Quoting from:
http://www.usatoday.com/money/general/2002/06/20/popcorn-factory.htm
Is butter flavoring ruining popcorn workers' lungs?
JASPER, Mo. — When the days turn humid in this farming
town, the air becomes thick with the smell of butter from
the Gilster-Mary Lee plant, a microwave-popcorn factory
and one of the area's largest employers. At night, when
the buildings' lights are ablaze, some residents say
they've seen a yellowish cloud emanate from the building
and fill the dark sky. For years, no one here complained
much about the odor or the fumes, figuring those were
harmless prices to pay for prosperity. But a growing
number of workers say the cause of that aroma is
destroying their lungs. Some former workers are afflicted
with a rare lung disease believed to be caused by
inhaling a substance never suspected as an on-the-job
hazard: the butter flavoring in microwave popcorn.
See the whole article here:
http://www.usatoday.com/money/general/2002/06/20/popcorn-factory.htm
Quoting from:
http://www.cdc.gov/niosh/02-128.html
NIOSH Evaluates Worker Exposures
at a Popcorn Plant in Missouri
The Centers for Disease Control and Prevention's (CDC)
National Institute for Occupational Safety and Health
(NIOSH) is working with management, employees,
State health officials, and others to assess workers'
potential risk for a serious lung disease from occupational
exposures at a company's popcorn packaging plant
in Jasper, Missouri. NIOSH has made interim
recommendations to reduce exposures as further study
continues.
From 1992 to 2000, eight former workers of the
Gilster-Mary Lee popcorn plant in Jasper, Missouri, developed
a rare lung disease called bronchiolitis obliterans. The
disease was severe enough for some workers to cause
them to be placed on lung transplant lists. In August 2000,
the Missouri Department of Health asked NIOSH to
determine if these cases of lung disease were due to an
exposure at the plant, and if any current workers were
at risk. After preliminary surveys were completed, NIOSH
recommended that all workers in microwave popcorn
production at the plant wear respiratory protection.
In November 2000, NIOSH conducted voluntary tests
of workers at the plant including confidential
questionnaires, breathing tests, and chest x-rays.
Current workers had chronic cough and shortness of breath
2.6 times as often as would be expected based on
national surveys. Breathing tests showed abnormally low
airflow 3.3 times as often as would be expected. About
twice as many workers as would be expected had been
told by their physicians that they had asthma or chronic
bronchitis.
In November 2000, NIOSH also measured the air
concentrations of dust and some of the ingredients of butter
flavoring, including diacetyl, a common ingredient in
artificial butter flavoring. Workers who spent more time in
areas with higher air concentrations of these substances
were more likely to have abnormal airflow in their
breathing tests. Higher exposures over time were
associated with lower airflow.
The testing results led NIOSH to make recommendations
for improvements to the ventilation of the plant. The
company made these changes, and repeated measurements
showed that the amount of dust and flavoring
ingredients in the air of the plant decreased significantly.
NIOSH also reemphasized use of respirators by
microwave popcorn production workers.
NIOSH repeated testing of current workers in April and
August 2001. Some workers had excessive declines in
their breathing tests despite the improvements in the
ventilation of the plant. It is not clear if the abnormal
declines in breathing tests are due to the earlier higher
exposures to airborne dust and flavoring ingredients or if
the lower air concentrations may still be too high.
NIOSH recommended that the company completely isolate
the sources of flavoring and dust in the air to prevent
further exposure of workers. The company is presently
implementing the necessary changes. In tests at NIOSH,
laboratory rats that breathed high concentrations of
vapors from the flavoring developed significant airway
damage in their lungs. A component of the flavoring,
diacetyl, was used as a marker for exposure because
it is easy to measure, but it is still unclear what role
diacetyl may or may not play in the development of
respiratory illness in workers exposed to the flavoring.
NIOSH, in cooperation with Gilster-Mary Lee, will
continue to monitor workers' lung function until it is no longer
decreasing faster than would be expected with normal
aging. NIOSH will also continue tests of air levels to
assess the effectiveness of engineering changes made
by the plant.
NIOSH has worked extensively with employees, the
community, the company, and health professionals to
disseminate its findings and recommendations. In
addition to immediate individual notification to workers of their
test results, NIOSH held town meetings in Jasper, Missouri,
in September 2001, in order to share its interim
findings with workers and others in the community,
emphasize the importance of respirator use by microwave
production workers, and encourage continued participation
in medical testing as the investigation continues.
NIOSH also presented its interim findings and
recommendations to local health care providers in
September 2001.
The current data indicate that bronchiolitis obliterans
occurring in former workers of this plant is most likely due
to the workers' occupational exposure to inhaled
flavoring vapors. Further research is needed to conclusively
identify the cause and the circumstances under which the
risk occurs. NIOSH is conducting surveys of other
companies that use flavorings to see if other workers are
at risk. These efforts will enable the development of
guidelines for safe use of flavorings by all companies.
The current investigation focuses on issues of worker
safety. NIOSH is not aware of any evidence to suggest
danger to consumers in the preparation and
consumption of microwave popcorn.