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Visualization of sneeze ejecta: steps of fluid fragmentation leading to respiratory droplets

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Abstract

Coughs and sneezes feature turbulent, multiphase flows that may contain pathogen-bearing droplets of mucosalivary fluid. As such, they can contribute to the spread of numerous infectious diseases, including influenza and SARS. The range of contamination of the droplets is largely determined by their size. However, major uncertainties on the drop size distributions persist. Here, we report direct observation of the physical mechanisms of droplet formation at the exit of the mouth during sneezing. Specifically, we use high-speed imaging to directly examine the fluid fragmentation at the exit of the mouths of healthy subjects. We reveal for the first time that the breakup of the fluid into droplets continues to occur outside of the respiratory tract during violent exhalations. We show that such breakup involves a complex cascade of events from sheets, to bag bursts, to ligaments, which finally break into droplets. Finally, we reveal that the viscoelasticity of the mucosalivary fluid plays an important role in delaying fragmentation by causing the merger of the droplet precursors that form along stretched filaments; thereby affecting the final drop size distribution farther downstream.

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References

  • Banner AS (1986) Cough: physiology, evolution, and treatment. Lung 164:79–92

    Article  Google Scholar 

  • Bansil R, Turner BS (2006) Mucin structure, aggregation, physiological functions and biomedical applications. Curr Opin Colloid Interface Sci 11:164–170

    Article  Google Scholar 

  • Bhat PP, Appathurai S, Harris MT, Pasquali M, Mckinley GH, Basaran OA (2010) Formation of beads-on-a-string during break-up of viscoelastic filaments. Nat Phys 6:625–631

    Article  Google Scholar 

  • Bourouiba L (2013) Understanding the transmission of H5N1. CAB Rev 17:1–9

    Google Scholar 

  • Bourouiba L, Dehandschoewercker E, Bush JWM (2012) The fluid dynamics of coughing and sneezing. In: Refereed proceedings of the International Society of Indoor Air Quality and Climate 10th healthy buildings conference Brisbane, AU

  • Bourouiba L, Dehandschoewercker E, Bush JWM (2014) Violent expiratory events: on coughing and sneezing. J Fluid Mech 745:537–563

    Article  Google Scholar 

  • CDC (2013) Emergence of avian inlufenza A(H7N9) virus causing severe human illness. MMWR 62(18):366–371

  • Culick F (1960) Comments on a ruptured soap film. J Appl Phys 31:1128–1129

    Article  Google Scholar 

  • Dekker J, Rossen JWA, Büller HA, Einerhand AWC (2002) The MUC family: an obituary. Trends Biochem Sci 27:126–131

    Article  Google Scholar 

  • Duguid JP (1946) The size and the duration of air-carriage of respiratory droplets and droplet-nuclei. J Hyg 44(6):471–479

    Article  Google Scholar 

  • Eggers J, Villermaux E (2008) Physics of liquid jets. Rep Prog Phys 71(036):601

    Google Scholar 

  • Grotberg JB (1994) Pulmonary flow and transport phenomena. Annu Rev Fluid Mech 26:529–571

    Article  Google Scholar 

  • Haward S, Odell J, Berry M, Hall T (2011) Extensional rheology of human saliva. Rheol Acta 50:869–879

    Article  Google Scholar 

  • James JEA, de Burgh Daly M (1969) Nasal reflexes: section of laryngology. Proc R Soc Med 62(December):1287–1293

    Google Scholar 

  • Johnson G, Morawska L, Ristovski Z, Hargreaves M, Mengersen K, Chao C, Wan M, Li Y, Xie X, Katoshevski D, Corbett S (2011) Modality of human expired aerosol size distributions. J Aerosol Sci 42:839–851

    Article  Google Scholar 

  • Kesimer M, Makhov AM, Griffith JD, Verdugo P, Sheehan JK (2010) Unpacking a gel-forming mucin: a view of MUC5B organization after granular release. Au J Physiol Lung Cell Mol Physiol 289:15–22

    Article  Google Scholar 

  • Lhuissier H, Villermaux E (2012) Bursting bubble aerosols. J Fluid Mech 696:5–44

    Article  MATH  Google Scholar 

  • Morawska L, Johnson G, Ristovski Z, Hargreaves M, Mengersen K, Corbett S, Chao C, Li Y, Katoshevski D (2009) Size distribution and sites of origin of droplets expelled from the human respiratory tract during expiratory activities. J Aerosol Sci 40:256–269

    Article  Google Scholar 

  • Munoz A, Blu T, Unser M (2001) Least-squares image resizing using finite differences. IEEE Trans Image Process 10:1365–1378

    Article  MathSciNet  MATH  Google Scholar 

  • Papineni RS, Rosenthal FS (1997) The size distribution of droplets in the exhaled breath of healthy human subjects. J Aerosol Med 10:105–116

    Article  Google Scholar 

  • Picard A, Davis RS, Glser M, Fujii K (2008) Revised formula for the density of moist air (cipm-2007). Metrologia 45:149–155

    Article  Google Scholar 

  • Pilch M, Erdman CA (1987) Use of breakup time data and velocity history data to predict the maximum size of stable fragments for acceleration-induced breakup of a liquid drop. Int J Multiphase Flow 13:741–757

    Article  Google Scholar 

  • Raynal BDE, Hardingham TE, Thornton DJ, Sheehan JK (2002) Gel-forming properties of saliva. Biochem J 296:289–296

    Article  Google Scholar 

  • Reyssat E, Chevy F, Biance A-L, Petitjean L, Quere D (2007) Shape and instability of free-falling liquid globules. EPL 80(34):005

    Google Scholar 

  • Sallam KA, Aalburg C, Faeth GM (2004) Breakup of round nonturbulent liquid jets in gaseous crossflow. AIAA J 42:2529–2540

    Article  Google Scholar 

  • Scharfman BE, Techet AH (2012) Bag instabilities. Phys Fluids 24(091):112

    Google Scholar 

  • Scharfman BE, Bush JWM, Techet A (2013) Hydrodynamic instabilities in round liquid jets in gaseous crossflow. In: Proceedings of 25th annual conferences of Institute for Liquid Atomozation and Spray Systems

  • Schipper RG, Silletti E, Vingerhoeds MH (2007) Saliva as research material: biochemical, physicochemical and practical aspects. Arch Oral Biol 52:1114–1135

    Article  Google Scholar 

  • Settles GS (2006) Fluid mechanics and homeland security. Annu Rev Fluid Mech 38:87–110

    Article  Google Scholar 

  • Stokes JR, Davies GA (2007) Viscoelasticity of human whole saliva collected after acid and mechanical stimulation. Biorhelogy 44:141–160

    Google Scholar 

  • Taylor GI (1959) The dynamics of thin sheets of fluid. III. Disintegration of fluid sheets. Proc R Soc Lond Ser A 253:313–321

    Article  Google Scholar 

  • Turner CE, Jennison MW, Edgerton EH (1941) Public health applications of high-speed photography. Am J Pub Health Nations Health 31:319–324

    Article  Google Scholar 

  • Villermaux E (2007) Fragmentation. Annu Rev Fluid Mech 39:419–446

    Article  MathSciNet  Google Scholar 

  • Villermaux E, Bossa B (2009) Single-drop fragmentation determines size distribution of raindrops. Nat Phys 5:697–702

    Article  Google Scholar 

  • Widdicombe JG (1979) Reflexes from the upper respiratory tract. In: Handbook of physiology: the respiratory system II, pp 363–394

  • Yang S, Lee GWM, Chen CM, Wu CC, Yu KP (2007) The size and concentration of droplets generated by coughing in human subjects. J Aerosol Med 20:484–494

    Article  Google Scholar 

  • Zayas G, Chiang M, Wong E, MacDonald F, Lange C, Senthilselvan A, King M (2012) Cough aerosol in healthy participants: fundamental knowledge to optimize droplet-spread infectious respiratory disease management. BMC Pulm Med 12(1):11

    Article  Google Scholar 

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Acknowledgments

The authors thank J. Bales, S. J. Lipnoski and the MIT Edgerton Center for access to their equipment. L.B. and J.B. acknowledge the financial support of the NSF (Grant DMS-1022356). L.B. thanks the Reed Funds and NSF (Grant CBET-1546990) for financial support of studies in mucosalivary fluids.

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Authors and Affiliations

  1. Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA

    B. E. Scharfman & A. H. Techet

  2. Department of Mathematics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA

    J. W. M. Bush

  3. Fluid Dynamics of Disease Transmission Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA

    L. Bourouiba

Authors
  1. B. E. Scharfman
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  2. A. H. Techet
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  3. J. W. M. Bush
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  4. L. Bourouiba
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Correspondence to L. Bourouiba.

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Scharfman, B.E., Techet, A.H., Bush, J.W.M. et al. Visualization of sneeze ejecta: steps of fluid fragmentation leading to respiratory droplets. Exp Fluids 57, 24 (2016). https://doi.org/10.1007/s00348-015-2078-4

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  • DOI: https://doi.org/10.1007/s00348-015-2078-4

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