Document Type : Regular Article

Author

Chemical Engineering Department, Hamedan University of Technology, P. O. Box: 65155, Hamedan, Iran

Abstract

The size and lifetime of evaporating sneeze droplets in the indoor environment were studied experimentally and theoretically. The effects of indoor temperature Tand indoor humidity RHon evaporating droplets with the initial diameters of 4.9, 8.1, 17.2, and 29.7 μm were investigated. The size distribution and mean size of droplets were obtained by a laser particle sizer. The experimental data showed that the possibility of aerosolized droplets increased from 25.5 to 36.1 % by increasing Tfrom 18 to 30 °C and decreased from 36.1 to 13.6 % by increasing RH from 30 to 60 %. A one-dimensional droplet evaporation model was used to estimate the lifetime of the droplet. A critical RH of 40 % was found; above it, the lifetime of the droplet exponentially increases. The effect of the initial diameter of droplets was higher than that of RH and also the impact of RH was higher than that of Ton the lifetime of the aerosolized droplet nuclei. A significant effect of environmental conditions on the lifetime of the droplet was found over the range of 26 °C ≤ T ≤ 30 °C and RH ≤ 40 %, while the effect decreased in the range of 18 °C ≤ T ≤ 22 °C and RH > 40 %, where a minimal shrinkage of droplets took place because of the hygroscopic growth of droplets. The results of this study do not imply that the COVID-19 virus will be deactivated at the end of the lifetime of the droplet, but it represents that controlling the indoor environment is important for droplets to carry the virus.

Keywords

Main Subjects

  • World Health Organization (WHO), “Modes of transmission of virus causing COVID-19: Implications for IPC precaution recommendations, scientific brief”, Geneva, (29 March 2020c). (https://apps.who.int/iris/handle/10665/331616/).
  • Noorimotlagh, , Jaafarzadeh, N. T., Martínez, S. S. and Mirzaee, S. A., “A systematic review of possible airborne transmission of the COVID-19 virus (SARS-CoV-2) in the indoor air environment”, Environ. Res., 193 (1), 110612 (2021).
  • Huang, C., Wang, Y., Li, X., Ren, L., Zhao, J., Hu, Y., Zhang, L., Fan, G., Xu, J. and Gu, X., “Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China”, Lancet, 395 (10223), 497 (2020).
  • Huang, N., Pérez, P., Kato, T., Mikami, Y., Okuda, K. I., Gilmore, R. C. and Domínguez, C., “The COVID-GRAM tool for patients hospitalized with COVID-19 in Europe”, JAMA Internal Medicine, 1 (1), 892 (2021).
  • Chan, J. F. W., “A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: A study of a family cluster”, Lancet, 395 (10223), 514 (2020).
  • Liu, J., Liao, X., Qian, S., Yuan, J., Wang, F., Liu, Y., Wang, Z., Wang, F. S., Liu, L. and Zhang, Z., “Community transmission of severe acute respiratory syndrome Coronavirus 2, Shenzhen, China”, Infect. Dis., 26 (1), 1320 (2020).
  • Balachandar, , Zaleski, S., Soldati, A., Ahmadi, G. and Bourouiba, L., “Host-to-host airborne transmission as a multiphase flow problem for science-based social distance guidelines”, Int. J. Multiph. Flow, 132 (1), 103439 (2020).
  • Liu, K., Allahyari, M., Salinas, J. S., Zgheib, N. and Balachandar, S., “Peering inside a cough or sneeze to explain enhanced airborne transmission under dry weather”, Rep., 11 (1), 9826 (2021).
  • Mikszewski, A., Stabile, L., Buonanno, G. and Morawska, L., “Increased close proximity airborne transmission of the SARS-CoV-2 Delta variant”, Total Environ., 816 (1), 151499 (2022).
  • de Oliveira, M., Mesquita, L. C. C., Gkantonas, S., Giusti, A. and Mastorakos, E., “Evolution of spray and aerosol from respiratory releases: Theoretical estimates for insight on viral transmission”, Proc. R. Soc. A, 477 (2245), 1 (2021).
  • Li, H., Leong, F. Y., Xu, G., Ge, Zh., Kang, Ch. W. and Lim, K. H., “Dispersion of evaporating cough droplets in tropical outdoor environment”, Fluids, 32 (1), 113301 (2020).
  • Tatsuno, K. and Nagao, S., “Water droplet size measurements in an experimental steam turbine using an optical fiber droplet sizer”, Heat Trans., 108 (4), 939 (1986).
  • Shang, Y., Tao, Y., Dong, J., He, F. and Tu, J., “Deposition features of inhaled viral droplets may lead to rapid secondary transmission of COVID-19”, Aerosol Sci., 154 (1), 105745 (2021).
  • Ismail, I. M. I., Rashid,, Ali, M., Saeed Altaf, B. A. and Munir, M,. “Temperature, humidity and outdoor air quality indicators influence COVID-19 spread rate and mortality in major cities of Saudi Arabia”, Environ. Res., 204 (Pt B), 112071 (2022).
  • van Doremalen, N., Bushmaker, T., Morris, D. H., Holbrook, M. G., Gamble, A. and Williamson, B. N., “Aerosol and surface stability of SARS-CoV-2 as compared with SARS-Cov-1”, Engl. J. Med., 382 (16), 1564 (2020).
  • Bourouiba, L., “Turbulent gas clouds and respiratory pathogen emissions: Potential implications for reducing transmission of COVID-19”, Rev. Educ., 323 (18), 1837 (2020).
  • Bake, B., Larsson, P., Ljungkvist, G., Ljungström, E. and Olin, A., “Exhaled particles and small airways”, Respiratory Research, 20 (1), 1 (2019).
  • Duguid, J. P., “The size and the duration of air-carriage of respiratory droplets and droplet-nuclei”, Hygiene, 44 (6), 471 (1946).
  • Edwards, D. A., Man, J. C., Brand, P., Katstra, J. P., Sommerer, K., Stone, H. A., Nardell, E. and Scheuch, G., “Inhaling to mitigate exhaled bioaerosols”, Natl. Acad. Sci., 101 (50), 383 (2004).
  • Chao, C., Wan, M., Morawska, L., Johnson, G., Ristovski, Z., Hargreaves, M., Mengersen, K., Corbett, S., Li, Y., Xie, X. and Katoshevski, D., “Characterization of expiration air jets and droplet size distributions immediately at the mouth opening”, Aerosol Sci., 40 (2), 122 (2009).
  • Han, Z. Y., Weng, W. G. and Huang, Q. Y., “Characterizations of particle size distribution of the droplets exhaled by sneeze”, R. Soc. Interface, 10 (88), 20130560 (2013).
  • Chaudhuri, S., Basu, S., Kabi, P., Unni, V. R. and Saha, A., “Modeling the role of respiratory droplets in Covid-19 type pandemics”, Fluids, 32 (6), 063309 (2020).
  • Yin, J., Norvihoho, L. K., Zhou, F., Chen, B. and Wu, W. T., “Investigation on the evaporation and dispersion of human respiratory droplets with COVID-19 virus”, Int. J. Multiph. Flow, 147 (1), 103904 (2022).
  • Wang, B., Wu, H. and Wan, X. F., “Transport and fate of human expiratory droplets-A modeling approach”, Fluids, 32 (083307), 1 (2020).
  • Rahimi, A. and Bakhshi, A., “A simple one-dimensional model for investigation of heat and mass transfer effects on removal efficiency of particulate matters in a venturi scrubber”, J. Chem. Eng. (IAChE), 6 (4), 3 (2009).
  • Robinson, J. F., de Anda, I. R., Moore, F. J., Reid, J. P., Sear, R. P. and Royall, C. P., “Efficacy of face coverings in reducing transmission of COVID-19: Calculations based on models of droplet capture”, Fluids, 33 (1), 1 (2021).
  • Liu, L., Wei, J., Li, Y. and Ooi, A., “Evaporation and dispersion of respiratory droplets from coughing”, Indoor Air, 27 (1), 179 (2017).
  • ANSI/ASHRAE, “ANSI/ASHRAE standard 169-2013”, Climatic data for building design standards, 8400, p. 104 (2013).
  • Bahramian, A., Mohammadi, M. and Ahmadi G., “Effect of indoor temperature on the velocity fields and airborne transmission of sneeze droplets: An experimental study and transient CFD modeling”, Total Environ., 858 (1), 159444 (2023).
  • Liu, K., Allahyari, M., Salinas, J. S., Zgheib, N. and Balachandar, S., “Investigation of theoretical scaling laws using large eddy simulations for airborne spreading of viral contagion from sneezing and coughing”, Fluids, 33 (1), 063318 (2021).
  • Morawska, L., Johnson, G. R., Ristovski, Z. D., Hargreaves, , Mengersen, K., Corbett, S., Chao, C. Y. H., Li, Y. and Katoshevski, D., “Size distribution and sites of origin of droplets expelled from the human respiratory tract during expiratory activities”, J. Aerosol Sci., 40 (3), 256 (2009).
  • Jafari, S., Khaleghi, H. and Maddahian, R., “Comparative analysis of a single fuel droplet evaporation”, Chem. Petrol. Eng., 53 (1), 81 (2019).
  • Chen, L. D., “Effect of ambient temperature and humidity on droplet lifetime-A perspective of exhalation sneeze droplets with COVID-19 virus transmission”, J. Hygiene & Environ. Health, 229 (1), 113568 (2020).
  • Balusamy, S., Banerjee, S. and Sahu, K. C., “Lifetime of sessile saliva droplets in the context of SARS-CoV-2”, Commun. Heat & Mass Transfer, 123 (1), 105178 (2021).
  • Katre, P., Banerjee, S., Balusamy, S. and Sahu, K. C., “Fluid dynamics of respiratory droplets in the context of COVID-19: Airborne and surfaceborne transmissions”, Fluids, 33 (1), 081302 (2021).
  • Reid, R. C., Paruznitz, J. M. and Polling, B. E., The properties of gases and liquids, fourth ed., McGraw-Hill, p. 582 (1987).