Yeah, I wouldn’t discourage people from wearing masks in public—which at least prevent the sort of projectile expulsion of droplets that could contamination a wide area, and if nothing else signals an awareness of the seriousness of the situation—but people need to understand that masks in and of themselves are insufficient to either protect themselves from infection or to prevent from spreading it to others. Actual physical distancing to the degree feasible, good handwashing hygiene and cleaning of commonly touched surfaces, and generally avoiding large congregations of people where mass contagion could occur are all important, as is the proper handling of masks and other potentially contaminated materials so as not to transfer contamination from mask to hand to other common surface like door knobs or products.
FWIW, I worked on a project a few weeks ago developing improvised N95-equivalent masks from commonly available materials (e.g. didn’t require 3D printing or anything you couldn’t readily source in a hardware store or stationary supply) for frontline health care workers and first responders. Making a frame that would give reasonably good fitment and a way to swap filtering materials was relatively easy, but (as I expected) we just were not able to find a material that would filter with anything near the effectiveness of the melt-blown polypropylene used in N95 masks and still have sufficient porosity that you could breathe through it. The NIOSH-certified lab that did some preliminary testing on the list of materials found that none of them (even material cut from surgical masks) were adequate to even approach N95 surgical mass standard by a large enough margin that they simply weren’t certifiable even for secondary use. I was hoping that wool felt would prove to be a reasonably good substitute but it was barely better than tight woven cotton, and HEPA filtering materials were worthless and potentially hazardous to a user even if they could manage to breathe through it.
Stranger