October 19th, 2010
By: David Gutierrez
Shoppers who do not regularly wash their reusable grocery bags may be placing themselves and their families at heightened risk of foodborne illness, according to a study conducted by researchers from Loma Linda University and the University of Arizona.
“It is estimated that there are about 76,000,000 cases of foodborne illness in the United States every year,” the researchers wrote. “Most of these illnesses originate in the home from improper cooking or handling of foods. Reusable bags, if not properly washed between uses, create the potential for cross-contamination of foods.”
Researchers asked shoppers at grocery stores in Arizona and California whether they washed their reusable shopping bags, finding that only 3 percent did so regularly. In addition, 75 percent of shoppers surveyed said they did not use separate bags for meat and produce. Another 33 percent said they also used the bags for toting objects other than food.
“[Contamination] potential exists when raw meat products and foods traditionally eaten uncooked (fruits and vegetables) are carried in the same bags, either together or between uses,” the researchers wrote. “This risk can be increased by the growth of bacteria in the bags.”
When the researchers tested 84 bags for bacteria, they found that 83 were contaminated with some variety of bacteria. Fifty percent were contaminated with coliform bacteria, suggesting human feces or raw meat. Twelve percent were contaminated with E. coli.
Fortunately, washing the bags by machine or hand reduced bacterial presence to nearly zero.
The study was funded by the American Chemistry Council, which is lobbying on behalf of single-use plastic bag manufacturers against a bill that would ban those bags from California grocery stores. The bill has already passed the California Assembly, and Governor Arnold Schwarzenegger has said he will sign the bill if the Senate approves it.
Plastic grocery bags have been implicated as the foremost source of beach pollution and a major threat to marine life.