Bisphenol A in infant urine and baby-food samples among 9- to 15-month-olds

Diet is the predominant source of bisphenol A (BPA) intake, but limited data are available on BPA levels in the diet of younger infants. This study investigated BPA levels in baby-food and urine samples collected from young infants (under 2 years old). Samples of homemade baby food (n = 210) and urine (n = 187) were collected at 9, 12, and 15 months after birth from a panel of Korean infants (n = 173). BPA levels in urine and food were measured using HPLC-MS/MS and GC-MS, respectively. BPA was above the limit of detection (LOD) in 85.5-85.7% of the urine samples and 32.5-76.3% of the baby-food samples. The median levels of BPA were 0.45 ng/g wet weight (IQR: not detectable to 5.16 ng/g wet weight) in homemade baby food, 0.93 μg/L (IQR: <LOD to 2.66 μg/L) in unadjusted urine samples, and 0.94 μg/L (IQR: <LOD to 2.80 μg/L) in urine samples adjusted for specific gravity. The BPA levels detected in this study were comparable or lower compared to previously reported levels of BPA in baby-food and infant urine samples. The BPA concentrations in the baby food of 15-month-old children (median: 5.09 ng/g) were significantly greater than those detected at 9 or 12 months of age (median: <LOD and 0.47 ng/g, respectively). Considering that the dietary changes from solid food with high water content to solid food as infants grew were accompanied by greater exposure to BPA, it is noteworthy that urinary BPA levels did not significantly differ according to infants' age. These results suggest that solid food with high water content did not drive the internal dose in younger infants, implying that there may have been other sources of exposure in their baby-food (other than weaning-food) and the environment, although further study would be needed to confirm this possibility.