But perhaps toilet reading endangers our health via contamination instead. Bathrooms are often viewed as microbial greenhouses, and reading materials might be vectors for the transmission of nasty infections. Although it is certainly true that toilets pose some infectious risk, that risk is often exaggerated. A study of microbe hotspots in the home shows that bathrooms come a distant second to kitchens in microbial density. Toilet seat and handles, and bathroom faucet handles and doorknobs, all had lower counts of bacteria and mold than kitchen sinks, countertops, stove knobs, coffee reservoirs and, most revolting of all, dish sponges. Arguably it is reading in the kitchen rather than the bathroom that should be taboo, with a special stigma attached to cookbooks.

On this note, we must address the idea that taking smartphones into the bathroom is especially inappropriate, more so than books or newspapers. Their much-fingered glass surfaces, warmed from within by battery power and without by pockets and bags, offer an appealing environment for bacteria. A British study reported that one in six smartphones has evidence of fecal contamination. Even so, our phones tend to be extensions of our personal microbiome, sharing around 82% of more common types of bacteria with our index fingers, so even if they are germ-ridden they mainly carry microbes already housed by our bodies rather than foreign invaders that might make us sick. So although it might be wise to put them away in public restrooms, a recent article concluded that “there is no direct evidence … that mobile phones present any more infection risk than any other human possession.”