Hands-Free Faucets Have More Bacteria: Study

Johns Hopkins Hospital in Baltimore has removed all of its electronic hands-free faucets, and suggests that other hospitals consider doing the same, after a study discovered that—whoops­—they’re actually less hygienic than old-fashioned manual ones. The study examined water samples from all Johns Hopkins' taps, and found that a full half of the electronic taps grew cultures of Legionella bacteria—which can cause pneumonia in those with weakened immune systems—compared to only 15% of manual faucets.

Researchers aren’t entirely sure why that is, but they suspect it’s because the automatic faucets’ more complex valve system gives bacteria more places to grow. “There's a growing literature to suggest that these faucets can be a problem,” one researcher tells LiveScience. The levels of bacteria observed aren’t enough to harm a healthy person, but “it should be at least something people think about.” (More hospital stories.)