title: Longitudinal decline in pulmonary diffusing capacity among nitrate fertilizer workers.
abstract: BACKGROUND
  This study is part of a 3-year follow-up of lung function among nitrate fertilizer production workers.
  
  
  OBJECTIVE
  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/m(3) (min-max: <0.93-45) and 0.21mg/m(3) (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.
authors: Department of Occupational Medicine and Epidemiology, National Institute of Occupational Health, N-0033 Oslo, Norway.
authors: K H
authors: KH
authors: Hovland
authors: M
authors: M
authors: Skogstad
authors: B
authors: B
authors: Bakke
authors: Ø
authors: Ø
authors: Skare
authors: K
authors: K
authors: Skyberg
mesh_terms: D000328:Adult; D001249:Asthma; D005260:Female; D005308:Fertilizers / Q000009:adverse effects*; D005541:Forced Expiratory Volume; D006801:Humans; D008137:Longitudinal Studies; D008168:Lung / Q000187:drug effects* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000009:adverse effects*; D016273:Occupational Exposure / Q000009:adverse effects*; D009790:Occupations; D011653:Pulmonary Diffusing Capacity / Q000187:drug effects*; D012129:Respiratory Function Tests; D012907:Smoking; D013147:Spirometry; D011795:Surveys and Questionnaires
chemical_list: D005308:Fertilizers; D009566:Nitrates
keywords: Ammonia; diffusion capacity; fertilizer workers; lung function; mineral dust; nitric acid; occupational exposure; spirometry; thoracic aerosols.