Kidney disease. A sweet ammonia smell on a person's breath, detectable even from behind a dentist's surgical mask.
The surgical mask is not as effective at trapping tiny particles and the paper mask is not effective at all.
Perhaps everyone riding bicycles, wearing Mao outfits with surgical masks.
As the scalpel cuts deeper, Liau's eyes are tense above her surgical mask.
She wore surgical masks and rubber gloves when handling samples.
