Health risk assessment using in vitro simulation in assessing bioavailability of cadmium in rice from main producing areas across China

Rice is a recognized source of cadmium (Cd) exposure. In this study, a total of 102 rice samples were obtained from main producing rice regions of China, and the bioavailability of Cd in rice were assessed by using an in vitro digestion method combined with a Caco-2 cell monolayer model. The results revealed that the average (range of) concentration of Cd in the rice samples was 0.2840 (0.0123-2.4710) mg/kg, and the average (range of) bioavailability of Cd in the rice samples was 23.94% (7.47-39.73%). We analyzed the recent rice consumption data and calculated the target hazard quotients (THQs) to evaluate the noncarcinogenic health risk of Cd in rice consumption for adults and children, respectively. We suggested that the most of investigated regions showed low risks of Cd in rice for general population, and the regions of Cd in rice near the limit deserves might be attracted more attention after taking bioavailability into account. PRACTICAL APPLICATION: The cadmium content of rice itself will affect its corresponding bioavailability to a certain extent. By studying the in vitro bioavailability of cadmium rice with different pollution levels, it is helpful for the dose selection of animal experiments or toxicity tests, and finally, we may provide some references for the establishment of appropriate treatment scheme of rice Cd poisoning.