1. University of Eastern Finland; Cochrane Work Review Group; Kuopio Finland 70201
2. University of Eastern Finland; Institute of Public Health and Clinical Nutrition, Occupational Health Unit; Kuopio Finland
3. University of Bristol; Population Health Sciences, Bristol Medical School; Bristol UK BS1 2NT
4. Finnish Institute of Occupational Health; Cochrane Work Review Group; TYÖTERVEYSLAITOS Finland FI-70032
5. Coronel Institute of Occupational Health; Cochrane Work Review Group; Academic Medical Center, University of Amsterdam PO Box 22700 Amsterdam Netherlands 1100 DE
6. University of Iowa Hospitals and Clinics; C512 GH, 200 Hawkins Drive Iowa City IA USA 52241
7. Finnish Institute of Occupational Health; P.O.Box 486 Tampere Finland FI-33101
8. Centers for Disease Control and Prevention (CDC); National Personal Protective Technology Laboratory (NPPTL), National Institute for Occupational Safety and Health (NIOSH); 626 Cochrans Mill Road Pittsburgh PA USA 15236