Face mask effectiveness: What we know now When the COVID-19 pandemic took off in 2020, so too did questions over the effectiveness of wearing a face mask to prevent the spread of the virus.

TUCSON (KVOA) - Pima County is now in the medium transmission category. Some school districts are dropping mask mandates and making masks optional.

The N95 respirator mask is regulated by the National Institute for Occupational Safety and Health (NIOSH), a division of the Centers for Disease Control and Prevention. Almost all N95 masks use ...