CINDAER Composition of indoor aerosols and their role in air quality

糟糕的空气质量是导致全球过早死亡的最大环境因素。在最近更新的《全球疾病负担》中，据估计，长期接触细颗粒物(PM2.5)每年导致490万人过早死亡，其中心肺疾病和癌症是主要原因。部署在空气质量网络和污染预报中的仪器可以用来在室外污染水平较高时发出警告，并就减少个人接触的步骤提供建议。然而，我们是否忽视了自己家中更大的风险呢？平均而言，个人的大部分时间都在室内度过(80%-90%)，因此了解室内空气质量对于估计主要污染源发生在哪里至关重要。室内环境中有许多可能的颗粒物来源，而且通常水平高于室外。燃烧来源，如木炉、烹饪、蜡烛和吸烟，可以直接向空气中排放颗粒物。挥发性有机化合物可以从各种来源散发出来，包括清洁、个人护理、香水，甚至人类的皮肤和呼吸。这些化合物可以反应并形成二次粒子，尽管这条路线的特征一直很差。最后，室外颗粒物可以通过打开的门窗以及建筑结构本身转移到室内。最近的研究表明，随着电气化车队的发展，室内排放的废气将越来越多地导致室外空气质量不佳。室内环境中的颗粒测量通常是使用低成本传感器进行的，这种传感器测量给定体积中的颗粒总质量或数量。当部署在家庭中时，这些设备可以提供关于短期颗粒物污染事件和背景浓度的信息。然而，如果没有对家庭活动的广泛监测，就很难确定哪些来源对接触研究最重要。实现这一点的一种潜在方法是利用气溶胶的化学成分来识别关键颗粒物来源，这是户外气溶胶常用的方法。由于浓度低，可供采样的空气数量少，以及气溶胶收集所需泵的噪音，在室内环境中很难做到这一点。因此，需要高灵敏度的方法来分离和鉴定室内气溶胶中的化学成分。该项目的主要目标是设计一种新的方法来采样和表征室内环境中的气溶胶。这将包括对不同类型的颗粒源进行实验室研究，并在不同类型的室内和室外大气中现场部署采样器。通过了解室内颗粒物中的化学示踪剂，可以确定导致室内空气质量差的关键来源。具体目标-开发一种适用于收集室内环境中颗粒物的新采样器-验证使用二维气相色谱确定有机颗粒和半挥发性气体有机成分的高分辨率方法-使用实验室模拟创建不同室内颗粒物来源的化学指纹-在一系列不同的室内环境中部署采样器-确定降低室内空气质量的有机颗粒物的关键来源，并制定干预措施以减少人体暴露。这名学生将在雅克·汉密尔顿教授和凯瑟琳·曼弗雷德博士的指导下工作。这名学生将在沃尔夫森大气化学实验室工作，该实验室是约克大学化学系的一部分。这些机构成立于2013年，包括一座最先进的专用研究大楼，这是英国第一座此类建筑。

Poor air quality is the biggest environmental factor contributing to premature mortality globally. In the recent update to the Global Burden of Disease, long-term exposures to fine particulate matter (PM2.5) was estimated to contribute to 4.9 million premature deaths annually, with cardiopulmonary diseases and cancer being the main contributors. Instrumentation deployed in air quality networks and pollution forecasts can be used to warn when pollution levels outside are high and there is advice on the steps to reduce our personal exposure. However, are we ignoring a much larger risk in our own homes? On average, individuals spend most of their time indoors (80-90 %) and so understanding indoor air quality is vital to estimate where the main sources of pollution exposure occur. There are many possible sources of particles in indoor environments and often levels are higher than outdoors. Combustion sources, such as wood stoves, cooking, candles and smoking can directly emit particles into the air. Volatile organic compounds can be emitted from a wide range of sources including cleaning, personal care, fragrances and even human skin and breath. These compounds can react and form secondary particles, although this route has been very poorly characterised. Finally, outdoor particles can be transferred indoors through open doors and windows as well as through the building fabric itself. Recent work has indicated that as electrification of the vehicle fleet grows, indoor emissions will be increasingly responsible for poor outdoor air quality. Particle measurements in indoor environments are often done using low cost sensors, that measure either the total mass or number of particles in a given volume. These can provide information on both short-term particle pollution episodes and background concentrations when deployed in a home. However, without extensive monitoring of household activities it can be difficult to assign which sources are most important for exposure studies. One potential way to achieve this, which is commonly used for outdoor aerosols, is to use the chemical composition of aerosols to identify key particle sources. This is difficult in indoor atmospheres due to low concentrations, the small amount of air available to sample and the noise associated with pumps needed for aerosol collection. Therefore, state of the art, highly sensitive methods are needed to separate and identify the chemical components in indoor aerosols. This overarching aim of this project is to design a new methodology to sample and characterise aerosols from occupied indoor environments. This will involve laboratory studies of different types of particle sources and field deployment of samplers into different types of indoor and outdoor atmospheres. By understanding the chemical tracers in indoor particles, the key sources contributing to poor indoor air quality can be determined.Specific Aims - Develop a new sampler suitable for collecting particles in indoor settings- Validate a high-resolution method to determine the organic composition of organic particles and semi-volatile gases using two-dimensional gas chromatography - Create chemical fingerprints of different indoor particle sources using laboratory simulations- Deploy the sampler in a range of different indoor environments-Identify the key sources of organic particles that degrade indoor air quality and develop interventions to reduce human exposure. The student will work under the supervision of Prof Jacqui Hamilton and Dr Katherine Manfred. The student will be based in the Wolfson Atmospheric Chemistry Laboratory, part of the Department of Chemistry at the University of York. These were established in 2013 and comprise a state-of-the-art dedicated research building, the first of its kind in the UK.