Assessment of the Potential for Cross Contamination of Food Products by Reusable Shopping Bags
Charles P. Gerba 1, David Williams 1 and Ryan G. Sinclair 2
1 Department of Soil, Water and Environmental Science, University of Arizona, Tucson, AZ
2 School of Public Health, Loma Linda University, Loma Linda, CA
Most food borne illnesses are believed to originate in the home. Reuse of bags creates an opportunity for cross contamination of foods. The purpose of this study was to assess the potential for cross contamination of food products from reusable bags used to carry groceries. Reusable bags were collected at random from consumers as they entered grocery stores in California and Arizona. In interviews it was found that reusable bags are seldom if ever washed and often used for multiple purposes. Large numbers of bacteria were found in almost all bags and coliform bacteria in half. Escherichia coli (E. Coli) were identified in 12% of the bags and a wide range of enteric bacteria, including several opportunistic pathogens. When meat juices were added to bags and stored in the trunks of cars for two hours the number of bacteria increased 10-fold indicating the potential for bacterial growth in the bags. Hand or machine washing was found to reduce the bacteria in bags by >99.9%. These results indicate that reusable bags can play a significant role in the cross contamination of foods if not properly washed on a regular basis. It is recommended that the public needs to be educated about the proper care of reusable bags by printed instructions on the bags or through public service announcements.