Objective: To follow-up lung function and airway symptoms in workers exposed to cobalt dust at a hard metal plant.
Methods: A total of 582 employees underwent spirometry and completed a questionnaire. A historical exposure matrix was created, assigning figures for historical and recent work-related exposure.
Results: At the time of employment, 5% reported symptoms from respiratory tract. At follow-up, 5% suffered from persistent coughing and 7% reported asthma; 20% were daily smokers. Among nonsmokers without asthma, an evident, statistically nonsignificant, dose–response effect was seen between increasing cobalt exposure and decline in FEV1 (forced expiratory volume in the first second). In all exposure categories, the FEV1 in smokers declined 10 mL more per year than for nonsmokers.
Conclusions: Even low levels of cobalt exposure seem to hamper lung function both in smokers and nonsmokers. This impact is considered low in relation to the effect of aging.
From the Department of Occupational and Environmental Medicine Uppsala University Hospital (Dr Rehfisch and Mr Lampa), Uppsala, Sweden; Department of Clinical Physiology Södersjukhuset (Dr Anderson), Stockholm, Sweden; Department of Occupational and Environmental Medicine (Mr Berg, and Drs Westberg and Gunnarsson), Örebro University Hospital, Örebro, Sweden; FagerstaHälsan AB, Occupational Health Service (Ms Nordling), Fagersta, Sweden; and Division of Occupational and Environmental Medicine (Drs Anderson and Svartengren), Department of Public Health Sciences, Karolinska Institute, Stockholm, Sweden.
Address correspondence to: Pia Rehfisch, MD, Medicine, Department of Occupational and Environmental Medicine, Uppsala University Hospital, Ulleråkersvägen 38-40, 751 85 Uppsala, Sweden (firstname.lastname@example.org).
Drs Rehfisch and Gunnarsson contributed in the design, carry out, data interpretation, and writing; Dr Svartengren contributed in the design and interpretation of lung function; Dr Anderson contributed in interpretation of lung function; Mr Berg and Dr Westberg contributed in exposure assessment; Mr Lampa contributed in statistical analyses; and Ms Nordling contributed in data sampling and spirometries.
This study was funded by Seco Tools AB.
This work is performed within the framework of Research Center for Working Life of Social Research, Future Occupational Health Services, research for continuous evaluation, learning and improvement (2010–1563).
The spirometries were performed by Y Nordling and paid by Seco Tools AB, Fagersta, Sweden. Seco also paid for the statistical analyses of all data and the report in Swedish written by P Rehfisch in cooperation with all the authors. In the agreement with Seco, it is stated that Seco has no influence on the scientific analyses and results presented in the scientific publication. Neither is the work on the English paper paid by Seco.