Determination of aflatoxin M 1 and ochratoxin A in breast milk in rural centers of Yazd, Iran: Exposure assessment and risk characterization

Breast milk (BM) is considered as the best source of nutrition which could have prevention effects on various diseases in the first years of a child. Along with nutritive compounds, presence of contaminants such as mycotoxins in BM could be transmitted into neonate. The aim of this study was to determine the occurrence, levels, and factors associated with the presence of aflatoxin M (AFM ) and ocratoxin a (OTA) in BM samples of nursing mothers in rural centers of Yazd, Iran. The presence and average AFM and OTA concentration in 72 BM samples was measured by competitive ELISA. The demographic and diet parameters of nursing mothers were collected by a questionnaire and were analyzed using SPSS 18 software. AFM and OTA were detected in 63 (87.5%) and 47 (65.2%) samples with the mean concentration levels of 19.46 ± 13.26 ng/L (ranges from 5.1 to 53.9) and 200 ± 160 ng/L (ranges from 100 to 2460), respectively. Of these, 32 samples (50.7%) for AFM and 23 samples (48.9%) for OTA had values exceeding the limit set by the European Union regulation for infant foods (25 ng/L for AFM and 500 ng/L for OTA). It was also found that the risk of AFM and OTA occurrence in BM increased significantly with the consumption of beans, bread, cereals, fruit juice and crackers, and cream, respectively. This study showed that the estimated daily intake for AFM and OTA by 1 month of age infants was 2.7 and 28.5 ng/kg bw/day, respectively, while, as the age of the infant increased, the values were lower and close to 0.9 and 9.9 ng/kg bw/day for AFM1 and OTA in 12 months of age infants, respectively. The high occurrence and noticeable levels of AFM and OTA detected in this study indicated that some infants receive undesirable exposures to AFM and OTA with breast milk. Therefore, it is recommended that mothers are advised to avoid certain foods during pregnancy and breastfeeding that are likely sources of mycotoxins.