Researchers propose that humidity from masks may lessen severity of Covid-19

Yeah, I've read it, and I've read everything cited in it. In the evidentiary contest between a review paper and empirical reality...reality wins. But let's put a pin in that for a second. This is a bad review, and people need to know why.

This review completely misrepresents the results of cited papers, and is extremely sloppy with many others. For example, they claim that this RCT [0] found evidence supporting mask use for influenza, when in reality, it found no significant difference versus the control. Yet the authors of the Howard review blatantly mis-represent the top-line conclusion of the trial:

> There has been one controlled trial of mask use for influenza control in the general community....It found that “in an adjusted analysis of compliant subjects, masks as a group had protective efficacy in excess of 80% against clinical influenza-like illness.”

Moreover, this review omits the only randomized controlled trial ever conducted for masks and Covid [1] (which found no statistically significant protective effect), presumably because the RCT didn't support their argument.

In general, this review's sloppy use of citations (as in the section you've quoted) mixes statements of facts with dubious assertions -- unsupported by any evidence at all -- in order to make it seem that those assertions are fact. For example, from your quote, it's trivial to see examples:

> "nonmedical masks use materials that obstruct particles of the necessary size"

I don't know what "nonmedical masks" are, but the category is so broad that a statement like this is utterly meaningless, even if it were backed by a citation (which it isn't).

> "nonmedical masks have been effective in reducing transmission of respiratory viruses"

Again, I'm not sure what a "nonmedical mask" is, but there's no citation here, so this is just a bald assertion.

The evidence base for masks -- of any sort -- against respiratory viruses is so weak that even recent a review published by the CDC in May 2020 argues that they have no effect [2]. For cloth masks specifically, the only randomized trial ever conducted showed that people wearing cloth masks were worse off than those wearing surgical masks [3].

There have been a number of fair, quality reviews of the mask debate (for example, [4]). This is not one of them.

[0] https://www.researchgate.net/profile/Esam_Azhar2/publication...

[1] https://www.acpjournals.org/doi/10.7326/M20-6817

[2] https://wwwnc.cdc.gov/eid/article/26/5/19-0994_article

[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4420971/pdf/bmj...

[4] https://www.cebm.net/covid-19/masking-lack-of-evidence-with-...

The idea isn't to go to sleep but to avert a full-blown cold or other respiratory infection if possible. Usually takes 15-45 minutes. But you have to catch it right at the start and you have to be at home, obviously.

If you're concerned about carbon dioxide you can either refresh the air periodically or you can create a small gap in the duvet to allow some exchange of air with the surrounding room (whilst keeping the humidity relatively high).

keyword: professionals