Nearly half of vending machines nationwide are contaminated with dangerous bacteria, according to a first-of-its-kind study.
Researchers in California say the problem is being “overlooked” after finding E. coli, salmonella and Pseudomonas aeruginosa linked to serious health consequences such as pneumonia, meningitis and other infections on the machines.
The team tested samples from self-service soda machines, water dispensers and outdoor tap water sources in rural eastern Coachella Valley.
About three-quarters of the samples exceeded limits set by the Environmental Protection Agency (EPA).
This isn’t the first indication that dangerous bacteria are lurking in fast food vending machines. For example, a grandfather in Washington died in June after drinking a milkshake from a local burger joint that was contaminated with listeria.
Loma Linda University researchers found that 41 percent of samples from all three supply sources in the eastern Coachella Valley, California, had traces of Salmonella, Pseudomonas aeruginosa and E. coli
The researchers said the findings underscore the importance of cleaning these machines and developing regulations to reduce the risk of contamination.
Dr. Thomas Hile, a biologist at Loma Linda University and lead author of the study, said, “To the best of our knowledge, our study is the first to assess water quality specifically from soda fountains, water dispensers, swabs and tap water in the eastern Coachella Valley.”
In the study, published in August in the journal drinking waterResearchers collected 72 water samples from fast food soda fountains, water vending machines and outdoor tap water sources in the eastern Coachella Valley of Southern California.
This area is largely rural and made up of farmers, many of whom are low-income immigrants.
They found that 41 percent of the soda machines, 20 percent of the water machines, 88 percent of the swab samples and 50 percent of the tap water samples had traces of Salmonella, Pseudomonas aeruginosa and E. coli.
They found these by measuring biofilms – collections of microorganisms that adhere to surfaces and each other – that can develop in the plastic pipes of water distribution systems.
The researchers wrote that plastic pipes are an ideal environment for biofilms to thrive because they can easily adhere to them.
This means that the filtration systems in these machines “are not sufficient to prevent consumers from drinking contaminated water,” the study authors write.
They also found that water dispensers and soda fountains “exhibited microbial contamination in excess of EPA-established limits.”
E. coli are bacteria typically found in the intestines of animals such as cattle, goats, sheep and deer.
While most are harmless, some can cause a range of gastrointestinal distress, including stomach cramps, bloody diarrhea and vomiting.
The exact numbers vary, but it is estimated that E. coli infections cause about 265,000 illnesses and 100 deaths per year.
Young children and older adults are at higher risk of becoming seriously ill, and most of these infections occur in the United States between June and September, according to the Mayo Clinic, although it is not clear why.
In rare cases, people can develop a type of kidney failure called hemolytic uremic syndrome (HUS).
This is a condition in which there is abnormal destruction of platelets and red blood cells.
Salmonella bacteria are transmitted through human or animal feces, and symptoms of infection usually begin six hours to six days after exposure. They usually resolve within another four to seven days without the need for medical intervention.
Some people have no symptoms. However, the condition can sometimes be more serious and require hospitalization.
People with underlying health conditions, weakened immune systems, children under 12 months and the elderly are particularly vulnerable to serious side effects – or even death.
Salmonella infects more than 1.3 million people each year, resulting in 26,500 hospitalizations 420 deaths annually.
Food contaminated with salmonella is almost always of animal origin, such as eggs. The bacteria can also lurk in unbaked or undercooked flour used to make dough or dough.
Pseudomonas aeruginosa is usually found in the environment, such as soil or water. It can also be found in wet areas such as sinks and bathtubs. This bacteria can cause infections of the blood, lungs, skin, gastrointestinal tract, and urinary tract. People with weakened immune systems are most at risk of becoming infected.
According to 2017 CDC data, the most recent data available, Pseudomonas aeruginosa caused 32,600 infections and about 2,700 deaths in the United States.
The study’s biggest limitation was that researchers only tested samples from the eastern Coachella Valley, which has a population of just over 21,000. However, researchers believe the results highlight the risk of contamination in underserved communities.
Dr. Ryan Sinclair, study author and assistant professor of earth and life sciences at Loma Linda University, said, “The study collected water samples from an underserved area where there is generally a lack of routine water quality monitoring and lack of maintenance of beverage fountains.” or water vending machines.’
Next, the researchers want to conduct a risk assessment to see whether the amount of bacteria in the samples could lead to health risks.