Rice University, Department of Statistics, PO Box 1892, MS 138, Houston, TX 77251-1892, USA.
Circulation. 2013 Mar 19;127(11):1192-9. doi: 10.1161/CIRCULATIONAHA.113.000027. Epub 2013 Feb 13.
Evidence of an association between the exposure to air pollution and overall cardiovascular morbidity and mortality is increasingly found in the literature. However, results from studies of the association between acute air pollution exposure and risk of out-of-hospital cardiac arrest (OHCA) are inconsistent for fine particulate matter, and, although pathophysiological evidence indicates a plausible link between OHCA and ozone, none has been reported. Approximately 300 000 persons in the United States experience an OHCA each year, of which >90% die. Understanding the association provides important information to protect public health.
The association between OHCA and air pollution concentrations hours and days before onset was assessed by using a time-stratified case-crossover design using 11 677 emergency medical service-logged OHCA events between 2004 and 2011 in Houston, Texas. Air pollution concentrations were obtained from an extensive area monitor network. An average increase of 6 µg/m(3) in fine particulate matter 2 days before onset was associated with an increased risk of OHCA (1.046; 95% confidence interval, 1.012-1.082). A 20-ppb ozone increase for the 8-hour average daily maximum was associated with an increased risk of OHCA on the day of the event (1.039; 95% confidence interval, 1.005-1.073). Each 20-ppb increase in ozone in the previous 1 to 3 hours was associated with an increased risk of OHCA (1.044; 95% confidence interval, 1.004-1.085). Relative risk estimates were higher for men, blacks, or those aged >65 years.
The findings confirm the link between OHCA and fine particulate matter and introduce evidence of a similar link with ozone.
越来越多的文献证据表明，空气污染暴露与整体心血管发病率和死亡率之间存在关联。然而，关于急性空气污染暴露与院外心脏骤停（OHCA）风险之间的关联，细颗粒物的研究结果并不一致，尽管病理生理学证据表明 OHCA 与臭氧之间存在合理的联系，但尚未有报道。美国每年约有 30 万人经历 OHCA，其中>90%的人死亡。了解这种关联为保护公众健康提供了重要信息。
利用时间分层病例交叉设计，使用 2004 年至 2011 年德克萨斯州休斯顿市的 11677 例急救医疗服务记录的 OHCA 事件，评估了 OHCA 与发病前数小时和数天的空气污染浓度之间的关联。空气污染浓度来自广泛的区域监测网络。发病前 2 天，细颗粒物浓度平均增加 6μg/m3 与 OHCA 风险增加相关（1.046；95%置信区间，1.012-1.082）。8 小时平均日最大臭氧浓度增加 20ppb 与事件当天 OHCA 风险增加相关（1.039；95%置信区间，1.005-1.073）。前 1 至 3 小时内，臭氧浓度每增加 20ppb，与 OHCA 风险增加相关（1.044；95%置信区间，1.004-1.085）。男性、黑人或年龄>65 岁的人的相对风险估计值更高。
这些发现证实了 OHCA 与细颗粒物之间的联系，并引入了与臭氧类似联系的证据。
