Ozone & Your Health
When is Ozone Good or Bad?
Ozone (O3) is a gas that forms when three atoms of oxygen combine. This same gas can be either beneficial or harmful to humans and the environment, depending on where it is located in Earth’s atmosphere.
The Ozone Layer: “Good” Ozone
The ozone layer is located in the stratosphere, a layer of the atmosphere between 10-30 miles away from the Earth’s surface. This layer shields us from the sun’s harmful ultraviolet rays (UV-b) that can cause skin cancer. The ozone layer has been a recent subject of environmental concern, as it is being thinned by manmade chemicals such as chlorofluorocarbons (CFCs) and halons.
Smog: “Bad” Ozone
Ozone can also form closeby, in the layer of the atmosphere directly surrounding the Earth. This layer, called the troposphere, extends to about 10 miles above the earth’s surface. Here, ground-level ozone is an air pollutant that damages human health and the environment, and is the key ingredient in urban smog. It is this “bad” ozone that Clean Air Counts is working to reduce.