The American Lung Association has given Butte-Silver Bow County an F for its air quality, but the report and a health official say part of that is due to summer wildfires in Idaho and Montana in 2012.
Paul Riley, environmental monitoring director for the Butte-Silver Bow Health Department, also said an air-quality ordinance enacted in 2012 and education about wood-burning stoves are paying off.
“As far as air quality in the winter months, which our program directly addresses, our air quality has improved,” Riley said Tuesday.
The lung association’s “State of the Air” report gave Silver Bow, Lewis and Clark (Helena), Missoula and Ravalli (Hamilton) counties an F for 24-hour particle pollution levels based on data compiled by the Environmental Protection Agency from 2010 through 2012.
The spikes in short-term particle pollution — also called soot — were related to the wildfires of 2012, according to the report released Wednesday.
The health effects of small-particle air pollution are numerous, especially on children, the elderly and those with underlying cardiac or respiratory disease such as asthma or chronic obstructive pulmonary disease, or COPD.
The small particles generated from wildfires or other sources can easily become inhaled into the lungs, leading to inflammation and lower-lung functions manifesting as such symptoms as coughs, wheezing and difficulty breathing.
The report said Montana counties are some of the cleanest for ozone pollution, but particle pollution continues to be a problem in several counties, including Silver Bow.
Flathead (Kalispell), Powder River (Broadus) and Richland (Sidney) counties got As on the report.
Due to smoke from the 2012 fires, Missoula had its worst-ever number of unhealthy days with an average of 8.5 over the three years, the report said.
Silver Bow County, which also got an F on last year’s report, averaged 8.7 unhealthy days, ranking it 17th worst in the nation.
Ravalli County, even more heavily impacted by 2012 wildfires in Idaho, ranked eighth nationally for short-term particle pollution and had 23.7 days of unhealthy air.
Butte’s air problems are tied largely to residential woodstove emissions and its location in a mountain valley, where cold temperatures can trap particulate pollution during winter inversions.
Riley said the wildfires in 2012 – events beyond Butte’s control – somewhat skewed the results used by the lung association in its report.
He said from this past November through March, particle pollution never exceeded a federal threshold for violation over a 24-hour period.
“This last winter was one of the first in a long time we didn’t exceed that,” he said. “Going into this part of the year we’ve usually had two or three days that exceeded the federal standard.”
The readings can be affected by natural factors such as the cold and wind, but Riley said an air-quality ordinance enacted in Butte-Silver Bow in 2012 and recent education efforts likely are having an effect.
The local law requires that wood-burning stoves installed after May 2012 meet EPA standards and it updated restrictions on outdoor burning, among other things.
“We are also getting information out to general public about changes in our program and bringing them up to speed about clean-burning methods and using the proper wood and being considerate of their neighbors,” Riley said.
Riley said local officials also are considering the possibility of a new program that would help those with lower incomes replace their old wood-burning stoves with newer ones that burn hotter and cleaner.
— Reach Smith at firstname.lastname@example.org or 406-496-5511.