Air quality in coastal Maine has improved enough for the state to consider asking to have the region taken off a national list of places that exceed standards for ground-level ozone.

The Board of Environmental Protection will hold a public hearing today before deciding whether to formally ask the federal government to re-evaluate air quality in nine coastal counties long considered "non-attainment" zones for ozone, a component of smog. The BEP is expected to make a formal request later this summer.

State and federal pollution-cutting measures since the early 1990s have not eliminated pollution, but have improved air quality enough so that the region from Kittery to Winter Harbor no longer belongs on the list, said Jeff Crawford, an environmental specialist with the Department of Environmental Protection.

Crawford said pollution control efforts include tighter emission controls on vehicles and power plants, which have reduced pollution generated in Maine and that blown in from other states.

Crawford said removing Maine counties from the federal list is a "technical matter" that does not mean the problem is solved. But he said it would help affirm the state and federal actions that have helped clean up Maine's air.

"It's a celebration of success," he said. "It's proof that the controls work."

While they applaud the improvements in Maine's air quality, representatives from environmental and public health groups said meeting federal standards is not enough. Recent studies suggest that ozone levels far below federal standards can be hazardous, said Ed Miller, chief executive officer of the American Lung Association of Maine.

"In no way should this be interpreted as saying the air there is healthy," he said. "There is no healthy level."

Ground-level ozone is a pollutant created when industrial and vehicular emissions containing volatile organic compounds undergo a chemical reaction in the presence of sunlight.

Exposure to ozone can make people more susceptible to respiratory infection and harm people, especially children and the elderly, with asthma or other breathing ailments.

High ozone levels during the summer months have been a concern in regions of coastal Maine since the 1970s. The state already has issued ozone warnings for towns along southern and midcoast Maine several times this summer. Even if the redesignation occurs, Crawford said the warnings are certain to continue.

The federal ozone standard is set at 84 parts per billion, with readings measured over an eight-hour period. Since the readings also are averaged over three years, there may be days of high ozone concentrations even in a region that meets the standard.

To be removed from the federal list, county data would have to show that the three-year average for the fourth worst eight-hour period falls below the federal minimum.

Dylan Voorhees of the Natural Resource Council of Maine said he believes the federal standard is a misleading benchmark. Even with every region in Maine on the verge of meeting this standard, he said there is still an ozone advisory somewhere in the state 20 percent of the time.

"That's obviously not clean enough air," he said.

Rather than focusing on ozone levels and federal standards, Voorhees said he would like to see public attention turn toward conservation and minimizing the causes of high ozone levels.

"I think the big picture is that ozone and particulate matter are forms of fossil fuel consumption," he said.

The BEP invites comments from the public on the redesignation proposal today at 9:30 a.m. at the Holiday Inn near the Augusta Civic Center.

Staff Writer Seth Harkness can be contacted at 282-8225 or at: