Air quality in three Maine counties has declined, according to a national report released today by the American Lung Association. Two other counties showed no improvement and continue to receive a grade of F.

Despite the seemingly pristine environmental conditions in much of the state, many areas – especially along the coast – have enough ozone pollution to cause or worsen respiratory problems in adults and children, the study says.

Maine already has the highest incidence of adult asthma of any state in the nation. Maine also reports higher-than-average rates of lung cancer, emphysema and other lung diseases.

The analysis, “State of the Air: 2003,” reports county-by-county ozone data from all 50 states. The data embraces the years 1999 through 2001. Nine representative counties in Maine were included.

Ozone, a powerful respiratory irritant, is a bluish gas formed when volatile organic compounds and nitrogen oxide gases, largely the byproducts of burning fossil fuels, combine in the presence of sunlight and heat.

The primary ingredient in smog, ozone is associated most often with urban areas heavy in automotive traffic, power plants and manufacturing facilities. But ozone is also transported easily on air currents, which accounts for at least some of the problem in Maine.

At first glance, there is some good news in the ALA report. Nationwide, many counties surveyed reported fewer days when the ozone level was dangerously elevated compared to last year’s report. But a significant number of counties saw air quality go down, including three of the nine counties monitored in Maine.

Penobscot, Knox and Cumberland counties all dropped a letter grade. York and Hancock stayed the same, each with an F. Piscataquis and Kennebec kept a B and a C, respectively. Data from Sagadahoc were incomplete. Only Oxford County got an A, as it has for each of the four reporting periods since 1996.

The letter grades are based on a tiered system of hazard levels keyed to a color chart. Statewide, there were 58 “orange” days – days when sensitive individuals, including very active adults and children and anybody with existing respiratory disease, should limit their outdoor activities. Seventeen of those days were in Hancock County, 15 in York and nine in Cumberland.

During the study period, there were 7 “red” days – days when sensitive groups should avoid prolonged outdoor activity and all people should limit their activity. There were two red days each in Hancock, Knox and York counties, and one in Cumberland.

There were no “purple” or “maroon” days in Maine, when the air is considered very unhealthy or hazardous.

Despite more than three decades of federally mandated air-quality initiatives, many areas of the United States continue to decline. Although some areas nationally demonstrated improved conditions, Jane Anne McNeish, spokesman for the American Lung Association of Maine, said in most cases, fewer days in the orange, red and purple danger zones are the result of cooler air patterns rather than payoff from effective air-quality measures.

Cooler weather in much of the country suppressed the production of ozone from 1999 through 2001, the three years covered in the study, she said. The hot summer of 2002 may reverse the national trends demonstrated by some of the data, she predicted.

McNeish said Maine’s ozone levels are high in part because of the state’s location in prevailing air currents. She said Maine acts “like a giant chimney” – especially along the coast – for emissions produced at power plants and manufacturing facilities in Midwestern states.

But Maine also has its own sources of pollution, including high-traffic areas, electrical power plants and manufacturing sites, she said.

The report cites the federal Clean Air Act of 1970 as one of the nation’s most effective environmental laws. But despite progress made in reducing emissions and increasing fuel efficiency in manufacturing, power production and vehicular transport, more needs to be done.

A revised ozone standard established in 1997 has yet to be enforced, for example, and Bush administration proposals aim to relax environmental restrictions on power plants and other polluters, according to the report.

The lung association encourages consumers to practice energy conservation, to educate themselves on the politics of pollution standards and to hold their political representatives accountable for passing and enforcing effective environmental laws.

The report may be viewed on the Web at www.lungusa.org.