A chiropractor in Victoria, B.C., is under investigation after writing a letter to his local newspaper that falsely suggests wearing a mask can cause "dangerous" accumulations of carbon dioxide.
On Saturday, the Victoria Times Colonist published a letter to the editor from chiropractor Richard Lambert, written in response to an earlier pro-mask letter.
Some of Lambert's letter falls in line with the advice of B.C. health officials, who have said that masks are not a silver bullet for stopping the spread of COVID-19 and recommend the use of face coverings in situations where two-metre distances can't be maintained.
But Lambert's letter also includes a widely debunked claim about the potential risks of wearing a mask.
"Excess mask-wearing time can lead to dangerous CO2 build-up causing headaches, dizziness and decreased mental functioning, along with rebreathing of exhaled particulates and bacteria," Lambert writes.
The letter has not been published on the Times-Colonist's website, but is available on the digital newspaper site PressReader.com.
The College of Chiropractors of B.C. was alerted to the existence of the letter after the same newspaper published a rebuttal from Dr. Wayne Ghesquiere, an infectious diseases expert at the University of B.C.
Ghesquiere called Lambert's claims "misleading and outright wrong."
In an email Thursday, registrar Michelle da Roza said the college's inquiry committee is now investigating the letter.
"Because the matter is now under investigation, I cannot comment specifically other than to say that the claims in the letter are of concern to the college. We take these matters very seriously," da Roza said.
No comment from chiropractor
Reached by phone on Thursday, Lambert said he was unaware of the investigation or the college's concerns.
"That is the college's position and I have no comment at the moment as I have heard nothing from them," he said.
The claim that masks cause buildup of carbon dioxide and other harmful gases has been discredited by numerous health professionals in recent weeks. Scientists say carbon dioxide particles are tiny and do not accumulate in significant amounts inside a cloth face covering.
Dr. Susy Hota, medical director of infection prevention and control at Toronto's University Health Network, told CBC earlier this month that she has not seen any scientific evidence to support claims of carbon dioxide buildup.
As Dr. Jennifer Kwan, a family physician in Burlington, Ont., pointed out, medical professionals wear masks all day and "it has not caused doctors or nurses or surgeons any harm."
For her part, Provincial Health Officer Dr. Bonnie Henry has said masks are safe for most people to wear, and they don't deprive the wearer of oxygen or exacerbate asthma or other lung conditions.
She has resisted calls to implement any mandatory mask rules, but urges those who can wear a face covering to do so in confined spaces where physical distancing isn't possible, calling it a matter of courtesy.
Because the novel coronavirus can be spread by people who have no symptoms, masks can help prevent droplets from an infected person from reaching those around them.
Chiropractors are not trained in treating or preventing infectious disease.
The B.C. college has previously warned a handful of chiropractors against marketing supplements or spinal manipulations they claimed could build immunity against COVID-19.