Development of human dermal PBPK models for the bisphenols BPA, BPS, BPF, and BPAF with parallel-layered skin compartment: Basing on dermal administration studies in humans

Occurrence of bisphenol analogues and their conjugated metabolites in foodstuff

Bisphenol analogues (BPs) are prevalent in diverse foodstuff samples worldwide. However, the occurrence of conjugated bisphenol A (BPA) and bisphenol S (BPS) metabolites in foodstuff remains poorly understood. This study analyzed eight BPs, and four conjugated BPA and BPS metabolites, in three animal-derived foodstuff and five plant-derived foodstuff samples from China. Results showed that fish foodstuff (9.7 ng/g ww) contained the highest mean concentration of BPA, followed by rice (5.1 ng/g ww) and beans foodstuff (3.6 ng/g ww). BPA-sulfate had higher mean concentrations than BPA-glucuronide in different foodstuff categories, except that in eggs foodstuff (p < 0.05). Compared with other foodstuff items, fish (3.4 ng/g ww) and vegetable (1.6 ng/g ww) foodstuff samples exhibited comparatively higher mean concentrations of BPS. Mean concentrations of BPS-sulfate were consistently higher than BPS-glucuronide in vegetables, meats, and fish foodstuff (p < 0.05). BPA contributed the major total dietary intake (DI) of BPs, with the mean DI of 435 ng/kg bw/day for women and 374 ng/kg bw/day for men, respectively. To our knowledge, this study is the first to investigate the occurrence of conjugated BPA and BPS metabolites in foodstuff, which enhances our comprehension of the origins of these conjugated metabolites in the human body.

Towards the assessment of exposure to bisphenols in everyday items with increased accuracy by the use of integrated calibration method (ICM)-based methodology

The most crucial purpose of the measurement is to obtain a reliable result that reflects the actual qualitative and/or quantitative features of the tested material. The overriding goal of analytical chemistry is to obtain accurate results after compensating of various interference effects as well as non-linear calibration dependence. A new approach based on an integrated calibration method (ICM) supported by H-point standard addition method (HPSAM) has been used to improve the quality of analytical results. The proposed methodological approach was extended using the step-by-step dilution procedure, and five measurement conditions were used to eliminate multiplicative, additive, and non-linear interferences. On this basis, a set of estimations is obtained to improve the quality of the analytical results. The analytical usefulness of the proposed approach was tested on the example of the determination of three compounds from the group of bisphenols (BPs) using the chromatographic technique - HPLC-DAD (high-performance liquid chromatography with diode array detection). Compared to the reference method - fluorescence spectroscopy - the obtained results were characterized by excellent accuracy (RE=3 % in most cases). The developed methodology allowed to carry out a risk assessment on BPA, BPF, and BPS present in samples of shop receipts and canned food. Store clerks have been shown to be particularly vulnerable to PBF and BPS in receipts due to skin permeation (exposure factors were equal to 308.97 µg/g for BPF and 181.89 µg/g for BPS). Consumers should also pay close attention to the BPA found in canned food samples (the average concentration was equal to 20.61 µg/mL, and the tolerable daily intake was exceeded over 165.000 times). The analytical method and the methodological approach were evaluated using the RGB model and the AGREE approach - it was shown that the method can be successfully used for other analytical purposes (the method is White) and is environmentally friendly (Significance=0.63).