Examining a probabilistic acute dietary exposure model to assess the risk of pesticide residues using nationwide food consumption data and multi-year national pesticide residue monitoring results from Japan

Regulatory bodies increasingly advocate probabilistic estimation of dietary exposure to better characterise variability and uncertainty. In response, we piloted a custom program tailored for Japan’s regulatory context, using boscalid as a case study. Using Japan’s national pesticide residue monitoring data (2013–2022) and food consumption data from a nationally representative survey (2016–2020) comprising 35,552 person-days from 4,444 individuals (including 861 children aged 1–6 years), we conducted Monte Carlo simulations with bootstrap re-sampling to characterise acute exposure distributions. Twenty-one food commodities with at least 25 positive samples or a positivity rate ≥20% were included. The results obtained from the custom program were compared with those obtained using concentration data simulated in Oracle Crystal Ball. At the 99.9th percentile, estimated acute exposures were well below the Acute Reference Dose: 0.12% (95% uncertainty interval: 0.11–0.14%) for general population (1–79 years) and 0.28% (95% uncertainty interval: 0.25–0.30%) for children aged 1–6 years. The results from the custom program and the Oracle Crystal Ball were comparable. These findings suggest that acute dietary exposure to boscalid is unlikely to pose a public health concern in Japan. The modelling framework developed here offers a practical foundation for more complex exposure assessments by Japanese regulatory bodies.