The role of Iraqi dust in inducing lung injury in United States soldiers—An interdisciplinary study

Abstract

United States soldiers are returning from the Greater Middle East with respiratory illnesses ranging from new onset asthma to constrictive bronchiolitis. The etiologies of the diseases are unknown. A study was conducted to determine the possible role of local mineral dust in the development of abnormal respiratory illnesses in soldiers during and after deployment in Iraq. A dust sample obtained in proximity to a burn pit in Camp Victory, Iraq (Camp Victory dust) was characterized both chemically and mineralogically. For comparison, a dust sample from Fort Irwin, California (Fort Irwin dust) was also collected. The ability of the dust samples to generate reactive oxygen species (ROS) was quantified, as well as their ability to generate an inflammatory stress response (ISR) in human lung epithelial cells. Both samples are composed of common silicate and carbonate minerals and contain heavy metals with concentration ranges expected for mineral dust. The ISR generated by each sample was within the range of inert material with the minimal stress generated associated with the carbonate phases. The findings based on this one sample suggest that the origin of the disease is not driven by the particles ability to generate ROS. However, it is likely that particle overload and associated complications, or endotoxin contributes extensively to pathogenesis.