URBAN AIR-POLLUTION AND CARDIOPULMONARY ILL HEALTH - A 14.5-YEAR TIME-SERIES STUDY

Objectives-To examine possible associations between daily concentratio ns of urban air pollutants and hospital emergency admissions and morta lity due to cardiac and pulmonary disease. Methods-A time series study was conducted in the City of Edinburgh, which has a population of abo ut 450000. Poisson log linear regression models were used to investiga te the relation of the daily event rate with daily air pollution conce ntrations of sulphur dioxide (SO2) and black smoke from 1981 to 1995, and of nitrogen dioxide (NO2), ozone (O-3), carbon monoxide (CO), and particulate matter (PM10) from 1992 to 1995. Adjustments were made for seasonal and weekday variation, daily temperature, and wind speed. Re sults-The most significant findings were positive associations over th e period 1981-95 between black smoke as a mean of the previous three d ays and daily all cause mortality in people aged greater than or equal to 65, and respiratory mortality also in this age group (3.9% increas e in mortality for a 10 mu g/m(3) increment in black smoke). For hospi tal emergency admissions between 1992 and 1995 the two most significan t findings (p<0.05) were for cardiovascular admissions of people aged greater than or equal to 65 which showed a positive association with P M10 as a mean of the 3 previous days, and a negative association with O-3 as a mean of the previous three days. Analyses of outcomes based o n linkage with previous cardiorespiratory emergency admissions did not show substantially different results. Conclusion-These data suggest t hat in the City of Edinburgh, after correction for confounders, there was a small but significant association between concentrations of blac k smoke and respiratory mortality in the older age group, probably att ributable to higher pollution levels in the early part of the study pe riod. There were also generally weak and variable associations between day to day changes in concentrations of urban air pollutants at a sin gle central point and emergency hospital admission rates from cardiac and respiratory disease.