Stop! Is that poop on your lemon? Rethinking Cornona?

I'm a big fan of the Today Show. While I walk in the morning I listen to the show on my radio. One of the things I leaned today was not to have lemon in my water and to think twice about having Coronas with limes in a restaurant.

"It's fairly common for restaurant staffers to place a lemon slice on the rim of a beverage glass as a flavor enhancer or decorative garnish. But who knows whether these lemons have been handled using sanitary procedures? Anne LaGrange Loving, a professor of science at Passaic County Community College, decided to find out.

Loving began her investigation after she saw a waitress’ fingertips dip into her soda as the drink was being brought to her table. Although lemon juice is known to kill germs, Loving devised a study to determine whether lemon slices contain germs when they are served to customers.

Using sterile collection swabs, Loving took two samples from each of 76 lemons that were served in restaurants in North Jersey. Patrons normally start to drink a beverage moments after it is served, so samples were taken right away, before a sip was taken and before anyone at the table touched it. One swab was rubbed along the rind, while a second was rubbed along the pulp. The restaurants were unaware that she was doing this. Samples were then analyzed for microbes at a clinical microbiology laboratory. A total of 25 different types of germs were found on 53 out of the 76 lemons that were sampled. Some were fecal in origin (either from dirty fingertips of the restaurant employees, or from meat-contaminated cutting boards and knives), while others were types commonly found in saliva, on the skin and in the environment.

Although there have been no reported outbreaks of illnesses attributed to lemon slices in beverages, every microorganism that was recovered had the potential to cause a variety of human infections. Establishment of an infection would depend upon the numbers and types of germs involved, the general health and age of the person and whether the person had chapped lips or a cold sore on the lips or gums.

At home, people can simply wash their lemons well with plenty of running water and soap to remove any protective wax that might have been added, then slice them using clean hands, a clean knife and a clean cutting board.

The study did not investigate other beverage garnishes such as olives, celery and limes. Alcoholic beverages were not tested. While alcohol is known to be antibacterial, studies would have to determine whether a beer, glass of wine or mixed drink would contain sufficient alcohol to kill germs quickly. Previous studies have shown, for example, that the communion wine left in a chalice after all parishioners have taken a sip is loaded with bacteria.

The full report of the investigation is in the December 2007 issue of the Journal of Environmental Health.