4 ms·
This is the only definitive study I've seen, and it recommends cotton masks: https://www.cambridge.org/core/services/aop-cambridge-core/content/view/64D368496EB
by geerlingguy 7y ago
This is the only definitive study I've seen, and it recommends cotton masks: https://www.cambridge.org/core/services/aop-cambridge-core/content/view/64D368496EBDE0AFCC6639CCC9D8BC05/S0950268809991658a.pdf/face_masks_to_prevent_transmission_of_influenza_virus_a_systematic_review.pdf https://www.cambridge.org/core/services/aop-cambridge-core/c...