Collaborative Research: RAPID--Urban Air Quality during the Coronavirus (COVID-19) Shelter-In-Place Orders

合作研究：RAPID——冠状病毒 (COVID-19) 就地避难令期间的城市空气质量

• 批准号: 2030112
• 负责人: Donald Blake
• 金额: $ 9.45万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-01 至 2021-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2030112&HistoricalAwards=false
• 关键词: Collaborative; Research; RAPID; Urban; Air

In this RAPID project, a collaborative PI team intends to collect time sensitive atmospheric samples in the Los Angeles, CA, area, where historically high pollutant levels of ozone (O3) and fine particulate matter (PM2.5) have plagued public health. By taking advantage of significant reductions in atmospheric emissions associated with current COVID-19 shelter-in-place orders, a natural experiment has presented itself that allows for observations to be made under uniquely useful conditions. Results will help constrain predictive models of pollutant concentrations and guide regulatory agencies in best strategies to mitigate poor air quality.Gaseous and particulate samples will be collected during and after the lifting of COVID-19 by co-locating sampling devices on Caltech’s established roof-top sampling platform, where continuous monitoring of essential parameters, including NOx, O3, and PM2.5, is ongoing. Focus in this study is on the detailed chemical speciation of the important precursor group of compounds denoted as volatile to intermediate volatility organic compounds (I/VOCs) containing 1 to 15 carbon atoms (C1-C15). These compounds are emitted through a number of different sources, including from fossil fuel production and burning, use of chemical products, and biological productivity. Their ill-defined sources and reactivities have been attributed to an existing gap in knowledge that could describe higher-than-expected O3 levels in megacities where precursor emissions have seen a general decrease in past decades. Here, I/VOC sources and source markers will be determined during a period when transportation associated emissions to VOCs and NOx are low. State-of-the-art analyses of collected samples at PIs’ laboratories include two-dimensional gas chromatography (GC×GC) with time-of-flight mass spectrometry (TOFMS) and a multi-column/detector GC system with 5 different types of separation and detection combinations. Results will (i) provide new insight into the intricate mechanisms of O3 and PM2.5 production under uniquely low NOx conditions and a changing mix of VOCs, and (ii) help constrain predictive models of atmospheric chemistry and air quality.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.

在该RAPID项目中，一个合作PI团队打算在加利福尼亚州洛杉矶地区收集时间敏感的大气样本，该地区历史上臭氧（O3）和细颗粒物（PM2.5）污染物水平高，一直困扰着公众健康。通过利用与当前COVID-19就地庇护订单相关的大气排放的显著减少，一个自然的实验出现了，它允许在独特有用的条件下进行观测。研究结果将有助于约束污染物浓度的预测模型，并指导监管机构采取最佳策略，以缓解空气质量差的问题。在COVID-19解除期间和之后，将通过在加州理工学院已建立的屋顶采样平台上共同定位采样设备来收集气体和颗粒物样本，该平台正在持续监测氮氧化物，O3和PM2.5等基本参数。本研究的重点是详细的化学形态的重要前体组的化合物表示为挥发性的中间挥发性有机化合物（I/VOC）含有1至15个碳原子（C1-C15）。这些化合物通过许多不同的来源排放，包括化石燃料的生产和燃烧、化学产品的使用和生物生产。它们的来源和反应性定义不清，这是由于现有的知识空白，可以描述在过去几十年前体排放量普遍减少的特大城市中高于预期的O3水平。这里，I/VOC源和源标记将在VOC和NOx的运输相关排放低的时期期间确定。在PI实验室对收集的样品进行的最先进分析包括二维气相色谱（GC×GC）和飞行时间质谱（TOFMS）以及具有5种不同类型分离和检测组合的多柱/检测器GC系统。结果将（i）提供新的洞察到O3和PM2.5的复杂机制下独特的低氮氧化物的条件和不断变化的混合挥发性有机化合物的生产，和（ii）帮助约束大气化学和空气质量的预测模型。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。