But down near Earth's surface, ozone isn't good. It's the main ingredient in smog. And it can damage our lungs and other tender tissues by a process known as oxidation. The sun is a good chemist. It likes to rearrange the chemicals that our cars, trucks, factories and power plants spew out after burning gasoline and other fossil fuels, such as coal and natural gas.
Ozone is one of the products the sun makes from the exhaust gases.
When these gases build up in the air, and the sun is bright and hot, ozone levels soar. But we humans aren't the only living things that suffer from ozone pollution. Plants have an even tougher time. They are more sensitive to ozone than people, and they can't come indoors. Agricultural Research Service scientists in Raleigh, North Carolina, have been studying the effects of ozone on different crops for almost 30 years.