HELENA – If you’ve noticed poor air quality recently, you’re not alone.

On Wednesday, air quality around Lewis and Clark County was downgraded to “poor” during the afternoon hours.

Lewis and Clark County Public Health Environmental Health Specialist Jay Plant said the poor rating is due in part to a weather inversion combined with wood-burning stoves and fuel exhaust.

“When you have people burning all those wood stoves out in the valley, all those cars and stuff, it quickly accumulates,” Plant said.

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A weather inversion, where cold air gets trapped under warmer air, also contributes to the problem by trapping pollutants in the air.

“The Helena Valley is like a bowl. We’re surrounded by mountains and when you have an inversion it really does act like a lid. It traps a lot of the pollutants, haze, moisture that normally would escape into the atmosphere, it kind of traps it right in the valley,” Curtis Grevenitz, Chief Meteorologist for KTVH, said.

According to Plant, particulates in the air are measured on an hourly basis and a classification rating is given depending on the results. A “good” rating means burning is allowed. A “watch” rating means the public is encouraged to voluntarily stop burning. Finally, a “poor” rating mandates that all burning stop and fines can be given for non-compliance.

When air quality does drop below good or moderate categories, it can pose a health risk.

“People with heart and lung disease, older adults, small children, any type of breathing problem should start being concerned,” Plant said.

Plant recommends limiting time spent outside if you have if you have asthma or any type of breathing issue. You can check air quality conditions in the Lewis and Clark County area here or by calling 406-447-1644.