Occurrence of AFM1 in urine samples of a Brazilian population and association with food consumption

This survey evaluated the presence of AFM1 in human urine samples from a specific Brazilian population, as well as corn, peanut, and milk consumption measured by two types of food inquiry. Urine samples from donors who live in the city of Piracicaba, State of São Paulo, Brazil were analyzed to detect the presence of aflatoxin M1 (AFM1), an aflatoxin B1 metabolite, which may be used as aflatoxin B1 exposure biomarker. The AFM1 analysis was performed using immunoaffinity clean-up and detection by high-performance-liquid chromatography with fluorescence detector. A total of 69 samples were analyzed and 45 of them (65%) presented contaminations ⩾1.8 pg ml−1, which was the limit of quantification (LOQ). Seventy eight percent (n = 54) of the samples presented detectable concentrations of AFM1 (>0.6 pg ml−1). The AFM1 concentration among samples above LOQ ranged from 1.8 to 39.9 pg ml−1. There were differences in food consumption profile among donors, although no association was found between food consumption and AFM1 concentration in urine. The high frequency of positive samples suggests exposure of the populations studied to aflatoxins.