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. 2021 Sep 15:261:118563.
doi: 10.1016/j.atmosenv.2021.118563. Epub 2021 Jun 21.

On the airborne transmission of SARS-CoV-2 and relationship with indoor conditions at a hospital

Zeynab Baboli  1   2 , Niloofar Neisi  3 , Ali Akbar Babaei  4   5 , Mehdi Ahmadi  4   5 , Armin Sorooshian  6   7 , Yaser Tahmasebi Birgani  4   5 , Gholamreza Goudarzi  2   4   5
Affiliations

On the airborne transmission of SARS-CoV-2 and relationship with indoor conditions at a hospital

Zeynab Baboli et al. Atmos Environ (1994). .

Abstract

The limited knowledge about the mechanism of SARS-CoV-2 transmission is a current challenge on a global scale. Among possible transmission routes, air transfer of the virus is thought to be prominent. To investigate this further, measurements were conducted at Razi hospital in Ahvaz, Iran, which was selected to treat COVID-19 severe cases in the Khuzestan province. Passive and active sampling methods were employed and compared with regard to their efficiency for collection of airborne SARS-COV-2 virus particles. Fifty one indoor air samples were collected in two areas, with distances of less than or equal to 1 m (patient room) and more than 3 m away (hallway and nurse station) from patient beds. A simulation method was used to obtain the virus load released by a regularly breathing or coughing individual including a range of microdroplet emissions. Using real-time reverse transcription polymerase chain reaction (RT-PCR), 11.76% (N = 6) of all indoor air samples (N = 51) collected in the COVID-19 ward tested positive for SARS-CoV-2 virus, including 4 cases in patient rooms and 2 cases in the hallway. Also, 5 of the 6 positive cases were confirmed using active sampling methods with only 1 based on passive sampling. The results support airborne transmission of SARS-CoV-2 bioaerosols in indoor air. Multivariate analysis showed that among 15 parameters studied, the highest correlations with PCR results were obtained for temperature, relative humidity, PM levels, and presence of an air cleaner.

Keywords: Aerosols; Airborne; Indoor air quality; RT-PCR; SARS-CoV-2.

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Conflict of interest statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Figures

Image 1
Graphical abstract
Fig. 1
Fig. 1
Schematic diagram of sampling area and air-sampler locations in the infectious and ICU wards of Razi hospital.
Fig. 2
Fig. 2
PCA analysis of the presence of SARS-CoV-2 in the COVID-19 ward and all indoor parameters: a) Pareto diagram, and b) PCA Biplot of the first two principal components (PC1 versus PC2) and visual correlation of SARS-CoV-2 with the most important factors affecting indoor air quality. Scores for variables are plotted versus the bottom and left axes.
Fig. 3
Fig. 3
Implementation of SOMs to analyze relationships between indoor parameters and presence of SARS-CoV-2 in the COVID-19 ward.
See this image and copyright information in PMC

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