1. john davies john davies United Kingdom says:

    Most masks don't stop bacteria @ ~  2 microns; The average size of covid 19 Virus is about 0.125 microns.

    A study of health-care workers in more than 1,600 hospitals showed that cloth masks only filtered out 3 percent of particles. An article in the New England Journal of Medicine stated, “Wearing a mask outside health care facilities offers little, if any, protection from infection” and that “the desire for widespread masking is a reflexive reaction to anxiety over the pandemic.”
    There are many other credible studies showing lack of mask efficacy, such as these studies published in the National Center for Biotechnology Information - Cambridge University Press - Oxford Clinical Infectious Diseases &  Influenza Journal, just to name a few.

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