2021 Yes https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7914660/ Deng, Shihan North America Exposure Study Students Elementary (K-5) Temperature Humidity Carbon Dioxide (CO2) Particulate Matter (PM) Absenteeism Absence rate Attendance Seasonal variation Midwest US During non-heating season, a 3% increase of IRA was estimated with 1,000,000-counts/L increase of particles that had a diameter less than 2.5 μm (PN2.5); during the heating season, a 3% increase of IRA were expected with 100 ppm increase of room averaged CO2 concentration; and (4) These results suggested that the IAQ and TC factors could associated with IRA differently between heating and non-heating seasons.