The effect of weather on virus transmission. Effect of relative humidity (RH = 10%, 50%, and 90%) on the coronavirus respiratory point cloud at temperatures 30 C and wind speeds of 4 kPF. The wind direction is from left to right. Credit: Talib Dabok and Dimitris Drakakiz
Evaporation effect on virus survival, concentration, transmission.
Like COVID-19 As cases continue to rise worldwide, there is more urgency to understand how the weather affects the continued spread of coronavirus, especially as winter virus infections are more common and Northern Hemisphere countries will soon see cooler temperatures.
In a paper The physics of fluids, Through AIP Publishing, the researchers studied the effects of relative humidity, ambient temperature and wind speed on respiratory cloud and virus viability. They found that the decisive factor for the transmission of infectious particles, which are absorbed into the respiratory clouds by drops of saliva, is evaporation.
“Suppose we have a good understanding of the relationship between evaporation and the effects of the atmosphere. In that case, we can more accurately predict the concentration of the virus and better determine its viability or the likelihood of surviving the virus. ‘
Despite the importance of airborne drip transmission, research on heat and mass transfer around and inside viral respiratory droplets has been rare.
To meet the challenge, the researchers developed theoretical relationships for stable evaporation of coronavirus-contaminated saliva drops. They implemented the theory on a platform of advanced computational fluid mobility and studied the effects of weather conditions on aerated virus transmission.
“The higher the temperature and the lower the humidity, the higher the evaporation rate of saliva-contaminated drops, leading to a significant reduction in the viability of the virus,” said co-author Talib Dubke.
In addition, the researchers found that the travel distance and the concentration of the dot cloud continued significantly, even at low temperatures if the relative humidity was high. Wind speed is another crucial factor that can change all the rules of the social distance guide.
These findings help explain why the epidemic spread to different crowded cities around the world, such as Delhi, during July, which experienced both high temperatures and high humidity. It also provides a decisive warning for the possibility of a second wave of epidemics in the coming autumn and winter asons Tuo, where low temperatures and strong wind speeds will increase the survival and transmission of atmospheric viruses.
This study adds to the growing body of research that reinforces the importance of social viruses and the use of facial masks to prevent the spread of the virus as a whole. The results show the importance of weather conditions in the viability of the virus, which can help guide the design of measures in both indoor and outdoor environments to reduce aerated virus transmission in private and public places.
Reference: 22 September 2020, “The Impact of Weather on the Survival of Aerated Coronavirus” by Talib Dubuk and Dimitris Drakakis The physics of fluids.
DOI: 10.1063 / 5.0024272
