Scientists studied the role of high temperatures and humidity
September 27, 2020 Share on FacebookShare Share on TwitterTweet Share on WhatsAppShare
People enjoy the night on Recreio dos Bandeirantes beach amid the coronavirus disease (COVID-19) outbreak in Rio de Janeiro, Brazil, on September 16, 2020. REUTERS / Ricardo Moraes
Researchers who have studied the effects of relative humidity, ambient temperature and wind speed on the respiratory cloud and the viability of the coronavirus, have found that a critical factor for the transmission of infectious particles, which are immersed in respiratory clouds of drops of saliva, is the evaporation , as published in the journal Physics of Fluids .
As COVID-19 cases continue to rise around the world, it is increasingly urgent to understand how weather affects the continued spread of the coronavirus, particularly as typical winter virus infections are more common and countries in the Northern hemisphere will soon see lower temperatures.
“Suppose we better understand evaporation and its relationship to climatic effects. In that case, we can more accurately predict the concentration of the virus and better determine its viability or the survival potential of the virus, ”explains Dimitris Drikakis, one of the authors.
Despite the importance of airborne droplet transmission, research on heat and mass transfer around and within respiratory droplets containing the virus has been scant.
To address the challenge, the researchers developed theoretical correlations for the unstable evaporation of saliva droplets contaminated with coronavirus. They implemented the theory on an advanced computational fluid dynamics platform and studied the effects of weather conditions on airborne virus transmission.
” We found that high temperatures and low relative humidity lead to high evaporation rates from saliva-contaminated droplets, significantly reducing virus viability,” adds co-author Talib Dbouk.
Furthermore, the researchers observed that the travel distance and the concentration of the droplet cloud remained significant, even at high temperatures if the relative humidity is high. Wind speed is another crucial factor that could upset all the rules of the social distancing guidelines.
These findings help explain why the pandemic increased during July in different busy cities around the world, such as Delhi, which experienced both high temperatures and high relative humidity.
It also provides a crucial alert to the possibility of a second wave of the pandemic in the coming fall and winter seasons, where low temperatures and high wind speeds will increase survival and airborne transmission of the virus.
This study adds to the growing body of research that reinforces the importance of social distancing and the use of face masks to prevent the full spread of the virus. The results reveal the importance of climatic conditions in the viability of the virus, which can help to guide the design of measures both indoors and outdoors, to reduce the transmission of the virus in the air in public and private spaces.
In Florida they encourage the use of masks on the beaches (EFE)
On the brink of a million dead
The new coronavirus pandemic has caused at least 993,438 deaths in the world since the WHO office in China reported the appearance of the disease in December, according to a balance established by AFP this Saturday at 1100 GMT based on sources officers. Since the beginning of the epidemic, more than 32,622,490 people have contracted the disease. Of these, at least 22,360,200 were recovered , according to authorities.
On Friday, 9,050 new deaths and 325,900 infections were registered in the world. The countries that registered the most deaths according to the latest official balances are Argentina with 3,901, as a result of an adjustment in their records, India (1,089) and the United States (887). T he number of deaths in the United States amounts to 203,782 with 7,033,925 infections. The authorities consider that 2,727,335 people were healed.
After the United States, the countries with the most fatalities are Brazil with 140,537 deaths and 4,689,613 cases, India with 93,379 deaths (5,903,932 cases), Mexico with 75,844 deaths (720,858 cases), and the United Kingdom with 41,936 deaths (423,236). cases).
Among the hardest hit countries, Peru has the highest mortality rate, with 97 deaths per 100,000 inhabitants , followed by Belgium (86), Bolivia (67), Spain (67), and Brazil (66).
China, without taking into account the territories of Hong Kong and Macao, registered a total of 85,337 infected people, of which 4,634 died and 80,536 were fully healed.
Since the beginning of the epidemic, Latin America and the Caribbean added 338,254 deaths (9,095,347 infections) , Europe 229,335 (5,199,762), United States and Canada 213,075 (7,184,066), Asia 132,856 (7,762,046), Medium East 44,120 (1,902,535), Africa 34,853 (1,447,328), and Oceania 945 (31,410).
With information from Europa Press