Ozone Action Days

Ozone Action! is a voluntary emissions reduction initiative that asks people to do what they can to reduce pollution on the days it counts the most. By following Ozone Action tips, we keep tons of ozone-forming pollutants out of the air we breathe and help to keep ozone levels down and air cleaner. Southeast Michigan has been taking Ozone Action since 1994. For more information on Ozone Action! visit the Ozone Action site of the Southeast Michigan Council of Governments (SEMCOG).

Is ozone a health problem?

It depends on where it is. At ground level, excess ozone is a human health threat, causing lung problems and eye irritation. Everybody is vulnerable to ozone's affects, but children, the elderly, people with respiratory conditions and those who work, exercise or play strenuously outdoors are particularly at risk. In the stratosphere, however, the ozone layer acts as a shield, protecting us from harmful ultraviolet rays.

When is Ozone Action! season in Southeast Michigan?

Because ozone formation relies on weather conditions associated with warm weather, it occurs during the spring and summer months, from April through September.

Who decides if it is an Ozone Action! Day?

The Clean Air Coalition's meteorology team forecasts Ozone Action! days according to a number of factors that include meteorological conditions like temperature, wind speed/direction, cloud cover and ultraviolet radiation. The team also considers the likelihood of ozone transport from other areas and expected emissions from regional sources. The Clean Air Coalition's meteorology team is led by meteorologists from the State of Michigan Department of Environment Quality and includes meteorologists from AIR, Inc., Horizon Environmental, Detroit Edison and General Motors.

What can the public do on Ozone Action! Days?

People can volunteer to reduce the emissions that cause ground level ozone. Following these tips on Ozone Action! Days (or any day) means cleaner air for everyone:

  • Refuel vehicles, lawn equipment and gas cans carefully.
  • Avoid topping off the tank and be sure to lift the hose high to avoid spilling gas when finished.
  • Choose to refuel after 6pm when the air is cooler and ozone formation is less likely.
  • Reduce automobile use and improve fuel consumption.
  • Avoid excessive engine idling because excessive idling emits more pollutants than restarting a warm motor.
  • Combine trips or consider car and van pools or public transit for commuting or enjoy the day by choosing to ride a bicycle or walk to various errands and activities.
  • Stay Informed. Ozone Action! Days are announced during weather reports on both television and radio and in local newspapers.