The Efficacy of Masks in Wildfire Smoke Protection.
Originally Published 2 years ago — by The New York Times

As smoke from wildfires in Canada drifts over large parts of the United States, the best thing to do to prevent breathing in pollutants is to stay indoors. But if you have to go outside, use N95 or better masks that cover both your nose and mouth, as they can filter tiny particles found in the wildfire smoke. Surgical masks, scarves, or bandannas won't be effective. Experts advise taking the smoke seriously and using air purifiers indoors.