Why your reusable shopping bag could make you very sick

bagMy most recent story that aired on WGME CBS 13 Portland was like a grown up science project. We collected five reusable bags from shoppers in a parking lot of a Portland grocery store, and we brought them to the Microbiology and Infectious Disease lab at the University of New England.

Our CBS 13 On Your Side investigation found your shopping bags could make you sick. We set out to do this story now that more people are using reusable bags in Portland. A new ordinance went on the books earlier this month. It costs you 5 cents for every disposable plastic and paper bag you get. The goal is to get more people to use reusable shopping bags.

But as you make the switch, we wanted to know what you might be carrying around in your bags besides your food.

Dr. Meghan May swabbed the bags for bacteria and viruses that may May-another agar platehave decided to move in to those bags we picked up. You can read more about her testing procedure on her blog.

We checked back in two days later.

“In the bags, I found a lot of bacteria. It’s always a little shocking to see bacteria growing on something that was touching your food,” Dr. May said.

She found bacteria on every bag she tested.

shigellaShigella, in the same family as E. coli, was the most concerning bacteria she found. The Centers for Disease Control says Shigella makes 500,000 people sick in the United States every year.

“You have fever with it. It lasts all week. In severe cases hospitalization for dehydration,” May explained.

Lab results show another Portland shopper was carrying around Bacillus Cereus in her bag.

“It’s going to cause you a pretty miserable few days. It can cause vomiting, diarrhea; it can cause both of those things, ” May said.

A public health study published in 2010 found “reuse of bags creates an opportunity for cross contamination of foods.” Researchers collected 84 bags in California and Arizona; they found large numbers of bacteria in all but one bag.

Another study in the Journal of Infectious Diseases concluded an entire soccer team got sick after eating food out of a contaminated reusable grocery bag.

If you’re making the switch to save, Dr. May says keep in mind these bags aren’t self-cleaning.

“Reusable bags are very important to a lot of people. I use them myself; however, I wash mine every week. I think that would be a key thing to take away from this,” May said.

That study in California found hand or machine washing your bags will reduce the bacteria in them by 99%. Yet, researchers found consumers almost never wash their reusable bags.

If you want to start fresh, this Wednesday, CBS 13 will be handing out new bags at the Portland Farmers’ Market from 7am-1pm.

Jon Chrisos

About Jon Chrisos

Award-winning journalist Jon Chrisos is the investigative and consumer reporter at CBS 13 in Portland. He also anchors weeknights at 5:30. Chrisos is “On Your Side” investigating the stories that make a difference in your life. He’s passionate about helping those who’ve been wronged, exposing government waste, asking tough questions, and uncovering the truth.