By Rocky Swift
TOKYO (Reuters) – Japanese supercomputer simulations have shown that wearing two masks has a limited advantage in blocking virus spread compared to one mask that fits.
The findings partly contradict the recent recommendations of the US Centers for Disease Control and Prevention (CDC) that two masks were better than one to reduce a person’s exposure to the coronavirus.
Researchers have used the Fugaku supercomputer to model the flow of virus particles from people wearing different types and combinations of masks, according to a study released Thursday by research giant Riken and Kobe University.
The use of a single surgical type mask, made of non-woven material, is 85% effective at blocking particles when worn tightly around the nose and face. The addition of a polyurethane mask on top has increased the effectiveness to just 89%.
Wearing two non-woven masks is not useful because air resistance builds up and causes leaks around the edges.
“The execution of double masking simply does not add up,” the researchers wrote, led by Makoto Tsubokura.
Overall, professional N95 masks were best for protecting infections, followed by non-woven masks, cloth masks and ultimately polyurethane types, the study showed.
Riken’s research team previously used the Fugaku supercomputer to model how humidity can affect viral infection and the risks of infection in trains, workspaces and other environments.
As the COVID-19 epidemic has disappeared, the scientific consensus has increased that the virus is spreading through the air and masks are effective in controlling infection.
(Reported by Rocky Swift; Edited by Lincoln Feast.)