An Integrated Study of Air Pollutant Sources in the Delhi National Capital Region (NCR)

2014年，德里被世界卫生组织评为世界上空气污染最严重的城市。大约有4600万人居住在德里及其周边，其中1800万人住在城市里，其余的人住在国家首都地区（NCR）。2014年，德里最重要的空气污染物颗粒物（PM）的年平均水平超过世卫组织指导方针的15倍，对健康造成了非常严重的慢性和急性影响，并带来了经济成本。制定改善空气质量的有效战略需要定量地了解空气中微粒物质的来源、形成过程、区域预算以及化学和物理性质；然而，这方面的知识还不具备。ASAP-Delhi解决了这一要求：该项目将对德里和周围NCR的PM的来源、特征、丰度和形成过程进行定量评估。该项目旨在解决关键的科学问题（如下），其理念是通过高质量的直接观察获得对污染源和预算的见解-即基于对德里地面空气中实际存在的物种的测量，而不依赖于其他数据。该项目代表了来自英国（伯明翰，萨里）和印度（IITD， NPL）的主要研究人员之间的重点合作，他们在德里以前资助的空气质量项目中有成功的联合合作和发表的记录。ASAP-Delhi将(i)对德里及其周边国家首都地区（NCR）迄今为止存在的PM进行最详细的物理和化学表征；（ii）生成德里主要PM来源的来源概况（化学特征）；（iii）通过应用多种独立、成熟和新颖的受体建模方法，如基于化学质量平衡、放射性碳和基于数量大小分布的源分配，确定和量化不同来源对德里（和NCR）颗粒物负担的贡献——包括颗粒物质量浓度和颗粒物数量[对健康的不同影响]；（iv）估计NCR排放对德里空气质量的影响（有效的区域空气质量政策的关键）和(v)评估污染期间PM形成的一系列新假设，这对于准确预测未来PM水平的模型至关重要。我们将通过在德里（城市背景地点——全年采样与两个“密集区”相结合）、周边NCR（五个地点的季节性测量）和农村背景地点（逆风150公里）进行一系列实地观测，结合在线测量和最先进的离线分析来实现这些目标。我们的测量策略结合了(i)已建立的方法-提供具有新颖空间分布的高质量，系统，连贯的测量数据集-以及（ii）最新的科学工具和分析方法。这在国际质量观察（支持ASAP-Delhi和其他项目组成部分）和新指标之间提供了平衡，同时也认识到在这种环境下实地工作的现实。德里空气质量评估中心将借鉴印度空气质量健康方案中其他项目的成果，并将提供关键的观测见解，以支持更广泛方案中空气质量模型的开发、人类健康影响的评估和缓解政策的制定。在处理公共卫生、政策和发展问题，并为加强印度的空气污染研究提供一个平台方面，亚太空气规划署德里办事处除了提供对德里PM来源的逐步转变的理解（决策者需要的关键洞察力）之外，还涉及(i)人员和（ii）研究方案的官方发展援助支持类别。

Delhi was rated the most polluted city in the world for ambient air pollution by the WHO in 2014. Some 46 million people live in and around Delhi - 18m in the city, and the remainder in the surrounding National Capital Region (NCR). Annual mean levels of particulate matter (PM), the most important air pollutant for health in Delhi, exceeded WHO guidelines by a factor of 15 during 2014, and are responsible for very substantial chronic and acute health impacts, with attendant economic costs. Development of effective strategies for improvement in air quality requires quantitative understanding of the sources, formation processes, regional budgets and chemical and physical nature of airborne particulate matter; however, such knowledge is not yet available. ASAP-Delhi addresses this requirement: The project will provide a quantitative assessment of the sources, characteristics, abundance and formation processes for PM in Delhi and the surrounding NCR. The project is designed to address key science questions (below), with a philosophy of obtaining insights into pollutant sources and budgets from high quality direct observation - i.e. based upon measurement of the species actually present in the air at ground level within Delhi, without dependence upon other data. The project represents a focussed collaboration between leading researchers from the UK (Birmingham, Surrey) and India (IITD, NPL), who have a track record of successful joint collaboration and publications from previous funded air quality projects in Delhi.ASAP-Delhi will (i) perform the most detailed physical and chemical characterisation of PM present in Delhi, and in the surrounding National Capital Region (NCR) to date; (ii) produce source profiles (chemical signatures) for the principal PM sources in Delhi; (iii) identify and quantify the contributions of different sources to the PM burden in Delhi (and the NCR) - for both PM mass concentration and particle number [with differing implications for health], by application of multiple, independent, established and novel receptor modelling approaches, such as chemical mass balance, radiocarbon, and number size distribution based source apportionment; (iv) estimate the impact of NCR emissions upon air quality in Delhi (key to effective regional air quality policy) and (v) evaluate a series of new hypotheses for the formation of PM during pollution episodes, essential for accurate model predictions of future PM levels.We will address these objectives through a series of field observations, combining online measurements with state-of-the-science offline analyses, in Delhi (urban background locations - year round sampling combined with two "intensives"), the surrounding NCR (seasonal measurements at five sites) and a rural background location (150 km upwind). Our measurement strategy combines (i) established methodologies - to deliver a high quality, systematic, coherent measurement dataset, with a novel spatial distribution - and (ii) new state-of-the-science tools and analytical approaches. This provides a balance between international quality observations (in support of ASAP-Delhi and other programme components) and novel metrics, whilst also recognising the realities of fieldwork in such environments. ASAP-Delhi will draw upon results of other projects in the APHH India programme, and will provide the key observational insights in support of air quality model development, evaluation of human health impacts, and development of mitigation policies in the wider programme. In addressing public health, policy and development issues, and providing a platform to enhance air pollution research in India, ASAP-Delhi addresses the ODA support categories of (i) people and (ii) research programmes, in addition to providing a step-change in understanding of the sources of PM in Delhi (the key insight required by policymakers).