Are cloth seats a public health hazard? Possibly.

Judging from a single, very small survey of San Francisco's BART and Muni systems, fabric seats on public transportation may not be the best choice for public health. A biologist tested one Muni plastic seat and one cloth BART seat—both chosen at random—for bacterial growth. The Muni seat had a couple of harmless bacteria that were easily cleaned off. The BART seat, on the other hand, was home to mold and several different kinds of bacteria, including some antibiotic-resistant strains. This sampling is small enough that it might just reflect a particular line, or part of the train, rather than a systemic issue. So I wouldn't panic if you have to ride BART every day. But it's certainly worrisome enough to warrant more study soon. (Submitterated by Jack)