It’s called toilet plume.
A toilet plume is the invisible to the naked eye, cloud-like dispersal of raw, infectious sewage particles as a result of flushing a toilet. Flush particles rapidly rise out of the bowl and several feet into the air after flushing. Aerosolized droplets can remain suspended in the air for tens of minutes between users, posing an inhalation risk. These invisible particles go on to coat and spread onto surfaces like floors and counters or objects like hand towels, bathmats, or even toothbrushes.



Yes, but there is incredibly strong evidence that mask wearing does reduce transmission rates. I haven’t looked (so definitely correct me if I’m wrong), but I suspect that lid closing likely does not have strong evidence for decreased transmission.
One factor that I think likely weighs heavily into this is that public toilets, where you could be exposed to particles from a stranger dont have lids usually, and they have a much more violent flush, while home toilets are mostly just used by your own household.
We’re not necessarily talking about transmission in this case, just the concept of poo particles spreading widely throughout your bathroom vs less widely