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 by the University of Arizona (UA) 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 the 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 soil, water, and environmental science professor 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," Gerba said.

Bacteria levels found in reusable bags were significant enough to cause a wide range of serious health problems and even death. The levels are a particular danger for young children who are especially vulnerable to food-borne illnesses, Gerba says.

The study also found that awareness of potential risks was very low. Ninety-seven percent of those interviewed never washed or bleached the reusable bags, says Gerba, adding that thorough washing kills nearly all bacteria that accumulate in the reusable bags.

For more information, go online to http://uanews.org/node/32521 or contact Gerba at gerba@ag.arizona.edu.