Seasonal Occurrence of Aflatoxin M1 in Raw Milk during a Five-Year Period in Croatia: Dietary Exposure and Risk Assessment.

This study's objective was to estimate the seasonal occurrence of aflatoxin M 1 (AFM 1 ) in cow's milk between winter 2016 and winter 2022 and to assess dietary exposure and risk assessment for the adult Croatian population. In total, 5817 cow milk samples were screened for AFM 1 concentrations using the enzyme immunoassay assay (ELISA). For confirmation purposes of AFM 1 concentration above the European Union maximum permitted level (MRL), ultra high-performance liquid chromatography with tandem mass spectrometry was performed. In 94.7% of milk samples, AFM 1 levels were below the detection limit (LOD) of the ELISA test. For 3.47% of samples, the AFM 1 was between the LOD and MRL values. Only 1.87% of all samples exceeded the MRL. The mean value of elevated AFM 1 in different seasons ranged between 59.2 ng/kg (autumn 2017) and 387.8 ng/kg (autumn 2021). The highest incidences of positive AFM 1 were determined in autumn and winter and the maximum (6.4%) was in winter 2019/2020. The largest percentage of positive samples (69.7%) was found in central Croatia. The estimated daily intakes for positive samples ranged between 0.17 and 2.82 ng/kg body weight/day. Risk assessment indicated a high level of concern during autumn and winter, especially for consumers of large amounts of milk.