Walters S, Griffiths R K, Ayres J G
Institute of Public and Environmental Health, University of Birmingham Medical School.
Thorax. 1994 Feb;49(2):133-40. doi: 10.1136/thx.49.2.133.
A study was performed to determine whether daily and weekly variations in the levels of smoke and sulphur dioxide (SO2) in Birmingham are related to hospital admissions for asthma and acute respiratory diseases.
Daily numbers of hospital admissions for asthma (ICD code 493) and acute respiratory conditions (ICD 466, 480-486, 490-496) for residents of Birmingham between 1988 and 1990 were obtained from West Midlands RHA Körner inpatient data. Average daily levels of sulphur dioxide and smoke were obtained from Birmingham City Council for the same period, together with daily meteorological summaries from the Department of Geography, University of Birmingham. With the exception of one day, all air pollution measurements remained within current EC guide levels. Data were divided into seasons and the relation between hospital admissions and pollutant levels were explored by stepwise least squares regression models. Meteorological variables (temperature, pressure, humidity) were entered into the model if they showed significant association with hospital admissions during the season in question. Analysis was undertaken for daily (same day and lagged by two days) and weekly pollutant levels. Admissions were lagged behind pollution levels to allow for delayed effects of pollutants.
The mean daily level of smoke was 12.7 micrograms/m3 and of SO2 was 39.1 micrograms/m3, with maxima of 188.3 micrograms/m3 and 126.3 micrograms/m3, respectively. Significant associations were found between hospital admissions for respiratory disease lagged by two days, and smoke and SO2 levels during winter. Associations between admissions for asthma and smoke and SO2 levels were significant at the 5% level. These were independent of temperature, pressure, and humidity. Stepwise regression including both pollutants showed that smoke, but not SO2, was a significant independent predictor of hospital admissions for both asthma and all respiratory conditions. During winter a rise of 100 micrograms/m3 smoke might result in five (95% CI 0.6 to 9) more asthma admissions and 21.5 (95% CI 10 to 33) more acute respiratory admissions each day in Birmingham. A 100 micrograms/m3 rise in SO2 might result in four (0 to 7) more asthma admissions and 15.5 (6 to 25) more respiratory admissions each day. Independent associations were also found between weekly mean smoke and SO2 levels and all respiratory admissions during autumn and winter. During summer, daily mean smoke and SO2 levels were significantly associated with non-lagged daily admissions for all respiratory diseases (p < 0.02). There was no association between air pollution and hospital admissions during spring.
Daily variations in smoke and SO2 levels are significantly associated with hospital admissions for asthma and respiratory disease during winter in Birmingham at levels of air pollutants within the EC guide levels. This association was independent of potential confounding effects of weather (temperature, pressure, humidity) and suggests that current levels of air pollution can still produce significant health effects.
开展了一项研究，以确定伯明翰市烟雾和二氧化硫（SO₂）水平的每日及每周变化是否与哮喘和急性呼吸道疾病的住院人数相关。
1988年至1990年间伯明翰市居民因哮喘（国际疾病分类代码493）和急性呼吸道疾病（国际疾病分类466、480 - 486、490 - 496）的每日住院人数来自西米德兰兹地区卫生局科纳住院患者数据。同期伯明翰市议会提供了二氧化硫和烟雾的每日平均水平，以及伯明翰大学地理系的每日气象摘要。除一天外，所有空气污染测量值均保持在当前欧盟指导水平范围内。数据按季节划分，并通过逐步最小二乘回归模型探讨住院人数与污染物水平之间的关系。如果气象变量（温度、气压、湿度）在相关季节与住院人数显示出显著关联，则将其纳入模型。对每日（当日及滞后两天）和每周污染物水平进行了分析。住院人数滞后于污染水平，以考虑污染物的延迟影响。
烟雾的每日平均水平为12.7微克/立方米，SO₂为39.1微克/立方米，最大值分别为188.3微克/立方米和126.3微克/立方米。发现冬季滞后两天的呼吸系统疾病住院人数与烟雾和SO₂水平之间存在显著关联。哮喘住院人数与烟雾和SO₂水平之间的关联在5%水平上具有显著性。这些关联独立于温度、气压和湿度。包括两种污染物的逐步回归显示，烟雾而非SO₂是哮喘和所有呼吸道疾病住院人数的显著独立预测因素。在冬季，伯明翰市烟雾水平每升高100微克/立方米，可能导致每日哮喘住院人数增加5例（95%可信区间0.6至9），急性呼吸道疾病住院人数增加21.5例（95%可信区间10至33）。SO₂水平每升高100微克/立方米，可能导致每日哮喘住院人数增加4例（0至7），呼吸道疾病住院人数增加15.5例（6至25）。还发现秋季和冬季每周平均烟雾和SO₂水平与所有呼吸道疾病住院人数之间存在独立关联。夏季，每日平均烟雾和SO₂水平与所有呼吸道疾病的非滞后每日住院人数显著相关（p < 0.02）。春季空气污染与住院人数之间无关联。
在欧盟指导水平内的空气污染水平下，伯明翰市冬季烟雾和SO₂水平的每日变化与哮喘和呼吸道疾病的住院人数显著相关。这种关联独立于天气（温度、气压、湿度）的潜在混杂效应，表明当前空气污染水平仍可产生显著的健康影响。
