Modeling aerosol transmission of SARS-CoV-2 from human-exhaled particles in a hospital ward

Saw, Lip Huat; Leo, Bey Fen; Nor, Norefrina Shafinaz Md; Yip, Chee Wai; Ibrahim, Nazlina; Hamid, Haris Hafizal Abd; Latif, Mohd Talib; Lin, Chin Yik; Nadzir, Mohd Shahrul Mohd

doi:10.1007/s11356-021-14519-9

Cited by 20 publications

(25 citation statements)

References 48 publications

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“…Most of the aerosol particles exhaled from the SARS-CoV-2 positive patient remained airborne and lingered in the air for a prolonged time. The effect of gravity is less significant for small particles than large droplets (Saw et al, 2021). The model also indicates that the particles exhaled from medium exhalation can travel further compared to the particles from weak exhalation.…”

Section: Transport Of Aerosol Particlesmentioning

confidence: 81%

“…It can be concluded that the location of the air purifier is an important factor to reduce the dispersion of exhaled particles in the open ward, hence, reducing nosocomial transmission through inhalation. However, the air purifier is not as effective when compared to an aerosol arrestor proposed in our previous study (Saw et al, 2021). Hence, it is advisable that the healthcare workers must wear the face mask and face shield when dealing with the SARS-CoV-2 patients to reduce the risk of transmission through inhalation and deposition.…”

Section: New Placement Of the Air Purifiersmentioning

confidence: 82%

“…A three-dimensional steady-state two-phase flow CFD simulation with Lagrangian tracking was used to investigate the dispersion of the SARS-CoV-2 virus particles in the common ward equipped with an air purifier and without air purifier. Humans exhale various sizes of particles, larger particle size (> 1 µm) is normally detected during coughing and sneezing (Tang et al, 2013;Chao et al, 2009;Fabian et al, 2011;Yang et al, 2007) while smaller particles are detected during tidal breathing (Papineni and Rosenthal, 1997;Saw et al, 2021;Edwards et al, 2004). Most of the particles exhaled during tidal breathing are less than 1 µm.…”

Section: Numerical Proceduresmentioning

confidence: 99%

“…The efficiency of the air purifier depends greatly on the location, design of the air purifier, flow rate of the conditioned air supply and location of the diffuser and outlet. The distribution of the airflow is one of the important factors that affect the dispersion of the aerosol particles in the room (Saw et al, 2021). In this study, the efficiency of the air purifier was evaluated at different heights.…”

Section: Proposed New Arrangement Of the Air Purifiermentioning

confidence: 99%

See 3 more Smart Citations

The Myth of Air Purifier in Mitigating the Transmission Risk of SARS-CoV-2 Virus

Saw

Leo

Lin

et al. 2022

Aerosol Air Qual. Res.

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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly infectious disease that emerged in December of 2019, threatening human health and leading to global public health crises. Airborne transmission via droplets and aerosol has been recently recognized as one of the infection modes for the SARS-CoV-2 virus. Hospitals have deployed/incorporated indoor air purifiers with the hope to minimize the transmission risk of SARS-CoV-2 virus. Nevertheless, the effectiveness of the indoor air purifier in reducing the transmission risk remained unknown. This study uses computational fluid dynamics to model the dispersion of the aerosol particles exhaled from the patient under the influence of an air conditioner, exhaust fans and air purifier. The numerical model showed that airflow from the diffusers, exhaust fans and placement of the air purifier significantly influenced the dispersion pattern of the aerosol particles in the common ward. Multiple air purifiers placed at 1 meter above the floor and next to a patient can increase the total efficiency from 37.14 to 59.91% for weak exhalation and from 36.44% to 48.81% for medium exhalation. No aerosol particles flew out from the door for weak and medium exhalation when multiple air purifiers were deployed in the common ward. Location and matching the clean air delivery rate with the size of the room are the important factors that affect the performance of the air purifier.

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Section: Transport Of Aerosol Particlesmentioning

confidence: 81%

Section: New Placement Of the Air Purifiersmentioning

confidence: 82%

Section: Numerical Proceduresmentioning

confidence: 99%

Section: Proposed New Arrangement Of the Air Purifiermentioning

confidence: 99%

See 2 more Smart Citations

The Myth of Air Purifier in Mitigating the Transmission Risk of SARS-CoV-2 Virus

Saw

Leo

Lin

et al. 2022

Aerosol Air Qual. Res.

Self Cite

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“…Respiratory aerosols smaller than 5 µm [16,17] released by sneezing can attain a velocity of up to 100 m s −1 , coughing can generate and proliferate the same types of aerosols with velocities of up to 50 m s −1 , talking ones with velocities of 5 m s −1 and normal breathing ones with velocities of 1 m s −1 [18][19][20]. These aerosols can propagate throughout indoor environments [21][22][23], posing a threat to the public. Therefore, chemical surveillance of such microscopic aerosols and their attachment on fomites requires attention beyond standard RT-PCR analysis.…”

Section: Introductionmentioning

confidence: 99%

The Post-COVID-19 Era: Interdisciplinary Demands of Contagion Surveillance Mass Spectrometry for Future Pandemics

et al. 2021

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Mass spectrometry (MS) can become a potentially useful instrument type for aerosol, droplet and fomite (ADF) contagion surveillance in pandemic outbreaks, such as the ongoing SARS-CoV-2 pandemic. However, this will require development of detection protocols and purposing of instrumentation for in situ environmental contagion surveillance. These approaches include: (1) enhancing biomarker detection by pattern recognition and machine learning; (2) the need for investigating viral degradation induced by environmental factors; (3) representing viral molecular data with multidimensional data transforms, such as van Krevelen diagrams, that can be repurposed to detect viable viruses in environmental samples; and (4) absorbing engineering attributes for developing contagion surveillance MS from those used for astrobiology and chemical, biological, radiological, nuclear (CBRN) monitoring applications. Widespread deployment of such an MS-based contagion surveillance could help identify hot zones, create containment perimeters around them and assist in preventing the endemic-to-pandemic progression of contagious diseases.

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Current and potential approaches on assessing airflow and particle dispersion in healthcare facilities: a systematic review

Tan

Wong

Othman

et al. 2022

Environ Sci Pollut Res

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An indoor environment in a hospital building requires a high indoor air quality (IAQ) to overcome patients’ risks of getting wound infections without interrupting the recovery process. However, several problems arose in obtaining a satisfactory IAQ, such as poor ventilation design strategies, insufficient air exchange, improper medical equipment placement and high door opening frequency. This paper presents an overview of various methods used for assessing the IAQ in hospital facilities, especially in an operating room, isolation room, anteroom, postoperative room, inpatient room and dentistry room. This review shows that both experimental and numerical methods demonstrated their advantages in the IAQ assessment. It was revealed that both airflow and particle tracking models could result in different particle dispersion predictions. The model selection should depend on the compatibility of the simulated result with the experimental measurement data. The primary and secondary forces affecting the characteristics of particle dispersion were also discussed in detail. The main contributing forces to the trajectory characteristics of a particle could be attributed to the gravitational force and drag force regardless of particle size. Meanwhile, the additional forces could be considered when there involves temperature gradient, intense light source, submicron particle, etc. The particle size concerned in a healthcare facility should be less than 20 μm as this particle size range showed a closer relationship with the virus load and a higher tendency to remain airborne. Also, further research opportunities that reflect a more realistic approach and improvement in the current assessment approach were proposed.

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Modeling aerosol transmission of SARS-CoV-2 from human-exhaled particles in a hospital ward

Cited by 20 publications

References 48 publications

The Myth of Air Purifier in Mitigating the Transmission Risk of SARS-CoV-2 Virus

The Myth of Air Purifier in Mitigating the Transmission Risk of SARS-CoV-2 Virus

The Post-COVID-19 Era: Interdisciplinary Demands of Contagion Surveillance Mass Spectrometry for Future Pandemics

Current and potential approaches on assessing airflow and particle dispersion in healthcare facilities: a systematic review

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