Of course it is. Nobody EVER claimed masks stop 100% of anything. Wear Saran Wrap if you need that. But masks DO block a measurable percentage of anything that is forced to pass through it. Some fibers are bound to get in the way of some particles. What percentage?? Is it significant enough to matter? That's unclear.
Of course it is. Nobody EVER claimed masks stop 100% of anything. Wear Saran Wrap if you need that. But masks DO block a measurable percentage of anything that is forced to pass through it. Some fibers are bound to get in the way of some particles. What percentage?? Is it significant enough to matter? That's unclear.