Liu Xiaoxiao, Bertazzon Stefania, Villeneuve Paul J, Johnson Markey, Stieb Dave, Coward Stephanie, Tanyingoh Divine, Windsor Joseph W, Underwood Fox, Hill Michael D, Rabi Doreen, Ghali William A, Wilton Stephen B, James Matthew T, Graham Michelle, McMurtry M Sean, Kaplan Gilaad G
Departments of Community Health Sciences (Liu, Coward, Tanyingoh, Windsor, Underwood, Rabi, Ghali, James, Kaplan) and of Geography (Liu, Bertazzon), University of Calgary, Calgary, Alta.; Department of History, Archaeology, Geography, Fine & Performing Arts (Bertazzon), University of Florence, Florence, Italy; School of Mathematics and Statistics and Department of Neuroscience, and CHAIM Research Centre (Villeneuve), Carleton University, Ottawa, Ont.; Air Health Science Division (Johnson), Health Canada, Ottawa, Ont.; Environmental Health Science and Research Bureau (Stieb), Health Canada, Vancouver, BC; Departments of Medicine (Coward, Tanyingoh, Windsor, Underwood, Hill, Rabi, Wilton, James, Kaplan); of Clinical Neurosciences (Hill, Ghali); and of Cardiac Sciences (Wilton), University of Calgary, Calgary, Alta.; Department of Medicine (Graham, McMurtry), University of Alberta; Mazankowski Alberta Heart Institute (McMurtry), Edmonton, Alta.
CMAJ Open. 2020 Oct 9;8(4):E619-E626. doi: 10.9778/cmajo.20190160. Print 2020 Oct-Dec.
In studies showing associations between ambient air pollution and myocardial infarction (MI), data have been lacking on the inherent spatial variability of air pollution. The aim of this study was to determine whether the long-term spatial distribution of air pollution influences short-term temporal associations between air pollution and admission to hospital for MI.
We identified adults living in Calgary who were admitted to hospital for an MI between 2004 and 2012. We evaluated associations between short-term exposure to air pollution (ozone [O], nitrogen dioxide [NO], sulfur dioxide [SO], carbon monoxide [CO], particulate matter < 10 μm in diameter [PM] and particulate matter < 2.5 μm in diameter [PM]), and hospital admissions for MI using a time-stratified, case-crossover study design. Air Quality Health Index (AQHI) scores were calculated from a composition of O, NO and PM. Conditional logistic regression models were stratified by low, medium and high levels of neighbourhood NO concentrations derived from land use regression models; results of these analyses are presented as odds ratios (ORs) with 95% confidence intervals (CIs).
From 2004 to 2012, 6142 MIs were recorded in Calgary. Individuals living in neighbourhoods with higher long-term air pollution concentrations were more likely to be admitted to hospital for MI after short-term elevations in air pollution (e.g., 5-day average NO: OR 1.20, 95% CI 1.03-1.40, per interquartile range [IQR]) as compared with regions with lower air pollution (e.g., 5-day average NO: OR 0.90, 95% CI 0.78-1.04, per IQR). In high NO tertiles, the AQHI score was associated with MI (e.g., 5-day average OR 1.13, 95% CI 1.02-1.24, per IQR; 3-day average OR 1.13, 95% CI 1.04-1.23, per IQR).
Our results show that the effect of air pollution on hospital admissions for MI was stronger in areas with higher NO concentrations than that in areas with lower NO concentrations. Individuals living in neighbourhoods with higher traffic-related pollution should be advised of the health risks and be attentive to special air quality warnings.
在显示环境空气污染与心肌梗死（MI）之间关联的研究中，一直缺乏关于空气污染固有空间变异性的数据。本研究的目的是确定空气污染的长期空间分布是否会影响空气污染与因MI入院之间的短期时间关联。
我们确定了2004年至2012年间在卡尔加里因MI入院的成年人。我们使用时间分层的病例交叉研究设计，评估了短期接触空气污染（臭氧[O]、二氧化氮[NO]、二氧化硫[SO]、一氧化碳[CO]、直径<10μm的颗粒物[PM]和直径<2.5μm的颗粒物[PM]）与因MI入院之间的关联。空气质量健康指数（AQHI）得分由O、NO和PM的成分计算得出。条件逻辑回归模型按土地利用回归模型得出的邻里NO浓度的低、中、高水平分层；这些分析的结果以比值比（OR）和95%置信区间（CI）表示。
2004年至2012年期间，卡尔加里记录了6142例MI。与空气污染较低的地区相比，长期空气污染浓度较高的社区居民在空气污染短期升高后因MI入院的可能性更大（例如，5天平均NO：OR 1.20，95%CI 1.03 - 1.40，每四分位间距[IQR]）（例如，5天平均NO：OR 0.90，95%CI 0.78 - 1.04，每IQR）。在高NO三分位数中，AQHI得分与MI相关（例如，5天平均OR 1.13，95%CI 1.02 - 1.24，每IQR；3天平均OR 1.13，95%CI 1.04 - 1.23，每IQR）。
我们的结果表明，空气污染对因MI入院的影响在NO浓度较高的地区比在NO浓度较低的地区更强。应建议居住在与交通相关污染较高社区的个人注意健康风险，并留意特殊的空气质量警告。
