Human exposure to micro/nano-plastics through vegetables, fruits, and grains - A predictive modelling approach

The emergence of human exposure (HE) to micro/nano-plastics (MN-P) via the food chain is a significant public health concern. This study aimed to evaluate HE from ingesting vegetables, fruits, and grains using linear regression models to analyse MN-P size-concentration relationships and bioaccumulation factors (BF). For Irish adults, the Estimated Daily Intake (EDI) of MN-Ps was calculated, considering potential internalisation in these foods, with a sensitivity analysis addressing variability and uncertainty. The simulated mean (SM) root stomatal diameter in selected plants was 620 nm, indicating the potential uptake of MN-Ps smaller than this size. The SM BF for vegetables was 24.24 for nanoplastics (NP). Limited NP data led to the use of metal nanoparticle (MNP) data, yielding an overall BF of 3.22 for pooled vegetables, fruits, and grains. Potential HE levels of MN-Ps in agricultural soil were simulated at 6.05 × 10⁴ n/kg (SM), with predicted MN-P levels in edible plants at 1.47 × 10⁶ n/kg of food products. The simulated EDI of MN-Ps through all crops was 1.62 × 10³ n/kg bw/day, with vegetables contributing the most to MN-P exposure, followed by fruits and grains. Sensitivity parameters are ranked as MN-P abundance in soil > bioaccumulation factor > food consumption.