Airborne SARS-CoV-2 is Rapidly Inactivated by Simulated Sunlight

Schuit, Michael; Ratnesar-Shumate, Shanna; Yolitz, Jason; Williams, Gregory; Weaver, Wade; Green, Brian; Miller, David; Krause, Melissa; Beck, Katie; Wood, Stewart; Holland, Brian; Bohannon, Jordan; Freeburger, Denise; Hooper, Idris; Biryukov, Jennifer; Altamura, Louis A; Wahl, Victoria; Hevey, Michael; Dabisch, Paul

Aerosols represent a potential route of transmission of COVID-19. This study examined the effect of simulated sunlight, relative humidity, and suspension matrix on the stability of SARS-CoV-2 in aerosols. Both simulated sunlight and matrix significantly affected the decay rate of the virus. Relative humidity alone did not affect the decay rate; however, minor interactions between relative humidity and the other factors were observed. Decay rates in simulated saliva, under simulated sunlight levels representative of late winter/early fall and summer were 0.121±0.017 min(-1) (90% loss: 19 minutes) and 0.379±0.072 min(-1) (90% loss: 6 minutes), respectively. The mean decay rate without simulated sunlight across all relative humidity levels was 0.008±0.011 min(-1) (90% loss: 125 minutes). These results suggest that the potential for aerosol transmission of SARS-CoV-2 may be dependent on environmental conditions, particularly sunlight. These data may be useful to inform mitigation strategies to minimize the potential for aerosol transmission.