Experts believe that a 6 ft social distancing recommended by the World Health Organization (WHO) may not be sufficient to prevent infection.
According to them, aerosol particles can accumulate and remain contagious for several hours in indoor air, NYP reported.
“Increasing evidence for SARS-CoV-2 suggests the 6 ft WHO recommendation is likely not enough under many indoor conditions where aerosols can remain airborne for hours, accumulate over time, and follow air flows over distances further than 6 ft,” they said.
Chia Wang of National Sun Yat-sen University in Taiwan, as well as Kimberly Prather and Dr. Robert Schooley of the University of California, San Diego, said that a significant proportion of the spread of COVID-19 appears to be occurring through the airborne transmission of aerosols.
Experts said that for society to resume normal, measures should be taken, including wearing masks and large-scale testing. They believe that both practices can help identify and isolate infected asymptomatic people.
“It is particularly important to wear masks in locations with conditions that can accumulate high concentrations of viruses, such as health care settings, airplanes, restaurants, and other crowded places with reduced ventilation,” they added.
Taiwan, Hong Kong, Singapore, and South Korea have introduced universal masks, which have proven most effective in reducing the spread of COVID-19.
The WHO 6 ft social distancing guidelines are based on studies of respiratory droplets of the 1930s. However, according to experts, technology to detect tiny aerosol particles did not exist.
Small aerosols evaporate faster than they settle, they added. Because of this, they can be affected by air currents that can carry them over long distances and cause them to remain in the air for hours.
“A lot of the evidence has been pointing to aerosol transmission of respiratory viruses,” Prather told WebMD. “This particular virus, a lot of evidence is mounting.”
A study by scientists in Hong Kong showed that the use of surgical masks can reduce the frequency of contactless transmission through respiratory drops or particles in the air by up to 75 percent.