Adults breathe about 20,000 times each day. When you are breathing, you just inhaled oxygen made up of only two atoms. Ozone is made up of ordinary oxygen but two, three oxygen(O₃). This is the only difference between oxygen(O₂) and ozone(O₃).
What is ozone? What does it do in our atmosphere?

Although ozone is all around us in the air, it is rare. In every million molecules of air, fewer than ten of the molecules are ozone. It occurs naturally about 10 to 30 miles above the Earth's surface(stratosphere) and shields us from sunburn, skin cancer and eye problems. Plants are also protected from crop damage.

Bad ozone is at Ground-level. This plays quite a different role and forms from a chemical reaction between NO_x, VOCs, oxygen and sunlight. The sunlight provides heat which transforms NO_x and VOCs into ozone. The formation of ground-level ozone is highest in hot. Ozone reacts with O_x to form NO₂ and, as urban areas tend to have higher levels of O_x than rural areas.

Good ozone

A large "ozone hole" was discovered above the continent of Antarctica during the springtime in 1985 and has reappeared annually, generally expanding each year.
Ozone layer is cooling now. This makes its recovery more difficult and also a little-noticed effect of global warming. The Antarctic ozone hole will reach sizes on the order of 8-10 million square miles nearly every year until about 2018 or so.

Scientists mostly blame Chlorofluorocarbons, a chemical used in an early form of refrigerant that they now realize was released into the atmosphere in larger quantities than forecast. As a result, the international agencies now say that injury to the Earth's ozone layer could take a quarter of a century longer to heal than previously expected.

Governments have responded to the threat of disappearing ozone. In September 1987, representatives from around the world met in Montreal to forge an unprecedented agreement called the Montreal Protocol. Countries agreed to keep their production of CFCs at 1986 levels, then cut production and CFC use in half over the next ten years. Since then, countries have agreed to phase out ozone-destroying compounds except for essential uses. Furthermore, industries have been successful in finding many ozone-friendly substitutes for CFCs but still all the older model refrigerators and car air-conditioning systems in the United States and Canada that are releasing ozone-killing chemicals. Both countries curbed those chemicals in newer products, it's hard to eliminate old one completely.
 

High altitude

Be especially careful about exposure to the sun at high altitudes. Sun exposure increases 4% for each 1000 feet of elevation above sea level. When a child is hiking at high altitudes, sunburn can occur quickly. The higher the elevation, the greater the UV exposure
 

High latitude

UV is strongest at the equator. The average annual exposure of a person living in Hawaii (20 degrees N) is approximately four times that of someone living in northern Europe (50 degrees N).

Got skin damage?
悪 皮膚を犯すもの

Can't see UV? Bees can!
視　UVはみえないけど蜂には

Vitamin D in 100g of food
栄　食品１００グラム中にビタミンDが…

Trans fat foods
脂　トランス脂肪酸

I am at a 35° latitude
偉　緯度35度