"Green" shopping bags could make you green around the gills

If you're like many environmentally conscious modern citizens, you're trying to do your part to keep it green. This might mean you've invested in a pile of those reusable shopping bags you see more and more often in stores these days, sometimes for as low as a buck at your speedy checkout lane.

The other day I was at my local Publix grocery store here in Florida, and I saw a tired mom, fighting the good fight. She was behind me in line when she remembered she'd forgotten her reusable shopping bags in the car. She tossed the keys to her reluctant pre-teen, and asked him to run out to the car to grab the bags from the trunk. After an editorial sigh, he started running.

She shrugged, and grinned at me, and said she was trying to teach her kids about taking care of their planet, one bag at a time. She said she had the kids stash the bags right back in the trunk after each grocery run. That way, the bags would always be at hand when they were needed. She mentioned that they often came in handy for different things they did together, as a family.

I wished her a nice day, passing her son carrying an armload of gnarly looking sacks on my way out. I carted my own plastic-bagged groceries out to my car, feeling a little guilty. I also felt a little uneasy, thinking about that jumble of bags living in the friendly woman's trunk. I got home, unpacked my groceries, and did some Googling.

Here's your SmartPlanet moment for the day

It turns out that, according to a joint research study conducted by the University of Arizona and Loma Linda University in California, "Reusable grocery bags can be a breeding ground for dangerous food-borne bacteria and pose a serious risk to public health."

If you'd like the details on how the research project was conducted, and more information about the nasty bacterial contamination the researchers found, download the PDF entitled, Assessment of the Potential for Cross Contamination of Food Products by Reusable Shopping Bags. It's really interesting, and really freaky.

It turns out that people use their reusable bags to bring meat, poultry, and fresh vegetables home from the grocery store, often throw all kinds of other stuff in their handy totes, use them to take lunch to work, sometimes even stash soiled gym clothes and kid's toys in them, leave them in their cars (where the warmth and moisture causes bacteria to grow), and keep using the same bags, over and over again, without washing them.

This is has some really dangerous implications for public health.

When you think about how E. coli is found on 50% of shopping carts, it makes you think twice about putting your purse where the toddler butt goes. But it seems like nobody is thinking twice about reusing these bags two, three, a dozen times. And it's time we started to change our ways, especially since we are encountering more and more nasty, rough and tough, treatment-resistant bacteria.

The public is being encouraged (some might even say pressured) to use these bags, but we're not being educated about how to use them safely. They really should be washed after each use, preferably in hot water.

I have a few of these types of bags around my house that I've gotten as freebies, and some of them don't look like they'd hold up very well to washing. One of them has a cardboard reinforced fabric insert in the bottom that definitely wouldn't make it through even one laundering. So if you're planning to reuse fabric shopping bags, look for ones made from sturdy cotton fabrics that can stand up to laundering in hot water, and make sure they're large enough to withstand some shrinkage.

I'm not sure how to measure it, but is it possible that all that hot water washing could make reusable bags a wash in terms of energy savings?

Here's a collaboration opportunity. Let's see if we can figure this out. I'm pretty sure some of you readers out there know how to do power measurements. How much energy does it take to wash a bag in hot water? What impact does that have on our environment? Finally, how does it balance against the waste created by all the disposable plastic bags?

I know that as a nurse, I've often been appalled by all the waste created by disposable items we use in hospitals. But I've always believed the explanation that avoiding the potential for contamination and contagion outweighs the possible environmental benefits of using non-disposable items.

It just makes me really sad to think that more people might wind up in the hospital because they're trying to be virtuous in their use of reusable grocery bags.

What do you think about the pros and cons of reusable bags? Do you think the benefits outweigh the risks? Let us know in the TalkBacks below.