A mathematical model for predicting the viability of airborne viruses

Posada, Alejandro; Redrow, John B; Çelik, İsmail

doi:10.1016/j.jviromet.2009.12.004

Cited by 26 publications

(30 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Efflorescence or crystallization of NaCl, a major component of respiratory droplets, due to loss of water is expected to occur between 40–50% RH [24]. According to our results, between 10–40% RH, D eq / D i varies by only 3.7% (0.402–0.417); in comparison, between 50–90% RH, the ratio varies by 21.7% (0.424–0.516).…”

Section: Resultssupporting

confidence: 45%

Dynamics of Airborne Influenza A Viruses Indoors and Dependence on Humidity

2011

View full text Add to dashboard Cite

There is mounting evidence that the aerosol transmission route plays a significant role in the spread of influenza in temperate regions and that the efficiency of this route depends on humidity. Nevertheless, the precise mechanisms by which humidity might influence transmissibility via the aerosol route have not been elucidated. We hypothesize that airborne concentrations of infectious influenza A viruses (IAVs) vary with humidity through its influence on virus inactivation rate and respiratory droplet size. To gain insight into the mechanisms by which humidity might influence aerosol transmission, we modeled the size distribution and dynamics of IAVs emitted from a cough in typical residential and public settings over a relative humidity (RH) range of 10–90%. The model incorporates the size transformation of virus-containing droplets due to evaporation and then removal by gravitational settling, ventilation, and virus inactivation. The predicted concentration of infectious IAVs in air is 2.4 times higher at 10% RH than at 90% RH after 10 min in a residential setting, and this ratio grows over time. Settling is important for removal of large droplets containing large amounts of IAVs, while ventilation and inactivation are relatively more important for removal of IAVs associated with droplets <5 µm. The inactivation rate increases linearly with RH; at the highest RH, inactivation can remove up to 28% of IAVs in 10 min. Humidity is an important variable in aerosol transmission of IAVs because it both induces droplet size transformation and affects IAV inactivation rates. Our model advances a mechanistic understanding of the aerosol transmission route, and results complement recent studies on the relationship between humidity and influenza's seasonality. Maintaining a high indoor RH and ventilation rate may help reduce chances of IAV infection.

show abstract

Section: Resultssupporting

confidence: 45%

Dynamics of Airborne Influenza A Viruses Indoors and Dependence on Humidity

2011

View full text Add to dashboard Cite

show abstract

“…According to Posada et al (2010), the inactivation rate of viruses in an aerosol can be described by:…”

Section: Virusesmentioning

confidence: 99%

Primary biological aerosol particles in the atmosphere: a review

Després¹,

Huffman

Burrows³

et al. 2012

Tellus B: Chemical and Physical Meteorology

1,191

1,114

View full text Add to dashboard Cite

A B S T R A C T Atmospheric aerosol particles of biological origin are a very diverse group of biological materials and structures, including microorganisms, dispersal units, fragments and excretions of biological organisms. In recent years, the impact of biological aerosol particles on atmospheric processes has been studied with increasing intensity, and a wealth of new information and insights has been gained. This review outlines the current knowledge on major categories of primary biological aerosol particles (PBAP): bacteria and archaea, fungal spores and fragments, pollen, viruses, algae and cyanobacteria, biological crusts and lichens and others like plant or animal fragments and detritus. We give an overview of sampling methods and physical, chemical and biological techniques for PBAP analysis (cultivation, microscopy, DNA/RNA analysis, chemical tracers, optical and mass spectrometry, etc.). Moreover, we address and summarise the current understanding and open questions concerning the influence of PBAP on the atmosphere and climate, i.e. their optical properties and their ability to act as ice nuclei (IN) or cloud condensation nuclei (CCN). We suggest that the following research activities should be pursued in future studies of atmospheric biological aerosol particles: (1) develop efficient and reliable analytical techniques for the identification and quantification of PBAP; (2) apply advanced and standardised techniques to determine the abundance and diversity of PBAP and their seasonal variation at regional and global scales (atmospheric biogeography); (3) determine the emission rates, optical properties, IN and CCN activity of PBAP in field measurements and laboratory experiments; (4) use field and laboratory data to constrain numerical models of atmospheric transport, transformation and climate effects of PBAP.

show abstract

“…As evaporation proceeds, the water vapor pressure at the surface, which is proportional to the molar fraction of water in the aerosol (Raoult's Law), decreases because water is lost to evaporation while solutes such as salts and proteins remain. Evaporation ceases when the vapor pressure at the aerosol's surface is reduced to that of ambient air, a point at which the water activity of the aerosol equals the ambient RH (42). The extent to which an aerosol evaporates depends on its solute content and RH, and the final size can be calculated using mathematical models based on thermodynamics and fluid mechanics (32,39,44).…”

Section: Rh Evaporation and Water Activitymentioning

confidence: 99%

Mechanisms by Which Ambient Humidity May Affect Viruses in Aerosols

Yang

Marr

2012

Appl Environ Microbiol

190

203

View full text Add to dashboard Cite

ABSTRACTMany airborne viruses have been shown to be sensitive to ambient humidity, yet the mechanisms responsible for this phenomenon remain elusive. We review multiple hypotheses, including water activity, surface inactivation, and salt toxicity, that may account for the association between humidity and viability of viruses in aerosols. We assess the evidence and limitations for each hypothesis based on findings from virology, aerosol science, chemistry, and physics. In addition, we hypothesize that changes in pH within the aerosol that are induced by evaporation may trigger conformational changes of the surface glycoproteins of enveloped viruses and subsequently compromise their infectivity. This hypothesis may explain the differing responses of enveloped viruses to humidity. The precise mechanisms underlying the relationship remain largely unverified, and attaining a complete understanding of them will require an interdisciplinary approach.

show abstract

A mathematical model for predicting the viability of airborne viruses

Cited by 26 publications

References 29 publications

Dynamics of Airborne Influenza A Viruses Indoors and Dependence on Humidity

Dynamics of Airborne Influenza A Viruses Indoors and Dependence on Humidity

Primary biological aerosol particles in the atmosphere: a review

Mechanisms by Which Ambient Humidity May Affect Viruses in Aerosols

Contact Info

Product

Resources

About