ASSESSING THE ACUTE AND CHRONIC CARDIO-RESPIRATORY HEALTH IMPACTS OF AMBIENT AIR POLLUTION IN CHINA

背景环境空气污染（AAP）的急性和慢性健康影响现在一致记录在整个流行病学文献。然而，大多数证据目前适用于发达地区，在这些地区，健康结果数据和污染物数据更容易获得，质量保证程度更高。因此，从发达地区到包括中国在内的低收入和/或中等收入国家（LMIC）的健康影响的一般外推在证据库中越来越常见。这种结果的外推往往是更好的选择，而低收入国家本身的研究往往受到方法问题的限制。这些问题源于其复杂的医疗保健系统，缺乏统一的健康数据记录以及一致的暴露错误分类。因此，关于低收入国家内人群接触AAP的健康影响的证据仍然是轶事。特别是在中国，经济发展的繁荣是以牺牲空气质量为代价的，据估计，AAP每年造成160万人死亡。然而，即使在中国，就AAP暴露对人口的确切健康影响而言，仍然存在很大的不确定性。此外，大多数高质量的流行病学研究都是在中国的“特大城市”内进行的，尽管AAP暴露无处不在，但很少考虑更广泛地区的健康影响。因此，该项目的目的是准确地确定急性和慢性的健康影响的AAP暴露在不同地区的中国，使用的方法以前保留几乎完全为发达regions.MethodsThis项目将利用中国嘉道理生物银行（CKB），一个队列的0.5万名参与者，覆盖10个不同地区的中国。通过健康保险数据链接提供高质量的标准化健康数据，将使健康结果能够准确地检查与CKB内个人的AAP暴露相关的健康结果。AAP暴露的急性健康影响将在中国五个城市地区的心血管和呼吸系统住院记录方面进行检查。这将涉及从中国国家空气污染监测网络获得的主要空气污染物（PM2.5，PM10，SO2，NOx，O3）的单一污染物建模。将进行时间序列分析（使用预先规定的滞后），并生成广义相加模型，以准确确定CKB受试者的AAP暴露与急性心血管/呼吸事件之间的关联。与大多数研究仅侧重于固定监测点的单一污染物建模不同，本项目将利用多污染物建模进行敏感性分析。它还将检查各种潜在的影响因素，如不同的地理区域，以及主要的混杂因素，包括人口统计学特征，季节趋势和气象变量。就AAP暴露的慢性健康影响而言，这将涉及检查;-长期AAP暴露与CKB参与者的血压/高血压的关联。- 长期AAP暴露与CKB参与者心血管/呼吸系统疾病发病率的相关性为量化长者健康巴士参与者长期接触空气污染物的情况，我们会利用卫星估计的PM2.5，并根据固定监测数据和个人接触评估作进一步校正。这些暴露评估方法将最大限度地减少暴露错误分类，为中国AAP暴露的健康影响提供更可靠的估计。参考书目（1）健康评估和评价研究所。空气质量差每年导致550万人死亡。2016年;可在www.example.com上获得。2016年10月24日访问。

BackgroundBoth the acute and chronic health impacts of ambient air pollution (AAP) are now consistently documented throughout epidemiological literature. However, the majority of evidence currently applies to developed regions where both health outcome data and pollutant data are more readily obtainable with greater degree of quality assurance. Thus, generic extrapolation of the health impacts from developed regions into low and/or middle income countries (LMIC's) including China is increasingly common within the evidence base. Such extrapolation of results often presents as the better option, with research in LMIC's themselves frequently restricted by methodological issues. These issues stem from their complex healthcare systems, lack of unified health data recording, and consistent exposure misclassification. Therefore, evidence on the health impacts of AAP exposure for populations within LMIC's exclusively remains anecdotal. Within China specifically, economic development has flourished at the inherent sacrifice of air quality, with AAP causing an estimated 1.6 million deaths annually (1). However, even within China there remains significant uncertainty in terms of the exact health impacts of AAP exposure on the population. Furthermore, the majority of high quality epidemiological studies are performed within the Chinese "mega-cities" with little consideration for the health effects in wider regions, despite the ubiquity of AAP exposure. This project therefore aims to accurately determine the acute and chronic health effects of AAP exposure within varying regions of China, using a methodology previously reserved almost exclusively for developed regions.MethodsThis project will utilise China Kadoorie Biobank (CKB), a cohort of 0.5 million participants covering 10 diverse regions of China. The availability of high quality standardised health data through health insurance data linkage will enable health outcomes to be accurately examined in relation to AAP exposure for individuals within the CKB. The acute health effects of AAP exposure will be examined in terms of both cardiovascular and respiratory hospital admissions, documented from five urban areas in China. This will involve single pollutant modelling for the primary air pollutants (PM2.5, PM10, SO2, NOx, O3) obtained from the Chinese National Air pollution monitoring network. Time-series analysis (using pre-specified lags) will be performed, and generalised additive models generated in order to accurately determine the association between AAP exposure and acute cardiovascular/respiratory events for CKB participants. Unlike the majority of studies which focus solely on single pollutant modelling from fixed monitoring sites, this project will perform sensitivity analysis utilising multi-pollutant modelling. It will also examine various potential effect modifiers such as differing geographic region, in addition to the main confounders including demographic characteristics, seasonal trends, and meteorological variables. In terms of the chronic health impacts of AAP exposure, this will involve examining;- The association of long term AAP exposure and blood pressure/hypertension in CKB participants. - The association of long term AAP exposure and incidence of cardiovascular/respiratory disease in CKB participants. To quantify long term exposure to AAP for CKB participants, satellite based estimates of PM2.5 will be utilised with further calibration from fixed monitoring measurements and personal exposure assessment. These methods of exposure assessment will minimise exposure misclassification providing a more reliable estimate of the health impacts of AAP exposure in China. Bibliography(1) Institute for Health Metrics and Evaluation. Poor air quality kills 5.5 million annually. 2016; Available at: http://www.healthdata.org/news-release/poor-air-quality-kills-55-million-worldwide-annually. Accessed 24/10, 2016.