Probabilistic health risk assessment of rare earth elements through rice (Oryza sativa L.) consumption using Monte Carlo simulation

Rice is a major dietary staple and an important pathway for exposure to rare earth elements (REEs), which are environment-borne contaminants. In this study, 265 rice samples from Taiwan were analyzed, and dietary exposure to 15 REEs was assessed using Monte Carlo simulation. Mean concentrations followed the order Ce > La > Y > Nd, with light REEs accounting for 77 %. Although heavy REEs were less abundant, they contributed proportionally higher non-carcinogenic risks. The mean estimated daily intake (0.012 μg kg⁻¹ bw⁻¹) and the 95th percentile (0.043 μg kg⁻¹ bw⁻¹) were both far below a commonly cited reference value of 70 μg kg⁻¹ bw⁻¹, indicating minimal risk. The highest exposures were observed in children aged 0–3 years, reflecting lower body weight and higher ingestion rates. Sensitivity analysis identified ingestion rate as the most influential factor, followed by body weight and the concentrations of Y, Ce, Eu, and La.