Monitoring and Dietary Risk Assessment of Pesticide Residues and Mycotoxins in Fresh Maize: A Nationwide Study from China.
Pesticide residues and mycotoxins are important maize contaminants, but their occurrence and dietary risks in fresh maize remain unclear. In this study, ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) methods were established for analyzing 70 pesticides and 15 mycotoxins and were applied to 302 fresh maize samples from three major regions in China. A total of 21 pesticides were detected at concentrations of 1.6-306 μg/kg and detection rates of 0.3-9.6%. Among the samples, 3.3% exceeded the Chinese maximum residue limits (MRLs). Three mycotoxins were detected at frequencies of 0.7-3.0% and concentrations of 2.6-19.1 μg/kg. Dietary risk assessment indicated that the estimated acute (%ARfD, 6.8 × 10-6-3.0 × 10-3) and chronic (%ADI, 7.0 × 10-5-1.2 × 10-1) risks from pesticide residues were well below 100%. The chronic dietary risk associated with the detected mycotoxins (%TDI) ranged from 3.9% to 30.1%, indicating no unacceptable risk.