[Association of air pollution and mortality: a review of recent epidemiological studies]

The aim of this study is to present a review of the work published over the past few years which deals with the relationship between air pollution (AP) and mortality from the epidemiological perspective, by examining the evolution of methodology used in the analysis along with changes in values considered as threshold levels. A literature review was carried out on of articles published in the MEDLINE and IME databases. From this search some 40 articles were selected. The review has been centred on those studies which examine the association of AP indicators and short term mortality. The design of the paper is usually retrospective and, in almost all cases, these are ecological studies. Study populations are, most of times, inhabitants of cities or particular geographic areas, with the usual analysis being a combination of time series approach and multivariate regression. Also taken into account in the majority of this papers, apart from time variables, are other confounding factors, especially meteorological conditions. The results of the papers reviewed are presented along with their principle methodological characteristics. A series of recent studies indicate that the relationship between AP, especially small particles, and mortality may exist below the guidelines established at National and International level. This study finishes with a discussion on the most outstanding aspects of the results of the papers reviewed. Also mentioned is the difficulty of determining AP indicators, and their levels, which are linked to mortality.