EDMONTON -- Some Alberta doctors are concerned the new rules for mask exemptions could flood them with people wanting exceptions, whether warranted or not. In Alberta, mask use is mandatory when in indoor public spaces, workspaces, places of worship, and anywhere else when a person may come within two metres of people outside of their household. Dr. Deena Hinshaw, chief medical officer of health for Alberta, announced new requirements Thursday where anyone exempt from wearing a mask due to a medical condition will need a letter from a health professional authorizing the exemption. “Wearing face masks is a critical public health measure that helps prevent the spread of COVID-19,” Hinshaw said.