The Formation and Characterisation of Secondary Organic Aerosol and its Contribution to PM10 Concentrations in the UK Atmosphere

空气污染对公众的健康有严重的不利影响。其中包括过早死亡、住院人数增加以及哮喘等呼吸系统疾病患者症状恶化。许多污染物都是造成这些影响的原因，但影响最大的是颗粒物。这个术语描述的是漂浮在空气中肉眼看不见的微小颗粒，它们可以被吸入肺部。这些颗粒有多种来源，最著名的是道路交通。然而，排放源并不是微粒的唯一来源，在大气中由气体的化学反应形成的微粒也起着越来越重要的作用。其中包括被称为硫酸盐和硝酸盐的化学物质，它们是由二氧化硫和氮氧化物排放形成的，其途径相当好理解。此外，空气中的颗粒中还有一类化学物质，称为次生有机化合物。它们是由大气中人造来源（例如汽油蒸气）和自然来源（特别是树木释放的化合物）产生的有机蒸气进行化学处理而形成的。这些二级有机化合物的化学组成非常多样化，它们对空气中颗粒物质量的贡献还没有得到很好的了解。该项目涉及测量英国大气中的二次有机化合物，以估计它们对空气中颗粒物总量的贡献。此外，该项目将测量这些颗粒的化学成分，并以此来了解它们是由哪种有机蒸汽形成的。通过这样的研究，将有可能推断出二级有机化合物质量的哪些部分可以通过减少人为来源来控制，哪些部分来自植被释放的自然化合物，这些化合物不易控制。

Air pollution has important adverse effects on the health of the public. These include premature mortality, additional hospital admissions and worsening symptoms for people with respiratory diseases such as asthma. A number of pollutants are responsible for these effects but the one with the biggest impact is known as particulate matter. This term describes tiny particles invisible to the naked eye floating in the air, which can be breathed into the lungs. These particles arise from a range of sources, the best known being road traffic. However, emission sources are not the only source of particles and a contribution of growing importance is from particles which form in the atmosphere from chemical reactions of gases. These include chemical substances known as sulphates and nitrates, which form from emissions of sulphur dioxide and oxides of nitrogen by pathways that are reasonably well understood. In addition, there is a class of chemical substances within airborne particles known as secondary organic compounds. These are formed through chemical processing in the atmosphere of organic vapours arising from both manmade sources (e.g. petrol vapour) and natural sources, especially from compounds released by trees. These secondary organic compounds are very diverse in their chemical composition and their contribution to the mass of particles in the air is not well understood. This project is concerned with measuring secondary organic compounds in the atmosphere of the UK, so as to estimate their contribution to the total amount of airborne particles. In addition, the project will measure the chemical composition of such particles, and use this to understand which organic vapours they are formed from. Through such studies it will be possible to infer which parts of the secondary organic compound mass can be controlled through abatement of anthropogenic sources, and which part arises from natural compounds released from vegetation, which is not readily amenable to control.