Large forest fires raging in northeast Alaska and British Columbia are likely contributing to hazy conditions in Juneau and have caught the attention of state air regulators concerned about possible health effects.
The regulators said Thursday they are watching Juneau's level of lung-irritating fine particulate pollution, which they attribute mostly to the wildfires, to see if it could cause air quality problems here or in other Southeast communities.
"We've kind of got an abnormal condition here," said Gerry Guay, program manager for the Air Monitoring Division in the Alaska Department of Environmental Conservation.
Smoke creeping in from the northeast fires has combined with the current high pressure system in Juneau to create a buildup of haze over the past seven days. The level of fine particulate pollution - a major component of haze - has doubled in Juneau since late last week, according to data collected by the state air monitoring division. If those levels worsen considerably over the weekend, Guay said his division may issue an air-quality advisory encouraging people with respiratory problems to restrict their outdoor activities.
The average particulate levels measured Wednesday and Thursday at the state's air monitoring station at Floyd-Dryden Middle School were 20 to 21 micrograms per cubic meter, well below the federal air quality limit of 65 micrograms.
However, even at much lower levels, fine particulate pollution can trigger respiratory problems such as asthma, according to a 2004 report by the federal Environmental Protection Agency.
The EPA is now reviewing the 65-microgram limit for fine particulates.
There may be no safe level, said Guay, the state air division official.
Guay said his agency would issue a health advisory if fine particulate levels exceed 40 micrograms.
Haze usually affects Juneau for one of two reasons smoke from wildfires in Canada and the Interior of Alaska or low clouds and fog from the Pacific, said Tom Ainsworth, a National Weather Service meteorologist based in Juneau.
Otherwise, Juneau has some of the best air quality, anywhere Ive ever been, Ainsworth said.
Wetter weather beginning next Tuesday likely will cause Juneaus haze to dissipate, Ainsworth said.
But for now, a curving windflow traveling clockwise from northeast Alaska over the Yukon and northern British Columbia is bringing smoke from those areas wildfires to the Alaska Panhandle.
The windflow hasnt changed in eight days, Ainsworth said.
As of Thursday evening, four major fires near Fort Yukon, Fairbanks and Tok had consumed hundreds of thousands of acres, crossed the Taylor Highway and stranded residents of Chicken. Also, the fire hazard potential for the Southeasts Tongass National Forest remained high due to dry conditions.
We definitely want it to rain soon, said Pamela Finney, spokeswoman for the U.S. Forest Service in Alaska.