IRFP: Understanding and predicting adverse health effects of transformation products formed from organic micropollutants during water treatment

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1064560CardThrough the NSF International Research Fellowship Program, early-career scientists and engineers may spend up to 24 months in international research collaborations. This experience enables postdoctoral fellows to forge long-term collaborations and conduct cutting-edge research in unique facilities and experimental conditions. This award will support a 24 month fellowship for Dr. Marcella Card to work with Dr. Beate Escher at the National Research Centre for Environmental Toxicology and the University of Queensland in Brisbane, Australia, and with Dr. Kathrin Fenner at the Swiss Federal Institute of Aquatic Science and Technology in Zurich, Switzerland. Myriad micropollutants are present in domestic wastewater due to the use of chemicals such as pharmaceuticals, cleaning products, fertilizers, and dyes. In wastewater treatment plants these micropollutants are transformed via biotic and abiotic processes, resulting in transformation products (TPs). Most TPs are equally or less toxic than the parent compounds, but in some cases they are significantly more toxic than the parent compound, and may impact human health where wastewater is recycled for human use. There is a need for an efficient, reliable way to identify chemicals of concern and to screen TP toxicity.This project will consist of three phases. In the first phase, using known biotic and abiotic transformation processes that occur in wastewater treatment plants, parent compounds that may be transformed into toxic TPs will be predicted. Selected parent compounds will not carry toxicophores (chemical structures which cause specific toxicity) but will have precursor structures which will be predicted to be transformed into toxicophores by abiotic and biotic processes. In the second phase of this research, the predicted parent compounds will be subjected to biotic (activated sludge) and abiotic (advanced oxidation) processes in a pilot-scale wastewater treatment plant. As transformations progress, the reaction mixtures will be tested for specific toxicity using bioassays. The prediction of toxic TP formation will be supported if toxicity increases with increased TP concentrations relative to the parent compound. Finally, the TPs will be positively identified using mass spectrometry in the third phase of this project.The broader impacts of this research include both societal and professional benefits. The results of this work will inform future policy decisions concerning US and international drinking water quality analyses. Thus this work may contribute to reductions in the incidence of chronic toxic effects in populations that consume recycled water. The profession will benefit through improved infrastructure (the observed biotic transformations will be entered into a free online database and predictive system) and the PI's participation in professional conferences. Finally, through this research, the PI will establish long-term collaborations with colleagues in both Australia and Switzerland at academic and industrial institutions, which will continue to aid the PI in future research pursuits long after the current research is completed.