Short-Term Effects of Air Pollution on Hospital Admissions of Respiratory Diseases in Europe: A Quantitative Summary of APHEA Study Results

Abstract

The Air Pollution and Health: a European Approach (APHEA) project is a coordinated study of the short-term effects of air pollution on mortality and hospital admissions. Five West European cities (i.e., London, Amsterdam, Rotterdam, Paris, Milano) contributed several years of hospital admissions data for all respiratory causes. In the current study, the authors describe the results obtained from the quantitative pooling (meta-analysis) of local analyses. The diagnostic group was defined by ICD 460-519. The age groups studied were 15-64 y (i.e., adults) and 65+ y (elderly). The air pollutants studied were sulfur dioxide; particles (i.e., Black Smoke or total suspended particles); ozone; and nitrogen dioxide. The pollutants were obtained from existing fixed-site monitors in a standardized manner. We used Poisson models and standardized confounder models to examine the associations between daily hospital admissions and air pollution. We conducted quantitative pooling by calculating the weighted means of local regression coefficients. We used a fixed-effects model when no heterogeneity could be detected; otherwise, we used a random-effects model. When possible, the authors investigated the factors correlated with heterogeneity. The most consistent and strong finding was a significant increase of daily admissions for respiratory diseases (adults and elderly) with elevated levels of ozone. This finding was stronger in the elderly, had a rather immediate effect (same or next day), and was homogeneous over cities. The elderly were affected more during the warm season. The Sulfur dioxide daily mean was available in all cities, and it was not associated consistently with an adverse effect. Effects were present in areas in which more than one station was used in the assessment of daily exposure. Some significant associations were observed, although no conclusion that related to an overall particle effect could be drawn. The effect of Black Smoke was significantly stronger with high nitrogen dioxide levels on the same day, but nitrogen dioxide itself was not associated with admissions. The ozone results were in good agreement with the results of similar U.S. studies. The coherence of the results of this study and other results gained under different conditions strengthens the argument for causality.

A tale of two cities: effects of air pollution on hospital admissions in Hong Kong and London compared.

“…The results for respiratory admissions were similar when the best single day lag was chosen, with all pollutants showing significant effects in both cities. These results are in line with many other studies (33). However, when the 0-1 day lag was compared, the cities were similar only for O 3 , with only Hong Kong showing significant effects of the other pollutants.…”

Comparison of different exposure settings in a case–crossover study on air pollution and daily mortality: counterintuitive results

“…The slightly wider confidence interval in the meta-analytical estimate reflected the addition of the result from Edinburgh (Prescott et al, 1998), a relatively small city. For respiratory admissions in adults aged 15-64 years the summary estimate was based upon the original APHEA 1 analysis of four cities (Amsterdam, London, Paris and Rotterdam) (Spix et al, 1998) together with the result from the West Midlands study. The summary relative risk was 1.006 (1.001, 1.010) per 10 µg/m 3 increase in BS.…”

Associations between ambient air pollution and daily emergency department attendances for cardiovascular disease in the elderly (65+ years), Sydney, Australia

“…Acute effects of ambient air pollution on mortality and hospital admissions have been well documented in both Australia and elsewhere (Simpson et al, 1997(Simpson et al, , 2000Sunyer et al, 1997;Morgan et al, 1998a, b;Spix et al, 1998;Kunzli et al, 1999;Schwartz, 1999;Samet et al, 2000;Pope et al, 2002). Fewer studies have investigated associations between ambient air pollutants and emergency department (ED) attendances and the majority of these have reported on the associations between air pollution and ED attendances for asthma (Schwartz et al, 1993;Castellsague et al, 1995;Smith et al, 1996;Stieb et al, 1996;Tenias et al, 1998;Fauroux et al, 2000).…”