Co-occurrence of mycotoxins contamination and risk assessment of dietary intake in maize (Zea mays L) from Nigeria

Abstract

The study assessed prevalence, co-occurrence and dietary risk of aflatoxins (AFs), ochratoxin A (OTA), zear alenone (ZEA) and deoxynivalenol (DON) in 90 composite maize samples from farms, stores and markets across Nigerian agro-ecological zones (AEZ) using Ultra High Performance Liquid Chromatography (UHPLC) with immunoaffinity cleanup. 92.2% of samples were contaminated with total AFs (mean 39.58 ±6.40 μg/kg; max 356.16 μg/kg). These exceeded European Union (EU; 10 μg/kg) and National Agency for Food and Drug Administration and Control (NAFDAC; 20 μg/kg) limits in 56.7% and 46.7% of samples, respectively with the highest mean level in Southern Guinea Savanna (SGS; 79.40 μg/kg). OTA occurred in 52.2% (mean 4.51 ±1.02 μg/kg; max 48.75 μg/kg), with highest means in Sahel and Sudan Savannas (11.85 and 11.76 μg/kg). ZEA was restricted to Humid Forest (HF; 66.7% positive; mean 238.88 ±86.53 μg/kg; max 897.02 μg/kg), while DON was found in 13.3% of samples (mean 8.28 ±3.31 μg/kg; max 157.36 μg/kg) with the highest mean in Sahel (31.02 μg/kg). The samples from markets and stores were more contaminated than samples from farms. Infants faced the greatest risk: aflatoxin MOE <1 in SGS (0.61; 11.86 liver cancer cases/100 000/year), OTA %TDI at 243 970% (Sahel), ZEA at 836 080% (HF), and DON at 10 857% (Sahel). National infant AFs exposure (138.5 ng kg 1 bw⋅day 1), compounded by hepatitis B, indicates a public health emergency requiring urgent, AEZ-specific regulatory interventions.