1. Centre for Clinical Science and Measurement, School of Biomedical and Life Sciences, University of Surrey, Guilford GU2 7XH, United Kingdom
2. Institute of Occupational, Social and Environmental Medicine, University of Erlangen-Nuernberg, 91054 Erlangen, Germany
3. Unit of Epidemiology, Scientific Institute of Public Health, B-1050 Brussels, Belgium
4. National Institute of Occupational Health, 2100 Copenhagen, Denmark
5. Higiene Industrial, Centro de Seguridad y Salud en el Trabajo, Gobierno de Cantabria, 39012 Santander, Spain
6. Laboratorio di Biochimica Clinica, Istituto Superiore di Sanità, 00161 Rome, Italy
7. Laboratoire de Toxicologie, UFR de Pharmacie, Université de Nantes, 44035 Nantes, France
8. Association Européenne des Metaux, 1150 Brussels, Belgium
9. Biomonitoring Laboratory, Topeliuksenkatu 41aA, Finnish Institute of Occupational Health, FIN-02500 Helsinki, Finland
10. MCA Laboratory, Queen Beatrix Hospital, 7101 BN Winterswijk, The Netherlands