About a year ago I bought a few of those light weight reusable grocery bags and I’ve tried to to get in the habit of taking them to the store with me.
Admittedly, I haven’t always remembered.
Although I liked the concept, my ardor dimmed somewhat early on when a package of raw chicken `leaked’ into the bag on the way home. Since then, I’ve mainly used these reusable bags for canned or boxed goods.
Today we’ve a report on studies conducted by two universities suggesting that these reusable bags – while eco-friendly – may harbor dangerous bacteria.
First this report from The University of Arizona News, then the abstract and a link to the study.
These are some of the dozens of grocery bags that were tested for contamination during the study.
These bags may be friendly to the environment, but not necessarily to you, according to a new report by researchers at two universities.
By University Communications June 24, 2010
Reusable grocery bags can be a breeding ground for dangerous food-borne bacteria and pose a serious risk to public health, according to a joint food-safety research report issued today by the University of Arizona and Loma Linda University in California.
The research study – which randomly tested reusable grocery bags carried by shoppers in Tucson, Los Angeles and San Francisco – also found consumers were almost completely unaware of the need to regularly wash their bags.
"Our findings suggest a serious threat to public health, especially from coliform bacteria including E. coli, which were detected in half of the bags sampled," said Charles Gerba, a UA professor of soil, water and environmental science and co-author of the study. "Furthermore, consumers are alarmingly unaware of these risks and the critical need to sanitize their bags on a weekly basis."
Bacteria levels found in reusable bags were significant enough to cause a wide range of serious health problems and even death. They are a particular danger for young children, who are especially vulnerable to food-borne illnesses, Gerba said.
The report is titled:
Charles P. Gerba, David Williams and Ryan G. Sinclair
Abstract (Reparagraphed for readability)
Most foodborne illnesses are believed to originate in the home. Reuse of bags creates an opportunity for cross contamination of foods. The purpose of this study was to assess the potential for cross contamination of food products from reusable bags used to carry groceries.
Reusable bags were collected at random from consumers as they entered grocery stores in California and Arizona. In interviews it was found that reusable bags are seldom if ever washed and often used for multiple purposes. Large numbers of bacteria were found in almost all bags and coliform bacteria in half.
Escherichia coli were identified in 12% of the bags and a wide range of enteric bacteria, including several opportunistic pathogens. When meat juices were added to bags and stored in the trunks of cars for two hours the number of bacteria increased 10-fold indicating the potential for bacterial growth in the bags.
Hand or machine washing was found to reduce the bacteria in bags by >99.9%. These results indicate that reusable bags can play a significant role in the cross contamination of foods if not properly washed on a regular basis. It is recommended that the public needs to be educated about the proper care of reusable bags by printed instructions on the bags or through public service announcements