Wearing a used mask could be more dangerous than not wearing one at all when it comes to warding off COVID-19, a new study has found.
They found that wearing a mask “significantly slows down” airflow, reducing a mask’s efficacy and making a person more susceptible to inhaling aerosols into the nose — where SARS-CoV-2 likes to lurk.
“It is natural to think that wearing a mask, no matter new or old, should always be better than nothing. Our results show that this belief is only true for particles larger than 5 micrometers, but not for fine particles smaller than 2.5 micrometers,” said author Jinxiang Xi.
The researchers found that wearing a mask with low (less than 30%) filtration efficiency can be worse than without.