Characterizing Emerging Sources of Organic Aerosol

城市活动将许多有机化合物排放到大气中。它们的化学反应形成颗粒物，导致空气质量差，危害人类健康。由于机动车辆通常被确定为污染物的主要来源，过去几十年的法规集中在控制车辆排放，从而减少空气污染。然而，未来的空气质量将越来越依赖于其他重要的颗粒物来源，如烹饪、野火和采用新技术的车辆发动机。在这项研究计划中，我们识别从新兴的空气污染源排放的有机化合物，并研究它们在大气中的化学反应。必须了解这些来源，以预测其对空气质量的影响，并制定具有成本效益的控制策略，以保障公众健康。 由于气候变暖，野火变得越来越普遍。众所周知，木材燃烧产生的颗粒物对人体健康有害，因为它含有对身体造成损害的自由基。借助先进的仪器，我们将测量木材烟雾中这些自由基的水平，并确定它们的化学结构，以了解导致它们形成的分子过程及其对人类健康的影响。 在城市中，烹饪食物会排放大量的颗粒物，但研究人员通常认为这些颗粒物很容易在大气中蒸发，因此并不认为它们很重要。然而，人们对有机颗粒的蒸发知之甚少，特别是那些长时间暴露在大气中的有机颗粒。我们将研究这些阻止粒子蒸发的大气反应。通过我们的实验，我们将建立一个数学模型来描述蒸发过程，并为计算机模型提供一个更准确的方法来预测空气质量。发动机技术正在迅速发展，使其更省油，但其中一项技术，汽油直喷，排放更多的颗粒，可以破坏空气质量。我们将测量这些发动机排放的有机化合物，并研究可能产生颗粒物的化学反应。我们的测量将提供一个更全面的评估，这些新兴的汽车技术将如何影响空气质量和人类健康。在所有研究方向中，我们使用详细的化学测量来获得基本的分子见解，并将其应用于了解大气行为。通过这些研究，学生获得他们的技术职业所需的重要科学和专业技能。他们还跨多个学科（化学，工程，政策，健康科学）工作，并创造急需的知识，以应对关键的环境挑战。

Urban activities emit many organic compounds into the atmosphere. Their chemical reactions form particulate matter which contributes to poor air quality and harms human health. Since motor vehicles have usually been identified as the main source of pollutants, regulations in the past decades have focused on controlling vehicular emissions, leading to reductions in air pollution. Future air quality, however, will depend increasingly on other important sources of particulate matter, such as food cooking, wildfires, and vehicular engines with new technologies. In this research program, we identify organic compounds emitted from emerging sources of air pollution and study their chemical reactions in the atmosphere. It is essential to understand these sources in order to predict their impacts on air quality and develop cost-effective control strategies to safeguard public health. Wildfires are becoming more common as a result of a warming climate. Particulate matter from wood burning is known to be harmful for human health, because it contains free radical species that cause damage to the body. With advanced instrumentation we will measure the level of these free radical species in wood smoke, and identify their chemical structures in order to understand the molecular processes that lead to their formation, and their effects on human health. Food cooking emits a large amount of particles in cities, but researchers have typically assumed that these particles readily evaporate in the atmosphere and therefore do not expect them to be important. However, there is little knowledge about evaporation of organic particles, particularly those that have been exposed to the atmosphere for a long time. We will study these atmospheric reactions that prevent particles from evaporating. From our experiments, we will build a mathematical model to describe the evaporation processes and provide computer models with a more accurate way to predict air quality. Engine technologies are rapidly evolving to make them more fuel-efficient, but one such technology, gasoline direct injection, emits more particles that can damage air quality. We will measure organic compounds emitted from these engines and study the chemical reactions that can produce particulate matter. Our measurements will provide a more comprehensive evaluation of how these emerging vehicle technologies will affect air quality and human health. In all research directions, we use detailed chemical measurements to gain fundamental molecular insights, and apply them to understand atmospheric behavior. Through these studies, students gain important scientific and professional skills required for their technical careers. They also work across multiple disciplines (chemistry, engineering, policy, health sciences) and create much needed knowledge to address critical environmental challenges.