> There's quite a difference between as well as and better than. I think that qualifies as editorializing, which is discouraged by HN guidelines. The "as well

> There's quite a difference between as well as and better than. I think that qualifies as editorializing, which is discouraged by HN guidelines. The "as well as" is comparing valved and un-valved N95s. The "better than" is between valved N95 vs cloth/surgical masks. Many jurisdictions in the US put valved N95 in the same category as no mask, where as this study says that they maybe better than the mandated face coverings. If you look at figure 6, you'll see that surgical masks performed at 20% penetration. The dotted line on that figure is what was reported in Rengasamy 2009. But not all surgical masks are the same. ASTM level 1 is I believe 80% filtering media. The wearer will get less than that due to fit. Most of the "surgical" masks in stores now (not in hospitals) has no ASTM rating at all, and the cotton masks that are sold also does very poorly in controlled penetration tests, even before considering their fit.