side notes:
Judge rules against workers in ‘popcorn-lung’ lawsuit | 2017-10-20 | The Indiana Lawyer
http://www.tandfonline.com/doi/full/10.3109/10408444.2014.930093?src=recsys
... More importantly, even though smokers arguably have the highest peak and cumulative diacetyl exposures of any definable cohort, smoking is not a risk factor for bronchiolitis obliterans. [Dr. F has agreed in this forum with the Critical Reviews in Toxicology, conclusion - “smoking has not been shown to be a risk factor for bronchiolitis (popcorn lung).“]
Akpinar-Elci and Elci claim that “A cluster of such a rare disease as
bronchiolitis obliterans indicates a possible risk factor related to the work environment”. As U.S. Supreme Court Justice Louis Brandeis noted when referring to the benefits of transparency, “sunlight is said to be the best of disinfectants”.
Let us shed some sunlight onto the above claim. First, they failed to note that only three of their alleged nine cases of bronchiolitis obliterans underwent lung biopsy to allow for confirmation of the suspected diagnosis. Of these, only one had findings that supported a possible diagnosis of bronchiolitis obliterans. Second, although
bronchiolitis obliterans is a fixed obstructive disease, there was no difference in the prevalence of obstruction between the diacetyl-exposed workers versus controls in either of the
Akpinar-Elci et al. (2005 Akpinar-Elci M, Stemple KJ, Enright PL, Fahy JV, Bledsoe TA, Kreiss K, Weissman DN. (2005). Induced sputum evaluation in microwave popcorn production workers. Chest, 128, 991–7.
[Crossref],
[PubMed],
[Web of Science ®],
[Google Scholar],
2006 Akpinar-Elci M, Stemple KJ, Elci OC, Dweik RA, Kreiss K, Enright PL. (2006). Exhaled nitric oxide measurement in workers in a microwave popcorn production plant. Int J Occup Env Health, 12, 106–10.
[Google Scholar]) studies of GML workers. Oddly, in neither study do they note that these findings completely contradict those of
Kreiss et al. (2002) Kreiss K, Gomaa A, Kullman G, Fedan K, Simoes E, Enright P. (2002). Clinical bronchiolitis obliterans in workers at a microwave-popcorn plant. N Engl J Med, 347, 330–8.
[Crossref],
[PubMed],
[Web of Science ®],
[Google Scholar], who claimed to have observed a significant relationship between diacetyl exposure and obstruction prevalence in workers at the same facility. Given the fact that
Kreiss et al. (2002) Kreiss K, Gomaa A, Kullman G, Fedan K, Simoes E, Enright P. (2002). Clinical bronchiolitis obliterans in workers at a microwave-popcorn plant. N Engl J Med, 347, 330–8.
[Crossref],
[PubMed],
[Web of Science ®],
[Google Scholar] is considered by Akpinar-Elci et al. to be a seminal study, failure to replicate the results of
Kreiss et al. (2002) Kreiss K, Gomaa A, Kullman G, Fedan K, Simoes E, Enright P. (2002). Clinical bronchiolitis obliterans in workers at a microwave-popcorn plant. N Engl J Med, 347, 330–8.
[Crossref],
[PubMed],
[Web of Science ®],
[Google Scholar] in their studies should warrant some mention in their papers. Similarly, in neither study do the authors inform the reader that in the original GML cohort (
Kreiss et al. 2002 Kreiss K, Gomaa A, Kullman G, Fedan K, Simoes E, Enright P. (2002).
Clinical bronchiolitis obliterans in workers at a microwave-popcorn plant. N Engl J Med, 347, 330–8.[Crossref], [PubMed], [Web of Science ®], [Google Scholar]), 57% of the cohort claimed to have had off-site (mostly farming-related) exposures to “other possible causes of lung disease”, including known inducers of bronchiolitis obliterans, such as nitrogen oxides (silo gas).
Furthermore, the authors are mistaken in suggesting that had we “more carefully” reviewed the findings of their analyses, our conclusions would have been different.
We have reviewed their studies at length, and believe that their claim of “findings that strongly indicate a relationship between occupational butter flavoring exposure and respiratory diseases among popcorn production workers” is desperately over-reaching. In fact, their own papers provide substantially more evidence to the contrary. For example, they found that:
(1)
Sputum characteristics were not related to pulmonary function.
(2)
There were no significant differences in spirometric values between highly exposed workers and the internal reference group.
(3)
The mean FEV1 and FEV1/FVC percent of predicted were both greater than 95% among all popcorn production workers (indicating a healthy workforce).
We find it disingenuous that Akpinar-Elci and Elci would attempt to cloak themselves in the Hippocratic oath.
One could easily argue that a rush to judgment on diacetyl has ushered in the heavy use of replacement chemicals which NIOSH scientists themselves are now claiming appear to be similar to or even more potent than diacetyl (
NIOSH 2011 NIOSH. (2011). Occupational exposure to diacetyl and 2,3-pentanedione. Draft criteria for a recommended standard: Department of Health and Human Services, National Institute for Occupational Safety and Health (NIOSH).
[Google Scholar],
Morgan et al. 2012 Morgan DL, Jokinen MP, Price HC, Gwinn WM, Palmer SM, Flake GP. (2012). Bronchial and bronchiolar fibrosis in rats exposed to 2,3-pentanedione vapors: implications for bronchiolitis obliterans in humans. Toxicol Pathol, 40, 448–65.
[Crossref],
[PubMed],
[Web of Science ®],
[Google Scholar],
Zaccone et al. 2013 Zaccone EJ, Thompson JA, Ponnoth DS, Cumpston AM, Goldsmith WT, Jackson MC, et al. (2013). Popcorn flavoring effects on reactivity of rat airways in vivo and in vitro. JTEH A, 76, 669–89.
[Google Scholar]).
In summary, we stand by our original premise, which is supported by Akpinar-Elci et al.'s own published findings: (1) all the food/flavoring cohorts had significant smoking histories, (2) cigarette smoke contains very high diacetyl levels, (3) none of the diacetyl exposure–response evaluations to date have accounted for this very large non-occupational source of diacetyl, therefore, (4) all such evaluations are inherently flawed (though unintentionally) and should be revisited.