Occupational Medicine (Oxford Journals). Vol. 64, Iss. 3, April 2014
Longitudinal decline in pulmonary diffusing capacity among nitrate fertilizer workers
Riassunto
Aims To study the possible adverse effects of occupational exposure to aerosols and gases on pulmonary diffusing capacity.
Methods A longitudinal study of a cohort of fertilizer workers who performed single-breath carbon monoxide diffusing capacity (DLco) tests and spirometry in 2007 and 2010. The workers completed a questionnaire on respiratory symptoms and smoking habits. Exposure to mineral dust, acid aerosols and inorganic gases was measured. The overall median inhalable and thoracic aerosol mass concentrations were 1.1mg/m3 (min–max: <0.93–45) and 0.21mg/m3 (min–max: <0.085–11), respectively.
Results There were 308 participants in 2007 with 168 returning subjects in 2010. Overall, we found a statistically significant decline in the DLco of 0.068 mmol/min/kPa/year, adjusted for gender, age, height, weight, smoking status and doctor-diagnosed asthma during the 3-year follow-up (P < 0.01). The change in DLco did not vary significantly between the various job groups. Subjects with respiratory symptoms did not show a larger decline in DLco than those without symptoms.
Conclusions This study indicates a larger than expected decline in the DLco of fertilizer workers during a 3-year follow-up. However, the decline was not related to specific exposures at work, or to possible covariates of exposure.