| Popis: |
It is widely reported that bisphenol A (BPA) and phthalates pose a threat to human health with children being more at risk. Humans are exposed to complex chemical mixtures which can potentially interact leading to unpredictable biological effects. Resin-based dental materials are a potential source of BPA exposure in some clinical situations. The purpose of this research was to develop and validate sensitive SPE-HPLCMS/MS methods for quantifying baseline urinary, blood and saliva concentrations of multiple endocrine-disrupting compounds in adult volunteers (n=30) and paediatric dental patients (n=63, urine/saliva only), and determine whether patients receiving resin sealants had elevated urinary concentrations 24-hours post-treatment (n=11). For adults, all compounds were within previously reported ranges. In children, baseline urinary BPA measurements were amongst the highest reported globally. Mean 24-hr post-treatment creatinine-adjusted urinary BPA concentrations were higher than baseline values (46.11 versus 9.36µg BPA/g creatinine, respectively) although the difference was insignificant (p=0.057). Some phthalate metabolite concentrations were highly correlated with BPA concentrations at baseline, but were not corelated post-treatment (5.70 versus 6.41µg MEHP/g creatinine, respectively (p=0.847)), despite similar exposure sources, suggesting the increased BPA concentrations measured were associated with sealant application. In-vitro experiments demonstrated considerable variability in resin volume applied depending on the dental tools used. BPA is largely eliminated after 24hours; it is therefore unlikely that the elevated urinary concentrations 24-hours post-treatment were associated with the application procedure, but potential evidence of continued exposure. Evidence that BPA is efficiently absorbed sublingually suggests that sealants represent a unique source of exposure and warrant further investigation. |
