Collaborative Research: Predicting Current-Use Pesticides and Emerging Flame Retardants in a Changing Arctic - Fate and Phototransformation

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The Arctic is experiencing rapid changes such as longer ice-free seasons. One issue that must be navigated in this changing landscape is the fate of the many synthetic organic chemicals that ultimately end up in the Arctic. Little is known about the fate of these chemicals once they reach the Artic, and any of these substances can harm organisms and people. The exposure risk of these compounds is tightly coupled to their environmental fate. This research will assess the abundance of these synthetic compounds and the ability of the Arctic environment to break down these substances. To support the education of future scientists on this emerging topic, a high school module will be delivered for the Alaska Summer Research Academy on Arctic environmental chemistry. Additionally, the research groups of Jennifer Guerard and Yu-Ping Chin will recruit a teacher for the Polar TREC (Teachers and Researchers Exploring and Collaborating) Program. If successful, this project will help direct contaminant mitigation efforts that will be required in the rapidly evolving Artic landscape. Organic chemicals from industry and agriculture have been recently detected throughout the Arctic in the tundra, air, water, organisms, and people. However, little is known about the Artic fate of current use pesticides (CUPs) or emerging brominated flame retardants (EBFRs). This collaborative work between the University of Alaska Fairbanks and the University of Delaware seeks to understand how the Arctic's unique environment influences the fate and transformation of CUPs and EBFRs. Photolysis may play a critical role in the fate of these substances due to continuous solar irradiance in summer months coupled with the presence of dissolved organic matter (DOM). These factors can catalyze contaminant attenuation through reaction with photo-derived reactive oxygen species (ROS) or other pathways. This project tests the hypotheses that: 1) Concentrations of CUPs and EBFRs in surface waters will be highest during and immediately following melt of snowpack; and 2) The formation of analyte-DOM complexes will render these substances more susceptible to photodegradation. The CUPs chlorpyrifos and chlorothalonil, and EBFRs 1,2-bis(2,4,6- tribromophenoxy)ethane and tetrabromobisphenol A, will be measured by atmospheric and aqueous sampling over two field seasons at Toolik Field Station. Partitioning to suspended solids, DOM, and phototransformation pathways influenced by Arctic DOM will be quantified through field and laboratory experiments. Critical measurements will be made of physical and biogeochemical parameters that can be incorporated into an Arctic-specific chemical fate model, including parameters for partitioning into environmental compartments and attenuation rates by photolytic pathways. A chemical fate model for CUPs and EBFRs in Arctic lakes will be developed to predict chemical behavior in Arctic waters under various physical and environmental conditions. Quantifying the persistence and transformation of these compounds will be indispensable for risk assessment and long-term policy development for Arctic region contaminants.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.