Monday, July 18, 2016
Health Risks of Banning Plastic Bags
It is becoming politically popular for cities and counties to ban single-use plastic bags for groceries and certain other items in the name of protecting the environment. People living in jurisdictions where such bans are being considered may benefit from my experience in Minneapolis.
Advocates of banning the bags claim they will be replaced by recyclable ones that will save money, energy and other resources in manufacturing and reduce municipal waste in landfills. Not true. Manufacturing the single-use plastic bags requires less than half the energy needed for compostable plastic or cloth bags and less than a third of what's required for paper bags. Making plastic bags requires less than 6 percent of the water needed to make paper bags. In a comparison of quantities of municipal waste by weight, the production, use and disposal of single-use plastic bags produced a net 15.51 pounds of municipal solid waste; compostable plastic bags, 42.32 pounds; paper bags, nearly 75 pounds.
I cited those facts in a letter to the Minneapolis Star Tribune when the city council was considering a ban on plastic bags. In that letter I first cited health risks because they are substantial and I thought council members would surely place human health above all other considerations. I was wrong. Nobody brought up the health issue at the city's meetings about banning the bags despite the Star Tribune having included on its editorial page some of my concerns about the health risk.
Not included was a warning that banning the single-use plastic bags was “creating a high risk of food poisoning,” according to Kofi Aidoo, probably the most highly qualified person in the world to speak on this issue. Here are his awesome credentials. He is president of the Royal Environmental Health Institute of Scotland, Professor of Food Safety and Microbiology at Glasgow Caledonian University (GCU) and program leader of the Food Bioscience Program at the University. He also leads GCU’s Food Research Laboratory, is a Fellow of the Institute of Food Science and Technology (IFST) and of the Royal Society for Promotion of Health. He serves on the Joint Expert Committee on Food Additives, Contaminants and Natural Toxicants (JECFA) of the Food and Agriculture Organization/ World Health Organization. He is the author of 56 publications.
A reporter for the Sunday Post in the U.K. wrote: “We took a selection of reusable bags for analysis at GCU’s School of Health and Life Sciences. There were plastic and cloth types. Four of the nine fell into the heavily contaminated category.”
“The lab analysis found staphylococcus aureus, a disease-causing bacteria that can grow and produce toxin. Yeasts and molds from food spoilage were regularly isolated. Asperigillus and Penicillium were the most common.” Professor Aidoo said, “Presence of these organisms on carrier bags could contaminate freshly-purchased open foods such as fruits and vegetables.”
Aidoo's concerns were echoed by Hugh Pennington, emeritus professor of bacteriology at Aberdeen University, who said banning plastic bags could result in “an increase in the number of cases of food poisoning”. Pennington has chaired two major inquiries into E. coli, including an outbreak in 1996 that killed 21 people. Although some studies report washing the bags is effective, Pennington says it “won't necessarily get rid of all of the bugs. The bag may look clean but you can still easily find these bugs." He also said flatly, “Any bag that's carrying meat, wrapped or unwrapped, shouldn't be used again.” Also, advocates of washing the recyclable bags don't include the cost of detergent, disinfectant or water hot enough to kill the bacteria.
Dr. Richard Summerbell is a professor at the School of Public Health at the University of Toronto and author of over 140 peer-reviewed scientific papers. He conducted a study which found “reusable grocery bags can become an active microbial habitat and a breeding ground for bacteria, yeast, mold, and coliforms.” The study also noted that the presence of yeast and mold may be of concern for people with compromised immune systems or allergies. In addition, the study showed that brand new bags, plastic or cloth, showed no evidence of bacteria, mold, yeast, or total coliform. It is important to note that the Canadian Department of Health validated the concerns of the Summerbell study.
In another study, microbiologist Dr. Charles Gerba said: “Our findings suggest a serious threat to health, especially from bacteria like E. coli, detected in half the bags sampled.”
USA TODAY reported a study conducted at a central California grocery store that “involved spraying bags with a bacteria not harmful to humans but transported in a similar way to norovirus, a leading cause of gastrointestinal disease linked to more than 19 million illnesses each year in the United States. The tracer bacteria was detected in high concentrations on shopping carts, at the checkout counter and on food items shoppers had touched but kept on the shelf.”
Reusable bags can transmit not only harmful bacteria but viruses. In Oregon, 9 of 13 members of a girls soccer team suffered vomiting and severe diarrhea from norovirus. Author of a study in the Journal of Infectious Diseases, epidemiologist Kimberly Repp explains “We demonstrated norovirus transmission without person-to-person contact. That’s why this is different.”
Dr. Gerba issued this statement: “This incident should serve as a warning bell: permitting shoppers to bring unwashed reusable bags into grocery and retail stores not only poses a health risk to baggers but also to the next shoppers in the checkout line." [Bold type is Dr. Gerba's] He also stated: “In reality, reusable bags are likely at fault much more often than we realize: cases often go unreported and uninvestigated.”
Like the norovirus, the influenza virus can by spread by contact with contaminated surfaces. An infected person who has touched his nose or eyes (conjunctiva) will transfer the virus to his hands and subsequently to other surfaces he touches, including a reusable shopping bag. The bag will then be able to transfer the influenza virus to others. A reusable bag coming from a home where there is illness, may be contaminated with the influenza virus. In the event of an influenza outbreak, it has even been suggested it may be necessary to require people to wash their bags before coming into the store or require clerks who handle bags to wear gloves.
Other diseases that can be caused by contaminated reusable bags include common cold, cold sores, conjunctivitis, croup, Giardia infection, lice, meningitis, rotavirus diarrhea, Respiratory syncytial virus (RSV), and strep.
Call7Investigators in Denver took several reusable bags from 7NEWS colleagues and a woman entering a grocery store and brought them to the University of Colorado Hospital for testing. Dr. Michelle Barron, the infectious disease expert there who analyzes lab results for a living, exclaimed, “Wow. Wow. That's pretty impressive.” Then, “Oh my goodness! This is definitely the highest count." She admitted she was shocked. “We're talking in the million range of bacteria," she said. Three of the samples had relatively low bacteria counts, posing little risk. Two had moderate risk, and two others had extremely high counts—330,000 to nearly 1 million colonies of bacteria. Four of the samples also had relatively high levels of yeast and mold.
“To demonstrate the risk, the grocery bags were dusted with a substance that glows in the dark to show how harmful germs can travel. With the lights off, it was clear the Glo-Germ had not only stuck to our groceries, it was also on Marchetta's hands, the counter top, and in the cupboard and refrigerator.”
"We're trying to be environmental. I fully support that,” said Barron. “But not at the cost of your health."
“At the very least,” says Aidoo, “people have to be given advice to clean these bags every time they use them." I doubt that many of the people who supported the ban would have done so if they had known they were going to have to wash them every time. Also, those most likely not to wash their bags are the homeless people, if for no other reason than they lack facilities to do so. So when they plunk down their unwashed reusable bag in a shopping cart or on the checkout counter, they pose a danger of infecting these surfaces for other customers.
The Keep America Beautiful campaign does not even rank plastic bags in the top ten sources of nationwide litter. Many major cities report less than 1 percent of municipal litter is from plastic bags, and many studies show that banning plastic bags has little or no effect on the total. In Minneapolis, Council Member Andrew Johnson spent an hour picking up litter in Minneapolis. He collected 498 items of which only 7 were plastic bags. He was one of only three members of the council to vote against the ban, which passed 10 to 3.