Arsenic Bioaccessibility in Rice and Its Application to Derive Health-Based Limits in China

Arsenic (As) contamination in rice is a global public health concern, particularly in Asian countries where rice is the staple food. Current health-based limits for As in rice are typically derived from total As concentrations, resulting in overly stringent values. This study aimed to determine As bioaccessibility in rice, estimate dietary intakes of inorganic As (iAs) at different consumption rates, evaluate the cancer and non-cancer risks associated with iAs exposure through rice consumption, and assess the feasibility of deriving more accurate health-based limits for As in rice after incorporating rice As bioaccessibility. Bioaccessibility of As ranged from 60.7% to 104.5% in rice samples. Estimated iAs intake varied from 0.04 to 1.40 μg/kg BW/day at rice consumption rates of 100-300 g/day. Incorporating rice As bioaccessibility resulted in lower iAs intake estimates of 0.03-1.18 μg/kg BW/day. The non-cancer and cancer risks associated with iAs exposure are concerning for populations with higher rice consumption rates and elevated rice iAs concentrations. Health-based limits for iAs in rice for different regions across China are discussed after incorporating rice As bioaccessibility. This study contributes to the development of regional or national safety limits for As in rice, based on As bioaccessibility in rice.