OTTAWA -- With face masks mandatory in Ottawa’s indoor public spaces, some residents have been wondering whether face shields can be worn instead.

Many people say they find them more comfortable than masks. Are they just as good?

The short answer, according to local public health experts: no.

“The evidence we have is that although face shields are better than nothing, they’re not as good as effective as a mask that is tightly wrapped around the chin and over the nose,” said Dr. Paul Roumeliotis, medical officer of health for Eastern Ontario.

The point of wearing cloth masks is to limit the spread of respiratory droplets, released when people breathe, talk and cough. Face shields, with the space they leave around your chin and the sides of your face, don’t do that as effectively.

“Masks are effective because they keep the respiratory secretions in more,” said Dr. Vera Etches, Ottawa’s medical officer of health, told Newstalk 580 CFRA. “If you’re wearing a face shield, it’s not tight against your face so the respiratory droplets can go out the bottom and out the side. So they aren’t as good.”

Masks are now ubiquitous, but face shields are taking on their own role as the coronavirus pandemic continues to grow. Qatar Airways is requiring passengers and crew to wear both face masks and face shields on flights.

Infectious diseases physician Dr. Eli Perenvevich argued in a much-discussed JAMA article that face shields “should be included as part of strategies to safely and significantly reduce transmission in the community setting.”

Face shields can be quickly and affordably made and distributed, can be reused indefinitely, are easy to clean and comfortable to wear, the article says.

But Ottawa Public Health’s official advice on its website says a face shield is not a substitute for a face mask.

“A face shield may provide additional protection for the wearer against droplets expelled from another person, however these droplets may still be inhaled around the shield,” OPH says. “Respiratory droplets expelled by the wearer may escape around the sides of the face shield, which therefore provides less protection to others.”

Local experts say face shields do provide some benefits. For people who are unable to wear masks due to a respiratory condition, mental health condition or disability, they are better than nothing.

But Ottawa Public Health says people who choose to wear face shields should wear them, if possible, in addition to properly-fitting cloth masks.

“The visor in addition to a mask adds protection to the person wearing it,” Dr. Roumeliotis said.

That’s why you see health care workers wearing both, he said. The face shield protects the wearer, but face masks protect everyone else around them.

Of course, no matter what you wear on your face, the most important thing to remember is to wash your hands and practice physical distancing whenever possible.