Evaluation of Aflatoxin M1 Contamination in Pasteurized Milk in Kerman and Rafsanjan Cities in 2019: A Descriptive Study

Aflatoxins are known as causative factors of hepatic and extra-hepatic carcinogenesis within humans. Aflatoxin B1 enters the animal body through contaminated feed and is partially secreted in milk after being metabolized in the liver to aflatoxin M1 (AFM1). The aim of this study was to determine the amount of aflatoxin M1 to evaluate the quality status of pasteurized milk.

This descriptive study was performed to determine the occurrence of AFM1 in 39 pasteurized milk samples collected during winter and summer 2019 in Kerman and Rafsanjan cities. Aflatoxin analysis was carried out by high-performance liquid chromatography. The non-parametric Mann–Whitney U and Kruskal–Wallis H tests were used to analyze data.

Aflatoxin M1 was detected in 100% of the pasteurized milk ranging from 5.41 to 125.37 ng/l. Toxin levels in 2.6% (1 sample) and 17.9% (7 samples) of the pasteurized milk samples exceeded the Iranian national standard (100 ng/L) and EU (50 ng/L) limit, respectively. The mean concentration of aflatoxin in pasteurized milk samples produced in various regions was significantly different (p <0.05). The carcinogenic risk assessment of AFM1 in milk was estimated, indicating that adult consumers in Kerman and Rafsanjan city are not at considerable cancer risk (HI<1). However, it was not the case for children (1<HI<10).

Large amount of AFM1 in milk samples might be a potential hazard for the public health. Thus, analyzing and reducing the levels of AFB1 in animal feedstuffs and AFM1 in raw milk delivered by dairy factories can be regarded as the initial step to control the transfer of AFM1 to humans.