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

北极正经历着快速的变化，比如更长的无冰季节。在这种不断变化的环境中，必须解决的一个问题是，最终进入北极的许多合成有机化学品的命运。人们对这些化学物质到达北极后的命运知之甚少，而这些物质中的任何一种都可能对生物和人类造成伤害。这些化合物的暴露风险与它们的环境命运密切相关。这项研究将评估这些合成化合物的丰度以及北极环境分解这些物质的能力。为了支持未来科学家对这一新兴主题的教育，将为阿拉斯加夏季研究学院提供一个关于北极环境化学的高中模块。此外，Jennifer Guerard和Yu-Ping Chin的研究小组将为Polar TREC（教师和研究人员探索和合作）项目招聘一名教师。如果取得成功，该项目将有助于直接开展在迅速变化的北极景观中所需的污染物缓解工作。最近在整个北极的冻土带、空气、水、生物和人身上都检测到工业和农业的有机化学物质。然而，人们对目前使用的农药（CUPs）或新兴的溴化阻燃剂（EBFRs）在北极的命运知之甚少。阿拉斯加费尔班克斯大学和特拉华大学之间的这项合作工作旨在了解北极独特的环境如何影响CUPs和ebfr的命运和转变。由于夏季持续的太阳辐照以及溶解有机物（DOM）的存在，光解作用可能在这些物质的命运中起关键作用。这些因子可以通过与光源活性氧（ROS）的反应或其他途径催化污染物的衰减。本项目对以下假设进行了验证：1)在积雪融化期间和之后，地表水中CUPs和EBFRs的浓度最高；2)分析物- dom络合物的形成使这些物质更容易被光降解。CUPs毒死蜱和百菌清以及EBFRs 1,2-双（2,4,6-三溴苯氧基）乙烷和四溴双酚A将在Toolik野外站的两个野外季节通过大气和水样进行测量。北极DOM对悬浮固体、DOM和光转化途径的影响将通过现场和实验室实验进行量化。将对物理和生物地球化学参数进行关键测量，这些参数可以纳入北极特定的化学命运模型，包括分配到环境隔间的参数和通过光解途径的衰减率。将开发北极湖泊中CUPs和ebfr的化学命运模型，以预测北极水域在各种物理和环境条件下的化学行为。量化这些化合物的持久性和转化对于北极地区污染物的风险评估和长期政策制定是必不可少的。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.