Session: Current Status of Environmental Research on Water Contaminants:

Long-range transport of persistent organic pollutants (POPs) to the Arctic has been occurring for decades. Exposure of these contaminants to organisms and people is expected to be tightly coupled to their environmental fate. However, little is known about current use pesticides (CUPs), which have now been detected throughout the Arctic, whereby they may have potential to undergo bioaccumulation or biomagnification. Dissolved organic matter (DOM) was isolated by PPLs and freeze-dried from Toolik Lake (68° 38'N) at multiple points in the summer Arctic field season, as well as a hydrologically isolated lacustrine system nearby. Preliminary data show seasonal- and location-specific enhancement of natural attenuation of the current-use pesticides chlorpyrifos and chlorothalonil, with differing responses to each contaminant, including ability to facilitate acid / base-catalyzed photolysis and photo-Fenton processes. For chlorpyrifos, DOM fluorescence index was also found to correlate with pseudo-first order rate loss constant. Understanding how the DOM impacts the persistence and transformation of these CUPs in the Arctic environment will be indispensable for risk assessment of ecosystem and community health amongst a rapidly changing climate.

Yu-Ping Chin

The Ohio State University

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