Are You Sure You Want to Use that Reusable Grocery Bag?

If you are, you’d better clean it after each use. Lots of folks use these bags to save the environment, or something, though the supposed benefits are hard to quantify. Turns out these reusable bags carry more than your groceries. Last year, there was a story about a norovirus outbreak that was traced to one of those bags. Here’s a portion of that from WebMD:

A new study shows just how easy it is to catch norovirus, the fast-spreading stomach bug that’s famous for causing misery on cruise ships.

The study tracked a 2010 outbreak of norovirus among young soccer players in Oregon. Seven out of 17 players who attended an out-of-state tournament fell ill with severe vomiting and diarrhea, but curiously, none of them had been in direct contact with the index case — the first girl to get sick.

Investigators were stumped.

“We conducted a very extensive interview; it’s called a shotgun interview, where we ask about every possible food exposure. There are over 800 questions on the questionnaire,” says Kimberly K. Repp, PhD, an epidemiologist with the Washington County Department of Health and Human Services in Hillsboro, Ore.

That helped the researchers figure out what the sick people ate and what the healthy people didn’t eat.

The common denominator? Cookies. All the girls who got sick had eaten cookies during a Sunday lunch. By Tuesday, they’d all fallen ill.

Grocery Tote Carried More Than Food

Norovirus is the leading cause food-borne illness in the U.S. But because the cases were isolated to this relatively small group, rather than widely reported by many people who ate the pre-packaged snacks, researchers didn’t think the cookies themselves were the source.

“It was something about the cookies, we knew, that was associated with the source of the outbreak,” Repp says.

The connection turned out to be a reusable grocery tote bag filled with the cookies and other food items like chips and grapes that had been sitting on the floor of the bathroom where the first girl had repeatedly gotten sick.

The study describes the bag as a reusable open-top grocery bag made from laminated woven polypropylene, a common type you might buy at many grocery stores these days for repeat use.

Now, there’s a paper about a study that shows that ER visits and deaths increased after San Francisco banned paper and plastic grocery bags. Here’s an excerpt:

Our results suggest that the San Francisco ban led to, conservatively, 5.4 annual additional
deaths. Using the EPA’s current estimated value of a statistical life, 8.4 million in current
dollars, this suggests an annual loss of about $45 million without considering the additional
hospital costs, either associated with these deaths or with the increased ER visits documented
above, or the personal costs suffered by individuals who do not seek medical care.

Against these costs, in 2004 San Francisco estimated that plastic bag waste cost it $8.5 million
annually,6 which is $10.3 million in current dollars. Especially given that plastic bags are
generally estimated to be cheaper to make than substitute bags, this implies that any
improvements to the environment owing to the bag ban need to be worth at least $35 million
annually to justify the bans on cost benefit grounds.

Something to think about. The authors suggest that if you’re going to use these bags, that you thoroughly clean them with a disinfectant after each use. Here’s a link to the paper, which is full of tables showing the statistical validity of the authors’ assertions.