Comprehensive mycotoxin analysis in Thai rice: method development, prevalence, exposure assessment and health risk evaluation

This study developed a high-performance, multi-analyte detection method for analyzing regulated mycotoxins presence in rice, and to assess their exposure levels and associated health risks within the Thai population. A high-throughput LC–MS/MS method was developed and validated to detect six regulated mycotoxins namely, aflatoxin B₁, ochratoxin A, fumonisin B_1, zearalenone, deoxynivalenol and T-2 toxin in rice. The method utilized a rapid dilute and shoot technique for sample preparation (267 samples including white and brown rice) from across different geographical regions in Thailand. Occurrence data revealed distinct patterns of contaminations. Fumonisin B₁ was the only mycotoxin detected in brown rice (12.73%) whereas a range of mycotoxins (except fumonisin B₁ and zearalenone) were found in white rice (0.37%). Exposure of the Thai population was assessed from consumption patterns (brown or white rice) and age factor (from young children to the elderly). The mycotoxin intake levels based on bodyweight in the 0–3, 3–6 and 6–13 age groups were higher than those of the other age groups for all mycotoxins found. Risk estimates, derived from comparing the exposures to ochratoxin A, fumonisin B1, zearalenone, deoxynivalenol and T-2 toxin with relevant health-based guidance values indicate low levels of health concern. However, the margin of exposure approach for aflatoxin B1 revealed high carcinogenic risks for all population groups, particularly for children aged 0–13 years. This finding highlights the importance of fit-for-purpose analytical methods to support monitoring programs and ensure that relevant safety standards are met, hence safeguarding public health and supporting market access for Thai rice.