Modeling the Evaporation and Dispersion of Airborne Sputum Droplets Expelled from a Human Cough

Details

• Personal Author:
  Celik I ; Feng Z-g ; Mao S ; Posada JA ; Redrow J
• Description:
  This study contributes a new model to simulate the evaporation and dispersion of sputum droplets from human coughs or sneezes. It is the first time different chemical components have been included in order to estimate the transport of sputum or similar biological droplets. This modified model demonstrates the ability to describe real-world phenomena that the widely used single droplet model lacks. Evaporation and dispersion of airborne sputum droplets originating from a human cough are simulated using this model combined with an initially buoyant turbulent jet. Constituents of sputum droplets such as NaCl, amino acids, carbohydrates, and lipids are included. Effects of these chemical components on evaporation rate, velocity, and temperature of droplets are investigated in detail. The results obtained for sputum droplets will provide a perspective of what conditions the viruses within a droplet might face upon being ejected from the mouth during a cough. Finally, computational fluid dynamics (CFD) and probability density function (PDF) techniques were used to complement the new model with a simulation of a cough jet and the dynamics of droplet nuclei in confined spaces. Numerical results indicate that a 10 microns sputum droplet will evaporate to become a droplet nucleus (3.5 microns) in 0.55 s at 0.8 or 80% RH, in 0.3 s at 0.5 or 50% RH, and in 0.25 s at 0.2 or 20% RH. The droplet temperature decreases rapidly from human body temperature to room temperature, which may affect the viability of any carried virus. [Description provided by NIOSH]
• Subjects:
  Aerosols Air Movements Air Pollutants, Occupational Communicable Diseases Humidity Occupational Health Safety Ventilation Viral Diseases
• Keywords:
  Aerosol Aerosol Particles Airborne Particles Air Flow Author Keywords: Biological Droplet Bioaerosols Buoyant Jet Disease Transmission Dispersion Evaporation And Dispersion Fluids Infectious Diseases Models Sputum Droplets Viral Diseases Virus-laden Droplet

  More +
• ISSN:
  0360-1323
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  New Mexico ; OSHA Region 3 ; OSHA Region 6 ; Texas ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  46
• Issue:
  10
• NIOSHTIC Number:
  nn:20060596
• Citation:
  Build Environ 2011 Oct; 46(10):2042-2051
• Contact Point Address:
  Shaolin Mao, T-5, Theoretical Division, Los Alamos National Laboratory, Mail Stop B284, NM 87545, USA
• Email:
  slm_wvu@yahoo.com
• Federal Fiscal Year:
  2012
• Performing Organization:
  West Virginia University
• Peer Reviewed:
  True
• Start Date:
  20060801
• Source Full Name:
  Building and Environment
• End Date:
  20100831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:b5537bc37aab23bf562df4920fed9276be5bf603aa70205d843613b0a0ee24d19c30c8ae31a228da25a06084abe7bd797bb3b1a363628865f2e0f14cb4e5b131
• Download URL:
  https://stacks.cdc.gov/view/cdc/224457/cdc_224457_DS1.pdf
• File Type:
  [PDF - 412.32 KB ]