Region 1: EPA New England
Ground-level Ozone (Smog) Information
Ground-level ozone presents a serious air quality problem in New England. In 2008, EPA revised the ozone standard to a level of 0.075 parts per million, 8-hour average. Over the last 5 years (2007 through 2011), there have been an average of 28 days per summer when New England's air exceeded this standard.
Ground-level ozone is formed by a chemical reaction between VOCs and oxides of nitrogen (NOx) in the presence of sunlight. Ozone concentrations can reach unhealthful levels when the weather is hot and sunny with little or no wind. View ozone concentrations and corresponding weather conditions for a day in 1998 when high ozone concentrations were measured across Southern New England. In New England, high ozone levels usually occur between 1:00 and 7:00 pm from May through September.
Visit EPA-New England's Air Quality Index page to get real-time and forecasted air pollution data in an understandable visual format. This information is provided so the public can take action to protect their health, and reduce pollution.