1. “Decreases oxygen intake.”
“A mask does not reduce oxygen intake nor does it make blood more acidic,” virologist Angela Rasmussen, a research scientist at Columbia University. Ben Neuman, Texas A&M University-Texarkana virologist, said a mask “will add some resistance to the breathing process, it may feel like it takes a bit more work to take a breath, but it won’t materially change the makeup of air that comes through the mask.”
2. “Increases toxin inhalation.”
“Toxins that we normally exhale as we breathe become trapped in the mask and re-inhaled into the lungs, increasing symptoms.”
Repeated, long-term usage of the same unwashed mask could potentially lead to bacteria accumulating on the inside, which is why paper masks shouldn’t be reused and cloth masks should be laundered between uses, Rasmussen said. “However, there’s no reason to worry about toxins,’’ she said. “The only potentially toxic molecule that you routinely exhale is carbon dioxide, which is only toxic when it displaces oxygen,” and it easily passes through the mask.
3. “Scientifically inaccurate.”
“Virologists measure COVID-19 to be 80-140 nm in size making the weave of material masks to be the equivalent of a chain-link fence to a mosquito.”
Rasmussen said virus particles are much smaller than the weave of masks, but infected people do not shed individual virus particles into the environment — they shed them in respiratory droplets. Masks prevent most, but not all, of these respiratory droplets from being dispersed into the environment.
“In addition, although we don’t know how many virus particles it takes to cause an infection, it’s almost certainly more than one. So you have to be exposed to enough respiratory droplets containing enough virus to establish an infection to actually become infected. Reducing droplet dispersal by wearing a mask greatly reduces this exposure risk, though it does not eliminate it completely,” she said.
Neuman said there is a growing number of research papers that demonstrate the effectiveness of surgical face masks in preventing transmission of a range of viruses, or demonstrate the effectiveness of face covering in limiting the novel coronavirus spread.
4. “Effectiveness not studied.”
“Absolutely no peer-reviewed studies have been carried out of mask effectiveness within a social environment to control, prevent or eliminate the spread of disease.”
Papers cited by Neuman are published and peer reviewed. One was published in April by the journal Nature, the other on June 11 by the National Academy of Sciences. In terms of being “within a social environment,” 246 individuals provided exhaled breath samples in the first study, roughly half with masks and half without; the second study was a review of coronavirus mitigation efforts undertaken in Wuhan, China, Italy and New York City.
Said Rasmussen: “It’s true that to my knowledge masks have not been subjected to a large, randomized clinical trial, but a growing body of evidence suggests that masks substantially reduce droplet spread.”
Doctors and nurses have been wearing masks in the OR for many years without any adverse effects.