When I was in high school a class of biology students conducted an experiment, they walked through the restrooms with petri dishes open to the air. Just petri dishes, just passing through. They did this for both genders and all bathrooms. I was not a participating student and I don’t remember how I became aware of it but the picture of “stuff” growing in EVERY SINGLE PETRI DISH is quite vivid in my memory. You can only hold your breath for so long, right? And, toilets in high schools don’t have lids, but when I saw this article…. Flashback. Read on at your own peril.
https://robertroybritt.medium.com/ew-this-is-what-happens-when-you-flush-the-toilet-c2b17fcdef46