Ozone

            Ozone plays an essential part in preserving human life on Earth. Surface ozone is a gas that appears in two layers: the troposphere, which extends from the ground level to ten miles up, and the stratosphere, which is located 10-30 miles above Earth’s surface. Ozone in the stratosphere protects the planet from harmful ultraviolet waves (UV-b). The ozone in the troposphere, however, damages Earth and its resident living beings and is a key ingredient of smog.

            The ozone both enables and threatens life on Earth. On the good side of ozone, it protects the Earth from the sun and its harmful UV rays. However, the weakening of the ozone could result in damages to human health, vegetation and many common materials.

            Surface ozone is formed when certain compounds react in direct solar radiation. When high levels of VOCs and NOx are in the air, they can react. When they react in the sunlight and warm weather, ground level ozone forms.

            Surface ozone can protect life on Earth from harmful ultraviolet rays, but they can also cause significant damage as well. Some examples include irritation of the respiratory system, reduction of lung function, aggravating asthma and chronic lung diseases, inflammation and damaging of cells that line the lungs and causing permanent lung damage. Other damaging effects include susceptibility to skin cancer, impaired immune systems and cataracts.

Contributions from:

http://ciese.org/curriculum/airproj/ozoneprimer.html

http://earthobservatory.nasa.gov/Features/Ozone/