Reusable-bag advice: Wash or risk illness
Becky Pallack Arizona Daily Star Posted: Friday, June 25, 2010 12:00 am

Reusable shopping bags are everywhere, it seems. Some are colorful string bags, some organic cotton fabric, some made of recycled materials. Some are insulated. Many are compact and easily foldable.

Tote-bag tips
• Separate produce, meat and other food.

• Don't use a food bag as a book bag, laundry bag or gym bag.

• Bags should be cleaned between uses.

That grocery tote bag that helps you use less plastic could actually be a bag of bacteria.

Researchers stopped shoppers at grocery stores in Tucson, Los Angeles and San Francisco, and swabbed 80 reusable polypropylene bags and a few others. They found "fairly large numbers" of bacteria - sometimes more than the number on your toilet seat, said University of Arizona microbiologist Charles Gerba.

He's a co-author of the new study, which was funded by about $30,000 from the American Chemistry Council.

Juices from produce and meat get on the bags, and the micro-organisms grow there, Gerba explained. On bags that had meat juices spilled on them and were put in the trunk of a hot car, the bacteria grew quickly.

The researchers found E. coli in 12 percent of bags.

Along the way, the researchers also asked shoppers how often they washed their bags and were surprised to find 97 percent never washed them.

"The last thing you want to be doing is growing salmonella in your sack," Gerba said.

As more people begin to use polypropylene bags, they must learn to wash them regularly, he said.

The researchers also purposefully spiked new sacks with bacteria, washed and dried them, and then did the same test. They didn't detect bacteria on cleaned bags.

It would be hard to link an illness to a bag as an exact cause, but if you don't wash your bags, you're taking a gamble, Gerba said.

Tucson shoppers are sticking with their reusable bags.

Marina Joy, 24, said she feels guilty choosing paper or plastic at the checkout line, so she started using tote bags years ago. They rarely get washed.

"I hadn't really thought about it," she said. But as a vegan, she doesn't put meat in them.

Her friend Anchen Texter, 28, said her bags are "convenient, they hold a lot of stuff, and they hold together." She washes them when they look like they need it, she said.

Shelley Michael, 56, said she has had reusable bags for at least five years "so I don't have to use a bunch of plastic."

But the self-described "germaphobe" also said she regularly puts her bags in the washing machine.