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

J Infect Dis. 2020 Jun 11;jiaa334. doi: 10.1093/infdis/jiaa334. Online ahead of print.

Abstract

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.

Keywords: COVID-19; SARS-CoV-2; aerosol decay; aerosol persistence; relative humidity; sunlight.