Vedal S, Schenker M B, Munoz A, Samet J M, Batterman S, Speizer F E
Am J Public Health. 1987 Jun;77(6):694-8. doi: 10.2105/ajph.77.6.694.
To identify acute respiratory health effects associated with air pollution due to coal combustion, a subgroup of elementary school-aged children was selected from a large cross-sectional study and followed daily for eight months. Children were selected to obtain three equal-sized groups: one without respiratory symptoms, one with symptoms of persistent wheeze, and one with cough or phlegm production but without persistent wheeze. Parents completed a daily diary of symptoms from which illness constellations of upper respiratory illness (URI) and lower respiratory illness (LRI) and the symptom of wheeze were derived. Peak expiratory flow rate (PEFR) was measured daily for nine consecutive weeks during the eight-month study period. Maximum hourly concentrations of sulfur dioxide, nitrogen dioxide, ozone, and coefficient of haze for each 24-hour period, as well as minimum hourly temperature, were correlated with daily URI, LRI, wheeze, and PEFR using multiple regression models adjusting for illness occurrence or level of PEFR on the immediately preceding day. Respiratory illness on the preceding day was the most important predictor of current illness. A drop in temperature was associated with increased URI and LRI but not with increased wheeze or with a decrease in level of PEFR. No air pollutant was strongly associated with respiratory illness or with level of PEFR, either in the group of children as a whole, or in either of the symptomatic subgroups; the pollutant concentrations observed, however, were uniformly lower than current ambient air quality standards. Moreover, since exposure estimation based on monitoring of ambient air likely results in misclassification of the true exposure, the negative findings of this study must be interpreted cautiously.
为了确定与煤炭燃烧造成的空气污染相关的急性呼吸道健康影响，从一项大型横断面研究中选取了一组小学适龄儿童，并对其进行了为期八个月的每日跟踪。选择儿童以获得三个规模相等的组：一组无呼吸道症状，一组有持续性喘息症状，一组有咳嗽或咳痰但无持续性喘息。家长完成了一份症状日记，从中得出上呼吸道疾病（URI）和下呼吸道疾病（LRI）的疾病组合以及喘息症状。在为期八个月的研究期间，连续九周每天测量呼气峰值流速（PEFR）。使用多元回归模型，对前一天的疾病发生情况或PEFR水平进行调整，将每24小时期间的二氧化硫、二氧化氮、臭氧的最大小时浓度、霾系数以及最低小时温度与每日URI、LRI、喘息和PEFR进行关联。前一天的呼吸道疾病是当前疾病的最重要预测因素。气温下降与URI和LRI增加相关，但与喘息增加或PEFR水平下降无关。无论是在整个儿童组中，还是在任何一个有症状的亚组中，均没有空气污染物与呼吸道疾病或PEFR水平密切相关；然而，观察到的污染物浓度均低于当前的环境空气质量标准。此外，由于基于环境空气监测的暴露估计可能会导致对真实暴露的错误分类，因此必须谨慎解释本研究的阴性结果。
