Evaluation of Glucuronide and Sulfate Metabolic Conjugates of Bisphenol-A (BPA) and Tetrabromobisphenol-A (TBBPA) in Municipal Wastewaters as Population Exposure Markers for the Endocrine Disrupting Chemicals
DescriptionThe assessment of population exposure to selected environmental contaminants iscrucial to the understanding of their risk posed on public health. Environmentalendocrine disrupting chemicals (EDCs) have aroused particular concerns around theworld as a number of these compounds, e.g. bisphenol-A (BPA) andtetrabromobisphenol-A (TBBPA), are ubiquitously present in our daily appliances. Theconventional way of estimating the extent of population exposure to contaminants viameasuring their levels in human tissues is resource-demanding and difficult to carryout. A new approach has emerged in recent years that analyzes drug residuals inmunicipal wastewater to assess the usage (and abuse) of pharmaceuticals in thecommunity within the wastewater catchment. This concept of Sewage Chemical-Information Mining (SCIM) has greatly simplified community-wide monitoring andshould also work for the estimation of population exposure to environmentalcontaminants as well. In order to do so, specific molecular markers in municipal sewage,that are collectively excreted by the community within the sewage catchment, have to beidentified. In this project, we targeted eight mono- and di-conjugated glucuronide andsulfate metabolites of BPA and TBBPA as potential candidate markers for the SCIM-basedestimation of population exposure to BPA and TBBPA. These conjugates are wellestablished Phase II metabolites of the EDCs. Although most of their authenticstandards are not commercially available, our research group has already established theprocedures for their chemical synthesis and purification. Our preliminary results havealso demonstrated the correlation between their levels in human urine and those of theirparent EDCs in human blood. Nevertheless, much more work is needed to ascertain theirfeasibility as molecular markers for SCIM-based community-wide human exposureassessment. Thus, a SCIM-based evaluation of these metabolites will be conducted tostudy the correlation between their levels at the household sewage sources and theircorresponding levels in the urine and blood samples collected from voluntary donorswithin the wastewater catchment. Municipal wastewater from up to four catchmentareas in Hong Kong will be involved. Results generated from our studies can begeneralized for nation-wide and international population exposure and public healthassessments of these environmental endocrine disrupting chemicals.
|Effective start/end date||1/09/13 → 28/08/17|