Friday, June 25, 2010

Wash that Bag!

There is an article in the LA Times today about a study done by the University of Arizona and Loma Linda School of Public Health regarding the growth of bacteria in "reusable bags." You can read the article HERE; it has a link to the full 14 page study. My cynical self wonders who funded the study; it's hardly a public health issue, perhaps more a matter of household hygiene. But I won't be surprised if the Plastic Bag industry incorporates this study into their argument. It's not exactly news; the concept was also included in the state-wide master environmental assessment completed in March.

The study sampled 84 reusable bags (of shoppers as they entered grocery stores), of which 80 were woven polypropylene, in California and Arizona. There is a little irony there because woven polypropylene is plastic, but at least it's not single use. Sounds to me like they sampled the standard reusable bag you see for sale in every grocery store, not cloth or other fibers, and definitely not a basket.

Of the 84 bags, all but one tested positive for some kind of bacteria, and 7 of the bags were positive for e. coli, the bacteria probably capable of wreaking the worst havoc, other than, say, an outbreak of MRSA.

I thought it was interesting that 75% of the people surveyed in the study reported not separating their meats from produce in their bags. The study makes the point that your produce could get infected by external bacteria on your meat packages; e.g. if the butcher has not washed his hands and contaminates the paper or plastic packaging. I hate to get all weird and paranoid about bacteria, but I'll pay attention to that the next time I buy meat. I hadn't really given that much thought, as I buy meats maybe once each week and it comes wrapped in paper that never leaks and goes home in a large (washable) produce bag.

Your organic produce, of course, doesn't have much chance of harboring any bacteria unless it is washed in contaminated water or otherwise comes into contact with fecal matter, from humans or animals. Generally, the bacteria comes into during the processing of the produce further down the line, e.g. salad that is washed and bagged as "ready to eat." I will post later on the FDA requirements for the farmers at the markets; it's highly regulated. In the meantime, here is a little link regarding worst-case of e. coli and fresh produce HERE. Reading something like this just reminds me why I can't bear to buy produce at most grocery stores, and why I never buy produce that is pre-processed unless it's unavoidable.

The study included a test of the ability of a polypropylene bag to grow bacteria: take a swatch of a bag, swab it with meat juices spiked with salmonella; place the swatch in a Ziploc baggie in the trunk of a car for 2 hours in the can grow bacteria 10 times faster with this method! What a surprise! The study gives a few other tips, like don't use your grocery bag for your dirty gym clothes too....should I wonder who would do that...?

I may not be representative, because I do the bulk of my shopping at the weekend markets and make menus during the week around what is in season. All of my purchases go into baskets, of course....which need nothing more than a little shake-out of a little loose dirt or piece of greens. But if you use one of the standard-issue bags for all your shopping, it sounds like washing it from time to time might be a very good idea!

I am still waiting for my new merchandise to come in from Morocco; this is what it will include, sweet little bucket tote with long lambskin handles:

Hats are in too today; check this evening for a post...


  1. I am totally cheating and taking a break from work/school/projects. :)

    I am wondering "Are they not ever washing or wiping down their bags?" I do so regularly. Of course my produce comes to me from my organic source in a huge plastic laundry basket that I wipe down each time. Due to a bout of horrific salmonella poisoning obtained in Egypt I put my meat in paper bags and then recycle the paper.

    I have to say that I was a bit suprised that this study came from U of A as they are generally known to be tree hugging, granola eaters. :)

  2. no idea where the study came from but I think it's all good, to promote awareness... you lived in Europe, where no bacteria had a chance to grow as it is cooked same day, so you appreciate...our system is so different here...back to your studies now!

  3. Right. I cannot believe how people will still buy produce in bags and plastic cases. Bagged salads hold no appeal for me at all; and of course the nasty bacteria held in them and the resulting illnesses to be had are a further caution.

  4. Thanks for this info. I'm with you~this may well have been put forth by some plastics lobby group. Even if the bags did retain some bacteria, a little common sense would help prevent illness. I put fish (I don't eat other meat but the same would apply) in a separate bag from vegetables. If I can't do this, I put it at the bottom of the bag so it doesn't drip on anything else. I also wipe down the inside of the bags regularly and wash my produce really well when I get home. Sorry~I hope this doesn't sound preachy. I'd just hate for people to be discouraged from using non-plastic bags for fear of bacteria.

  5. Thanks for stopping by, Bonnie. You're not preachy, your common sense.....sounds like you have it all sorted.