The U.S. Environmental Protection Agency recently announced updated National Ambient Air Quality Standards for ozone, a life-threatening air pollutant. The new standard of 70 parts per billion (ppb) is a change from the previous standard of 75 ppb that had been in place since 2008.

Ozone irritates and inflames the lungs and the respiratory system. Scientists, physicians and the health community at large have long recognized ozone’s potential to cause premature death. Unsafe levels of ozone can cause difficulty breathing, shortness of breath, wheezing and coughing and asthma attacks, and can result in trips to the emergency room and admissions to the hospital. Ground level ozone is the nation’s most widespread air pollutant and a primary component of smog.

Heather Selin, a farmer from Jackson stated, “I’ve had asthma for as long as I can remember, and I had several stays in the hospital as a child. Now I feel the effects most severely on high ozone days – often having to restrict my time outside. As a farmer, that means I lose time at work and our business suffers as a result. For me, our nation’s ozone standard is not some vague environmental issue, it affects my health, my productivity, and my overall quality of life. Today’s new standard is a positive step that will give us all better information and help clean up the air.”

Southern and coastal Maine experience the highest ozone levels in the state. In the Lung Association’s 2015 “State of the Air” report, York County received a grade of “F” for its number of high ozone days, while Cumberland, Knox, and Hancock all received a grade of “C”.

The full rule, including maps, fact sheets, and impact data can be found on the EPA’s website at