Occup Environ Med 66:105-110 doi:10.1136/oem.2008.039560
  • Original article

A cross-sectional study of lung function and respiratory symptoms among chemical workers producing diacetyl for food flavourings

  1. F G B G J van Rooy1,2,5,5,
  2. L A M Smit1,
  3. R Houba2,
  4. V A C Zaat2,
  5. J M Rooyackers2,3,
  6. D J J Heederik1,4
  1. 1
    Division of Environmental Epidemiology, Institute for Risk Assessment Sciences, Utrecht, The Netherlands
  2. 2
    Netherlands Expertise Centre for Occupational Respiratory Disorders, Utrecht, The Netherlands
  3. 3
    Department of Pulmonology, University Medical Centre Utrecht, Utrecht, The Netherlands
  4. 4
    Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht, Utrecht, The Netherlands
  5. 5
    Arbo Unie Expert Centre for Chemical Risk Management, Utrecht, The Netherlands
  1. F G B G J van Rooy, Division of Environmental Epidemiology, Institute for Risk Assessment Sciences, PO Box 80.178, NL-3508 TD Utrecht, The Netherlands; f.vanrooy{at}
  • Accepted 1 August 2008
  • Published Online First 19 September 2008


Objectives: Four diacetyl workers were found to have bronchiolitis obliterans syndrome. Exposures, respiratory symptoms, lung function and exposure–response relationships were investigated.

Methods: 175 workers from a plant producing diacetyl between 1960 and 2003 were investigated. Exposure data were used to model diacetyl exposure. Lung function and questionnaire data on respiratory symptoms were compared to a general population sample and respiratory symptoms to an internal reference group.

Results: Workers were potentially exposed to acetoin, diacetyl, acetaldehyde and acetic acid. Historic diacetyl exposure ranged from 1.8 to 351 mg/m3, and from 3 to 396 mg/m3 for specific tasks. Diacetyl workers reported significantly more respiratory symptoms compared to the general population sample (continuous trouble with breathing (prevalence ratio (PR) = 2.6; 95% CI 1.3 to 5.1), daily cough (PR = 1.5; 95% CI 1.1 to 2.1), asthma attack (ever) (PR = 2.0; 95% CI 1.2 to 3.4), doctor diagnosed asthma (PR = 2.2; 95% CI 1.3 to 3.8) and asthma attack in the last year (PR = 4.7; 95% CI 1.9 to 11.4)) and to a minimally exposed internal reference group (ever trouble with breathing (PR = 2.8; 95% CI 1.1 to 7.0) and work-related shortness of breath in the last year (PR = 7.5; 95% CI 1.1 to 52.9)). Lung function did not differ between groups. A positive relationship between exposure and FEV1 was found.

Conclusion: The excess of respiratory symptoms in this retrospective cohort suggests that diacetyl production poses an occupational hazard. Limited historical exposure data did not support a quantitative individual diacetyl exposure–response relationship, but our findings suggest that preventive measures are prudent.


  • Funding: This study was supported by a company under a contract which guaranteed the independence of the research group according to criteria set by the Dutch Royal Academy of Sciences (KNAW) in close collaboration with the occupational health service.

  • Competing interests: None.

  • Patient consent: Obtained.