Davies et al is encouraging as regards the benefits of surgical masks. Still, letting 10% in is a lot worse than letting 5% in, and the fact that the Wikipedia page about N95 masks says “Collection efficiency of surgical mask filters can range from less than 10% to nearly 90% for different manufacturers’ masks when measured using the test parameters for NIOSH certification” suggests that maybe Davies et al got lucky in which surgical masks they tested.
Davies et al is encouraging as regards the benefits of surgical masks. Still, letting 10% in is a lot worse than letting 5% in, and the fact that the Wikipedia page about N95 masks says “Collection efficiency of surgical mask filters can range from less than 10% to nearly 90% for different manufacturers’ masks when measured using the test parameters for NIOSH certification” suggests that maybe Davies et al got lucky in which surgical masks they tested.