title: Occupational lung disease risk and exposure to butter-flavoring chemicals after implementation of controls at a microwave popcorn plant.
abstract: OBJECTIVE
  After an outbreak of severe lung disease among workers exposed to butter-flavoring chemicals at a microwave popcorn plant, we determined whether or not lung disease risk declined after implementation of exposure controls.
  
  
  METHODS
  National Institute for Occupational Safety and Health staff performed eight serial cross-sectional medical and industrial hygiene surveys at the plant from November 2000 through August 2003. Medical surveys included standardized questionnaires and spirometry testing. Industrial hygiene surveys measured levels of production-related air contaminants, including butter-flavoring chemicals such as diacetyl. All diacetyl concentrations above detectable limits were corrected for the effects of absolute humidity and days to sample extraction.
  
  
  RESULTS
  Ventilation and isolation of the production process resulted in one to three orders of magnitude reductions in diacetyl air concentrations in different areas of the plant. Workers with past high exposures had stable chest symptoms over time; nasal, eye, and skin irritation symptoms declined. New workers had lower symptom prevalences and higher lung function than workers with past high exposures, and they did not worsen over time. In workers who had at least three spirometry tests, those with past high exposures were more likely to experience rapid declines in lung function than new workers.
  
  
  CONCLUSIONS
  Implemented controls lowered exposures to butter-flavoring chemicals and decreased lung disease risk for much of the plant workforce. Some workers with continuing potential for intermittent, short-term peak and measurable time-weighted exposures remain at risk and should use respiratory protection and have regularly scheduled spirometry to detect rapid lung function declines that may be work-related. Close follow-up of such workers is likely to yield additional information on risks due to peak and time-weighted exposure levels.
authors.affiliation: Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, 1095 Willowdale Rd., MS H-2800, Morgantown 26505, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Kanwal
authors.forename: Greg
authors.initials: G
authors.lastname: Kullman
authors.forename: Kathleen B
authors.initials: KB
authors.lastname: Fedan
authors.forename: Kathleen
authors.initials: K
authors.lastname: Kreiss
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000395:Air Pollutants, Occupational / Q000032:analysis / Q000633:toxicity*; D003430:Cross-Sectional Studies; D003931:Diacetyl / Q000032:analysis / Q000633:toxicity*; D005260:Female; D005511:Food Handling; D006801:Humans; D008171:Lung Diseases / Q000139:chemically induced*; D008297:Male; D008875:Middle Aged; D009314:National Institute for Occupational Safety and Health, U.S.; D009784:Occupational Diseases / Q000139:chemically induced*; D016273:Occupational Exposure / Q000009:adverse effects* / Q000032:analysis; D012129:Respiratory Function Tests; D014481:United States; D014691:Ventilation; D055815:Young Adult
chemical_list: D000395:Air Pollutants, Occupational; D003931:Diacetyl