Assessing the health risks of rice cadmium content standards in China

With increasing understanding of cadmium (Cd) exposure levels and toxicity mechanisms, the adequacy of current Cd limit standards for protecting public health requires comprehensive evaluation. Here, we found that 39.04% of rice Cd content surpassed the fifth percentile of benchmark dose lower limit (BMDL₅; 17.100 micrograms per day) threshold for dietary Cd associated with chronic kidney disease in Jiangsu Province. Moreover, more than 90% of rice Cd levels posed potential health hazards, with some samples presenting lifetime carcinogenic risks. Blood and urinary Cd levels demonstrated age-dependent increases, with 48.40 and 20.61% of participants exceeding BMDL₅ levels for blood Cd (0.640 micrograms per liter) and urinary Cd (0.120 micrograms per liter), respectively. The derived reference values for dietary Cd were 0.149 and 0.018 micrograms per kilogram of body weight per day for adults and children, respectively. The lowest concentrations of Cd in rice consumed by adults and children were also observed, which indicated that current Cd limit standards appear insufficient to protect public health, indicating a need for more stringent safety thresholds.