Unhealthy air quality is predicted for today, June 10, for all of Connecticut, all of Rhode Island, all of Massachusetts (except Cape Cod and the Islands) and Southern New Hampshire, due to ground-level ozone. Cooler air and northwesterly winds are forecast for Wednesday, which should bring an end to poor air quality.

"As this heat wave continues we are expecting more unhealthy air quality for Tuesday in most of southern New England," said Robert W. Varney, administrator of Environmental Protection Agency's New England office. "On these days, EPA and the medical community suggest that people limit their strenuous outdoor activity."

This summer, New Englanders can expect an increase in the number of air quality alert days, resulting from EPA's recent lowering of the level of the ground-level ozone air quality health standard. The new ozone standard is set at 0.075 parts per million on an 8-hour average basis. Air quality alerts will be issued when ozone concentrations are expected to exceed this new standard. EPA previously issued air quality alerts when 8-hour average ozone levels were at, or predicted to be at, 0.085 ppm or above. So far this year, there have been 7 days in New England when ozone concentrations have exceeded the new ozone standard.

A preliminary list of this summer's unhealthy readings can be found at http://www.epa.gov/region1/airquality/o3exceed-08.html.

Exposure to elevated ozone levels can cause serious breathing problems, aggravate asthma and other pre-existing lung diseases, and make people more susceptible to respiratory infection. When smog levels are elevated, people should refrain from strenuous outdoor activity, especially sensitive populations such as children and adults with respiratory problems.

Ground-level ozone (smog) forms when volatile organic compounds and oxides of nitrogen interact in the presence of sunlight. Cars, trucks and buses give off the majority of the pollution that makes smog. Fossil fuel burning at electric powerplants, particularly on hot days, emit smog-making pollution. Gasoline stations, print shops, household products like paints and cleaners, as well as lawn and garden equipment also add significantly to the ozone smog.

When ozone is forecast to be unhealthy, EPA asks the public to take ozone action. The public can help reduce ozone-smog by:

Using public transportation, car pooling and/or combining trips;

Refueling cars at night to reduce gasoline vapors getting into the air during the daytime when the sun can cook the vapors and form ozone;

Avoiding the use of small gasoline powered engines, such as lawn mowers, chain saws, and leaf blowers.

EPA and the New England states provide real-time ozone data and air quality forecasts at http://www.epa.gov/ne/aqi/. People can also sign up at this Web site to receive free air quality alerts by e-mail when poor air quality is predicted in their area.