CALGARY -- A group of Canadian physicians are calling on governments to require everyone to wear cloth masks.

MASKS4CANADA want to see face coverings required in all indoor public spaces, outdoor crowds and on public transit.

Calgary physician Dr. Amy Tan says recent research is continuing to strengthen the economic and public health cases for mandatory mask use.

“There’s a study out of Yale that shows one cloth mask can save the economy $3000 to $6,000,” Tan said

She also says German research shows even simple cloth masks can reduce the spread of COVID-19 by as much as 40 per cent.

The virus can be exhaled or put into the air by coughing or sneezing and hang in a room for long periods of time.

Dr Tan says some research is pointing to as many as one third of people with COVID-19 showing no symptoms while still spreading the disease.

Alberta’s chief medical officer of Health Dr. Deena Hinshaw has so far resisted calls for mandatory mask use — saying the science needs to be reviewed and policy discussed to avoid any unintended consequences.