#Evergreen needles act as air quality monitors
“#Evergreen needles act as air quality monitors” Peter Lippert (left) and Grant Rea-Downing examine artificial pine branches being tested as passive air quality monitors. Photo from Sept. 2019. Credit: Paul Gabrielsen/University of Utah Every tree, even an evergreen, can be an air quality monitor. That’s the conclusion of researchers at the University of Utah who…