I bet your initial surprise about the source of a completely avoidable food safety hazard -- reusable grocery bags -- probably mirrored my own, until you thought about it for a second or two. Bacteria levels in grocery bags tested in Los Angeles, San Francisco and Tucson, Ariz., were high enough to cause a wide range of serious health problems -- including death -- according to researchers at the University of Arizona and Loma Linda University.

Almost everyone who was interviewed for the study never considered sanitizing their reusable bags, although thorough washing kills virtually all of the nasties that can accumulate in them. In fact, various forms of coliform bacteria, which includes the very popular E.coli bacteria was found on half of the 84 bags sampled. Additionally, half of the bags tested were used more than once a week, mostly for transporting groceries.

And, it's not a great idea -- especially if you live in a warmer climate -- to pack your store-bought meats in the trunk of your car for very long either. After meat juices were added to reusable bags stored in a car trunk for two hours, the amount of bacteria exploded by a factor of 10 when the indoor temperature was 116 degrees.

All that said, the lead author of the report believes the findings of his study don't suggest that there's a looming outbreak of disease looming in our future, and some health experts believe the average healthy person won't be sickened by the crud growing in our reusable grocery bags either.

That "healthy" skepticism won't stop me from washing my reusable bags very soon, however.

UA News June 24, 2010 Free Full Text Study

NPR June 25, 2010