Airway Inflammation in Cement Production Workers
- 1 Department of Occupational and Environmental Medicine, Telemark Hospital, Skien, Norway;
- 2 Department of Respiratory Medicine, Faculty Division Rikshospitalet, University of Oslo, Norway;
- 3 Department of Respiratory Medicine, Rikshospitalet University Hospital, Oslo, Norway
- Correspondence to: Anne Kristin Møller Fell, Occupational and Environmental Medicine, Telemark Hospital, Telemark Hospital, Seksjon for arbeidsmedisin, Ulefossveien 55, Skien, 3710, Norway; anne-kristin.fell{at}sthf.no
- Received 28 April 2009
- Accepted 24 September 2009
- Published Online First 22 October 2009
Abstract
Objective: Cement aerosol exposure is associated with increased morbidity of airway disease among exposed workers. The aim of this study was to compare the levels of inflammatory cells and soluble inflammatory markers in induced sputum samples of cement production workers between exposed and unexposed periods, and to compare these variables between cement workers and references.
Methods: A total of 35 healthy, non-smoking aerosol-exposed production workers from a cement plant in Norway provided a blood sample and performed induced sputum and spirometry after 5 days without exposure and again during a period of exposure during regular work. We compared these values with those obtained from an internal low-exposed reference group of 15 office workers from the plant and an external reference group (ERG) comprising 39 non-exposed workers. Differential cell counts and inflammatory markers were assessed.
Results: The median thoracic aerosol concentration over one work shift (8 hours) was 0.6 mg/m3 (range, 0.2 to 8.1) in maintenance workers and 1.75 mg/m3 (0.2 to 15.5) in furnace department workers. In the cement production workers (from the maintenance and furnace department), the median percentage of airway neutrophils was 51% (32 to 66) in the exposed period, which was significantly higher than in the unexposed period (median, 38%; range, 23 to 55) (p=0.04) and than in the external reference group (30%; 19 to 44) (p=0.001). The median interleukin-1β concentration was elevated compared with the office workers (p=0.05), and compared with the external reference group (p=0.006).
Conclusions: A significantly higher percentage of neutrophils was observed in cement production workers during the exposed period compared with the non-exposed period and with the external reference group. This elevated percentage corresponded with an elevated IL-1β concentration. These data indicate that cement aerosol exposure in concentrations below the Norwegian occupational limits (respirable dust, 5 mg/m3; total dust, 10 mg/m3) may cause airway inflammation.
