1. Department of Chest Medicine Centre Hospitalier Universitaire UCL NamurUniversité catholique de Louvain Yvoir Belgium
2. Specialization School in Occupational Medicine University of Pavia Pavia Italy
3. Unità Operativa di Medicina del LavoroSezione di Allergologia Istituti Clinici Scientifici Maugeri Pavia Italy
4. Scientific Support Unit Centre Hospitalier Universitaire UCL Namur Université catholique de Louvain Yvoir Belgium
5. Service Médical Fedris (Agence fédérale pour les risques professionnels) BrusselsBelgium