Department of Health Science, Shiga University of Medical Science, Shiga, Japan.
Neuroepidemiology. 2012;38(2):84-92. doi: 10.1159/000335654. Epub 2012 Feb 16.
Exposure to high levels of air pollution can increase the risk of cardiovascular events. However, there is no clear information in Japan on the effect of pollution on the incidence of stroke and acute myocardial infarction (AMI). Therefore, we investigated the effects of air pollution on the incidence of stroke and AMI in a setting where pollutant levels are rather low.
Data were obtained from the Takashima Stroke and AMI Registry, which covers a population of approximately 55,000 in Takashima County in central Japan. We applied a time-stratified, bidirectional, case-crossover design to estimate the effects of air pollutants, which included suspended particulate matter (SPM), sulfur dioxide (SO(2)), nitrogen dioxide (NO(2)) and photochemical oxidants (Ox). We used the distributed lag model to estimate the effect of pollutant exposure 0-3 days before the day of event onset and controlled for meteorological covariates in all of the models.
There were 2,038 first-ever strokes (1,083 men, 955 women) and 429 first-ever AMI cases (281 men, 148 women) during 1988-2004. The mean pollutant levels were as follows: SPM 26.9 μg/m(3); SO(2) 3.9 ppb; NO(2) 16.0 ppb, and Ox 28.4 ppb. In single-pollutant and two-pollutant models, SO(2) was associated with the risk of cerebral hemorrhage. Other stroke subtypes and AMI were not associated with air pollutant levels.
We observed an association between SO(2) and hemorrhagic stroke; however, we found inconclusive evidence for a short-term effect of air pollution on the incidence of other stroke types and AMI.
暴露于高水平的空气污染可增加心血管事件的风险。然而，在日本，关于污染对中风和急性心肌梗死（AMI）发病率影响的信息尚不清楚。因此，我们在污染物水平相对较低的环境中研究了空气污染对中风和 AMI 发病率的影响。
数据来自位于日本中部高岛县的高岛中风和 AMI 登记处，该登记处涵盖了约 55000 人的人群。我们应用时间分层、双向、病例交叉设计来估计空气污染物（包括悬浮颗粒物（SPM）、二氧化硫（SO2）、二氧化氮（NO2）和光化学氧化剂（Ox））的影响。我们使用分布式滞后模型来估计暴露于污染物后 0-3 天对事件发生日的影响，并在所有模型中控制气象协变量。
1988 年至 2004 年期间，共有 2038 例首发中风（1083 例男性，955 例女性）和 429 例首发 AMI 病例（281 例男性，148 例女性）。平均污染物水平如下：SPM 26.9 μg/m3；SO2 3.9 ppb；NO2 16.0 ppb，Ox 28.4 ppb。在单污染物和双污染物模型中，SO2 与脑出血风险相关。其他中风类型和 AMI 与空气污染物水平无关。
我们观察到 SO2 与出血性中风之间存在关联；然而，我们发现空气污染对其他中风类型和 AMI 发病率的短期影响证据不足。
