3 ms·

So the surgical mask, the only one actually designed for a medical use, is good at filtering. Who knew!

• mikestew 6y ago
  Who knew? Probably anyone with a lick of sense. But if that's the only take-away, then one probably missed the point of the article.
• kevincox 6y ago
  The research would be fairly questionable if they didn't compare it to some sort of baseline.