A commenter mentioned a few weeks ago that reusable cups, bags, and water bottles are going out of favor in parts of the country due to concerns about coronavirus. Starbucks and some other chains have stopped taking reusable cups. The states of Massachusetts and New Hampshire, along with several grocery chains, are no longer allowing reusable bags. Single-use plastic water bottles are flying off the shelves. It seems intuitive that disposables would have fewer germs than reusables, so you may be wondering — is banning reusables good policy? For this blog post, I will discuss reusable bags.
The reusable bag bans are largely intended to protect the health of retail workers. Governor Chris Sununu of New Hampshire said: “Our grocery store workers are on the front lines of COVID-19, working around the clock to keep New Hampshire families fed. With identified community transmission, it is important that shoppers keep their reusable bags at home given the potential risk to baggers, grocers and customers. This Emergency Order directs all grocers and retail stores in the state to temporarily transition to only use new paper or plastic grocery bags provided by stores as soon as feasibly possible.”
In a related push, the Plastics Industry Association recently requested that the US Department of Health and Human Services speak out about the “public safety risk” of reusables, and “stop the rush to ban” single-use bags and other items. (1)
“Galaxy Brains” meme credit: Emma Listgarten
If you are like me, you may be wondering about the science behind this. I could not find any evidence of a rise in communicable diseases associated with adoption of reusable bags, either in the US or in Europe, which has been using them for much longer. In fact, I found a detailed rebuttal to the one study I could find that purported to show this. Fortunately, the Plastics Industry Association request mentioned above cites three studies as the basis for their request, so I was able to read up on those. Two are related: they involve the same university, one shared investigator, and one shared funder (the American Chemistry Council (2)).
The first of those studies (from 2010) looked at 84 bags that people were using at grocers in three different cities and found some type of bacteria in nearly all of them. The researchers verified it was readily removed with washing. The report observes that it would be possible for cross-contamination (e.g., meat juices on an apple) to occur in such a bag, and recommends washing the bags and/or using a separate bag for raw items like meat. The second referenced study (from 2018) sprayed 25 reusable bags with a simulated virus and tracked where the virus appeared in the stores after volunteers went shopping with the bags — mostly on the hands of the shopper, the clerk, and the purchased food. The study concludes that stores should promote “hand hygiene” and consider disinfecting checkout surfaces.
Amount of contaminant found in various places after being sprayed on a reusable grocery bag (RGB) (source: NEHA)
You can see that neither of these studies provides much information about disease transmission in the real world. As the first report acknowledges, most bacteria are harmless and are generally found in our environment. Cross-contamination can occur in many places, including shopping carts and kitchens and disposable bags, and we are not given any information about the magnitude of the problem that can be attributed to reusable bags. We also don’t “thoroughly spray” bags with viruses in real life, as the second study did. Even if we did, the best response is hand hygiene, which would control for contamination on other “fomites” the study identified, such as the purchased food products and checkout stand. I cannot discern any meaningful information about the risk of real-world disease transmission from reusable bags in these studies.
That brings us to the third and final study that the Plastics Industry Association cites, which is in fact a real-world event. It’s a little gross, but bear with me. In 2010, a soccer team of 13-14 year-old girls from Oregon went to a weekend tournament in Washington state. One of the girls got sick on Saturday night (vomiting and diarrhea from norovirus), and isolated herself in a room with an adult chaperone. The two of them left early Sunday, but within two days seven of the others went on to get similarly sick. How was that possible, given that the sick girl was isolated? It turned out that the seven that got sick had all eaten cookies from a (reusable) bag of snacks that the girl and her chaperone had left behind. Unfortunately, that bag had been hanging in the same room (the bathroom) where the girl and her chaperone had been experiencing the unfortunate side-effects of their illness. (Ew.) So in this case, as in the others, the bag served as a fomite for a viral disease. But was the problem in this case that the bag was reusable? Or was the problem that someone hung a bag (any bag) of food in a bathroom with very contagiously sick people? (Ew.) I’m kind of surprised that is the best that the Plastics Industry Association was able to come up with.
Coronavirus is no joke. How best can we protect retail workers from the potentially infected visiting public? One way to do that is to close the store and offer delivery only, while controlling the hygiene of the workers in the store. In that vein, we are familiar with grocers that deliver, and I’ve recently seen a small hardware store operate this way, with workers standing outside and retrieving items that customers want. Another way to protect store workers is to require customers to clean their hands and other items (wallets, bags, credit cards) that could contaminate the surfaces and workers. That is implausible. A third option is to assume customers’ hands and items are dirty, and have retail workers wear gloves and wipe down surfaces, effectively cleaning up after customers. Given all that, can leaving your reusable bag at home help? Sure. But how much?
What do the medical experts say? The Wall Street Journal quotes one as saying reusable bags present an “incredibly low likelihood” to be the primary vector for transmission, while another says it is “better to be extra careful”. The Boston Globe quotes another as saying both that it “seems like a very small contribution” and also that “I can’t say (using a disposable bag) won’t help.”
So I went to another set of experts, the people working at the grocery stores. Or at least one of them. My sister recently started helping out at a grocery in Minneapolis. She said that where she works, the store is taking responsibility for cleaning between customers (option 3 above). They wipe the checkout counters and shopping carts with a bleach solution between each customer, and the clerks clean their hands between customers. My sister says this helps customers feel better and it protects the workers. Despite these and other store policies (e.g., maintaining 6-foot distances and prohibiting returns), there is still a wide range of caution among the store visitors. Some are not very mindful (e.g., shopping in groups) and others are covered head-to-toe in hats, glasses, masks, and gloves. (3) I asked my sister about an article that suggested people offer to pack their own groceries to minimize the clerk’s exposure, and she groaned. When it’s busy, if the customers don’t know how to pack, she said the checkout can grind to a halt… Given the precautions her store is already taking, her suggestion is to let the professionals do it.
So, that is what I learned, you can draw your own conclusions. My takeaway is to (a) wash my reusable bags occasionally; (b) wash my hands before going into a store (not just after); and (c) reduce clerk exposure to my purchases by doing self check-out or at least packing my own bag, though I usually do that anyway to save time. (4) I know people who are more careful in stores (gloves, masks), and others who are less careful, and best practices are evolving. In any case, I hope those who do switch to single-use bags will make a point to redevelop their reusable habit when the threat of community spread is diminished.
I hope everyone is staying healthy and staying sane…
Notes and References
0. Thank you to my daughter Emma for doing much of the research behind this blog and for doing the meme.
1. Thank you to Politico for acquiring and publishing the letter from the Plastics Industry Association to the Department of Health and Human Services.
2. The American Chemistry Council, nee the Chemical Manufacturers’ Association, represents the interests of chemical manufacturers, including plastics manufacturers.
3. From a worker’s perspective, my sister says this is “more frightening than anything else. It makes you wonder why they are in the store at all.”
4. I am not bad at it. I worked at a grocery store in college.
5. I am not covering reusable cups here, but I did read that we should wash them (no surprise there). Services that sanitize reusables can provide a convenient alternative. One of those, CupClub, was recently piloted by Palo Alto coffee shops Verve and Coupa Cafe.
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