User:DavidLang1973/Diacetyl

Diacetyl

Diacetyl is known to cause the lung disease bronchiolitis obliterans in those individuals exposed to it in an occupational setting.

In the year 2000 8 cases of bronchiolitis obliterans were detected in former employees of a microwave popcorn plant. Many of these individuals had initially been misdiagnosed as having other pulmonary diseases such as COPD and asthma initially. NIOSH investigated the worksite and suggested that artificial butter flavoring containing diacetyl was the most likely causative agent for the cases of bronchiolitis obliterans. Follow up investigations at the plant revealed that 25% of employees had abnormal spirometry exams. The plant effectively implemented changes reducing air concentrations of diacetyl by 1 to 3 orders of magnitude in the years following. A stabilization of respiratory symptoms was seen after this point in those who had been exposed to high levels of diacetyl. However, declines in lung function as measured by spirometry continued. Other studies also found cases of bronchiolitis obliterans in workers at 4 other microwave popcorn production facilities. Additionally further studies have demonstrated a large increase in abnormal spirometry values in workers exposed to flavoring chemicals with a clear dose-response relationship.

Biochemical Toxicity of Diacetyl

Significant laboratory evidence points to the toxicity of diacetyl. Diacetyl has been shown to alter the amino acid arginine which could interfere with protein structure and function. Additionally diacetyl can bind to DNA and form guanosine adducts which can cause DNA uncoiling and cell death. In vitro studies on human cells also suggest that diacetyl alters the structure and function of the extracellular matrix and modifies epithelial cell responses to growth factors. Human cells exposed to diacetyl also increase secretion of substance P which causes mucus hypersecretion, airway smooth muscle contraction, and edema. Studies in rats have demonstrated significant airway epithelial damage and necrosis after exposure to diacetyl.