Air purifiers: how do they work and who should get one?

Outdoor air quality affects indoors, and many are turning to air purifiers - here's what to know if you want to buy oneFor several decades, air quality in the US was trending up by many measures. Data indicated that fine, inhalable airborne particulate matter, known as PM2.5, was declining in 41 states before 2016.But the increasing frequency and severity of wildfires has undone that progress "about 25%" in the last eight years, says Jienan Li, a research scientist specializing in indoor air quality at Colorado State University. Continue reading...