Just when you thought you could head indoors to be safe from the air pollution that plagues the Salt Lake Valley, new research shows that elevated air pollution events, like horror movie villains, claw their way into indoor spaces. The research, conducted in conjunction with the Utah Division of Facilities Construction and Management, is published in Science of the Total Environment.
In a long-term study in a Salt Lake-area building, researchers found that the amount of air pollution that comes indoors depends on the type of outdoor pollution. Wildfires, fireworks and wintertime inversions all affect indoor air to different degrees, says Daniel Mendoza, a research assistant professor in the Department of Atmospheric Sciences and visiting assistant professor in the Department of City & Metropolitan Planning. The study is unique, Mendoza says, combining a long-term indoor air quality monitoring project with paired outdoor measurements and research-grade instruments.
“We all know about the inversions,” Mendoza says. “We all know how large of a problem wildfires are. But do we really know what happens when we’re inside?”
Mendoza, who also holds appointments as an adjunct assistant professor in the Pulmonary Division at the School of Medicine and as a senior scientist at the NEXUS Institute, and his colleagues set up their air monitoring equipment at the Unified State Laboratories in Taylorsville, Utah. They placed three sensors to measure airborne concentrations of particulate matter: One on the roof to measure outdoor air, one in the air handling room–where the outdoor air comes in–and one in an office. The building uses a 100% outside air filtration system; this is not typical for most commercial buildings, which usually use some amount of recirculated air.
The sensors stayed in place from April 2018 to May 2019, just over a year. In the Salt Lake Valley, a year’s air quality events include fireworks-laden holidays on Independence Day and Pioneer Day (July 24), smoke from wildfires throughout the West that settles in the bowl-like valley and wintertime inversions in which the whole valley’s emissions are trapped in a pool of cold air.