Should I microwave my mail? Your COVID-19 questions answered

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 COVID@cbc.ca 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 CBC News Network.

So far, we've received thousands of emails. Your questions have surprised us, stumped us and got us thinking, including a number of questions about what to do with your mail — in particular this question from Claire L.:

Would putting letters in the microwave for a short time destroy the COVID-19 virus?

We've received a lot of questions from people who want to know whether microwaves can be used to kill the novel coronavirus. According to a recent study, the virus persists on some surfaces, including paper products such as cardboard for up to 24 hours.

But Dr. Sumon Chakrabarti, an infectious disease specialist at Trillium Health Partners, says most people are infected when the virus enters their respiratory tract — not through the skin. "Theoretically, if someone freshly sneezes on the mail, you touch it and … immediately touch your nose or mouth, then it can infect you. But this is very unlikely," he said.

Chakrabarti recommends opening mail as you would normally, but avoid touching your face. When you've finished with the mail, wash your hands immediately afterward.

And while heat can kill the virus, putting paper in the microwave is a fire hazard, so don't do that.

I have read that putting food in the refrigerator and freezer can actually preserve the virus. Can your experts comment?

Now that we've tackled microwaves, we'll get to another kitchen appliance. This is a great followup question from Nancy S., who wants to know whether the virus can survive in her fridge or freezer.

We put that question to Colin Furness, an infection control epidemiologist at the University of Toronto. Unlike microwaves, freezers can preserve the virus, he said. "It's just like thinking about fresh meat," said Furness. "If you freeze it, it'll last for a long time. It's very similar to that."

The BC Centre for Disease Control points out, however, "there are no special precautions needed when storing food."

"We recommend washing your hands after putting away food you have purchased and before preparing food."

We are currently self-isolating in an effort to 'flatten the curve.' What markers are health experts using to determine if this is happening? Is there a plan as to when and how to relax restrictions?

After a few weeks of making significant sacrifices, many Canadians are wondering if we've done enough to "flatten the curve," including Sandra C. So how will health experts decide when our lives can get back to normal?

The major indicator, according to Mount Sinai infectious disease specialist Dr. Allison McGeer, would be the number of daily new cases. If that figure stays the same or goes down, it could signal that we're getting COVID-19 under control.

However, she warns that if there isn't enough testing, it could be an obstacle in determining whether the spread is slowing down. "So you can't actually look every day and know for sure what's going on," McGeer said.

As for when we can expect physical distancing restrictions to be relaxed, a number of experts say it is still too soon to tell. Ontario just extended its state of emergency for another two weeks, and B.C.'s top doctor, Dr. Bonnie Henry, said it is unlikely things will return to normal "before at least the summer."

"And then we need to be preparing for the potential of a second wave in the fall," said Henry.

What should parents do about shared custody arrangements? Is it safe for children to go between homes if both parents have been self-isolating and are healthy?

We are receiving many questions from parents who are trying to share custody during the pandemic, including Stephanie B., who wants to know if it's safe for her children to travel between homes to spend time with both mom and dad.

With all of the physical-distancing guidelines, it might be tempting to want to keep your child at one parent's home longer than normal. However, Vancouver lawyer Leena Yousefi said there is minimal risk in putting the child in a car and taking them to the other parent's home.

And if a pre-existing court order, agreement or arrangement is in place for children, parents need to comply with that.

"It's a balancing act," said Mahzulfah Uppal, a family lawyer in Brampton, Ont., who advises parents to contact a family lawyer for legal advice before deciding to change pre-existing arrangements.

"With the help of a lawyer, they can address concerns that they have regarding COVID-19, and the other parent's behaviour to see if they can work out a proper arrangement for children under these conditions."

Are smokers putting others at risk? For example, if I am two metres away, but the other person is smoking and I breathe in some of the smoke, can I get the virus in my lungs? What about vaping?

Public health experts are sounding the alarm about the possible connections between lung damage caused by smoking or vaping and increased vulnerability to COVID-19.

There is evidence that smoking not only leads to respiratory diseases and chronic lung conditions, but also suppresses and harms the immune system, "so that when people do get sick, they have a harder time fighting it," said David Hammond, a professor in the School of Public Health at the University of Waterloo.

There is less research on the effects of vaping and risk of viral infection, but Hammond said people who vape regularly are exposing their respiratory tracts to different toxicants.

"We expect it to be much less than smoking, but it is possible that it still increases susceptibility in terms of the severity of experiencing COVID-19," he said.

As for whether second-hand smoke could transmit the virus, the experts we spoke to said they were not aware of any research on the topic, but that such transmission was unlikely.

"Tobacco smoke is too fine [of a] particle size to likely carry the virus — vaping the same," said Neil Johnston, a registered respiratory therapist and head of the Manitoba Lung Association.

But he emphasized the importance of avoiding second-hand smoke and maintaining the proper two-metre distance from everyone — including smokers.

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