Avol E L, Navidi W C, Rappaport E B, Peters J M
University of Southern California, Division of Occupational and Environmental Medicine, School of Medicine, Los Angeles, USA.
Res Rep Health Eff Inst. 1998 May(82):iii, 1-18; discussion 19-30.
Southern California children (10 to 12 years old) participated in a two-season study to assess the potential acute respiratory effects of ambient ozone (O3). Asthmatic (n = 49), wheezy (n = 53), and healthy (n = 93) children completed a four-day (Friday through Monday) study protocol, once in spring and again in summer, that included the use of daily activity and symptom diaries, heart rate recording devices, personal O3 samplers, and maximal effort spirometry several times per day. Data from regional monitoring stations were used to establish ambient hourly O3 concentrations. Analyses revealed that the children spent more time outdoors and were more physically active in the spring. Girls spent less time outdoors and were less physically active than boys. Personal O3 samplers correlated poorly with, and generally gave lower readings than, outdoor ambient monitors. Higher personal O3 exposures were associated generally with increased inhaler use, more outdoor time, and more physical activity. Children with asthma spent more time outdoors and were more active in the spring on high-O3 days (measured by personal sampler), and had the most trouble breathing, the most wheezing, and the most inhaler use on these days. Activity pattern data suggested that children with asthma protected themselves by being less physically active outdoors during the summer on high-O3 days. Wheezy children had the most trouble breathing during the summer on low-O3 days (measured by personal sampler). Observed relationships between O3 and pulmonary function were erratic and difficult to reconcile with existing knowledge about the acute respiratory effects of air pollution. We conclude that although asthmatic and wheezy children behave differently from their healthy peers with regard to symptoms and patterns of activity when challenged by ambient ozone, the nature of these changes remains inconsistent and ill-defined.
南加州10至12岁的儿童参与了一项为期两个季节的研究，以评估环境臭氧（O₃）对急性呼吸道的潜在影响。哮喘儿童（n = 49）、喘息儿童（n = 53）和健康儿童（n = 93）完成了一项为期四天（周五至周一）的研究方案，春季和夏季各进行一次，其中包括使用每日活动和症状日记、心率记录设备、个人臭氧采样器，以及每天多次进行的最大用力肺活量测定。来自区域监测站的数据用于确定每小时的环境臭氧浓度。分析表明，孩子们在春季户外活动时间更长，身体活动也更频繁。女孩在户外的时间比男孩少，身体活动也不如男孩频繁。个人臭氧采样器与室外环境监测器的相关性较差，且读数通常低于室外环境监测器。较高的个人臭氧暴露通常与吸入器使用增加、更多的户外时间和更多的身体活动有关。哮喘儿童在春季臭氧浓度高的日子（通过个人采样器测量）户外活动时间更长，活动更频繁，且在这些日子里呼吸困难、喘息和使用吸入器的情况最为严重。活动模式数据表明，哮喘儿童在夏季臭氧浓度高的日子里通过减少户外活动来保护自己。喘息儿童在夏季臭氧浓度低的日子（通过个人采样器测量）呼吸困难最为严重。观察到的臭氧与肺功能之间的关系不稳定，难以与关于空气污染对急性呼吸道影响的现有知识相协调。我们得出结论，尽管哮喘和喘息儿童在受到环境臭氧挑战时，在症状和活动模式方面与健康同龄人表现不同，但这些变化的性质仍然不一致且定义不明确。
