Quebec’s acting director of public health, Dr. Luc Boileau, said last Thursday that wearing an N95 mask was no safer than wearing a medical mask for school and daycare staff. His predecessor, Dr. Horacio Arruda, had also said the same thing on several occasions.
This opinion of the government is based in particular on an analysis made by the National Institute of Public Health of Quebec (INSPQ).
The N95 mask, provided it is properly worn and fitted, is more effective than the medical mask in reducing exposure to small aerosols, says this reportHave (New window)Have, while adding that
in real work contexts, the two masks [médicaux et N95] are effective in preventing SARS-CoV-2 infection and scientific knowledge does not demonstrate that one is superior to the other.
When a person wears a medical mask, the vast majority of aerosols of all sizes appear blocked, says theINSPQ.
But according to Linsey Marr, one of the world’s top aerosol scientists and an expert in airborne virus transmission at Virginia Tech University, the problem is that medical masks rarely fit properly to provide a adequate protection. Too often they let particles through the sides and top.
In his opinion, the N95 type mask covers the face better and more easily than a medical mask and therefore offers superior protection.
She believes N95 masks should be worn anywhere there are many people in an enclosed area for a long time. L’
scientific data suggests that the risk of transmission is increased in cramped and poorly ventilated spaces in the presence of a high density of occupants for an extended period.
Of course, wearing a cloth mask or a medical mask is preferable to wearing none, but Linsey Marr believes that N95 masks are even more necessary since the arrival of the Omicron variant, which is highly transmissible and even more transmissible than measles.
According to several studies, a person infected with the Omicron variant would infect at least three others on average.
It’s not just this expert who recommends more widespread use of the N95 mask.
Ottawa favors N95 masks
In fact, the recommendations of theINSPQ and the Government of Quebec go against those of the Canadian government, which last November modified its directives concerning the types of masks to be preferred.
In general, although non-medical masks [en tissu] can help prevent the spread of COVID-19, medical masks and respirators (N95/KN95) provide better protection, says the government.
On Friday, the Centers for Disease Control and Prevention (CDC) in the United States updated its mask guidelines for the general public, now saying that the public can choose to wear N95 and KN95 masks, as they offer the best protection against COVID-19.
The difference of opinion between Ottawa and Quebec also relates to the need to adjust the mask. In the federal document, we can read that a respirator mask (N95/KN95) worn in the community does not need a formal fit test, while theINSPQ continues to say that a formal adjustment is necessary.
You can’t have a fabric mask with a single layer, said the chief administrator of the Public Health Agency of Canada, Dr. Theresa Tam, during an interview with CBC.
Medical masks filter viruses better. However, even a three-layer surgical mask might not be enough., she said. Like Linsey Marr, Dr. Tam argues that N95-type respirators cover the face better than medical masks.
The degree of transmission of the Omicron variant is so high that we need to improve our measures, especially the type of mask and ventilation, also supported Dr. Tam during a press briefing on Friday.
Moreover, the Commission for Standards, Equity, Health and Safety at Work (CNESST) has been requiring since the end of December that the wearing of N95 type masks be extended.
to those who provide care in the most risky situations, including certain situations in cold areas.
Remember that access to N95 masks for Quebec health care workers has been a struggle since the start of the pandemic.
It was not until March 23, 2021 that the Administrative Labor Tribunal decided that employers in the health network should provide N95 type masks not only to workers in hot zones, but also to those in warm zones. .
The judge then indicated that, given the scientific uncertainties, the precautionary principle should have been retained by the authorities. He also rejected arguments from public health experts who argue that N95 is difficult to handle, which would increase the risk of self-contamination.
Change of approach
Linsey Marr was also shocked when she was asked to remove her N95 mask to put on a medical mask while traveling on a bus in Canada last December.
It’s absurd. I just put their mask over mine, she said, adding that someone should never be asked to replace their N95 mask with a medical mask. She also challenged the Canadian government on this subject on Twitter.
In Quebec, people who are going to be vaccinated are frequently asked to remove their N95 mask to wear a medical mask.
Linsey Marr says N95 masks are more frequently used by the public in the United States than in Canada.
This researcher does not at all understand this stubbornness of governments not to properly inform the public about the mode of transmission of SARS-CoV-2 and about wearing better masks.
N95 is much better and they will have to supply more.”,”text”:”Public health authorities want to avoid talking about airborne transmission. They are in denial. They probably know that if they recognize the existence of aerosol transmission of the virus, they will be forced to recognize that an N95 mask is much better and that they will have to provide more.”}}”>Public health authorities want to avoid talking about airborne transmission. They are in denial. They probably know that if they recognize the existence of aerosol transmission of the virus, they will be forced to recognize that an N95 mask is much better and that they will have to provide more.
They still prefer to promote hand washing and physical distancing to avoid having to invest in N95 masks, laments Ms Marr.
This is really a misunderstanding of scientific facts, she says.