Insights into the Formation of Chlorinated Polycyclic Aromatic Hydrocarbons Related to Chlorine in Salt-Tolerant Rice: Profiles in Market Samples, Effects of Saline Cultivation, and Household Cooking

Abstract

Halogenated polycyclic aromatic hydrocarbons (XPAHs) present potential risk owing to their greater toxicity than PAHs. This study aimed to explore their profiles in commercial salt-tolerant rice, effects of saline cultivation (0‰ and 3‰ saline conditions), and formation during home cooking. A validated SPE–GC–MS/MS method was used to analyze PAHs and XPAHs in 16 commercial salt-tolerant rice samples. The PAH24 and XPAH18 concentrations were 6.95–32.73 μg kg^–1 and 0.013–0.593 μg kg^–1, respectively. Chlorinated PAHs (ClPAHs) were significantly greater in salt-tolerant rice (0.14 μg kg^–1) than in normal rice (0.048 μg kg^–1). During cooking, a notable increase (210–1120%) in ClPAHs and a significant correlation (r = 0.70–0.81, p < 0.05) between newly formed ClPAHs and their parent PAHs were observed, suggesting cooking-induced chlorination of PAHs. Moreover, chlorine radical-induced chlorination of PAHs may be the primary mechanism involved. These findings highlight increased exposure to ClPAHs due to saline cultivation and cooking and provide new insight into ClPAH formation from household cooking.