[Meta-analysis of respiratory function of workers exposed to asbestos]

The monitoring of health conditions in workers exposed to asbestos for prolonged periods is a problematic issue. The Occupational Health physician being required to carry out his activity of prevention of the medical consequences and protection of the workers can use various instruments among which there is the evaluation of lung function. We have performed a meta-analysis on the scientific evidence on this matter in order to identify significant alterations of the lung function parameters in subjects professionally exposed to asbestos compared with controls. By the means of a bibliographic search and the application of selected inclusion and exclusion criteria, we identified 21 articles presenting data from controlled studies. Our results show that the number of controlled trials is very small compared to the totality of studies performed on this matter (1 to 70 ratio) and that the number of the subjects included in the majority of the analyzed studies is oddly divided in the experimental and control group. For this and other reasons the analyzed studies are very heterogeneous. Despite these difficulties, the meta-analysis evidences that some parameters of respiratory functioning are more likely to be influenced by asbestos exposure taking into account the smoking habit and that other parameters are sinergically influenced by both asbestos exposure and smoking. Our meta-analysis points out the necessity to define a common methodology about the technical and operatives procedures in the evaluation of the effects on lung function measures determined by an occupational exposure to asbestos and a thorough examination of the intensity of abnormality levels that could allow using the values obtained from the above mentioned measures in a discriminating diagnostic way.