Not sure, if you were interested you'd just do it yourself. But you can also read up on studies of wearing a mask for hours a day instead. But you seem to have a more petulant rather than curious attitude https://www.frontiersin.org/articles/10.3389/fmed.2022.844710/full

Clearly you don't understand gas exchange if you think you're directly breathing oxygen molecules

So I'll throw this in just in case you actually are curious, a mask will catch the larger exhaled moisture, those "droplets" which would not travel through the air. Those that would, travel unimpeded. This both restricts breathing and does not have a measurable effect on viral spread