Aflatoxins are a category of poisonous compounds found in most plants, milk and dairy products. The present research was carried out to detect the presence of aflatoxin M₁ (AFM₁) in samples of milk collected from Hamadan province, Iran.

Twenty five samples of ultra-high temperature (UHT) and 63 samples of pasteurized milk were collected and the amount of AFM₁ was measured by an Enzyme-Linked Immunosorbent Assay method. In addition, the estimated daily intake (EDI) and hazard index (HI) of AFM₁ was determined by the following equations:(EDI= mean concentration of AFM₁ × daily consumption of milk/body weight; HI= EDI/Tolerance Daily Intake).

AFM₁ was detected in 21 (84%) UHT milk samples and in 55 (87.30%) pasteurized milk samples. Seven (28%) samples of UHT and 21 (33.33%) pasteurized milk samples had higher AFM₁ content than the limit allowed in the European Union and Iranian National Standard Limits (0.05 μg/kg). None of the samples exceeded the US Food and Drug Administration limit (0.5 μg/kg) for AFM₁. EDI and HI for AM₁ through milk were 0.107 ng/kg body weight/day, and 0.535, respectively.

A significant percentage of milk produced by different factories in Iran (84% of UHT and 87.3% of pasteurized milk) was contaminated with AFM₁. Therefore, more control and monitoring of livestock feeding in dairy companies may help reduce milk contamination with AFM₁. As the HI value was lower than 1, it can be assumed that there was no risk of developing liver cancer due to milk consumption.