California Study Indicates Many Fast Food Soda Dispensers Are Riddled With Deadly Bacteria

Researchers at Southern California’s Loma Linda University discovered in regional soda fountains high levels of bacteria which surpass Environmental Protection Agency (EPA) regulations.

The study, published in August in the journal Drinking Water, was co-authored by Thomas Hile, Stephen Dunbar, and Ryan Sinclair. Their results found that over 40 percent of samples from soda dispensers at local fast-food restaurants showed signs of contamination.

Hile and Sinclair were conducting an experiment related to drinking water at nearby Oasis Mobile Home Park. EPA officials have previously warned that Oasis’ drinking water supply contains toxic levels of arsenic. The scientists were testing water vending machines and other local sources for bacteria to determine preferable water sources for Oasis residents. During a stop for lunch, they decided to add soda dispensers to the list of alternative resources.

Overall, they took 70 water samples from soda fountains, taps, and vending machines. All three sources showed traces of E. coli and other deadly bacteria. E. coli and waterborne pathogens such as Pseudomonas can lead to gastrointestinal or respiratory illness, hepatitis infection, or even death.

Soda fountains, the report noted, contained “microbial contamination above limits set by the EPA.” The report notes that biofilms—a collection of organisms which stick to surfaces—accumulate within the tubing of the soda fountains. Often, the machines are operated with simple plastic piping, which happens to be biofilm’s ideal environment for growth.

“If that [level of contamination] was in tap water," Sinclair told USA Today, "there would be all sorts of alarms that go off."

Although this study was on an admittedly smaller scale, other reports indicate the contamination issues aren’t limited to California. Research conducted in Virginia in 2013 likewise found that regional soda fountains contained microbial contaminants. Those researchers attributed the problem to a lack of regulations concerning the tubing in the machines, as well as an absence of consistent maintenance and inspection on the part of the owners.

Researchers in California recommended fast food chains use antimicrobial tubing as opposed to the cheaper plastic option. They also called for more laws regulating the maintenance of soda dispensers and other water dispensers.

“Restaurant owners/operators whose soda fountains tested positive for total coliform must immediately thoroughly clean and sanitize the unit,” Kristin Lorge, deputy director of the Riverside County Department of Environmental Health, promised in an email to USA Today. “Soda fountains, like all food contact surfaces, must be properly cleaned and sanitized to prevent food contamination and the incidence of food/waterborne illness.”