Institute of Environmental Medicine, Karolinska Institutet, Nobels väg 13, SE-17177 Stockholm, Sweden.
Eur Heart J. 2014 Apr;35(13):861-8. doi: 10.1093/eurheartj/eht489. Epub 2013 Dec 2.
Although ozone (O3) and other pollutants have been associated with cardiovascular morbidity and mortality, the effects of O3 on out-of-hospital cardiac arrest (OHCA) have rarely been addressed and existing studies have presented inconsistent findings. The objective of this study was to determine the effects of short-term exposure to air pollution including O3 on the occurrence of OHCA, and assess effect modification by season, age, and gender.
A total of 5973 Emergency Medical Service-assessed OHCA cases in Stockholm County 2000-10 were obtained from the Swedish cardiac arrest register. A time-stratified case-crossover design was used to analyse exposure to air pollution and the risk of OHCA. Exposure to O3, PM2.5, PM10, NO2, and NOx was defined as the mean urban background level during 0-2, 0-24, and 0-72 h before the event and control time points. We adjusted for temperature and relative humidity. Ozone in urban background was associated with an increased risk of OHCA for all time windows. The respective odds ratio (confidence interval) for a 10 µg/m(3) increase was 1.02 (1.01-1.05) for a 2-h window, 1.04 (1.01-1.07) for 24-h, and 1.05 (1.01-1.09) for 3 day. The association with 2-h O3 was stronger for events that occurred outdoors: 1.13 (1.06-1.21). We observed no effects for other pollutants and no effect modification by age, gender, or season.
Short-term exposure to moderate levels of O3 is associated with an increased risk of OHCA.
尽管臭氧（O3）和其他污染物与心血管发病率和死亡率有关，但臭氧对院外心脏骤停（OHCA）的影响很少被涉及，并且现有研究的结果不一致。本研究的目的是确定短期暴露于空气污染（包括 O3）对 OHCA 发生的影响，并评估季节、年龄和性别对其的影响修饰作用。
从瑞典心脏骤停登记处获得了 2000-10 年斯德哥尔摩县的 5973 例由紧急医疗服务评估的 OHCA 病例。采用时间分层病例交叉设计分析了暴露于空气污染与 OHCA 风险之间的关系。O3、PM2.5、PM10、NO2 和 NOx 的暴露定义为事件和对照时间点前 0-2、0-24 和 0-72 小时的城市背景平均水平。我们对温度和相对湿度进行了调整。城市背景中的臭氧与所有时间窗口的 OHCA 风险增加相关。相应的比值比（置信区间）分别为 2 小时窗口增加 10μg/m3 时为 1.02（1.01-1.05），24 小时窗口时为 1.04（1.01-1.07），3 天窗口时为 1.05（1.01-1.09）。2 小时 O3 与发生在户外的事件的关联更强：1.13（1.06-1.21）。我们没有观察到其他污染物的影响，也没有观察到年龄、性别或季节的影响修饰作用。
短期暴露于中等水平的 O3 与 OHCA 的风险增加相关。
