Modelling uncertainty in the relative risk of exposure to the SARS-CoV-2 virus by airborne aerosol transmission in well mixed indoor air

Jones, Benjamin; Sharpe, Patrick; Iddon, Christopher; Hathway, Elizabeth Abigail; Noakes, Catherine; Fitzgerald, Shaun

doi:10.1016/j.buildenv.2021.107617

Cited by 74 publications

(90 citation statements)

References 51 publications

(60 reference statements)

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“…Small airborne particles and aerosols (diameter < 5 µm) can remain up to several hours in the air [43]. So far, most COVID-19 risk assessments for indoor environment are based on calculations applying spreadsheet models including relevant environmental and physiological parameters [8,44,45]. Typical standard settings represent classrooms, office spaces or receptions with space volume < 400 m 3 and less than 50 persons present.…”

Section: Discussionmentioning

confidence: 99%

Experimental Investigation of Aerosol and CO2 Dispersion for Evaluation of COVID-19 Infection Risk in a Concert Hall

Schade

Reimer

Seipenbusch³

et al. 2021

IJERPH

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The dispersion of small aerosols in a concert hall is experimentally studied for estimating the risk of infection with SARS-CoV-2 during a concert. A mannequin was modified to emit an air stream containing aerosols and CO2. The aerosols have a size distribution with a peak diameter (δ) close to 0.3 µm and a horizontal initial particle velocity (vp,x ) of 2.4 m/s. The CO2 -concentration (c) emitted simultaneously is 7500 ppm. It is investigated, if the spatial dissipation of aerosols and CO2 can be correlated. This would allow the use of technically easier CO2 measurements to monitor compliance with aerosol concentration limits. Both aerosol and CO2 concentrations are mapped by different sensors placed around the mannequin. As a result, no significant enrichment of aerosols and CO2 was obtained outside a radius of 1.5 m when the fresh air ventilation in the concert hall has a steady vertical flow with a velocity of vg,z= 0.05 m/s and the installed ventilation system was operating at an air change rate per hour (ACH) of 3, corresponding to an air exchange rate of 51,000 m3/h. A Pearson correlation coefficient of 0.77 was obtained for CO2 and aerosol concentrations measured simultaneously at different positions within the concert hall.

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Section: Discussionmentioning

confidence: 99%

Experimental Investigation of Aerosol and CO2 Dispersion for Evaluation of COVID-19 Infection Risk in a Concert Hall

Schade

Reimer

Seipenbusch³

et al. 2021

IJERPH

View full text Add to dashboard Cite

show abstract

“…Many researchers have noted the possibility of the virus transmission by aerosols [11][12][13][14][15], and the US Mine Safety and Health Administration (MSHA) has confirmed its importance, which recommends that miners wear appropriate masks to prevent respiratory droplets or aerosols from reaching others [31]. Based on the results of the study [28][29][30], how many viruses can be potentially absorbed by the respiratory system during a working day was estimated when there is one infected person in the team of employees and 6.7 mg/min.…”

Section: Discussionmentioning

confidence: 99%

“…Literature data proved that virus-containing body secretions can be aerosolized into infectious virus-containing droplets or particles in a variety of ways; moreover, respiratory secretions are known to be aerosolized through normal daily activities (e.g., talking, singing, exhaling, coughing, or sneezing) [6]. In terms of the latest research, several papers have highlighted the role of aerosol in the transmission of coronavirus SARS-CoV-2 by the airborne route [11][12][13][14][15]. Additionally, studies conducted after the SARS-CoV-1 epidemic demonstrated that airborne transmission was the most likely mechanism explaining the spatial pattern of infections.…”

Section: Introductionmentioning

confidence: 99%

Transport of Aerosols in Underground Mine Workings in Terms of SARS-CoV-2 Virus Threat

et al. 2021

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This paper presents a method of implementation and the results of aerosol dispersion tests in underground mine workings. Numerous tests were carried out to determine the potential risk of SARS-CoV-2 coronavirus infection in the underground environment of the mines. The influence of selected parameters of mine air on the possibility and method of aerosol transmission through ventilation routes was experimentally determined in real conditions. The concentration of additional aerosols in the class of ultrafine and fine aerosols increased with the distance from the generator, while the concentration of coarse particles decreased. Assuming the consumption of the solution with which aerosols were generated, even at a small level of 1 cm3/min., the number of additional aerosols was several hundred particles in one cubic centimeter of air at a distance of 50–70 m from the generator. The concentration of ultrafine particles in the range of 40–20,000 nm increased from 122 particles/cm3 to 209 particles/cm3 at air temperature of 12 °C and relative humidity of 95–96%, and from 90 particles/cm3 to 243 particles/cm3 at air temperature of 17 °C and relative humidity of 76–82%, with the increasing distance from the generator (10 m to 50 m).

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“…This was due to the presence of a temporally fluctuating horizontal air flow with v H = 0.01 m/s. These results show the importance of even slight and temporally changing air flow conditions on aerosol dispersion, which will be very difficult to consider in models when calculating infection risks by airborne routes of viral droplets (Jones et al, 2021).…”

mentioning

confidence: 99%

Viral aerosol transmission of SARS-CoV-2 from simulated human emission in a concert hall

Schade¹,

Reimer²,

Seipenbusch³

et al. 2021

International Journal of Infectious Diseases

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The dispersion of aerosols was studied experimentally in several concert halls to evaluate their airborne route and thus the risk of SARS-CoV-2 spreading. For this, a dummy is used that emits simulated human breath containing aerosols with a mean diameter of 0.3 µm, and horizontal exhalation velocity of v =2.4 m/s measured 10 cm in front of the mouth as well as CO 2 . Aerosol and CO 2 concentration profiles were mapped using sensors placed around the dummy. No substantial enrichment of aerosols and CO 2 was found at adjacent seats, provided that: (1) there are floor displacement outlets under each seat enabling a minimum local fresh air vertical flow of v v =0.05 m/s, (2) the air exchange rate (ACH) constitutes more than 3 h -1 , and (3) the dummy wears a surgical face mask. Knowledge of dispersion of viral droplets by airborne routes in real environment helps to establish risk assessment when re-opening concert halls and theaters after pandemic lock down.

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Modelling uncertainty in the relative risk of exposure to the SARS-CoV-2 virus by airborne aerosol transmission in well mixed indoor air

Cited by 74 publications

References 51 publications

Experimental Investigation of Aerosol and CO2 Dispersion for Evaluation of COVID-19 Infection Risk in a Concert Hall

Experimental Investigation of Aerosol and CO2 Dispersion for Evaluation of COVID-19 Infection Risk in a Concert Hall

Transport of Aerosols in Underground Mine Workings in Terms of SARS-CoV-2 Virus Threat

Viral aerosol transmission of SARS-CoV-2 from simulated human emission in a concert hall

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