TIME-SERIES ANALYSIS OF AIR-POLLUTION AND CAUSE-SPECIFIC MORTALITY

Ten large European cities provided data on daily air pollution as well as mortality from respiratory and cardiovascular mortality. We used P oisson autoregressive models that controlled for trend, season, influe nza epidemics, and meteorologic influences to assess the short-term ef fects of air pollution at each city. We then compared and pooled the c ity-specific results in a mete-analysis. The pooled relative risks of daily deaths from cardiovascular conditions were 1.02 [95% confidence interval (CI) = 1.01-1. 04] for a 50 mu g/m(3) increment in the concen tration of black smoke and 1.04 (95% CI = 1.01-1.06) for an increase i n sulfur dioxide levels in western European cities. For respiratory di seases, these figures were 1.04 (95% CI = 1.02-1.07) and 1.05 (95% CI = 1.03-1.07), respectively. These associations were not found in the f ive central European cities. Eight-hour averages of ozone were also mo derately associated with daily mortality in western European cities (r elative risk = 1.02; 95% CI = 1.00-1.03 for cardiovascular conditions and relative risk = 1.06; 95% CI = 1.02-1.10 for respiratory condition s). Nitrogen dioxide did not show consistent relations with daily mort ality. These results are similar to previously published data and add credence to the causal interpretation of these associations at levels of air pollution close to or lower than current European standards.