CAREER: Multiphase Oxidation and Fate of Pesticides in Dry and Wet Deposition

农药是通过在警察身上的施用而被故意引入环境的。一旦施用，农药就会进入大气，在那里它们与气溶胶颗粒发生反应，并最终沉积在可能远离施用点的表面。然而，人们对农药在悬浮时对这些颗粒发生的化学反应以及这些过程如何影响它们的空间分布知之甚少。在这个职业奖中，PI打算整合实验室和实地研究，以增加对颗粒上农药氧化反应及其沉积的了解。最先进的仪器用于表征反应物和产品以及现场样品中的组件。众多本科生将参与这项研究的各个层面，并在指导来自不同高中的学生方面发挥重要作用，从而为培养一支准备充分的STEM劳动力做出贡献。研究的目标集中在增加目前对农药在大气中的命运的了解，特别是通过(i)气溶胶颗粒吸附的农药的非均质氧化和（ii）区域大气运输和沉积过程。农药膜的非均相氧化速率和产物将在受控的实验室条件下，使用先进的仪器，包括衰减全反射-傅里叶变换红外（ATR-FTIR）光谱和液相色谱/四极杆飞行时间质谱（LC/QToF-MS）。区域运输和沉积将通过在俄亥俄州一个区域网络的4个地点进行测量来确定，那里的玉米和大豆田经常使用除草剂。气团反轨迹和跨地点和季节样品中农药水平的统计测试将有助于评估当地或区域来源是否主导农药沉积。研究结果将有助于深入了解农药及其降解产物是否会导致空气质量差、对人类和生态系统的健康风险以及远离农药使用地区的作物受损。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。

Pesticides are introduced into the environment deliberately through their application to cops. Once applied, pesticides can enter the atmosphere where they react on aerosol particles and eventually deposit back to surfaces that may be far removed from their point of application. Little is known, however, about the chemical reactions that pesticides undergo on these particles while suspended and how these processes impact their spatial distribution. In this CAREER award, the PI intends to integrate laboratory and field studies to increase understanding of pesticide oxidation reactions on particles and their deposition. State-of-the-art instrumentation is used to characterize reactants and products as well as components in field samples. Numerous undergraduate students will be involved at every level of this research and play a significant role in mentoring students from diverse high schools thus contributing to the development of a well-prepared STEM workforce. Objectives of the research focus on increasing current understanding of the atmospheric fate of pesticides, specifically through processes of (i) heterogeneous oxidation of pesticides adsorbed on aerosol particles and (ii) regional atmospheric transport and deposition. Rates and products of heterogeneous oxidation of pesticide films will be determined under controlled laboratory conditions, using advanced instrumentation, including Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopy and liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/QToF-MS). Regional transport and deposition will be determined through measurements performed at 4 sites in a regional network in Ohio, where herbicides are regularly used on corn and soybean fields. Air mass back trajectories and statistical testing of pesticide levels in samples across sites and seasons will aid in assessing whether local or regional sources dominate pesticide deposition. Findings will provide insight into whether pesticides and their degradation products cause poor air quality, health risks to humans and ecosystems, and crop damage in regions distant from pesticide application.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.