SL conceived the study, participated in its design and in data analysis, coordinated its realization, made substantial contribution to the interpretation of results, and drafted the manuscript. FF conceived the study, participated in its design, made substantial contribution to the interpretation of results and participated in drafting the manuscript. RP participated in the design of the study, selected the study subjects and coordinated the clinical monitoring. II participated in data acquisition and data management, and carried out the statistical analysis. PM participated in the design and in the coordination of the data collection. VF participated in the data management and statistical analysis. AM and GZ coordinated the monitoring of atmospheric pollutants and the analysis of environmental samples. BDO participated in design of the study and made substantial contribution in the interpretation of results.