Humidity ‘helps disperse virus’

TOKYO: A Japanese supercomputer has shown that humidity can have a large effect on the dispersion of virus particles, pointing to heightened coronavirus contagion risks in dry, indoor conditions during the winter months.

The finding suggests that the use of humidifiers may help limit infections during times when window ventilation is not possible, according to a study released by Riken and Kobe University.

The researchers used the Fugaku supercomputer to model the emission and flow of virus-like particles from infected people in a variety of indoor environments.

Air humidity of lower than 30% resulted in more than double the amount of aerosolised particles compared to levels of 60% or higher.

The study indicated that clear face shields are not as effective as masks in preventing the spread of aerosols.

It also concluded that diners are more at risk from people on their side of the table compared to those opposite and the number of singers in choruses should be limited and spaced out.

Health experts largely agree that the virus can be spread through the air — the US Centers for Disease Control and Prevention revised its guidance this month to say the pathogen can linger in the air for hours.

The Riken research team has previously used the supercomputer to model contagion conditions in trains, work spaces and classrooms. That study showed that opening windows on commuter trains can double or triple the ventilation, lowering the concentration of ambient microbes.