Linn W S, Shamoo D A, Anderson K R, Peng R C, Avol E L, Hackney J D, Gong H
Environmental Health Service, Rancho Los Amigos, Medical Center, Downey, California 90242, USA.
J Expo Anal Environ Epidemiol. 1996 Oct-Dec;6(4):449-72.
We studied 269 school children from three Southern California communities of contrasting air quality in two successive school years, to investigate short-term effects of ambient ozone (O3), nitrogen dioxide (NO2), or particulate matter (PM) on respiratory health. We measured lung function and symptoms twice daily for one week each in fall, winter and spring; and concurrently assessed time-activity patterns and personal exposures. Average daily personal exposures correlated with pollutant concentrations at central sites (r = 0.61 for O3, 0.63 for NO2, 0.48 for PM). Questionnaire-reported outdoor activity increased slightly in communities/seasons with higher pollution. Lung function differences between communities were explainable by age differences. Morning forced vital capacity (FVC) decreased significantly with increase in PM or NO2 measured over the preceding 24 hours. Morning-to-afternoon change of forced expired volume in one second (FEV1) became significantly more negative with increase in PM, NO2, or O3 on the same day. Predicted FVC or FEV1 loss on highest- vs lowest-pollution days was < 2%. Daily symptoms showed no association with current or prior 24-hour pollution, but increased with decreasing temperature. Parents' questionnaire responses suggested excess asthma and allergy in children from one polluted community while children in the other polluted community reported more symptoms, relative to the cleaner community. We conclude that Los Angeles area children may experience slight lung function changes in association with day-to-day air quality changes, reasonably similar to responses seen by others in less polluted areas. Although short-term pollution effects appear small, they should be assessed in longitudinal lung function studies when possible, to allow maximally accurate measurement of longer-term function changes.
在连续两个学年里，我们对来自南加州三个空气质量不同的社区的269名学童进行了研究，以调查环境臭氧（O3）、二氧化氮（NO2）或颗粒物（PM）对呼吸健康的短期影响。我们在秋季、冬季和春季各进行为期一周的每日两次肺功能和症状测量；同时评估时间活动模式和个人暴露情况。平均每日个人暴露与中心站点的污染物浓度相关（O3的r = 0.61，NO2的r = 0.63，PM的r = 0.48）。问卷调查显示，在污染较高的社区/季节，户外活动略有增加。社区间的肺功能差异可通过年龄差异来解释。早晨用力肺活量（FVC）随前24小时测量的PM或NO2增加而显著下降。同一天，随着PM、NO2或O3增加，一秒用力呼气容积（FEV1）从早晨到下午的变化变得显著更负。污染最高日与最低日之间预测的FVC或FEV1损失<2%。每日症状与当前或之前24小时的污染无关，但随温度降低而增加。家长的问卷调查答复表明，与清洁社区相比，一个污染社区的儿童哮喘和过敏情况较多，而另一个污染社区的儿童报告的症状更多。我们得出结论，洛杉矶地区的儿童可能会随着日常空气质量变化而经历轻微的肺功能变化，这与其他污染较轻地区的情况类似。虽然短期污染影响似乎较小，但在可能的情况下，应在纵向肺功能研究中进行评估，以便最大限度地准确测量长期功能变化。
