1. Department of Mechanical Engineering, Politecnico di Milano, Via Privata Giuseppe la Masa 1, 20156 Milano, Italy
2. Centre for Research in Occupational Safety and Health, Laurentian University, Sudbury, ON P3E 2C6, Canada
3. INAIL, Medicine, Epidemiology, Occupational and Environmental Health Department, Via di Fontana Candida, 00040 Monte Porzio Catone, Italy
4. Clinical Unit of Occupational Medicine, Department of Medical Sciences, University of Trieste, Via della Pietà 19, 34129 Trieste, Italy