Purpose: The purpose of this study was to determine if the risk of microbial cross-contamination between produce and non-produce items could be decreased at farmers’ markets by vendor booth configurations.
Methods: Three common farmers’ market configurations were identified from USDA guidelines (US, LS, and SS). Eighteen groups, consisting of three volunteers each (n = 108) participated in an LS, a US, or a SS mock markets. Cross-contamination patterns were studied using fluorescent-compound (FC; Glo Germ® lotion). A standard curve was created by dissolving known amounts of the FC into 200 proof ethanol and measuring absorbance at OD370. One gram of FC was spread on both hands of each participant. Once the participants walked through the mock markets, produce (tomatoes, green peppers, apples, onions, and cantaloupe) and non-produce items (plastic and glass containers) were swabbed using a 25 cm2 plastic template. Swabs were placed in 7 ml of ethanol and vortexed for 20 s prior to analyzing absorbance at OD370 to enable quantification.
Results: The US market demonstrated the lowest level of average absorbance (OD370 = 0.049), with produce booths separated by non-produce booths. The highest average absorbance levels were observed in LS (OD370 = 0.128) and SS markets (OD370 = 0.118) when produce and non-produce items separated. Overall, the US market configuration demonstrated the lowest probability of cross-contamination.
Significance: This study indicates that the layout of farmers’ markets can play a critical role in the risk of cross-contamination of produce and non-produce items. Overall, layout recommendations for farmers’ markets should be considered to improve public health by enhancing the safety of fresh produce sold at market.