Objective

To assess the relationship between short-term exposure to outdoor ambient air pollutants (fine particulate matter [PM_2.5] and black carbon [BC]), ischemic stroke (IS) and its different subtypes, and the potential modifying effect of neighborhood greenspace and noise.

Methods

This time-stratified case-crossover study was based on IS and transient ischemic attacks (TIA) recorded in a hospital-based prospective stroke register (BASICMAR 2005–2014) in Barcelona (Catalonia, Spain). Daily and hourly pollutant concentrations and meteorological data were obtained from monitoring stations in the city. Time-lags (from previous 72 h to acute stroke onset) were analyzed. Greenness and noise were determined from the Normalized Difference Vegetation Index (NDVI) and daily average noise level at the street nearest to residential address, respectively.

Results

The 2742 cases with known onset date and time, living in the study area, were analyzed. After adjusting for temperature, no statistically significant association between pollutants exposure and overall stroke risk was found. In subtype analysis, an association was detected between BC exposure at 24–47 h (odds ratio, 1.251; 95% confidence interval [CI], 1.001–1.552; P = 0.042) and 48–72 h (1.211; 95% CI, 0.988–1.484; P = 0.065) time-lag prior to stroke onset and large-artery atherosclerosis subtype. No clear modifying effect of greenness or noise was observed.

Conclusions

Overall, no association was found between PM_2.5 and BC exposure and acute IS risk. By stroke subtype, large-artery atherosclerotic stroke could be triggered by daily increases in BC, a diesel fuel-related pollutant in the study area.

中文翻译：

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西班牙巴塞罗那短期内遭受与交通有关的空气污染和缺血性中风的发作

客观的

评估短期暴露于室外环境空气污染物（细颗粒物[PM _2.5 ]和黑碳[BC]），缺血性中风（IS）及其不同亚型之间的关系，以及邻域绿地和噪声的潜在调节作用。

方法

这项时间分层的病例交叉研究基于在巴塞罗那（西班牙加泰罗尼亚）基于医院的前瞻性卒中寄存器（BASICMAR 2005–2014）中记录的IS和短暂性脑缺血发作（TIA）。从城市的监测站获取每日和每小时的污染物浓度和气象数据。分析了时滞（从之前的72小时到急性中风发作）。绿度和噪声分别由归一化植被指数（NDVI）和最接近住宅地址的街道上的每日平均噪声水平确定。

结果

分析了居住在研究区域的2742例发病日期和时间已知的病例。调整温度后，未发现污染物暴露与总体中风风险之间的统计学显着关联。在亚型分析中，检测到24-47小时的BC暴露（赔率为1.251； 95％置信区间[CI]为1.001-1.552；P = 0.042）与48-72小时（1.211； 95％CI为0.988–1.484；P = 0.065）中风发作和大动脉粥样硬化亚型之前的时间滞后。没有观察到绿色或噪声的明显改变效果。

结论

总体而言，未发现PM _2.5和BC暴露与急性IS风险之间存在关联。按中风亚型，大动脉粥样硬化性中风可以由研究区域内与柴油相关的污染物BC的每日增加触发。