Health risk assessment of aflatoxin M1 exposure through traditional dairy products in Fasa, Iran

Milk and dairy products are an important source of essential nutrients for human health. However, contamination of these foods poses a significant public health concern. In this study, risk assessment of aflatoxin M1 (AFM1) exposure associated with the consumption of traditional milk and dairy products in Fasa, Fars Province, Iran, was carried out. A total of 180 samples, comprising raw milk, boiled milk, cheese, yoghurt, as well as Doogh and Kashk, two traditional fermented milk-based products, were collected during two seasons of summer and winter and then analyzed using enzyme-linked immunosorbent assay (ELISA). The findings indicated that 85.55% of all samples were contaminated with AFM1 with the mean concentration of positive samples as 251.15 ± 71.97 ng/kg (1.10-453.50 ng/kg). The results also showed that in 68.88% of tested samples, the toxin concentration exceeded the limit set by the national standard of Iran and the European Union standard. Dietary exposure value calculated for the study population was 0.13 ng/kg BW/day. Based on calculations resulting from risk characterization, hazard index (HI), liver cancer risk (LCR), and margin of exposure (MOE) for AFM1 were 0.67, 7.6 × 10^-4, and 15,291, respectively. For yoghurt consumers, results showed a significant risk for the study population regarding non-carcinogenic and carcinogenicity hazard (HI > 1, LCR > 10^-4, MOE < 10,000). Yoghurt showed the highest contribution rate for AFM1 exposure in various dairy products due to its higher consumption rates, followed by milk. Based on these results, there are needs for rigorous monitoring and control of cattle feeds to decrease the risk of contamination with aflatoxins.