Face mask

So viruses are stopped and CO2 is trapped?

In a well fitting mask that is made of appropriate materials, the chance of transmission is reduced by intercepting large droplets that carry the virus and by buffering and slowing down the exhaled particles. It isn't perfect. Perhaps a good analogy would be a parachute - it doesn't stop you from falling, but it slows you down.

The term we use in cybersecurity is defense in depth. You have multiple enforcing layers of security or protection. Masks alone aren't going to do much, but combine them with people trying to maintain social distance and transmission drops further.

Diameter of covid-19 virus: .1micron. It doesn't get transmitted by itself, but through water droplets 1 micron in diameter. Diameter of CO2 molecule: .00033 microns. Assuming they are circular (they're not, but should do for demonstration purposes), and assuming my math is correct, the volume of a covid-carrying droplet is almost 28 BILLION times as big as the volume of a CO2 molecule. But masks trap CO2, & covid gets a free pass through.
lol @ anti-maskers

We are treating the symptoms, not the cause.

The firehose of falsehood, or firehosing, is a propaganda technique in which a large number of messages are broadcast rapidly, repetitively, and continuously over multiple channels (such as news and social media) without regard for truth or consistency.