Ponce de Leon A, Anderson H R, Bland J M, Strachan D P, Bower J
Department of Public Health Sciences, St George's Hospital Medical School, London.
J Epidemiol Community Health. 1996 Apr;50 Suppl 1(Suppl 1):s63-70. doi: 10.1136/jech.50.suppl_1.s63.
To investigate whether air pollution levels in London have short term effects on hospital admissions for respiratory disease.
Poisson regression analysis of daily counts of hospital admissions, adjusting for effects of trend, seasonal and other cyclical factors, day of the week, holidays, influenza epidemic, temperature, humidity, and autocorrelation. Pollution variables were particulates (black smoke: BS), sulphur dioxide (SO2), ozone (O3), and nitrogen dioxide (NO2), lagged 0-3 days.
All immediate admissions for respiratory disease (ICD 460-519) to hospitals in London health districts in the five years April 1987 to February 1992 for all ages and the 0-14, 15-64, and 65+ age groups.
O3 (lagged one day) was significantly associated with an increase in daily admissions among all age groups, except the 0-14 group, and this effect was stronger in the "warm" season (April-September). In this season, the relative risks of admission associated with an increase in 8 hour O3 levels of 29 ppb (10th to 90th centile) were 1.0483 (95% CI 1.0246, 1.0726), 1.0294 (0.9930,1.0672), 1.0751 (1.0354,1.1163), and 1.0616 (1.0243,1.1003) for all ages and age groups 0-14, 15-64, and 65+ respectively. Very few significant associations were observed with the other pollutants, though these tended to be positive. Controlling for other pollutants made little difference to the O3 coefficients. There was evidence of a threshold at about 40-60 ppb O3 (maximum hourly or maximum 8 hour).
O3 levels in London have a small but significant effect on hospital admissions for respiratory disease at all ages. The possible role of aerollergen as a confounding factor needs to be examined. Unlike other cities where similar effects have been reported, little or no effect of particulates was observed in London.
调查伦敦的空气污染水平是否对呼吸道疾病的住院率有短期影响。
对每日住院人数进行泊松回归分析，对趋势、季节和其他周期性因素、星期几、节假日、流感流行、温度、湿度和自相关的影响进行调整。污染变量为颗粒物（黑烟：BS）、二氧化硫（SO₂）、臭氧（O₃）和二氧化氮（NO₂），滞后0至3天。
1987年4月至1992年2月这五年间，伦敦各卫生区医院收治的所有年龄段以及0至14岁、15至64岁和65岁及以上年龄组因呼吸道疾病（国际疾病分类460 - 519）的所有即时住院病例。
除0至14岁年龄组外，O₃（滞后一天）与所有年龄组的每日住院人数增加显著相关，且在“温暖”季节（4月至9月）这种影响更强。在这个季节，8小时O₃水平从第10百分位数增加到第90百分位数29 ppb时，所有年龄段以及0至14岁、15至64岁和65岁及以上年龄组的入院相对风险分别为1.0483（95%置信区间1.0246，1.0726）、1.0294（0.9930，1.0672）、1.0751（1.0354，1.1163）和1.0616（1.0243，1.1003）。与其他污染物的显著关联很少，尽管这些关联往往是正向的。控制其他污染物对O₃系数影响不大。有证据表明在约40 - 60 ppb O₃（每小时最大值或8小时最大值）存在一个阈值。
伦敦的O₃水平对各年龄段呼吸道疾病的住院率有微小但显著的影响。需要研究气传变应原作为混杂因素的可能作用。与其他报告了类似影响的城市不同，在伦敦几乎未观察到颗粒物的影响。
