Potential health risk in using reusable grocery bags

An effort aimed at making things better for the environment could lead to making us sick.

The Columbia City Council recently shelved a proposal to ban plastic bags at the city’s grocery and convenience stores, and charge 10 cents for each paper bag a shopper wanted to use. And the state legislature has been grappling with the issue as well.

The idea was to cut down on waste. But the plan to ban the bags may even have some unintended consequences.

According to the CDC, there are about 76 million cases of food-borne illness in the U.S. each year. Most of those come from improper cooking or handling of foods, like putting raw meat in the same bag as foods you will eat raw.

“If you are for example, putting your vegetables, fruits, produce right in the bag directly without some sort of secondary other containment, those may become cross-contaminated,” MU Biological Sciences Professor Bethany Stone said. “A bag is a little bit porous. It has those grooves for bacteria to get into and sit.”

Abc 17 talked to more than 20 shoppers with reusable bags in Columbia. One in three used separate bags for meats and produce.

“I typically have them bag my meats separately,” grocery shopper Candace Stormer said.

“I try to use separate, particularly when they’re packing it, I make sure they do it that way,” Michael Diamond said.

But only three in 22 people said they washed their bags on a consistent basis. And more than that said they do not even wash their bags, ever.

“No, I don’t wash my bags at all,” Armine Alioto said.

“Not this one,” Lynn Fair said. “I use it ’til it rots.”

“I didn’t even know they were washable,” Paul Huwiler said.

“I never thought to wash them,” Marcey Combs said.

“I haven’t thought of it yet,” Hanna Klachko said.

“No, I probably should,” Karen Nazario said.

This is similar to a university study done just a few years ago that found 97 percent of people surveyed did not wash their bags.

To find out what this could mean to you, the shopper, Abc 17 swabbed the 22 bags and found what was growing inside. A MU class on infectious diseases helped and put the samples in an incubator at body temperature for two days. When Abc 17 when back to the lab, we found bacteria was in all but four of the bags tested.

“They’re an indicator that there is a bacterial population that’s growing and thriving inside your grocery bags,” Stone said.

Students looked at bacteria under a microscope and found several different types. One was cocci bacteria. Both staph and strep are examples of cocci. Another type students found was bacillus bacteria. Some examples of bacillus are salmonella and E. coli.

“There was one bacterium that has the same shape that we see in an E. coli cell. And so it’s possible that that was an E. coli, it’s possible it wasn’t. But it’s just another example of just be mindful. Think about what you’re doing and what you might be doing to put yourself at risk to these pathogens.”

The University of Arizona and Loma Linda University study found coliform bacteria in more than half the bags it tested, which means they were contaminated by raw meats or other uncooked foods. Researchers also found E. coli bacteria in 12 percent of the bags collected, which means fecal contamination.

But Stone said there is a simple way to use the sustainable bags without putting yourself at risk. Students tested a used bag, and then sterilized it with a household cleaner.

“The before was pretty much covered,” MU student Chris White said. “The whole side of that plate was covered in the culture. And the other side, after we had disinfected it and took another swab, there was nothing. I was surprised at how well it actually did work.”

So even though the bags might not look dirty-

“They all look pretty clean, but I don’t know what’s inside,” Klachko said.

“They don’t get filthy you know,” Huwiler said.

-researchers found hand washing or machine washing reduced bacteria by 99.9 percent.

“It’s a good strategy just to help protect yourself, make sure you don’t transmit those food-borne pathogens and possibly put yourself at risk,” Stone said.

Students also tested a plastic, paper and used reusable bag to compare the samples. The paper and unused bags also showed bacteria growing inside, but zero bacteria was found inside the plastic bag. So even though plastic bags might not be as good for the environment, they may be better for your health.

Last month, the city council voted unanimously to withdraw the ordinance banning plastic bags because of pending state legislation. The Missouri Senate is expected to vote on a bill this week that would make it illegal for cities to ban plastic bags.