Assessment of Aflatoxin M1 in Commercial Milk and Implications for Child Nutrition Safety in Kano State

Aflatoxin M1, the hydroxylated metabolite of aflatoxin B1 excreted in milk following contaminated feed ingestion, poses a cancer risk and immunosuppression concern for children who consume substantial volumes of dairy. This study assessed aflatoxin M1 levels in commercial milk products and estimated the implications for child dietary safety in Kano State, North West Nigeria. Eighty commercially available milk samples including pasteurized, ultra-high temperature treated, and powdered milk products were obtained from supermarkets and informal retailers in Kano Metropolis. Aflatoxin M1 quantification was performed using high-performance liquid chromatography with fluorescence detection. Dietary exposure was estimated using a probabilistic risk assessment model applied to child milk consumption survey data from 200 households. Aflatoxin M1 was detected in 67.5% of samples, exceeding the European Union limit of 0.05 micrograms per litre in 31.3% of samples. Risk assessment modeling estimated that children aged 12 to 36 months faced the highest exposure relative to body weight, with the 95th percentile exceedance exceeding the tolerable daily intake. Ultra-high temperature treated milk products had significantly lower contamination rates than raw and pasteurized alternatives. The study concludes that aflatoxin M1 contamination of commercial milk in Kano State poses a risk to young children. Supply chain quality monitoring, mycotoxin-free feed certification for dairy farms, and consumer awareness are recommended. Keywords: aflatoxin M1, milk safety, child nutrition, Kano State, dietary risk assessment