Staying 2 metres apart is not enough to stop COVID-19 without masks: study

MONTREAL -

A new study by researchers from Quebec and the U.S. has found that two-metre distancing is not enough to control the spread of COVID-19 without masks.

“Mask mandates and good ventilation are critically important to curb the spread of more contagious strains of COVID-19, especially during the flu season and winter months as more people socialize indoors,” explains Saad Akhtar, a former doctoral student under the supervision of Professor Agus Sasmito at McGill University.

 

 

 

 

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This comes as the Quebec government announced Tuesday an easing of restrictions in the province, including bars and restaurants no longer needing to keep a register of clients and the lifting of mandatory mask-wearing in high schools, except in common spaces and on transportation, as of Nov. 15.

According to the provincial government, 87 per cent of eligible teens aged 12 to 17 have received both doses of a COVID-19 vaccine.

THE RESEARCH

The team of researchers -- from McGill University, Université de Sherbrooke, Texas A&M University and Northern Illinois University -- developed a computer program that "accurately simulates coughing dynamics" in indoor spaces.

In the simulation, they found that wearing a mask indoors reduces the range of contamination of airborne particles by 67 per cent.

When people are unmasked, more than 70 per cent of airborne particles pass the two metres threshold within 30 seconds.

By contrast, less than one per cent of particles cross the two-metre mark if people are wearing masks.

A new study by researchers from Quebec and the U.S. has found that two-metre distancing without masks is not enough to control the spread of COVID-19.

"While ventilation, a person’s posture and mask-wearing impacted the spread of the bio-contaminants significantly, the impact of age and gender was marginal," the study notes.

In addition, coughing remains one of the main sources of the spread of airborne viruses by symptomatic individuals.

“This study advances the understanding of how infectious particles can spread from a source to its surroundings and can help policymakers and governments make informed decisions about guidelines for masks and distancing in indoor settings,” Akhtar states.

The findings, “Implication of coughing dynamics on safe social distancing in an indoor environment — A numerical perspective,” were published in Building and Environment.