Longitudinal decline in pulmonary diffusing capacity among nitrate fertilizer workers

Occup Med (Lond). 2014 Apr;64(3):181-7. doi: 10.1093/occmed/kqt174. Epub 2014 Feb 10.

Abstract

Background: This study is part of a 3-year follow-up of lung function among nitrate fertilizer production workers.

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/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.

Keywords: Ammonia; diffusion capacity; fertilizer workers; lung function; mineral dust; nitric acid; occupational exposure; spirometry; thoracic aerosols..

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Asthma
  • Female
  • Fertilizers / adverse effects*
  • Forced Expiratory Volume
  • Humans
  • Longitudinal Studies
  • Lung / drug effects*
  • Lung / physiopathology
  • Male
  • Middle Aged
  • Nitrates / adverse effects*
  • Occupational Exposure / adverse effects*
  • Occupations
  • Pulmonary Diffusing Capacity / drug effects*
  • Respiratory Function Tests
  • Smoking
  • Spirometry
  • Surveys and Questionnaires

Substances

  • Fertilizers
  • Nitrates