STAR Grant R832737: Development Of Receptor- To Population- Level Analytical Tools For Assessing Endocrine Disruptor Exposure In Wastewater-Impacted Estuarine Systems
This project is aimed at the production of new tools for identifying and quantifying endocrine-active contaminants in complex environmental mixtures and for defining endocrine disruptor exposure in sensitive estuarine systems. The work complements and extends previous and current research on development of targeted, quantitative analytical methods and bioassays for specific classes of endocrine disrupting chemicals (EDCs) in environmental samples.
The specific objectives of the proposed research are to:
- Develop nuclear hormone receptor-affinity extraction techniques as tools for isolating (EDCs) from complex wastewater mixtures.
- Apply these methods in combination with high performance mass spectrometry for activity-directed analysis of EDCs in wastewater and estuarine receiving waters on the SC coast.
- Utilize sensitive vertebrate (zebrafish) and invertebrate (copepod) EDC-exposure laboratory bioassays to link exposure measurements (above) to biological effects.
- Apply novel biomolecular endpoints to assess EDC exposure in field populations of sensitive meiobenthic invertebrates in wastewater-impacted estuarine environments.
Our research plan will address these objectives through development of novel bioanalytical methods and application of bioassays already in current use by the investigators. Specifically, we will utilize commercially-available (estrogen, androgen, and thyroid hormone) and custom (ecdysone/ultraspiracle) recombinant nuclear hormone receptors to construct bioaffinity-extraction columns for identifying, concentrating and purifying receptor-binding EDCs from two important wastewater discharge regimes impacting the SC coast (surface-water discharge and land-application). Isolates will then be analyzed using HPLC-MS/MS (quadrupole/time-of-flight and triple quadrupole) and GC-MS for both target (e.g. estrogens, alkylphenols, hydroxylated PCBs and bisacylhydrazine insecticides) and non-target EDCs. In vivo activity of receptor-isolated EDCs will then be examined by sensitive laboratory endocrine assays, including vitellogenesis in male fish and copepods, and population/molecular endpoints in copepods, in order to provide a link between measured EDCs and biological effects. Finally, as a field validation of analytical and lab bioassay results, we will utilize biomolecular endpoints (ecdysteroid and lipovitellin titres) to assay EDC exposure in field populations of estuarine meiobenthic copepods proximal to a coastal golf course receiving wastewater irrigation.
The results of this work will provide a powerful screening tool for rapid detection and quantification of EDCs in natural waters. The resulting tool will provide a means of rapidly assessing the risk of EDC exposure posed by a specific ground- or surface water, without the need for extensive sample preparation and preconcentration, allowing far more waters to be tested than would be possible with current methods. Preliminary results indicate that the tool will be highly selective, identifying the presence of specific compounds and families of compounds with excellent accuracy.
Susan Laessig at email@example.com