Ozone in Our Zone?

Ozone is a form of oxygen that can be good or bad for people depending upon where it is.
Good ozone is found in the stratosphere, about 20 to 50 miles above the ground. It is a natural part of the Earth's outer shell that blocks harmful ultraviolet radiation from the sun so it's important that we have it above us. In the last decade, scientists have discovered that ozone levels in the stratosphere have dipped annually to extremely low levels before recovering. It's believed that this "ozone hole" is due to various pollutants, that humans have produced, interacting with the normal formation of Ozone.

Pollution near the ground can, on the other hand, lead to ozone production and that ozone becomes pollution. Ground-level ozone is formed on sunny days with calm wind when pollutants chemically combine with oxygen. Higher ozone levels are more common in our summer but it's not because of the heat, it's more related to the amount and intensity of sun. When ozone is found at ground level it is dangerous because our bodies cannot use it and it irritates the lungs. It causes breathing problems for people with asthma and other lung conditions. The Environmental Protection Agency uses a color coded scale to let you know what the overall air quality is. Find ozone forecasts for other cities in the United States.

You may notice more ozone alerts than in the past. Part of the reason for that is deteriorating air quality but another part of that is better ozone measurement and the fact that some of the thresholds for the ozone levels were lowered slightly at the start of 2008.

Air Quality Index

Index Value Description Steps to Stay Healthy
0 - 50 Good. Color=Green. No problems.
51 - 100 Moderate. Color=Yellow. If you are unusually sensitive to air quality, consider limiting time outside.
101 - 150 Unhealthy for some. Color=Orange. Active kids and adults, especially those with breathing difficulties should limit strenuous activity outside.
151 - 200 Unhealthy. Color=Red. Everyone should limit strenuous activity outside, especially people with breathing difficulty.
Over 200 Very Unhealthy. Color=Purple. Everyone should limit strenuous activity outside. People with respiratory difficulties should stay inside.

You can help prevent pollution that creates ozone by...

Conserving electricity
Limiting your driving
Using public transportation or carpooling
Avoid using gasoline-powered lawn equipment
Refueling your vehicle only after 6pm
Minimize use of household, workshop, and garden chemicals

The Environmental Protection Agency collects a lot of information on Ozone Depletion in the upper atmosphere while you can get daily ozone readings at ground level from ADEM, Alabama Department of Environmental Management. Check NOAA's role in air quality monitoring.