Mycotoxin exposure assessment from maize flour-based porridge consumed by infants and young children in South Kivu, Democratic Republic of the Congo

Infants and young children in the Democratic Republic of the Congo (DRC) may be highly exposed to dietary mycotoxins due to reliance on maize flour-based complementary foods. This cross-sectional study assessed exposure across urban and rural health zones in South Kivu, DRC. A total of 428 maize flour samples were pooled into 48 composite samples and analyzed using validated LC-MS/MS methods. Dietary exposure was assessed using Estimated Daily Intake (EDI), Margin of Exposure (MoE), Monte Carlo simulations, and liver cancer risk modeling. Children under five were exposed to levels of aflatoxin B 1 (AFB 1 ; EDIs > 200 ng/kg bw/day) exceeding safety limits. MoE values (1.1-23.1) were far below the recommended threshold of 10,000, indicating high carcinogenic risk. The children were also exposed to fumonisins (0.03-0.74 µg/kg bw/day), deoxynivalenol (0-0.44 µg/kg bw/day), and zearalenone (0-0.50 µg/kg bw/day). Cumulative risk was highest in white (hazard index, HI = 297.8) and pale red maize flours (HI = 275.4). White maize flour contributed the highest AFB1-related liver cancer burden (3.05 cases per 100,000 children annually). These results highlight the need for food safety surveillance and for targeted myotoxin mitigation programs. • LC-MS/MS revealed multi-mycotoxins contamination in maize flour consumed in South Kivu by Infant and Young Children • Infants had high AFB1 exposure levels exceeding safety limits, with EDIs of 230 ng/kg bw/day in infants (0 - 11 months) and 210 ng/kg bw/day in toddlers (12 - 23 months) • MoE values from 1.1 to 23.1, far below the recommended threshold of 10,000, indicating high carcinogenic risk • Fumonisins, DON, and ZEN widely co-occurred in samples • White maize flour posed the highest cumulative health risk with HI of 297.8 • White maize flour contributed the highest AFB₁-related liver cancer burden with 3.05 cases per 100,000 children annually