Part of a post by Rose42 on 5/15

We do not recommend requiring the general public who do not have symptoms of C****-**-like illness to routinely wear cloth or surgical masks because:
There is no scientific evidence they are effective in reducing the risk of SARS-CoV-2 t***smission
Their use may result in those wearing the masks to relax other distancing efforts because they have a sense of protection
We need to preserve the supply of surgical masks for at-risk healthcare workers.
A 2020 study in Seoul, South Korea looked at the effectiveness of surgical and cotton masks in blocking C****-** in a controlled comparison of four patients. The C***D-infected patients were put in negative pressure isolated rooms. The scientists compared disposable surgical masks (3 layers) with reusable cotton masks.
Patients were instructed to cough 5 times while wearing no mask, surgical mask, or cotton mask. Interestingly, all swabs from the outer masks—including surgical masks—were positive for C****-**. Inner masks were also found to be contaminated. That means the mask did not effectively filter out the C***D v***s since it is too small. The authors assert:
Neither surgical nor cotton masks effectively filtered {C****-**} during coughs by infected patients.” Conclusion: “both surgical and cotton masks seem to be ineffective in preventing the dissemination of SARS–CoV-2 from the coughs of patients with C****-** to the environment and external mask surface.”

The World Health Organization does not support healthy people wearing masks