Andrea D. Harrington

Iraq dust is respirable, sharp, and metal-laden and induces lung inflammation with fibrosis in mice via IL-2 upregulation and depletion of regulatory T cells.

Objectives: Determine whether surface dust grab samples taken from a large military base in Iraq are toxic and respirable. Methods: X-ray diffraction for mineral content, x-ray fluorescence for elemental content, in vivo mouse dust challenges for assessment of histological changes, bronchoalveolar lavage for cytokines, polarizing light microscopy for crystals in lung tissue, and Fluorescence Activated Cell Sorting for cell surface and intracellular markers were utilized. Results: Camp Victory, Iraq dust taken during wartime contains respirable particles 2.5 microns in size, constituting particulate matter air pollution. Dust particles are angular and have sharp edges. Trace metals (including titanium) calcium and silicon are present. Mice with airway instillation of dust have polarizable crystals in lung and septate inflammation. Regulatory T cells (CD4+CD25+FOXP3+) are decreased in thymus and spleen. Interleukin-2 (IL-2) is upregulated in bronchoalveolar lavage. Conclusions: Respirable Iraq dust leads to lung inflammation in mice similar to that seen in patients with polarizable crystals, which seem to be titanium.

Titanium and iron in lung of a soldier with nonspecific interstitial pneumonitis and bronchiolitis after returning from Iraq.

To the Editor:The abnormal respiratory illnesses of soldiers after Iraq deployment reported by King et al1 are corroborated by our studies. Their discovery of crystalline material in lung tissue is enhanced by our identification of copper and hotspots of titanium and iron in lung tissue of an affect

Quantification of particle-induced inflammatory stress response: a novel approach for toxicity testing of earth materials

BackgroundReactive oxygen species (ROS) are vital regulators of many cellular functions in the body. The intracellular ROS concentration is highly regulated by a balance between pro-oxidants and anti-oxidants. A chronic excess of pro-oxidants leads to elevated ROS concentrations and inflammation, possibly initiating or enhancing disease onset. Mineral-induced generation of ROS, the role of minerals in upregulating cellular ROS, and their role in the development of several occupational diseases are now widely recognized. However, there is no standard protocol to determine changes in ROS production in cells after exposure to mineral dust or earth materials in general. In this study, a new method for determining the degree of cellular toxicity (i.e., cytotoxicity) of particles is described that will help bridge the gap in knowledge.ResultsBy measuring the production of ROS and the viability of cells, an inflammatory stress response (ISR) indicator is defined. This approach normalizes the ROS upregulation with respect to the number of viable cells at the time of measurement. We conducted experiments on a series of minerals and soils that represent materials that are inert (i.e., glass beads, anatase, and a soil with low trace element content), moderately reactive (i.e., soil with high trace element content), and highly reactive (i.e., pyrite). Inert materials generated the lowest ISR, averaging 350% compared to the control. Acid washed pyrite produced the highest ISR (1,100 fold higher than the control). The measurements conducted as a function of time showed a complex response. Most materials showed an increase in ISR with particle loading.ConclusionsThe amount of cellularly generated ROS and cell viability combined provide a better understanding of particle-induced oxidative stress. The results indicate that some earth materials may solicit an initial burst of ROS, followed by a second phase in which cell viability decreases and ROS production increases, leading to a high ISR value. Hence, measurements conducted over a range of particle loading combined with multiple data measurements up to 24 hours can provide new insights in the possible effect of exposure to earth materials on human health.

Metal-sulfide mineral ores, Fenton chemistry and disease--particle induced inflammatory stress response in lung cells.

The inhalation of mineral particulates and other earth materials, such as coal, can initiate or enhance disease in humans. Workers in occupations with high particulate exposure, such as mining, are particularly at risk. The ability of a material to generate an inflammatory stress response (ISR), a measure of particle toxicity, is a useful tool in evaluating said exposure risk. ISR is defined as the upregulation of cellular reactive oxygen species (ROS) normalized to cell viability. This study compares the ISR of A549 human lung epithelial cells after exposure to well-characterized common metal-sulfide ore mineral separates. The evaluation of the deleterious nature of ore minerals is based on a range of particle loadings (serial dilutions of 0.002m(2)/mL stock) and exposure periods (beginning at 30min and measured systematically for up to 24h). There is a wide range in ISR values generated by the ore minerals. The ISR values produced by the sphalerite samples are within the range of inert materials. Arsenopyrite generated a small ISR that was largely driven by cell death. Galena showed a similar, but more pronounced response. Copper-bearing ore minerals generated the greatest ISR, both by upregulating cellular ROS and generating substantial and sustained cell death. Chalcopyrite and bornite, both containing ferrous iron, generated the greatest ISR overall. Particles containing Fenton metals as major constituents produce the highest ISR, while other heavy metals mainly generate cell death. This study highlights the importance of evaluating the chemistry, oxidation states and structure of a material when assessing risk management.

Rux largely restores lungs in Iraq PM-exposed mice, Up-regulating regulatory T-cells (Tregs)

ABSTRACT Background Military personnel post-deployment to Iraq and Afghanistan have noted new-onset respiratory illness. This studys primary objective was to further develop an animal model of Iraq Afghanistan War Lung Injury (IAW-LI) and to test a novel class of anti-injury drug called RuX. Methods Particulate Matter (PM) samples were obtained in Iraq then characterized by spectromicroscopy. C57BL/6 mice underwent orotracheal instillation with PM, followed by drinkable treatment with RuX. Lung histology, inspiratory capacity (FlexiVent), thymic/splenic regulatory T cell (Treg) number, and whole-lung genomics were analyzed. Results Tracheal instillation of Iraq PM led to lung septate thickening and lymphocytic inflammation. PM-exposed mice had suppression of thymic/splenic regulatory T-cells (Tregs). Drinking RuX after PM exposure attenuated the histologic lung injury response, improved lung inspiratory capacity, and increased Tregs. Pooled whole lung genomics suggest differences among gene expression of IL-15 among control, PM, and PM + RuX groups. Conclusions RuX, a ruthenium and alpha-lipoic acid complex, attenuates lung injury by improving histology and inspiratory capacity via upregulation of Tregs in Iraq PM-exposed C57BL/6. Plausible genomic effects may involve IL-15 whole lung gene expression.

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.