Health News Digest

June 8, 2009

Reusable Bags—Recycling Infection

Filling a reusable bag

By  Michael D. Shaw

Few issues within the environmental movement are more contentious than grocery bags. And few issues better illustrate the superficiality of trendy proponents.

Some years ago, it was all the rage for checkers and their helpers to ask customers whether they wanted paper or plastic. The “T-shirt” style plastic bags (so-named because they resemble sleeveless T-shirts) had come on the scene, and with their built-in handles were much easier to carry than the ubiquitous plain brown paper grocery bags. However, the paper bag was reinvented to include handles, shortly thereafter.

Perhaps because paper bags derive from trees—a renewable resource—and because paper appears to be more fragile amidst the elements, paper products were deemed more recyclable, more biodegradable, and more eco-friendly than their plastic counterparts. It was later found, though, that paper—along with most other materials—does not degrade all that quickly in landfills. Moreover, plastic grocery bags require far less energy to manufacture and transport than paper, and consume 91% less energy to recycle, while taking up far less space in landfills.

The demonization of plastic bags probably goes back to a Canadian study [Piatt, J.F. and D.N. Nettleship. 1987. Incidental catch of marine birds and mammals in fishing nets off Newfoundland, Canada. Marine Pollution Bulletin 18(6B): 344-349], which found that, between 1981 and 1984, more than 100,000 marine mammals and birds were killed by discarded nets. “Plastic bags” were not mentioned in this study, but when the work was quoted in a 2002 Australian report, the deaths were inexplicably and mistakenly attributed to plastic bags.

As it happens, this error was not fixed until 2006, thus paving the way for millions of viral Internet impressions, and a host of bandwagon-jumping plastic bag bans and user fees. Studies, including one examining the net effects of Ireland’s 2002 plastic bag tax (Packaging and Films Association with findings corroborated by the Scottish Parliament), indicate that while plastic grocery bag use dropped, sales of other plastic bags—such as garbage bags—increased by 400 percent. Apparently, many people were using those mean old plastic grocery bags for other purposes, such as trash disposal, lunch bags, and pet waste pick-up.

Still, by 2005, most grocery stores would be offering (for purchase, of course) handsome new reusable shopping bags. Clearly, in terms of energy use—given the transportation from China, as well as the far greater energy use in production—most of these bags were losers, when compared with the single-use (paper or plastic) alternative. One might argue that long-term use of the reusables would improve the picture, but that introduces an entirely different problem.

In a report released on April 21, 2009, entitled “A Microbiological Study of Plastic Reusable Bags and ‘First or single-use’ Plastic Bags,” findings indicate that reusables are a breeding ground for bacteria and pose public health risks—food poisoning, skin infections such as bacterial boils, allergic reactions, triggering of asthma attacks, and ear infections. It is noted that in the control group (single-use plastic bags and first-use reusables), there was no evidence of bacteria, mold, yeast, or total coliforms.

64% of the previously-used reusables showed the presence of some levels of bacterial contamination. It is easy enough to posit that bacteria are everywhere, but the counts observed strongly suggest that the bag surface can harbor or breed significant bacterial populations. Moreover, the presence of yeasts in some of the bags tested is quite troubling. Since yeasts are typically not seen in ambient household dust, they are likely thriving in the bags—based on the bags’ available food and water sources.

It is also easy for the proponents of reusables to recommend cleaning them regularly, but even this course is not without its pitfalls. Organic deposits are not simple to remove, and absent thorough drying, microbial growth could actually be encouraged. Other Greenies are warning users to avoid putting non-grocery items, such as diapers and gym clothes into the bags, blithely ignoring that contamination can occur by virtue of grocery items, as well. At any rate, the majority of the users of the reusables employ them as multi-purpose totes.

A further scenario of cross-contamination occurs when the checker handles a contaminated reusable, and transfers microbes to the merchandise of successive customers. As such, investigations of food poisoning are made far more complex: How will it be determined if the root cause originates from the food as it came off the shelf, or a pathogen transferred from a bag?

Some are even calling for regulatory agencies to issue specific protocols on the proper use of reusables, as well as a schedule for their more frequent replacement.

Once again, we see the consequences of naive, superficial, and short-sighted “feel good” actions that fail to take all aspects of the environment into account. Sadly, this is to be expected of feckless politicians, but the rest of us must maintain higher standards.