Wearing surgical masks or cloth face coverings does not restrict the amount of oxygen a person breathes in, nor does it cause a dangerous buildup of carbon dioxide, study shows.

Wearing surgical masks or cloth face coverings does not restrict the amount of oxygen a person breathes in, nor does it cause a dangerous buildup of carbon dioxide, study shows. https://t.co/nhghtFRmkS

— NBC News (@NBCNews) October 3, 2020