Risk Assessment of Arsenic in Rice Cereal and Other Dietary Sources for Infants and Toddlers in the US

Currently, there are no set standards or quantitative guidelines available in the U.S. for arsenic levels in rice cereal, one of the most common first solid foods for infants. The objective of this study was to evaluate whether the detected levels of inorganic arsenic (As-i) in rice cereal in the U.S. market are safe for consumption by infants and toddlers. A risk assessment was conducted based on literature reviews of the reported As-i in rice cereal from the U.S. Food and Drug Administration's (FDA) survey and the recommended daily intake of rice cereal by body weight, for infants and toddlers between four and 24 months old. As a part of risk management, a maximum contaminant level (MCL) for As-i in rice cereal was computed considering overall exposure sources including drinking water, infant formula, and other infant solid foods. Hazard quotients (HQs) for acute and chronic exposures were calculated based on the U.S. Agency for Toxic Substances and Disease Registry's (ATSDR) Minimal Risk Level (MRL)(acute) (5.0 x 10(-3) mg/kg/day) and MRLchronic (3.0 x 10(-4) mg/kg/day). A cancer slope or potency factor of 1.5 mg/kg/day was used to predict an incremental lifetime cancer risk (ILCR). Exposure assessment showed that the largest source of As-i for infants and toddlers between four and 24 months old was rice cereal (55%), followed by other infant solid food (19%), and drinking water (18%). Infant formula was the smallest source of As-i for babies (9%) at the 50th percentile based on Monte Carlo simulations. While HQ(acute) were consistently below 1.0, HQ(chronic) at the 50 and 75th percentiles exceeded 1.0 for both rice cereal and total sources. ILCR ranged from 10(-6) (50th) to 10(-5) (75th percentile). MCLs for As-i in rice cereal ranged from 0.0 (chronic) to 0.4 mg/kg (acute exposures).