Pathways of heavy metal uptake in rice under varying salinity conditions and probabilistic risk analysis for exposed populations in Bangladesh

Rice is a dietary staple for over half the world's population, but it tends to accumulate harmful elements, posing health risks to consumers. The primary aim of the study was to assess the presence of heavy metals (As, Fe, Cu, Mn, Ni, Zn, Cd, Cr, Pb) and potential health risks associated with their consumption in four BRRI rice varieties under arsenic-polluted and salinity conditions in two districts of Bangladesh (Jashore and Satkhira). Findings indicated that chromium was identified as a hyperaccumulator (Transfer Factor>1), with pollution indices indicating severe arsenic contamination in rice, particularly in Jashore. The Estimated Daily Intake (EDI) values for As, Cr, and Ni exceeded the Maximum Tolerated Daily Intake (MTDI), and Target Hazard Quotient (THQ) values for As, Fe, and Ni were above 1.00, indicating non-carcinogenic risks. Arsenic accounted for 39% of the hazard index for both children and adults. The Monte Carlo Simulation (MCS) findings indicated arsenic and nickel pose a high probability of non-carcinogenic and carcinogenic health risks to adults and children across multiple locations. Heavy metal accumulation in rice poses a serious health threat, underscoring the need for stringent regulations to ensure food crop safety in the studied regions.