Reusable Bags Harbor Bacteria
New research has determined that few people wash their reusable grocery shopping bags, 8% of reusable bags harbor E. coli, and nearly all unwashed bags harbor other pathogenic bacteria. The research, published in Food Protection Trends, the journal of the International Association for Food Protection, analyzed 87 bags randomly collected from grocery shoppers as they entered food stores in Arizona and California during the summer of 2010.
The bags were swabbed for bacteria and the swabs were analyzed in a laboratory. The research was led by University of Arizona Microbiologist Dr. Charles Gerba. “I was surprised to learn through this study that only three percent of shoppers surveyed actually said they washed their reusable bags between uses. More surprising were the numbers of people who stated they used the bags not only for food shopping, but also to transport clothing and other products to and from work and the gym,” commented Dr. Gerba. “There has been a growing movement to use reusable bags when we shop, but without proper washing, these bags can expose our families to bacteria that can cause illness.”
The researchers also tested washing bags, and found that machine washing removed over 99.9% of the bacteria content in the bags.
“Although it may be a nuisance, washing must be done to ensure your food is safe to eat. I’d recommend washing it with hot, soapy water after each use,” added Dr. Gerba.
The researchers also noted that packaged meats may be a central reason many bags are contaminated. Other research has confirmed that some meat packaging plants harbor pathogenic bacteria, and many outbreaks have been attributed to contaminated meat.
Most environmental experts agree that there is still good reason to use reusable bags. Research on plastic content in waterways and oceans has determined that plastic bags contribute a significant amount of plastic pollution into our environment, and a plastic bag can take up to 500 years to fully decompose.
David L. Williams, Charles P. Gerba, Sherri Maxwell, Ryan G. Sinclair. Assessment of the Potential for Cross-contamination of Food Products by Reusable Shopping Bags. Food Protection Trends, vol. 31, no. 8, pp. 508-513, August 2011 Volume 31, Issue 8.