BANGOR, (AP) – Maine air meets federal standards for tiny airborne particles, 30 times smaller than a human hair, according to a report from the Environmental Protection Agency.

But environmental officials say it’s important to keep levels of the particles low, because they contribute to the same health problems as the ozone that can be a problem in Maine.

The government has regulated fine particulate matter since 1997, and since then, pollution controls have reduced the amount of the particles. But multiple studies of the particles’ health impact have to question whether existing federal standards are tight enough sufficient to protect human health.

People can inhale the fine particles, which can make healthy people cough. For people with asthma, heart disease or diabetes, they can be a major health risk.

“The data all seems to point to the fact that the standard needs to go down,” Jim Brooks, director of the Maine Department of Environmental Protection’s air bureau, said Tuesday.

In the 30 years Maine has been keeping records, particulate matter has never been more than a low-level problem, he said.

The EPA has begun reviewing the new data, partly because of a scheduled review of Clean Air Act rules, and partly because of lawsuit threats from environmental groups. The agency must recommend by 2006 whether the standard needs updating, and drafts could be proposed by next summer.

“We don’t think the standard should be lowered by any means, and perhaps it should be strengthened,” said Dave Conroy, manager of air quality planning at the regional EPA office in Boston.

Fine particulate matter includes any particles smaller than 2.5 microns in diameter. Many of the particles are created by combustion in factories, forest fires and cars, but natural chemical reactions and dust also can supply the airborne particles.

In high densities, the tiny particles are a major component of the haze and smog that can combine with ozone to obscure views in summer.

AP-ES-06-30-04 0216EDT