Influence of evaporation on survival, concentration and transmission of the virus.
How COVID-19 The cases continue to increase worldwide. Understanding how climate will affect the further spread of the coronavirus is becoming increasingly urgent, especially as winter virus infections become more common and countries in the northern hemisphere will soon experience cooler temperatures.
In a newspaper in Physics of liquidsFrom AIP Publishing, researchers examined the effects of relative humidity, ambient temperature, and wind speed on the viability of the breath cloud and virus. They found that evaporation is a critical factor in the transmission of the infectious particles submerged in breath clouds of droplets of saliva.
“Let’s assume we have a better understanding of evaporation and its relationship to climate effects. In this case, we can more accurately predict the virus concentration and better determine its viability or the survival potential of the virus, ”said Dimitris Drikakis, one of the authors.
Despite the importance of airborne droplet transmission, research on heat and mass transfer around and in respiratory droplets containing the virus is scarce.
To meet this challenge, the researchers developed theoretical correlations for the transient evaporation of droplets of saliva contaminated with coronavirus. They implemented the theory in an advanced computational fluid dynamics platform and studied the effects of weather conditions on the transmission of viruses in the air.
“We found that high temperatures and low relative humidity lead to high rates of evaporation of droplets contaminated with saliva, thus significantly reducing the viability of the virus,” said co-author Talib Dbouk.
In addition, the researchers observed that the travel distance and the concentration of the droplet cloud remained significant even at high temperatures and high relative humidity. Wind speed is another crucial factor that could change all of the rules for social distancing guidelines.
These results explain why the July pandemic increased in various crowded cities around the world such as Delhi, which were both high in temperature and high relative humidity. It’s also a crucial alarm for the possibility of a second wave of the pandemic in the coming fall and winter seasons, when low temperatures and high wind speeds improve survival and airborne virus transmission.
This study complements the growing body of research that underscores the importance of social distancing and the use of face masks to prevent viruses from spreading completely. The results show how important weather conditions are to the viability of the virus. This can help develop measures both indoors and outdoors to reduce the transmission of viruses in the air in private and public spaces.
Reference: “Effects of the weather on the survival of coronaviruses in the air” by Talib Dbouk and Dimitris Drikakis, September 22, 2020, Physics of liquids.
DOI: 10.1063 / 5.0024272