Occurrence and dietary risk of bisphenols and parabens in raw and processed cow's milk

Raw cow's milk collected from farmers and processed cow's milk purchased from local grocery stores were analysed for the presence of six bisphenols (bisphenol A, bisphenol S, bisphenol F, bisphenol AF, bisphenol B, and bisphenol E) and five parabens (methylparaben, ethylparaben, propylparaben, butylparaben, and benzylparaben). The analytes were determined in their unconjugated form and (after enzymatic deconjugation) as the sum of conjugated and unconjugated compounds. The results show the presence of bisphenols mainly in the processed milk bought in stores while parabens were found in all samples of both raw and processed cow's milk. The average concentration of bisphenol A found in milk from cartons (0.87 ng mL(-1)) was greater than in milk from plastic bottles (0.35 ng mL(-1)). No such difference was found for parabens. Also, no considerable difference between the content of conjugated and total bisphenols and parabens was found except for ethylparaben. The determined compounds were always found below 2.0 ng mL(-1) and calculations of the hazard quotients and the hazard index have shown that consumption of such milk is safe.

Automated summary

The study analyzed the presence of bisphenols and parabens in raw and processed cow's milk, finding that processed milk mainly contained bisphenols, while parabens were found in all samples. Different packaging types showed varying concentrations of bisphenol A, but not for parabens. The levels of these compounds in the milk were below safety thresholds, indicating that consumption of such milk is safe.