2024 No Particulate matter in mechanically ventilated high school classrooms https://doi.org/10.1016/j.buildenv.2020.106986 Ren, Jianlin North America Experimental Exposure Students High School (9-12) Particulate Matter (PM) Particles PM Emissions Resuspension Flooring Schools Two-year field study measured airborne particulate matter (PM) in 39 Texas high school classrooms with mechanical ventilation. PM levels varied by flooring and outdoor sources. Understanding PM exposure can inform design and filtration strategies for student health. 2020