FAIRBANKS -- The U.S. Environmental Protection Agency says parts of the Fairbanks North Star Borough are not in compliance with federal air-quality standards.

The EPA based its decision on air-quality monitoring data from 2006 until 2008.

Parts of the borough have too much fine-particle pollution, which can harm lungs and cause long-term health problems. Fairbanks was flagged for the same violations in 2008.

"It's been fairly well-known that Fairbanks would be a non-attainment area," said Krishna Viswanathan, an EPA spokesman.

The EPA said problem pollution areas in the Pacific Northwest tend to have poor winter air because of old wood stoves and oil furnaces, and occasional stagnant air that lets pollution sit rather than dissipate.

The news was better in Alaska's capital city of Juneau. It's in compliance with federal standards after previously failing to meet them. Officials chalk up the improvement to the city's wood-burning ordinance, tougher enforcement and a public education campaign, the Juneau Empire reported.

"Juneau's air quality is improving, and Juneau's efforts to reduce air pollution have been exemplary," said Larry Hartig, state commissioner of environmental conservation.