Quantifying Environmental Mitigation of Aerosol Viral Load in a Controlled Chamber With Participants Diagnosed With Coronavirus Disease 2019.

Autor:	Parhizkar H; Institute for Health and the Built Environment, University of Oregon, Portland, Oregon, USA.; Energy Studies in Buildings Laboratory, University of Oregon, Eugene, Oregon, USA., Dietz L; Institute for Health and the Built Environment, University of Oregon, Portland, Oregon, USA.; Biology and the Built Environment Center, University of Oregon, Eugene, OregonUSA., Olsen-Martinez A; Institute for Health and the Built Environment, University of Oregon, Portland, Oregon, USA.; Biology and the Built Environment Center, University of Oregon, Eugene, OregonUSA., Horve PF; Institute for Health and the Built Environment, University of Oregon, Portland, Oregon, USA.; Biology and the Built Environment Center, University of Oregon, Eugene, OregonUSA.; Institute of Molecular Biology, University of Oregon, Eugene, Oregon, USA., Barnatan L; Biology and the Built Environment Center, University of Oregon, Eugene, OregonUSA., Northcutt D; Institute for Health and the Built Environment, University of Oregon, Portland, Oregon, USA.; Energy Studies in Buildings Laboratory, University of Oregon, Eugene, Oregon, USA., Van Den Wymelenberg KG; Institute for Health and the Built Environment, University of Oregon, Portland, Oregon, USA.; Energy Studies in Buildings Laboratory, University of Oregon, Eugene, Oregon, USA.; Biology and the Built Environment Center, University of Oregon, Eugene, OregonUSA.
Jazyk:	angličtina
Zdroj:	Clinical infectious diseases : an official publication of the Infectious Diseases Society of America [Clin Infect Dis] 2022 Aug 24; Vol. 75 (1), pp. e174-e184.
DOI:	10.1093/cid/ciac006
Abstrakt:	Background: Several studies indicate that coronavirus disease 2019 (COVID-19) is primarily transmitted within indoor spaces. Therefore, environmental characterization of severe acute respiratory syndrome coronavirus 2 viral load with respect to human activity, building parameters, and environmental mitigation strategies is critical to combat disease transmission. Methods: We recruited 11 participants diagnosed with COVID-19 to individually occupy a controlled chamber and conduct specified physical activities under a range of environmental conditions; we collected human and environmental samples over a period of 3 days for each participant. Results: Here we show that increased viral load, measured by lower RNA cycle threshold (CT) values, in nasal samples is associated with higher viral loads in environmental aerosols and on surfaces captured in both the near field (1.2 m) and far field (3.5 m). We also found that aerosol viral load in far field is correlated with the number of particles within the range of 1-2.5 µm. Furthermore, we found that increased ventilation and filtration significantly reduced aerosol and surface viral loads, while higher relative humidity resulted in lower aerosol and higher surface viral load, consistent with an increased rate of particle deposition at higher relative humidity. Data from near field aerosol trials with high expiratory activities suggest that respiratory particles of smaller sizes (0.3-1 µm) best characterize the variance of near field aerosol viral load. Conclusions: Our findings indicate that building operation practices such as ventilation, filtration, and humidification substantially reduce the environmental aerosol viral load and therefore inhalation dose, and should be prioritized to improve building health and safety. (Published by Oxford University Press for the Infectious Diseases Society of America 2022.)
Databáze:	MEDLINE
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