Q. One of my co-workers always asks for a slice of lemon in his water. I shudder every time I see that piece of lemon floating in his glass but I don’t have the nerve to tell him it’s probably loaded with germs. Am I mistaken?
A. You are correct. Microbiologist Anne LaGrange Loving was served a Diet Coke with a slice of lemon she had not requested. She decided to check whether the lemon was likely to be contaminated.
She and her co-author surreptitiously swabbed 76 lemon slices served at 21 different restaurants, then cultured the results. Two-thirds of the lemon slices had bacteria on either the rind or the pulp (Journal of Environmental Health, Dec., 2007). Many of these germs have the potential to cause illness, although the study was not designed to discover if any patrons actually became sick.
You’re not the only one to wonder about this. Another reader wrote: “I wish you would address the way water is served in restaurants. It frequently comes with a lemon floating in the water. Tests on lemons from various restaurants found fecal bacteria. They should ask whether you want lemon or not.” We agree with that recommendation.