Efectos a corto plazo de la contaminación atmosférica sobre la mortalidad: resultados del proyecto EMECAM en dos ciudades de Asturias

BACKGROUND: The studies conducted to date regarding the possibility that air pollutants are capable of having impact on human health have not led to homogenous findings. This study is aimed at estimating the degrees of relationship between the daily levels of the pollutants and the death rate on a short-terms basis in the two most populated cities in Asturias (Gijon and Oviedo), as well as contributing to increasing the statistical importance and the representative nature of the EMECAM Project, within which this study is comprised. METHODS: Ecological time series study, Estimate of degrees of group exposure based on the readings taken at the pollution control stations. Modeling of the death rate series, including control variables, by means of Poisson regression. Estimating risks related to each pollutant for the death rate, controlling the series-based autocorrelation. FINDINGS: Throughout the 1993-1996 period, the pollution by means of particles in suspension and CO was greater in Gijon, that involving SO2 and NO2 having been greater in Oviedo. In these two cities, the levels can be considered to be low and to fall within what is considered admissible under the laws currently in impact. Most of the relative risk forecasts neared the zero impact point, although significant positive (especially for NO2) as well as negative relationships have been found to exist. The significant relationships found were not proven to be consistent in these two cities for the periods studied. CONCLUSIONS: Based on the findings of this study, the conclusion cannot be drawn that a clear-cut relationship exists between the pollutants studied (particles, SO2, NO2, CO) and the death rate on a short-term basis, at least at the levels detected in Gijon and Oviedo.