Occurrence of aflatoxin M1 in milk and exposure estimation for its consumption in the Chilean population

The aim of this study was to estimate the occurrence of aflatoxin M1 (AFM1) in milk and the exposure to aflatoxin from milk consumption in Chile in different age groups. For this, a total of 50 batches of the most consumed milk, were collected from hypermarkets from January to July 2022: 24 infant formulas and 26 powdered or fluid milk packages for general consumption. AFM1 levels were analyzed by ELISA using a com-mercial kit (RIDASCREEN, detection range 5-80 ng/L). Exposure was evaluated using the estimated daily intake (EDI) approach, which considered the levels found, in a modified lower bound (mLB) and upper bound (UB), and five age groups (0-2 years, 3-5 years, 6-13 years, 14-18 years and adults). The risk was estimated by the margin of exposure (MOE), considering an MOE of <10,000 as a concern to public health.The occurrence of AFM1 in milk was 42% (21/50), of which 14 samples could be quantified, with a mean level of 7.5 (+/- 1.7) ng/L. The mean UB and mLB levels were 5.8 (+/- 1.4) ng/L and 2.8 (+/- 3.5) ng/L, respectively. The occurrence of AFM1 in infant formulas was 63%, versus 23% in milk for general consumption. According to exposure calculations, in almost all models, the MOE was less than 10,000 in children aged 0-13 years. Although the concentrations of AFM1 found in milk were within Chilean regulatory limits, AFM1 was considered a problem for public health in children between 0 and 13 years of age, with infants being particularly vulnerable. Special regulation for infants and young children is recommended, according to local risk assessments.