Reducing pesticide residues on produce: a scoping review of household produce washing methods

IntroductionDiet, particularly fruits and vegetables, contributes to pesticide exposure in the general population due to the presence of numerous pesticide residues on commonly consumed produce. Research on the effectiveness of produce washing for reducing pesticide levels can inform interventions to decrease overall pesticide exposure.MethodsWe analyzed data from 47 peer-reviewed studies on produce washing, encompassing 23 produce items and 79 pesticides. Individual reduction-efficacy data points were collected for four methods: rinsing with tap water (n = 187), soaking in tap water (n = 440), soaking in a baking soda solution (n = 282), and soaking in vinegar/acetic acid (n = 191).ResultsAcross the dataset, reductions ranged from 0.0% to >94.0% for rinsing (median=30.2%), 0.6% to >99% for water soaking (median=33.7%), 0.2% to >99.0% for baking soda soaking (median=50.9%), and 8.6% to >99.0% for vinegar/acetic acid soaking (median=54.2%). While plain water washing was effective in multiple studies, baking soda or vinegar/acetic acid soaking showed more than a 15.0% greater median average reduction across studies. However, the high solution concentrations commonly studied may limit generalizability to typical household use. Pesticide physico-chemical properties, washing method, and produce characteristics were the most frequently reported factors impacting pesticide reduction.DiscussionHousehold washing is likely to reduce dietary pesticide exposure. We recommend future research that reflects real-world consumer exposure, expanded biomonitoring for pesticides in people, and regulatory testing that prioritizes pesticides persistent on specific produce after washing.