High CO 2 Exposure Due to Facemask Wear Does Not Impair Students’ Cognition

COVID-19 provided the opportunity to study responses to long-term exposure of significantly elevated CO2 concentrations from facemask wear. Our study examines how high CO2 exposure impacts cognition. We hypothesize despite a sharp increase of local CO2, facemask wear will not impact cognition due to long-term adaptation from mandated wear.  This randomized control trial involved 60 college students, divided into an experimental group with surgical masks and a control without. Subjects remained in a controlled summer environmental room (temperature 31.5° C, relative humidity 30%), completed six cognitive tests, and surveys within 90 min. Ten subjects had a second 30 min visit to measure CO2 concentration at the ala of the nose with and without surgical masks. Cognitive performance was the primary outcome. This study is under WPI IRB #20-0001. From October 28, 2021, through February 16, 2022, 60 participants (mean age 20·93 [SD 2·62] years, 36·67% female) were randomly assigned to the control (N=30) or experimental group (N=30).For results, a p < 0·05 determined significance. The experimental group showed significantly lower risk taking (p=0.047, 9·93 [4·06] vs 12·13 [4·33]) and higher short-term memory scores (p=0.037, 0·55 [0·12] vs 0·47 [0·17]). Wearing a surgical mask sharply increased local CO2 concentration (25767.2 [2317.8] ppm). Facemask mandates can be safely reinstated during viral outbreaks. Despite high local elevations of CO2 when wearing surgical facemasks, humans might have become adapted to long-term wear and high CO2 exposure, and cognition was not severely inhibited. Our study considered healthy college students and surgical masks. Therefore, results may not be generalized to other populations or facemask.Funding: National Science Foundation (#1931077) and TRIAD grant of Worcester Polytechnic Institute.Declaration of Interest: To the authors’ knowledge, there is no conflict of interest.Ethical Approval: The research protocol was approved by the Institutional Review Board at Worcester Polytechnic Institute (#20-0001).