This study presents the first nationwide study on the chronic health risks of chlorothalonil and its metabolite (4-OH-chlorothalonil) for Chinese adults and breastfed infants via dietary intake. The determination of chlorothalonil and 4-OH-chlorothalonil in dietary samples was accomplished by cold-induced liquid-liquid extraction using liquid chromatography─high-resolution mass spectrometry. Chlorothalonil and 4-OH-chlorothalonil were detected in 43.1 and 46.1% of total dietary samples, respectively, while only 4-OH-chlorothalonil was detected in 100% of breast milk samples. Chlorothalonil and 4-OH-chlorothalonil residues in dietary samples of Northwest China and Shandong regions were higher in comparison to those of other regions. No correlation between 4-OH-chlorothalonil residues in breast milk and adult daily dietary intake to total chlorothalonil indicates the presence of other exposure routes besides dietary exposure. Furthermore, a residue analysis of 4-OH-chlorothalonil in breast milk between urban and rural areas in all sampling locales showed no statistical difference (p > 0.05). The findings of this study reveal that the chronic health risks caused by dietary exposure to chlorothalonil and 4-OH-chlorothalonil are low for Chinese adults and breastfed infants.
Keywords: biomonitoring; chlorothalonil; dietary intake; risk assessment; total diet study.