A new analysis of 172 studies, funded by the World Health Organization, confirms what scientists have said for months: N95 and other respirator masks are far superior to surgical or cloth masks in protecting essential medical workers against the coronavirus.
The results, published on Monday in The Lancet, make it clear that the W.H.O. and the Centers for Disease Control and Prevention should recommend that essential workers like nurses and emergency responders wear N95 masks, not just surgical masks, experts said.
“It’s been disappointing that both the W.H.O. and the C.D.C. have suggested that surgical masks are adequate, and they’re clearly not,” said David Michaels, a professor at George Washington University who headed the Occupational Safety and Health Administration under President Obama.
“Reliance on surgical masks has no doubt led to many workers being infected,” he said.
N95 masks offered 96 percent protection, the analysis found, while the figure for