CAREER: SPatiotemporal INvestigation of Urban Pollution and Air Quality (SPIN-UP-AQ)

挥发性有机化合物（VOCs）造成的空气污染对世界各地城市社区的空气质量和人类健康产生重大影响。在城市地区，挥发性有机化合物以广泛的浓度、挥发性、反应性和毒性存在。城市空气中的挥发性有机化合物包括中挥发性有机化合物（ivoc）和半挥发性有机化合物（SVOCs）。这些馏分越来越成为空气污染研究的焦点，因为它们可能包含有毒成分或为特定的大气过程和来源提供独特的标记。然而，由于I/SVOCs在空气样本中的浓度相对较低以及分析仪器的局限性，测量它们极具挑战性。化学电离质谱法的最新进展和商用高分辨率质谱仪的可用性已经开启了对超低浓度大气污染物进行测量的可能性。在这些进展的基础上，这个CAREER项目的首席研究员建议测量全光谱I/SVOCs的当地和区域大气浓度。这些化合物将作为时间和来源位置的函数进行量化，重点是绘制通常位于工业或其他人为污染源附近的低收入城市社区已知和新出现的空气污染物的地图。德克萨斯州的奥斯汀大都市区将被用作示范系统。这项研究的成功完成将通过产生新的数据和基础知识来促进对污染源和影响城市空气质量和有毒物质暴露的因素的定量理解和评估，从而造福社会。进一步的社会效益将通过学生教育和培训来实现，包括在德克萨斯大学奥斯汀分校指导一名研究生和一名女本科生。CAREER项目的总体目标是以50米的分辨率测量并准确量化整个奥斯汀市（TX）大都市区空气样本中中挥发性有机化合物（IVOCs）和半挥发性有机化合物（SVOCs）的时空浓度，这在以前的城市空气污染调查中尚未实现。本研究的指导假设是，在奥斯汀等城市的大都市区，I/SVOCs的组成和浓度在空间上具有异质性，位于高速公路、机场、污水处理厂、垃圾填埋场和工业等主要空气污染源附近的富裕社区和低收入社区之间存在显著差异。为了验证这一假设，首席研究员（PI）建议在移动实验室车辆上部署最先进的质子转移反应时间飞行质谱仪，该车辆配置用于进行区域道路空气质量空间测量。研究的具体目标是：(1)利用移动测量方法定量分析大气中I/SVOCs的空间组成；(2)利用稳态测量方法定量研究了特定群落受体位点I/SVOCs的时间组成变化；(3)利用移动和固定空气质量测量数据，建立并验证了多变量模型，该模型可用于量化奥斯汀大都市区社区的暴露风险和环境正义指标；(4)从移动和静止测量中量化源分配，构建Austin都市圈I/SVOCs社区源指纹库。这项研究的成功完成有可能产生变革性的影响，产生新的数据和基本知识，这将促进对城市污染源和影响空气质量和社区接触的因素的定量了解。为了实现该CAREER项目的教育和培训目标，PI将利用研究结果更新他在奥斯汀德克萨斯大学（UT）的体验式空气质量课程。此外，PI计划与德克萨斯大学奥斯汀分校的“全社区-全健康”项目合作，教育和帮助受空气污染影响的当地社区，根据PI调查得出的空气质量数据和暴露风险估计，表达他们的关切。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。

Air pollution by volatile organic compounds (VOCs) has a significant impact on air quality and human health in urban communities throughout the world. In urban areas, VOCs are present in wide ranges of concentration, volatility, reactivity, and toxicity. VOCs in urban air include intermediate-volatility organic compounds (IVOCs) and semi-volatile organic compounds (SVOCs). These fractions are increasingly the focus of air pollution studies as they may include toxic constituents or provide unique markers for specific atmospheric processes and sources. However, measurements of I/SVOCs are extremely challenging due to their relatively low concentrations in air samples and analytical instrument limitations. Recent advances in chemical ionization mass spectrometry and the availability of commercial high-resolution mass spectrometers have opened the possibility of conducting measurements of atmospheric pollutants at ultralow concentrations. Building upon these advances, the Principal Investigator of this CAREER project proposes to measure the local and regional atmospheric concentrations of a full spectrum of I/SVOCs. These compounds will be quantified as a function of time and source location with a focus on mapping known and emerging air pollutants in low-income urban communities that are often located close to industrial or other anthropogenic pollution sources. The Austin metropolitan area in Texas will be used as a model system. The successful completion of this research will benefit society through the generation of new data and fundamental knowledge to advance the quantitative understanding and evaluation of pollution sources and factors affecting air quality and toxic exposures in urban areas. Further benefits to society will be achieved through student education and training including the mentoring of a graduate student and a female undergraduate student at the University of Texas at Austin.The overarching goal of this CAREER project is to measure and accurately quantify the spatiotemporal concentrations of intermediate-volatility organic compounds (IVOCs) and semi-volatile organic compounds (SVOCs) in air samples throughout the City of Austin (TX) metropolitan area at a resolution of 50 meters that has not been achieved in previous investigations of urban air pollution. The guiding hypothesis of the proposed research is that the compositions and concentrations of I/SVOCs in the metropolitan area of a city like Austin are spatially heterogenous with significant differences between wealthy communities and low-income communities located near major sources of air pollution including freeways, airports, wastewater treatment plants, landfills, and industries. To test this hypothesis, the Principal Investigator (PI) proposes to deploy a state-of-the-art proton transfer reaction time of flight mass spectrometer in a mobile lab vehicle configured to carry out regional on-road spatial measurements of air quality. The specific objectives of the research are to: (1) Quantify the spatial compositions of I/SVOCs using mobile measurements; (2) Quantify the changes in temporal compositions of I/SVOCs at a selected community receptor site using stationary measurements; (3) Use the data collected during the mobile and stationary air quality measurements to build and validate multivariate models that could be used to quantify exposure risks and environmental justice indices for communities in the Austin metropolitan area; and (4) Quantify the source apportionment from the mobile and stationary measurements to build a community source fingerprint inventory for I/SVOCs in the Austin metropolitan area. The successful completion of this research has the potential for transformative impact through the generation of new data and fundamental knowledge that will advance the quantitative understanding of urban pollution sources and factors affecting air quality and community exposure. To implement the educational and training goals of this CAREER project, the PI will leverage the research findings to update his experiential air quality courses at the University of Texas (UT) at Austin. In addition, the PI plans to partner with the Whole Community-Whole Health program at UT-Austin to educate and assist local communities that are affected by air pollution to voice their concerns based on the air quality data and exposure risk estimates from the PI’s investigations.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.