1. Centre for Workplace HealthHealth and Safety LaboratoryBuxtonUK
2. Department of Respiratory MedicineUniversity of Newcastle upon TyneNewcastle upon TyneUK
3. North West Lung Research CentreUniversity of South ManchesterWythenshawe, ManchesterUK
4. Occupational Health DepartmentUniversity Hospital BirminghamBirminghamEngland
5. Division of Health SciencesUniversity of WarwickCoventryUK
6. Occupational Lung Disease UnitHeartlands HospitalBirminghamUK