: emitted by forest fires, cars, or form from gases emitted.
Impacts of particulate pollution Health impacts –Small particles get into the smallest air sacs of the lungs. Can scar them Environmental impacts –PM2.5 causes haze