Air pollution and mortality in Barcelona.
STUDY OBJECTIVES: Studies conducted in Barcelona reported a short term relation between daily air pollutant values and emergency department admissions for exacerbation of chronic obstructive pulmonary diseases and asthma. Air pollution in Barcelona is mainly generated by vehicle exhaust and is below the World Health Organization air quality guidelines. The acute relation between air pollution and mortality was assessed. DESIGN: Daily variations in total mortality, mortality in subjects older than 70 years, and cardiovascular and respiratory mortality were related with daily variations in air pollutants for the period 1985-91, using autoregressive Poisson regression models that allow to control for temperature, relative humidity and variables handling temporal and autoregressive patterns. MAIN RESULTS: Black smoke and sulphur dioxide (SO2) were related to total mortality (relative risks (RR) for 100 micrograms/m3 = 1.07 and 1.13 respectively), elderly mortality (RR = 1.06 and 1.13), cardiovascular mortality (RR = 1.09 and 1.14), and respiratory mortality (RR = 1.10 and 1.13); all the associations being statistically significant, except for respiratory mortality (p = 0.07). The association between SO2 and respiratory mortality was stronger in summer (1.24, p < 0.01) than in winter (1.08, p > 0.1). Oxidant pollutants (nitrogen dioxide and ozone) were positively related with elderly mortality (RR = 1.05 and 1.09, respectively) and cardiovascular mortality (RR = 1.07 and 1.09) during the summer (p < 0.05), but not during the winter. CONCLUSIONS: Current air pollutant levels were related to mortality in Barcelona. These results were consistent with similar studies in other cities and coherent with previous studies with emergency room admissions in Barcelona.