KNED Help Desk

File VI: Air Pollution

Ozone

Ozone is a gas that forms in the atmosphere when three atoms of oxygen are combined (O₃). Ozone is not emitted directly into the air, but at ground level is created by a chemical reation between oxides of nitrogen and volatile organic compounds in the presence of sunlight. According to U.S. EPA Office of Air Quality Plan and Standard, ground level ozone is an air pollutant that causes human health problems and damages crops and other ecosystems.

Good Ozone

Ozone that occurs in the stratosphere (the layer that extends upward from about 10 to 30 miles away from the earth) protects life on earth from the sun's harmful ultraviolet rays (UV-b) is categorized as Good Ozone Layer. This good ozone layer is gradually destroyed by manmade chemicals called chlorofluorocarbons and other ozone depleting substances. These depleting substances degrade the stratospheric layer that protects us from UV-b and we will be exposed to more health hazards such as skin cancer, cataracts, impaired immune systems, and reduced crop yields.

Bad Ozone

Ozone that occurs in troposphere (the layer surrounding the earth's surface that extends to a level about 10 miles up away from the earth) is called Bad Ozone Layer. Motor vehicle exhaust and industrial emissions, gasoline vapors, and chemical solvents are some of the causes of bad ozone.

Health Problems

Ozone can irritate lung airways and cause inflamation like sunburn. Other symptoms include wheezing, coughing, pain when taking deep breath, and difficulties during exercise. Ozone can also aggravate asthma, pneumonia and bronchitis.

What Can We Do?

Protect yourself against sunburn. Wear sunglasses and a hat with a wide brim.
Keep your car well-tuned and maintained. Also, you can carpool, walk, bicycle or reduce driving on hot hours.
Fill your gas tank during cooler hours.