[1] Univ Milan, EPOCA, Res Ctr Occupat Clin & Environm Epidemiol, Dept Occupat & Environm Hlth, I-20122 Milan, Italy
[2] Ist Clin Perfezionamento, Epidemiol Unit, Dept Occupat Hlth & Safety, Milan, Italy
[3] Hlth Directorate Reg Lombardia, Reg Epidemiol Off, Milan, Italy