Aflatoxin M1 in Milk from South-Central and Northwest China: Prevalence and Integrated Risk Characterization for...

Aflatoxin M1 (AFM1) is a Group 1 human carcinogen that poses a public health risk through milk contamination. This study investigated AFM1 contamination in pasteurized and ultra-high temperature (UHT) milk from south-central and northwest China, and assessed the associated health risks for consumers based on age, sex, and milk consumption scenarios. In total, 902 milk samples (493 pasteurized, 409 UHT) were collected during the summer and winter seasons of 2023-2024. AFM1 levels were determined using a validated enzyme-linked immunosorbent assay. AFM1 was detected in 75.39% of samples (mean concentration, 12.35 ± 10.27 ng/L; maximum, 75.57 ng/L). While 1.55% of samples exceeded the EU maximum limit (50 ng/L), all complied with the Chinese limit (500 ng/L). Contamination was significantly higher in south-central China than northwest China, higher in winter than summer, and higher in pasteurized milk than UHT milk (p < 0.05). Preschool children in south-central China consuming 400 mL/day of milk are the group with the highest AFM11 exposure risk. And the margin of exposure and population risk of liver cancer suggested little carcinogenic risk. Therefore, targeted monitoring strategies for AFM1 in milk are recommended, along with dietary guidance for high-risk groups, especially vulnerable young children, to mitigate exposure.