The Montana Department of Environmental Quality has rated the air quality in Helena and surrounding areas as "unhealthy" on Sunday.
The poor air quality is due to wildfires burning in Montana and other Western states.
An "unhealthy" (red) rating means that active children and adults, and people with respiratory disease, such as asthma, should avoid prolonged outdoor exertion; everyone else, especially children, should limit prolonged outdoor exertion.
Other areas of Montana are also rated "unhealthy" including Great Falls, Bozeman, Lewistown, Malta, and the Seeley/Swan region.
Parts of the Flathead Valley are currently rated as "very unhealthy" (purple), which means that active children and adults, and people with respiratory disease, such as asthma, should avoid all outdoor exertion; everyone else, especially children, should limit outdoor exertion.
The DEQ rates air quality based on the amount of particulate matter (PM) in the air, which is often caused by smoke from wildfires. In addition to being emitted from wildfires, PM can also come directly from other sources, such as construction sites, unpaved roads, fields, and smokestacks. The EPA says that PM is a mixture of solid particles and liquid droplets found in the air. Some particles, such as dust, dirt, soot, or smoke, are large or dark enough to be seen with the naked eye. Others are so small they can only be detected using an electron microscope.
Here are the ratings and their corresponding color codes, listed in order of increasing danger or health risks:
- Good (green): No negative health effects.
- Unhealthy for Sensitive Groups (orange): Increasing likelihood of respiratory symptoms in sensitive individuals, aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly. People with respiratory or heart disease, the elderly and children should limit prolonged exertion.
- Unhealthy (red): Increased aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly; increased respiratory effects in the general population. People with respiratory or heart disease, the elderly, and children should avoid prolonged exertion; everyone else should limit prolonged exertion.
- Very Unhealthy (Purple): Significant aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly; significant risk of respiratory effects in the general population. People with respiratory or heart disease, the elderly, and children should avoid any outdoor activity; everyone else should avoid prolonged exertion.
- Hazardous (maroon): Serious aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly; serious risk of respiratory effects in the general population. Everyone should avoid any outdoor exertion.
RELATED:
- Shellrock and 467 Trail fires update (August 18)
- Montana firefighters returning home after battling California fires
- Wildland firefighting terms: what do they mean?
VIDEO FROM THE HOWE RIDGE FIRE IN GLACIER NATIONAL PARK:
