Will oversanitizing weaken my immune system? Your COVID-19 questions answered

We're answering your questions about the pandemic. Send yours to and we’ll answer as many as we can. We’ll publish a selection of answers every weekday online, and also put some questions to the experts during The National and on CBC News Network.

From mask anxiety to your immune system, here's what you’re asking us today.

Frequent handwashing and sanitizing is likely not having a negative impact on your immune system, experts said. (Troy Fleece/The Canadian Press)

We're breaking down what you need to know about the pandemic by answering your questions. You can send us your questions via email at and we'll answer as many as we can. We'll publish a selection of answers every weekday on our website, and we're also putting some of your questions to the experts on the air during The National and News Network. So far we've received more than 43,000 emails from all corners of the country. 

Are we weakening our immune systems through excessive handwashing and disinfecting everything?

With all the focus on handwashing, sanitizing and disinfecting, we're hearing from many readers like Jerry W. who is wondering if all this germ-killing is going to do a number on our immune system.

The answer is probably not. 

Health Canada told us in an email there's "no scientific evidence" of a direct link between frequent handwashing, sterile environments and a loss of adaptive immunity.

The experts we spoke with said there is much we don't know. 

Infectious disease experts say the best way to stay safe during the COVID-19 pandemic is to wash your hands thoroughly and frequently. (Indranil MukherJee/Getty Images)

"There are some hypotheses that exposure to different and mostly harmless pathogens can help us build up our immunity," said Alain Simard, a professor of immunology at the Northern Ontario School of Medicine. "But I would not say that sanitizing our hands and keeping a certain distance weakens it in our current scenario."

Steve Theriault, a virologist specializing in infectious disease in Winnipeg, said that there are "cases where people who have been away from populations and have had constantly clean areas have not shown that the immune system gets compromised."

Theriault used astronauts on the International Space Station as an example.

While our experts agreed that there are no studies on the impact of fastidiousness and our immunity, they agreed we're probably not hurting our immune systems by practising physical distancing and disinfection.

For one, even while we're sanitizing and distancing, we're still being exposed to pathogens.

"Our immune system is still being challenged by what goes in our mouth, by organisms we pick up from surfaces between handwashing episodes and the people and pets we live with," said Bob Hancock, a professor of microbiology and immunology at the University of British Columbia.

Given our present situation, Hancock said, our immune systems are not going to be harmed by excessive washing and isolating during this pandemic.

"Basically you cannot undermine decades of challenging your immune system simply by handwashing and social distancing for a few months." 

What can I do if I find it hard to breathe while wearing a mask?

Masks can feel uncomfortable and difficult to wear. Sara M. wrote to say it's particularly hard for people like her who suffer from anxiety and lung disorders like asthma.

So what should they do?

Dr. Samir Gupta, a clinician-scientist at the Li Ka Shing Knowledge Institute of St. Michael's Hospital in Toronto, said while there's no evidence that masks trigger underlying lung conditions, some people will find it harder to breathe through a mask — especially if they have chronic lung disease.

"For these people, and those with anxiety, if they can't wear a mask, they can only physically distance — but this would be a minority of people," Gupta said. 

Dr. Sumon Chakrabarti, an infectious diseases physician at Trillium Health Partners in Mississauga, Ont., agrees, and said that some people may feel claustrophobic when wearing a mask. For them, he suggested only wearing one when you need it.

"I've seen people going for walks, properly physically distanced, wearing a mask outside," he said. "This is unnecessary, and going mask-free here could help."

Chakrabarti suggested taking the mask off for a "breather" — as long as you're away from others and you wash your hands before and after touching the mask.

A man wears a face mask as he walks along an extended sidewalk on Ste-Catherine Street in Montreal on Saturday. (Graham Hughes/The Canadian Press)

He also recommends trying different types of masks until you find one that's comfortable.

"If you choose to wear a mask, you will eventually get used to it," he said.

Gupta said he thinks everyone should try to wear a mask according to the public health guidelines.

If your mask is giving you anxiety or making you feel claustrophobic, Steve Joordens, a psychology professor at the University of Toronto-Scarborough, said you should practise relaxation exercises. 

"One cannot be both anxious and relaxed at the same time, so rather than trying to not be anxious, a person should instead learn how to formally relax."

Joordens recommended listening to guided relaxation exercises you can find online and said if you practise, you can learn to get into that state quickly, which can slow your breathing and heart rate.

Can my employer force me to wear PPE?

Some companies are telling their employees to wear a mask on the job, which has readers like Paul T. wondering if businesses can force workers to put on personal protective equipment (PPE). 

Actually, they can. 

Richard Powers, a business professor at the Rotman School of Management at the University of Toronto, said the answer to this is simple because there are laws about workplace safety.

"The store owner or business owner has a legal obligation to create a safe work environment for employees," Powers said. "If that involves PPE, that's what they have to do. An employee would have to comply or else they wouldn't be working."

Employment lawyer Samara Belitzky said that in general, if it's for health and safety reasons, "an employer can designate that employees have to wear PPE."

"However, there might be exceptions to this where, for example, medical or religious accommodations are required for certain employees."

Michael Bryant, director of the Canadian Civil Liberties Association, said because of human rights provisions, employees, for example, "wouldn't have to wear a mask if they had a disability or medical condition."

But he said he'd be surprised to hear if employees — especially those who deal directly with customers — wouldn't want to wear a mask.

"Ordinarily those health and safety standards are sought by employees, and they want their employer to provide them a mask." 

Even in situations where you may not be interacting with customers, experts say it's important to remember that wearing a mask protects everyone in your workplace — including your co-workers. 

On Saturday, we answered questions about whether or not a store can force you to wear a mask to shop there.

Keep your questions coming by emailing us at

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