Rodent Study Suggests Diacetyl Harmful to Lungs
A new study shows that exposure to the chemical diacetyl, a component of artificial butter flavoring, can be harmful to the nose and airways of mice. Scientists at the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health, conducted the study because diacetyl has been implicated in causing obliterative bronchiolitis (OB) in humans.
OB is a debilitating but rare lung disease, which has been detected recently in workers who inhale significant concentrations of the flavoring in microwave popcorn packaging plants.
When laboratory mice inhaled diacetyl vapors for three months, they developed lymphocytic bronchiolitis--a potential precursor of OB. None of the mice, however, were diagnosed with OB.
"This is one of the first studies to evaluate the respiratory toxicity of diacetyl at levels relevant to human health," said Daniel L. Morgan, Ph.D., head of the Respiratory Toxicology Group at the NIEHS and co-author on the paper that appears online in the journal, Toxicological Sciences. "Mice were exposed to diacetyl at concentrations and durations comparable to what may be inhaled at some microwave popcorn packaging plants." The study was done in collaboration with Duke University researchers.
The authors conclude that these findings suggest that workplace exposure to diacetyl contributes to the development of OB in humans, but more research is needed.
The National Toxicology Program, headquartered at the NIEHS, plans to do a larger set of studies to provide inhalation toxicity data on artificial butter flavoring and the two major components, diacetyl and another compound called acetoin.
For additional information, visit the NIEHS Web site at www.niehs.nih.gov. For more information about NIH and its programs, visit www.nih.gov.