Unhealthy air quality is predicted for most of Connecticut, all of Rhode Island, southeastern and central into northeastern Massachusetts, southeastern New Hampshire, and coastal Maine on Wednesday, Sept. 1, due to ground-level ozone.

Unhealthy air quality is expected to continue for these areas into Thursday, Sept. 2.

“With more hot weather predicted on Wednesday and Thursday this week, there will likely be unhealthy air quality days in many parts of New England,” said Curt Spalding, administrator of EPA’s New England office.

“When air quality is poor, EPA and the medical community suggest that people limit their strenuous outdoor activity. People can also help reduce emissions during these times.”

Due to Wednesday’s forecast of hot weather, the demand for electricity in New England is also forecast to reach high load levels. Given the air quality and high load forecasts, EPA is asking homeowners and employers to make a special effort to reduce their electricity consumption. Employers can consider asking employees to dress casually and turn their air conditioning to a higher temperature setting and turn off any unnecessary lights and computers when not in use. Homeowners can turn air conditioners to a higher temperature setting, turn off unnecessary lights and appliances, and defer household activities like laundry until later hours.

Exposure to elevated ozone levels can cause serious breathing problems, aggravate asthma and other preexisting 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. Burning of fossil fuels at electric power plants, particularly on hot days, emits 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.

In 2008, EPA strengthened the ozone air quality health standard to 0.075 parts per million (ppm) on an eight-hour average basis. Air quality alerts are issued when ozone concentrations exceed, or are predicted to exceed, this level.

In January, EPA proposed to strengthen the ozone standard even further. A final decision is scheduled for August. So far this year, there have been 23 days in New England when ozone concentrations have exceeded the new 2008 ozone standard.