Popcorn workers' lung

You've probably never heard of bronchiolitis obliterans and you certainly don't want to have it. The name tells the story. The bronchioles are the smaller airway tubes that transport oxygen and carbon dioxide to and from the portions of your lungs where the gases are exchanged in the blood. If you obliterate those small tubes, well, you figure it out. The condition is debilitating and sometimes fatal. As I said, you don't want it.

Want it or not, that's the fate of dozens of workers in factories that make manufacture microwave popcorn or the artificial butter flavor that goes into the popcorn. One has already died and several are on lists awaiting lung transplants. This is a newly discovered condition in some ways -- we've known about it for a little more than five years (see this NIOSH Alert; .pdf)-- but in other ways we've known about it for too long without doing anything about it. Anything like what? Like OSHA issuing recommendations or protections to safeguard workers. OSHA has in fact done almost nothing.

The chemical culprit here is not completely certain. It seems to be either a substance called diacetyl, the chief constituent of artificial butter flavor, or something closely connected to diacetyl, either a by-product or something that is present along with it. The first cases appeared in a Missouri microwave popcorn plant in 1999 (more details of this story can be found at the terrific website of the Scientific Knowledge and Public Policy [SKAPP]).

OSHA's response was perfunctory. NIOSH took it more seriously (NIOSH is the chronically underfunded occupational health federal research agency as opposed to OSHA, which is the regulatory agency). They quickly identified high levels of diacetyl in the plant and found high rates of chronic cough, shortness of breath, asthma or chronic bronchitis, compared to the general population. Pulmonary function tests verified the existence of some kind of respiratory risk in the workforce. NIOSH issued interim recommendations and advised the workers to wear respirators because the actions taken by the company were not sufficient to protect them. Here is what happened next, according to Michaels, Morgan and Montforton's version at the SKAPP site:

Recognizing that exposure to artificial butter flavor was not limited to the one Missouri popcorn plant, OSHA and NIOSH each took steps to address the problem. The quality of their responses, despite the seriousness of the hazard, could not be more different. NIOSH applied a traditional public health approach, collecting extensive information about the distribution and determinants of lung disease in other popcorn plants and conducting laboratory studies to better understand the chemical hazard itself. In order to carry out their field investigations, NIOSH developed sampling and analytical methods for measuring exposure to flavoring-related chemicals. The agency scientists measured exposure to butter flavoring vapors at 10 microwave popcorn facilities and assessed the prevalence of respiratory impairment among many of the workers. Through the development of science-based approaches to reducing exposure, NIOSH attempted to prevent additional cases of occupational lung disease.

NIOSH examined the effects of exposure through experiments on laboratory animals. In the first of these studies, rats were exposed to airborne concentrations of butter flavoring for a single, six-hour period. The researchers were alarmed to discover significant lung damage among rats whose exposure was "not extraordinary when compared with levels measured in the workplace." According to the study's lead investigator, Dr. Ann Hubbs, the findings were "the most dramatic cases of cell death ever seen." NIOSH scientists then conducted a study in which rats were exposed to pure diacetyl and found similar results. A toxicological study of guinea pigs exposed to pure diacetyl found exposure to the chemical caused adverse effects to respiratory tissue and structure.

[snip]

In contrast to the NIOSH scientists' efforts to identify the hazard and the prevalence of disease, OSHA's response has been trivial. When faced with a hazard for which no standard has been set, OSHA has the authority to issue an emergency temporary standard or to invoke the "general duty clause" and require employers to reduce or eliminate clear hazards. OSHA selected neither of these options. Despite significant "bodies in the morgue" evidence, OSHA maintains that "a cause-effect relationship between diacetyl and bronchiolitis obliterans has not been established, as food-processing workers with this lung disease were also exposed to other flavoring agents."

In September, 2002 OSHA's Regional Office in Kansas City (Region VII) entered "an agreement establishing an alliance" with The Popcorn Board, the trade association representing popcorn manufacturers. This move was part of a larger effort by OSHA to form alliances with corporations, trade associations, and other organizations, to voluntarily develop and share information regarding worker health and safety. OSHA's Assistant Secretary reported in February 2004 that the agency had forty-six national and 105 regional alliances. There are no specific requirements for forming an alliance with OSHA and by design, the agreements "do not include an enforcement component."

If you don't work in a popcorn factory you may be tempted to shake your head about the lack of care for worker health and go on about your business. There is a lot of bad stuff in the world today and this is another example. But there is suspicion the problem is wider than just "popcorn workers' lung," as the condition is coming to be called. Many other food industry workers may also be at risk because diacetyl is used to make artifical flavors in candy, pastries, frozen foods and pet foods. More and more cases are being identified now that there is recognition of the problem. The big question is whether it isjust diacetyl or other ingredients are involved. Of over 1000 flavoring ingredients used in food manufacture thought to represent a respiratory hazard , NIOSH has established recommended limits and OSHA permissible limits in a total of only 46. Whether there is a hazard when you make microwave popcorn at home is unknown.

Faced with this lack of response, workers have sought a traditional remedy: they are suing the companies. So far more than $100 million has been awarded by juries or through settlements. In the course of this litigation it was discovered that as far back as 1993 one of the manufacturers of diacetyl found results later rediscovered by NIOSH in its animal experiments. The studies were never published or publicly released.

More frivolous lawsuits, I guess. Just like the frivolous lung condition, bronchiolitis obliterans.