HELENA - Smoke from wildfires in Canada blew into Helena Wednesday, degrading the local air quality and producing a moderate health risk rating that the city shared with Bozeman, Butte and Billings.
The health risk comes from the particles within that smoke, which are perhaps 25 to 30 times smaller than the thickness of a human hair, said Kathy Moore, the environmental division administrator with Lewis and Clark Public Health.
These particles are small enough to potentially pass through lung tissue into a person’s blood, she added.
These particles contained within smoke are also hard to cough out of the lungs and can become lodged there, Moore said.
Wednesday night's smoke contained slightly more than 30 micrograms of particulates per cubic meter of air, enough to earn the moderate health risk rating, she said.
The moderate health risk rating is the first among five downward steps that rate air quality over a 24-hour period as it deteriorates.
When the air is rated as moderate, the possibility exists of aggravating heart or lung disease among those with cardiopulmonary disease and the elderly.
A result of breathing air containing elevated levels of the particulates and gasses produced by wildfire includes more people seeking medical attention and an increased consumption of medications, Moore said.
Those who sought to cool their homes on Wednesday night by placing fans in their windows were actually bringing more of the wildfire smoke into their homes, Moore said.
Her advice to those who have air-conditioning is to close the windows and use the air-conditioner to cool the home and reduce the level of smoke in the home.
Those without air-conditioning should also try to keep their windows closed to reduce the level of smoke in the home, Moore said, adding that people can also go to the library during the day to escape the heat and smoky air.
The Rocky Mountain Development Council’s Neighborhood Center is also a place where people can go, she added.
The air over Great Falls was slightly worse than that in Helena on Wednesday night, the Department of Environmental Quality website (www.deq.mt.gov/FireUpdates/default.mcpx) indicated. This website provides a daily wildfire smoke update.
Air quality in Helena deteriorated to the moderate level around 7 p.m. and remained there until about 1 a.m. Thursday, according to the state’s air monitoring data at its Helena site. The site data can be accessed at http://1.usa.gov/1LG0NP7 and provides hourly data on past days as well.
People with access to computers and who are sensitive to increased smoke in the air can monitor these websites, Moore said.
The county also has a telephone message at 447-1644 that provides air-quality updates, she added and noted that people who have questions can also call her at 457-8926.
A dense plume of smoke observed in images taken by satellite was curling its way south across the border from Canada on Thursday morning, according to the wildfire smoke update from the Department of Environmental Quality.
By day’s end, the update continued, most areas in Montana will have been impacted by the smoke, especially those east of the Continental Divide.
While atmospheric conditions on Thursday trapped much of the smoke from Canada in Montana, surface and mid-level winds on Friday afternoon over Eastern Montana are expected to shift and help interrupt the flow of smoke into the state, according to the website.
Weather conditions in Canada are anticipated to disrupt the flow of smoke, as is a stronger cold front expected to push through Montana on Saturday night and into Sunday.
This weather system is forecast to clear much of the remaining smoke from the area, the website stated.
The National Weather Service website is calling for the cold front to arrive in Great Falls about 7 p.m. after passing through Cut Bank area about 4 p.m. Wind gusts could be near 40 mph.