First, how infectious are bathrooms really?

We know they can be infectious by touch. We wipe and potentially contaminate everything we touch with microbes that come from stool, like norovirus and E. coli, before our hands get washed.

Bathrooms can also be infectious by air. With some respiratory viruses, such as influenza, if enough infectious particles are airborne breathing in a previously shared airspace can pose a hazard. The best example is measles — if someone with measles enters a room, the air is potentially infectious for two hours.

Bathrooms have another unique hazard: toilet plume. With each flush, the toilet releases an invisible army of microbes into the