[The short-term effects of air pollution on mortality. The results of the EMECAM project in the city of Valencia, 1994-96. Estudio Multcéntrico Español sobre la Relación entre la Contaminación Atmosférica y la Mortalidad].

BACKGROUND

To determine the short-term impact of air pollution on mortality in the city of Valencia throughout the 1994-1996 period by employing the analysis method of the Spanish multicenter study with regard to the relationship between air pollution and the mortality (EMECAM Project).

METHODS

The daily levels of black smoke, sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO) and ozone (O3) were obtained from the Valencia air pollution monitoring network. The death rate indicators analyzed were the daily number of death due to all causes, except the external ones, the deaths of those over age 70, and the deaths resulting from respiratory and cardiovascular diseases. Following the methods of the EMECAM Project, autoregressive Poison regression models were built up, controlling the different confounding factors (seasonality, trend, calendar, weather variables and flu impact).

RESULTS

For total mortality except the external ones, a significant impact of black smoke (RR 10 micrograms/m3: 1.013; CI95% 1.003 to 1.023) and for CO 24 la (RR 1 mg/m3: 1.024; CI95% 1.003 to 1.046) was found. For the mortality of those individuals over 70, the estimated impact was somewhat greater than for black smoke (RR 10 micrograms/m3: 1.017; CI95% 1.005-1.029), as well as for CO2 1 h (RR 10 micrograms/m3: 1.007; CI95% 1.001-1.013). No significant relationship was found with the mortality due to respiratory or cardiovascular diseases for the entire period.

CONCLUSIONS

The current levels of pollution in the city of Valencia show a significant impact on daily mortality. These findings are consistent with the previous research and are coherent with those obtained on analyzing the relationship between air pollution and morbidity indicators.