FRIDAY, Dec. 19, 2014 (HealthDay News) -- Potentially illness-causing E. coli bacteria were found on nearly one-quarter of herbs bought at farmers markets, according to a new study.
Researchers checked cilantro, basil and parsley from almost 50 vendors from 13 farmers markets in Los Angeles and Orange counties in California, and in the Seattle area. Out of almost 150 samples tested, 24 percent were positive for E. coli. One sample was positive for salmonella, according to the researchers.
Both types of bacteria can cause sometimes serious or even deadly illness.
E. coli can cause symptoms such as severe stomach cramps, vomiting and diarrhea that may become bloody. Salmonella symptoms can include diarrhea, abdominal cramps and fever around 12 to 72 hours after consumption that can last four to seven days, the researchers said.
Of the herb samples found to have E. coli, 16 had levels considered unsatisfactory under Public Health Laboratory Service guidelines. While only one sample tested positive for salmonella, 14 others had suspicious growth, according to the study.
The study was published recently in the Journal of the Science of Food and Agriculture.
"While farmers markets can become certified to ensure that each farmer is actually growing the commodities being sold, food safety is not addressed as part of the certification process," study co-author Rosalee Hellberg, assistant professor in the Food Science Program at Chapman University in Orange, Calif., said in university news release.
"Certain herbs such as parsley, basil and cilantro have been implicated in many food outbreaks over the past two decades, so our study focused specifically on the safety and quality of these three herbs," she added.
More than 8,000 farmers markets were listed in the U.S. Department of Agriculture's National Farmers Market directory as of August 2013.
The U.S. National Library of Medicine has more about food safety.