Thursday, November 03, 2005

Popcorn Worker's Lung (II) - Emergence of the Endemic

BrooklynDodger revealed his IH roots by starting the popcorn workers thread with exposure levels. The Dodger sympathized with the NIOSH team, parsing a pattern of devastating illness in relation to a chemical previously thought benign [diacetyl, or 2,3-butanedione].

The case study of interest would be the emergence of this situation on the ground from the perspective of the health care and public health practitioners. The USA Today article mostly tells the story from a victims perspective.

The quote immediately below is from the MMWR report, which appeared roughly simultaneously with the NEJM paper [same year being simultaneous]. It emerges that there were 8 victims of a very rare and severe condition in 8 years in a small town in Missouri. Who put this together, how, and why did it take that long?

The outbreak is maybe epidemic compared to the general population, but it was an endemic problem in the factory.

The next quote is from the on-the-ground NIOSH investigation. Typical of illness triggered HHE's, the investigators only accessed [had access to?] the current workers. The index cases, and possible additional cases who terminated [were terminated from?] employment for health reasons, are not in the survivor cohort. This practice is an endemic problem.

Therefore, the prevalence rates quoted in the abstract are prevalence among survivors and therefore do not reflect the full force of the toxic agent.

Finally comes the question of active case finding in the remaining facilities, and active measurement of the diacetyl and other exposures. Happening or not?

And even more finally, what's the diacetyl exposure level for consumers of products with artificial butter flavor. Are they still using diacetyl?

>>>>>>>>>>>>>>>>>>>>>>>> http://jama.ama- MMWR. 2002;51:345-347

In May 2000, an occupational medicine physician contacted the Missouri Department of Health and Senior Services (MoDHSS) to report eight cases of fixed obstructive lung disease in former workers of a microwave popcorn factory. Four of the patients were on lung transplant lists. All eight had a respiratory illness resembling bronchiolitis obliterans with symptoms of cough and dyspnea on exertion, had worked at the same popcorn factory (factory A) at some time during 1992-2000, and had spirometric test results that were lower than normal for both FEV1 (forced expiratory volume in 1 second) and FEV1/FVC (forced vital capacity) ratio. Employment durations ranged from 8 months to 9 years. MoDHSS requested assistance from CDC's National Institute for Occupational Safety and Health in evaluating factory A for respiratory hazards to workers.


Of the 116 participating employees who underwent spirometric testing, 31 had abnormal results on spirometry: 10 had low FVC values alone, 11 had airway obstruction alone, and another 10 had airway obstruction and low FVC values. The prevalence of airway obstruction increased with increasing cumulative exposure to diacetyl. The rates of airway obstruction, according to quartiles of increasing exposure, were 10.3 percent, 10.3 percent, 24.1 percent, and 27.6 percent (P for trend=0.03). The proportion of workers with abnormal results on spirometry (airway obstruction or a low FVC value) also increased with increasing cumulative exposure, to 13.8 percent, 24.1 percent, 31.0 percent, and 37.9 percent in successive quartiles (P for trend=0.02). Workers in each quartile of increasing cumulative exposure to diacetyl had decreasing average FEV1 values (Figure 2). The average FEV1 was 4.5 percent, 8.9 percent, and 12.5 percent lower than the predicted value in the second, third, and fourth quartiles of diacetyl exposure, respectively, than in the first quartile.

N Engl J Med. 2002 Aug 1;347(5):330-8.

Clinical bronchiolitis obliterans in workers at a microwave-popcorn plant.

Kreiss K, Gomaa A, Kullman G, Fedan K, Simoes EJ, Enright PL.

Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Morgantown, WVa 26505, USA.

...In May 2000, eight persons who had formerly worked at a microwave-popcorn production plant were reported to have severe bronchiolitis obliterans. No recognized cause was identified in the plant. ... We evaluated the relation between exposures and health-related outcomes by analyzing the rates of symptoms and abnormalities according to current and cumulative exposure to diacetyl, the predominant ketone in artificial butter flavoring and in the air at the plant. ... Of the 135 current workers at the plant, 117 (87 percent) completed the questionnaire. These 117 workers had 2.6 times the expected rates of chronic cough and shortness of breath, according to comparisons with the national data, and twice the expected rates of physician-diagnosed asthma and chronic bronchitis. Overall, the workers had 3.3 times the expected rate of airway obstruction; those who had never smoked had 10.8 times the expected rate. Workers directly involved in the production of microwave popcorn had higher rates of shortness of breath on exertion and skin problems that had developed since they started work than workers in other parts of the plant. There was a strong relation between the quartile of estimated cumulative exposure to diacetyl and the frequency and extent of airway obstruction. ...


From USA Today:

Below is a partial list of factories in the U.S. that reportedly produce microwave popcorn and other snack foods. This list is not meant to imply that any workers at these plants have been injured by exposure to artificial butter flavoring.

CaliforniaConagra Grocery Products, Irvine; Gaslamp Popcorn Company, San Diego ConnecticutLincoln Snacks Company, Stamford; Newman's Own, Westport FloridaBarnard Nut Company, Miami IllinoisCornfields, Gurnee; Gilster-Mary Lee Corp., Chester; Lee Gilster-Mary Corp., Momence; Tee Lee Popcorn, Shannon IndianaAmish Country Popcorn, Berne; Ellis Popcorn Co., West Terre Haute; Family Time Popcorn, Inc., Valparaiso; Gettelfinger Popcorn, Palmyra; Jones Popcorn, New Albany; Kirk's Popcorn Co., Topeka; Vogel Popcorn, Corydon; Weaver Popcorn Co., Markle, Crawfordsville, Huntingburg, Van Buren, Indianapolis & New Richmond; Yoder Popcorn Inc., Topeka IowaAmerican Pop Corn Co., Sioux City; Conagra Foods, Hamburg; Manson Industries, Manson; Noble Distributor, Sac City KentuckyEllis Popcorn Company, Murray MassachusettsNew England Pretzel & Popcorn, Lawrence MinnesotaConagra Foods, Minneapolis MissouriMary Lee Packaging Corp., Perryville NebraskaLincoln Snacks Company, Lincoln PennsylvaniaReist Popcorn Company, Mount Joy South CarolinaInternational Cup Corp., Bennettsville; Soller, Bennettsville

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