Masks: Understanding that wearing masks is required and is a good practice, the efficacy of masks depends on how well they fit. The better the mask fits the more effective.
BTW, there is a shortage of masks in the US as it seems they are produced largely in China. CDC officials are saying masks should be reserved for medical personnel. Trump has mentioned the US has a supply of 33 million masks on hand.
On Amazon: "3M Particulate Respirator 8210, N95, Smoke, Dust, Grinding, Sanding, Sawing, Sweeping, 20/Pack," is $300 USD or $15 each for a "one use" mask.