Reusable Shopping Bags May Carry More Than Groceries

By Nancy K. Crevier

Billions of reusable shopping bags travel from home to store and back again, a response of the environmentally conscious American opposed to the one-use plastic bags. Over the past decade, cloth bags or bags made of nonwoven polypropylene, many imprinted with the name of a business or organization, have become a common sight in supermarkets, libraries, and other businesses where disposable bags once ruled the scene.

Who would have thought that “going green” could mean feeling green, though, if proper steps are not taken to decontaminate that reusable cloth shopping bag?

A June 2010 study by Charles P. Gerba and David Williams of the Department of Soil, Water, and Environmental Science at the University of Arizona in Tucson, and Ryan G. Sinclair of the School of Public Heath, Loma Linda University in California, suggests that cross-contamination of foods carried in reusable bags occurs quite commonly. The study repeats results found in a 2008 study sponsored by the Environmental and Plastics Industry Council of Canada, when mold and bacteria levels 300 times the safe limits were found in the reusable bags studied.

The 2010 study of 84 bags collected from the San Francisco and Los Angeles area, and from the Tucson area, found “large numbers of bacteria in almost all bags… The results of this study indicate that large numbers of bacteria occur in reusable bags and are capable of increasing ten-fold in a trunk within a two-hour period of time. Slightly more than half of the bags contained coliform bacteria, indicating contamination by raw meats or other uncooked food products. The indicator bacterium E. coli, used to indicate fecal contamination, was detected in 12 percent of the bags. The presence of these bacteria demonstrates reusable bags do get contaminated by enteric organisms and a risk from food borne pathogens does exist.”

Bags in which raw meats had been carried were highly likely to harbor potentially dangerous bacterias, noted the study, as some leakage may occur from packaged raw meat.

Cross contamination occurs when bacteria laden bags are reused for another purpose, often that of carrying foods that are meant to be consumed raw, such as fresh fruit or lettuce. Because reusable bags are often stored in the trunk of the car, bacteria have the opportunity to multiply in the warm and moist environment. When that bag is used for another purpose, bacteria can be transferred to the person’s hands or to the items in the bag.

The research found that 75 percent of the people did not use separate bags for raw meats and vegetables.

The study also found that 97 percent of people utilizing reusable shopping bags never wash the bags. Laundering bags proved to be a simple way to keep an earth friendly habit a healthy habit.

By hand washing or machine washing the bags, even without the use of bleach, nearly 100 percent of the bacteria was eliminated from contaminated bags. Machine washed bags were washed for a half-hour cycle using common household laundry detergent, and dried for 20 minutes in the drier.

Hand washing also produced desirable results, with the bags soaked for 30 minutes first, and dried overnight.

According to the Center for Disease Control (CDC), nearly 76 million cases of illness from foodborne diseases occur in the US each year, resulting in 5,000 deaths. More than 200 known diseases are transmitted through food contamination.

While many foodborne illnesses are thrust unknowingly upon consumers, here is a simple way to not get “sacked” by germs in the reusable bag. Empty the bag of groceries, and toss it into the hamper. Wash, dry, and then — reuse.