[The joint effects of various atmospheric pollutants: a meta-analysis]

Epidemiological and experimental papers on respiratory effects of air pollution published between 1980 and 1988 were reviewed, using a meta-analytical approach. Forty epidemiological papers dealing with sulfur dioxide (SO2) and total suspended particles (TSP) were used to scrutinize the interaction between the two pollutants, and suggested that the effect of the acid gas was enhanced by the joint presence of TSP. Oxidant pollution combining O3 and NO2 was also found more noxious than ozone alone, using 32 experimental design papers. These results stem from the multivariate modelization of the relationship between the relative risk of cough or the relative decrease of FEV1.0, and the pollutants concentration, and illustrated some of the advantages of this quantitative approach to literature review. Underlying physiopathological processes are discussed, in the light of the important literature available on this topic.