1. Ozone "Good up high, bad nearby"

2. Ozone is a gas that occurs both in the Earth's upper atmosphere and at ground level. Ozone can be "good" or "bad" for your health and the environment, depending on its location in the atmosphere.

3. Ground-level or "bad" ozone is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight.

4. Industrial Facilities Electric Power Plants Vehicle Exhaust Gasoline vapors Chemical Solvents

6. At ground level, ozone is a harmful pollutant. Ozone pollution is a concern during the summer months because strong sunlight and hot weather result in harmful ozone concentrations in the air we breathe.

7. Breathing ozone can trigger a variety of health problems including chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma. "Bad" ozone also can reduce lung function and inflame the linings of the lungs. Repeated exposure may permanently scar lung tissue. Ground-level or "bad" ozone also damages vegetation and ecosystems. It leads to reduced agricultural crop and commercial forest yields, reduced growth and survivability of tree seedlings, and increased susceptibility to diseases, pests and other stresses such as harsh weather. In the United States alone, ground- level ozone is responsible for an estimated $500 million in reduced crop production each year. Ground-level ozone also damages the foliage of trees and other plants, affecting the landscape of cities, national parks and forests, and recreation areas. CAUTION. CAUTION. CAUTION.

8. http://www.airnow.gov/index.cfm?action=airnow.mapcenter&mapcenter=1 Current AQI for Ohio Current AQI Nationwide Current Ozone Levels Current PM 2.5 AQI Loop Ozone January in comparison to June 20th Population--> Hong Kong Google Earth AQI, PM 2.5, OZONE http://www.airnow.gov/index.cfm?action=airnow.local_city&cityid=151&mapdate= http://epic.epd.gov.hk/EPICDI/air/station/

9. Ozone... "_______________ up high, bad nearby."

10. Now…. we are talking about the GOOD ozone

11. Earth's good ozone is in the stratosphere and forms a protective layer from Earth's powerful UV rays.

12. Without this good ozone, the suns harmful ultra-violet rays could be too powerful for life to survive. But, in the 1980's scientists determined that the ozone layer was slowly being depleted.

13. So... what's the big deal? This allows more UV radiation to reach the Earth's surface. This can cause people to have a greater chance of getting too much UV radiation. Too much UV can cause bad health effects like skin cancer and eye damage.

14. How is it depleting? 1. In the late 1920s, chemicals called chlorofluorocarbons (cloro-floro-carbons) or CFCs, were invented. These chemicals were not poisonous and didn't harm fabrics, plants or people. Companies thought they were great and used them in refrigerators, air conditioners, styrofoam packaging, and spray cans. From the 1920s to the 1970s, billions of CFC molecules were released into the air

15. How is it depleting? 2. In the 1970s, scientists began to wonder what might happen to all those CFCs after they had been in the air for a while. They eventually learned that CFCs could float past the troposphere up into the stratosphere where UV rays would break them down. The chemicals that make up CFCs, mainly chlorine and fluorine, would float around the stratosphere, breaking up ozone molecules. This was bad, because scientists knew that ozone in the stratosphere protects the Earth from too many UV rays.

16. Fixing the problem... In 1979, many countries, including the U.S., banned CFCs from being made or used. This was a big step toward fixing the problem. Today, no spray cans contain CFCs. Other chemicals are gradually replacing the CFCs in air conditioners

17. But what about all of the CFC's that have already been emitted? CFCs already in the atmosphere can take up to 50 years to reach the stratosphere. Once there, they hang around in the stratosphere for many years, doing damage. Also, the products that still contain CFCs need to be treated with care. Examples of this are a car air conditioner and refrigerators. When these are taken to a junkyard, the CFCs need to be carefully taken out and recycled or stored so that they don't leak into the air.

18. Not Convinced?

19. On September 25, 2010, the hole reached its maximum size of 22 million square kilometers. The 2010 hole was slightly smaller than North America, which is 25 million square kilometers. Just how big is this ozone hole?

20. "In 2100, CFCs will still be 20 percent more abundant in the atmosphere than they were in 1950. So while it's not getting any worse, it won't get better fast." The Not so depressing news... T he good news is that this hole isn't getting any larger. "In fact, we have definitive evidence to show that these manmade chemicals are decreasing," says Paul Newman, NASA Goddard Space Flight Center's chief atmospheric scientist. Good news for fans of planet Earth: The seasonal hole in the ozone layer over Antarctica was at its second- smallest point in the past 20 years, according to new research from NASA and the National Oceanic and Atmospheric Administration (NOAA).

21. Key Take-Away's: What did you learn?