1. Division of Occupational and Environmental Medicine, Department of Laboratory MedicineLund UniversityBox 117, SE‐221 00LundSweden
2. Ergonomic and Aerosol TechnologyLund UniversityBox 118, SE‐22100LundSweden
3. Department of Occupational and Environmental MedicineSahlgrenska University HospitalSE‐41345GöteborgSweden
4. Institute of Environmental Medicine (IMM)C6, Occupational medicine, Solnavägen 4113 65StockholmSweden