Acute inhalation toxicity in nine white ibis ( Eudocimus albus ) exposed to theatrical fog containing triethylene glycol and propylene glycol

Abstract

Nine wild American white ibis (Eudocimus albus) were found deceased or were moribund and subsequently euthanized within 24 hours after exposure to theatrical fog containing propylene glycol and triethylene glycol at a Halloween event at a zoological institution. Gross examinations revealed that all birds had congestion, edema, and hemorrhage throughout the lungs. Histologically, all birds had pathologic changes within the trachea and lungs indicative of acute respiratory insult. Microscopic changes in the trachea included segmental to diffuse epithelial attenuation with loss of cilia, alternating with regions of goblet cells filled with abundant mucus. In the lungs, all birds had perivascular edema and degenerative changes to the epithelium lining primary and secondary bronchi including hypereosinophilia and apical cytoplasmic blebbing of bronchial epithelial cells. In addition, in the lungs of 4 birds with longer intervals between exposure and death, there was granulomatous pneumonia, heterophilic perivascular cuffing, and multifocal bronchial epithelial necrosis. Propylene glycol and triethylene glycol were detected in lung and kidney tissues by gas chromatography-tandem mass spectrometry (GC-MS/MS). Traces of oxalic acid were found, along with presence of glycolic acid. While exposure to aerosolized glycols has been shown to cause irritation and minor degenerative changes to the respiratory epithelium in laboratory animals and humans, this study represents a unique investigation into the first reported incidence of acute inhalation toxicity and death following exposure to aerosolized glycol-containing theatrical fog in birds.