Residual behavior and risk assessment of prochloraz in bayberries and bayberry wine for the Chinese population

The bayberry is an important economic fruit as well as a minor crop in China, and few pesticide products are registered for bayberry. Prochloraz is a widely used fungicide with a high detection rate on bayberry. This study evaluated the potential dietary risk of prochloraz for different populations in China based on field trial data and market surveillance. The results indicate that one-time applications at dosages of 1000 and 1500 mg/kg with a recommended preharvest interval of 20 days do not pose a chronic or acute dietary risk. However, applying the above dosages twice will cause a potential short-term dietary risk. Risk assessment results conducted on surveillance samples indicated acceptable long-term risks for the general population, with a hazard quotient < 0.82. Furthermore, simulated washing and wine production processes were performed to mimic household practices to investigate residue transfer and distribution. We found that rinsing with tap water for 1 min was an effective way to remove residue, and the processing factors of prochloraz for both bayberry and wine were < 1, indicating that wine production could reduce residue levels. Prochloraz had a strong capacity to transfer to wine due to its high log Kow value, with transfer percentages up to 43%. This study supports the recommendation on good agricultural practices for prochloraz application and provides a guide for safe consumption.