Shibata et al. 2016 — Arsenic Risk Assessment for US Infant Rice Cereal
This 2016 US risk assessment modeled cumulative iAs exposure for infants and toddlers (4–24 months) from rice cereal, infant formula, drinking water, and other infant solid foods using probabilistic Monte Carlo simulation. Evidence tier B: uses modeled inputs from FDA survey data, not independent primary measurements.
Key numbers
Rice cereal iAs concentration distribution (FDA survey data): Total As range 0.050–0.723 mg/kg; iAs fraction approximately 63%; derived iAs range approximately 0.023–0.283 mg/kg (23–283 µg/kg). Triangular distribution for modeling.
CDI (chronic daily intake) at 50th percentile: Rice cereal only: 0.40 µg/kg bw/day. All dietary sources combined: 0.73 µg/kg bw/day.
Infant formula iAs (literature): mean 7.48×10⁻⁶ mg/L (approximately 7.5 µg/L reconstituted). Note: this value is older literature and predates OBRS scrutiny.
Methods
Monte Carlo probabilistic risk assessment. Concentration data from FDA market survey and published literature. EPA Child-Specific Exposure Factors. LADD (lifetime average daily dose) calculation. Classified B for concentration data: concentrations are modeled inputs, not independently measured.
Implications
Certification: CDI estimate of 0.73 µg/kg bw/day from all sources at median is useful context for exposure modeling. The 63% iAs fraction in rice cereal is consistent with FDA survey data.