Dietary exposure assessment and risk characterization of aflatoxin B1 in cereal grains consumed in Somalia

Abstract

Aflatoxin $$\hbox {B}_1$$ (AFB $$_1$$ ) is a genotoxic carcinogen that frequently contaminates cereals in tropical food systems. Somalia lacks nationally representative dietary intake data to support exposure assessment and risk management. To estimate dietary exposure to AFB $$_1$$ from maize and sorghum among Somali adults and children and to characterize risk using internationally endorsed toxicological reference points. A deterministic exposure assessment integrated AFB $$_1$$ occurrence data from Somali market surveys with per-capita daily cereal intake derived from SIHBS 2022. Average Probable Daily Intake (APDI; ng/kg bw/day) was calculated for adults (60 kg) and children (20 kg) across mean, P50, P95, and P97.5 consumption levels combined with minimum, median, and maximum contamination scenarios. Margin of Exposure (MOE) was computed using BMDL $$_{10}$$ = 400 ng/kg bw/day. Maize—especially white maize—dominated exposure. Under median contamination, adult maize APDI ranged 293–1366 ng/kg bw/day (MOE 1.37–0.29), while children’s APDI ranged 878–4101 ng/kg bw/day (MOE 0.46–0.10). Sorghum generally contributed much lower exposure except under maximum contamination for red sorghum. Children had approximately three-fold higher exposure than adults on a body-weight basis. Estimated MOEs were far below 10,000, indicating very high priority for risk management. Strengthened regulation, monitoring, and post-harvest interventions are urgently needed, alongside improved dietary data systems.