Assessment of boscalid residue and dietary intake risk in watercress

To evaluate the safety of boscalid in watercress, the samples were pretreated using QuEChERS method and quantitatively analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The final residues in watercress were detected, and a comparative analysis of long-term intake risk using two different diets was conducted. The results showed that the average recoveries of boscalid in watercress was 89%-100%, with the relative standard deviation (RSD) of 5%-12%. Under the GAP conditions, the final residue was between 0.16-37.1 mg/kg. National estimates daily intake (NEDI) of boscalid was 1.215 1 mg/(kg bw). Therefore, risk quotient (RQ) was 48.2%, which indicated that potential health risk caused by boscalid was not significant. If the individual dietary intake of each agricultural product provided by WHO was considered, the daily intake of boscalid was 0.083 0 mg/(kg bw), which lead to the RQ of 3.3%. Using comparative analysis, it is recommended to use diet data provided by WHO for long-term dietary risk assessment.