Do we need masks outdoors? Experts weigh in

Do we need masks outdoors? Experts weigh in

It's a familiar sight in some US cities like Washington, New York and San Francisco: people walking on the street, riding bikes or sitting in parks with their masks on even when they're far away from others. Certain states, like Maine, have kept in place outdoor mask mandates for hiking trails and beaches. So where does the evidence lie? And is there any harm in public health measures that go beyond the science, or if people behave more cautiously than they need?

Outdoors are much safer

Scientists have learned a lot about COVID-19 since the pandemic began. In terms of how it's transmitted, we now know surfaces aren't a major vector, and heightened disinfection efforts are a misplaced use of time and resources. Second, the top experts now believe the disease is primarily airborne. That means it's mostly spread through fine respiratory particles that remain suspended in the air for some time-as opposed to larger droplets from coughing and sneezing that fall quickly to the ground.

This in turn makes outdoors much safer than indoors, said Jose-Luis Jimenez, a leading aerosol scientist at the University of Colorado Boulder. "Indoors are much more dangerous because the walls and the ceiling and the floor trap