"Fact checking" straw men

Typical straw man "fact checking" by Reuters:

Fact check: Wearing masks does not cause cancer 
https://www.reuters.com/article/uk-factcheck-masks-cause-cancer-idUSKBN26Q22N

Reuters says: "Wearing masks does not cause cancer" by "debunking" the claim that it is the lack of oxygen that causes cancer. A claim I've never heard and that does not seem the least bit plausible or relevant.

The oxygen deprivation is a real and serious issue, cf. medical study proving that doctors experience a significant drop in blood oxygen levels already after 1 hour during an operation while wearing medical masks:

Preliminary report on surgical mask induced deoxygenation during major surgery 
https://pubmed.ncbi.nlm.nih.gov/18500410/

But this is not the reason face masks represent a cancer risk.

The real reason is this:

PTFE or Polytetrafluoroethylene

Medical Masks may contain PTFE or Polytetrafluoroethylene. This is a toxic chemical that has been linked to a variety of health issues, including cancer.  

Please note that there are a lot of terms and acronyms for fluorochemicals, here is a summary of terms fyi:

• The class, or family, of per- and poly-fluorinated compounds are sometimes called PFCs or PFASs.
• Teflon® is the best known trade name for polytetrafluoroethylene- or PTFE-based fluorocarbon formulas.
• PFOA and PFOS are two fluorochemicals that were widely used for decades. They are also called C8 to signify a chain of eight carbon atoms surrounded by fluorine atoms. In 2015, fifty years after scientists first documented their potential for human health harm, C8 was phased out in the US.
• C8 has been replaced by many forms of similar, shorter-chain molecules called C6 (perfluorohexanoic acid or PFHA) and C4 (PFBS). These replacements are more rapidly excreted by humans but have not been well tested for toxicity. They are increasing in humans and the environment, and they appear to be associated with health harm similar to that of their “relative,” C8.

The fact that some medical masks are treated with such products implies that there is a substantial risk that the users will absorb not just microplastics, but also Polytetrafluoroethylene and that means yes, masks may potentially cause cancer!

They can't dismiss it without adressing this issue - and they'll need an actual medical study that spans at least 10 years of observations to determine the risk, one way or the other. Which they don't have.

But people will remember that Reuters said that facial masks do not cause cancer - they will say that it was "debunked".