Missoula officials, public-health staff weigh air-quality trade-offs of prescribed burns and rising wildfire smoke

Juanita Vero, a Missoula County commissioner, opened a Missoula County Commissioners podcast episode by introducing Carrie Mueller of Missoula Public Health to discuss local air quality, its history and public-health implications. Commissioners Dave Stromer and Josh Slotnick joined the conversation.

Mueller explained that Missoula’s surrounding mountains create a bowl where cold air can sink and a warmer layer above can ‘cap’ the valley, trapping emissions underneath — a meteorological setup known locally as an inversion. “An inversion is what it sounds like. It’s inverted air masses,” Mueller said, describing how the warm layer can act like a blanket over the valley and trap pollution from cars, wood stoves and industry.

The discussion traced Missoula’s air-quality improvements to mid-20th-century regulatory shifts and local programs. Panelists recalled a time when frequent winter ‘‘stage 1’’ alerts were common because of wood-stove use and mill emissions. Mueller said the Clean Air Act opened the door for local authority and stricter controls on…