Repetitive sulfur dioxide exposure in mice models post-deployment respiratory syndrome

Soldiers deployed to Iraq and Afghanistan have a higher prevalence of respiratory symptoms than nondeployed military personnel and some have been shown to have a constellation of findings on lung biopsy termed post-deployment respiratory syndrome (PDRS). Since many of the subjects in this cohort reported exposure to sulfur dioxide (SO2), we developed a model of repetitive exposure to SO2 in mice that phenocopies many aspects of PDRS, including adaptive immune activation, airway wall remodeling, and pulmonary vascular (PV) disease. Although abnormalities in small airways were not sufficient to alter lung mechanics, PV remodeling resulted in the development of pulmonary hypertension and reduced exercise tolerance in SO2-exposed mice. SO2 exposure led to increased formation of isolevuglandins (isoLGs) adducts and superoxide dismutase 2 (SOD2) acetylation in endothelial cells, which were attenuated by treatment with the isoLG scavenger 2-hydroxybenzylamine acetate (2-HOBA). In addition, 2-HOBA treatment or Siruin-3 overexpression in a transgenic mouse model prevented vascular remodeling following SO2 exposure. In summary, our results indicate that repetitive SO2 exposure recapitulates many aspects of PDRS and that oxidative stress appears to mediate PV remodeling in this model. Together, these findings provide new insights regarding the critical mechanisms underlying PDRS.NEW & NOTEWORTHY We developed a mice model of "post-deployment respiratory syndrome" (PDRS), a condition in Veterans with unexplained exertional dyspnea. Our model successfully recapitulates many of the pathological and physiological features of the syndrome, revealing involvement of the ROS-isoLGs-Sirt3-SOD2 pathway in pulmonary vasculature pathology. Our study provides additional knowledge about effects and long-term consequences of sulfur dioxide exposure on the respiratory system, serving as a valuable tool for future PDRS research.

Deployment to Military Bases With Open Burn Pits and Respiratory and Cardiovascular Disease

Importance

Many veterans who served in Afghanistan and Iraq during Operations Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) were deployed to military bases with open burn pits and exposed to their emissions, with limited understanding of the long-term health consequences.

Objective

To determine the association between deployment to military bases where open burn pits were used for waste disposal and the subsequent risk of developing respiratory and cardiovascular diseases.

Design, Setting, and Participants

This retrospective observational cohort study used Veterans Health Administration medical records and declassified deployment records from the Department of Defense to assess Army and Air Force veterans who were deployed between 2001 and 2011 and subsequently received health care from the Veterans Health Administration, with follow-up through December 2020. Data were analyzed from January 2023 through February 2024.

Exposure

Duration of deployment to military bases with open burn pits.

Main Outcomes and Measures

Diagnosis of asthma, chronic obstructive pulmonary disease, interstitial lung disease, hypertension, myocardial infarction, congestive heart failure, ischemic stroke, and hemorrhagic stroke.

Results

The study population included 459 381 OEF and OIF veterans (mean [SD] age, 31.6 [8.7] years; 399 754 [87.0%] male). Median (IQR) follow-up from end of deployment was 10.9 (9.4-12.7) years. For every 100 days of deployment to bases with burn pits, veterans experienced increased adjusted odds for asthma (adjusted odds ratio [aOR], 1.01; 95% CI, 1.01-1.02), chronic obstructive pulmonary disease (aOR, 1.04; 95% CI, 1.02-1.07), hypertension (aOR, 1.02; 95% CI, 1.02-1.03), and ischemic stroke (aOR, 1.06; 95% CI, 0.97-1.14). Odds of interstitial lung disease, myocardial infarction, congestive heart failure, or hemorrhagic stroke were not increased. Results based on tertiles of duration of burn pit exposures were consistent with those from the continuous exposure measures.

Conclusions and Relevance

In this cohort study, prolonged deployment to military bases with open burn pits was associated with increased risk of developing asthma, COPD, and hypertension. The results also point to a possible increased risk in ischemic stroke. The novel ability to use integrated data on deployment and health outcomes provides a model for additional studies of the health impact of environmental exposures during military service.

Improving care for veterans' environmental exposure concerns: applications of the consolidated framework for implementation research in program evaluation

BACKGROUND

Healthcare systems, like the US Department of Veterans Affairs (VA), need policies and procedures for delivering care to special populations including those with environmental exposure concerns. Despite being common and pervasive, especially among Veterans, environmental exposures are largely overlooked by healthcare providers. To successfully implement care for Veterans with military environmental exposure concerns, an understanding of contextual factors impeding care on the provider (e.g., knowledge and beliefs) and organizational (e.g., leadership's priorities) level is needed. Our goal was to conduct an operational needs assessment of providers to examine provider educational needs regarding Veterans' military environmental exposure concerns.

METHODS

In 2020, we surveyed 2,775 VA medical and behavioral health providers. Our cross-sectional assessment was informed by the Consolidated Framework for Implementation Research (CFIR) and assessed barriers and facilitators to the uptake and application of knowledge regarding interdisciplinary care for environmental exposure concerns. The web-based survey was emailed to providers across the United States representing a variety of disciplines and practice settings to reflect the interdisciplinary approach to care for environmental exposures. We used bivariate statistics to investigate the intervention setting, inner setting, and individual characteristics of providers regarding care for environmental exposure concerns.

RESULTS

Approximately one-third of VA medical and behavioral health clinicians report low to no knowledge of environmental exposure concerns. We find 88% of medical and 91% of behavioral health providers report they are ready to learn more about environmental exposures. Half of medical and behavioral health providers report they have access to information on environmental exposures and less than half report care for environmental exposures is a priority where they practice.

CONCLUSIONS

Our findings suggest interdisciplinary providers' knowledge of and discussion with Veterans about environmental exposures may be influenced by contextual factors at the organizational level. Considering individual-level factors and organizational culture is important to consider when supporting care for environmental exposures. Since this needs assessment, VA established targeted programs to improve care related to military environmental exposures in response to legislation; future exploration of these same variables or contextual factors is warranted.

Impact of poor air quality while deployed on respiratory health: a systematic review

INTRODUCTION

British military personnel deploy internationally to areas with high levels of ambient air pollution. Air pollution can cause acute respiratory symptoms which lead to concern about potential long-lasting health effects. There is a requirement for evidence-based policy on chronic respiratory disease associated with military deployments to areas with poor air quality (AQ). This literature review examines the published evidence relating to the development of chronic respiratory disease in military personnel after exposure to poor AQ while deployed.

METHODS

A literature search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Embase, MEDLINE and Global health databases were searched for English language studies published since 2014 examining the respiratory health of military personnel deployed to Southwest Asia since 2001. A quality appraisal of selected articles was conducted using the Critical Appraisals Skills Programme checklist and a descriptive review completed.

RESULTS

Eleven studies were found, eight of which had objective outcome measures. Two prospective cohort studies were included; the remainder of the data were retrospective.

CONCLUSION

High rates of respiratory symptoms are reported by personnel who deploy to areas of poor AQ, giving rise to high levels of concern. Spirometry testing has found mild deficits, mostly of an obstructive nature, in a third of those with ongoing symptoms post deployment. These have not been consistently linked with deployment length. An increased risk of asthma appears to be multi-factorial in aetiology and there is no evidence for an increased risk of chronic obstructive pulmonary disease or histological pathology post deployment. At present, there is no definitive evidence of chronic respiratory disease due to exposure to poor AQ while deployed. Further objective longitudinal studies are required to continue to investigate the association, diagnosis and management of those with ongoing symptoms.

Nontraditional Occupational Exposures to Crude Oil Combustion Disasters and Respiratory Disease Risk: A Narrative Review of Literature

PURPOSE OF REVIEW

Burning of petroleum products has been consistently associated with adverse respiratory health effects. Combustion of crude oil, specifically, produces toxic byproducts, but there have been relatively few studies of health effects. Burning of crude oil is increasingly employed as a means of mitigating environmental disasters despite the potential health risks to workers involved in clean-up efforts. Here, we review epidemiological studies of respiratory effects following unique crude oil burning events to (1) characterize respiratory health effects from this nontraditional occupational exposure and (2) identify approaches used to characterize exposures that could be applied to future disaster-related studies.

RECENT FINDINGS

We searched PubMed and EMBASE for references from inception to January 30, 2023. We also manually screened references cited in eligible articles. We identified 14 eligible publications. Our review suggests that exposure to crude oil combustion has adverse respiratory effects, including reduced lung function and increased occurrence of respiratory symptoms and disease. However, the evidence is inconsistent, and quality of data varied across studies. While some studies used quantitative, modeled exposure estimates, most used self-reported proxies of exposure. Although disasters involving crude oil combustion are relatively rare, limited evidence suggests that some worker populations may be at risk for respiratory effects from burning exposures in disaster settings. Future studies that use improved exposure assessment methods (e.g., personal monitors, remote sensing data) may help further quantify the respiratory risk from crude oil burning exposures.

Deployed Veterans exhibit distinct respiratory patterns and greater dyspnea during maximal cardiopulmonary exercise: A case-control study

BACKGROUND

Exertional dyspnea and exercise intolerance are frequently endorsed in Veterans of post 9/11 conflicts in Southwest Asia (SWA). Studying the dynamic behavior of ventilation during exercise may provide mechanistic insight into these symptoms. Using maximal cardiopulmonary exercise testing (CPET) to experimentally induce exertional symptoms, we aimed to identify potential physiological differences between deployed Veterans and non-deployed controls.

MATERIALS AND METHODS

Deployed (n = 31) and non-deployed (n = 17) participants performed a maximal effort CPET via the Bruce treadmill protocol. Indirect calorimetry and perceptual rating scales were used to measure rate of oxygen consumption ([Formula: see text]), rate of carbon dioxide production ([Formula: see text]), respiratory frequency (f R), tidal volume (VT), minute ventilation ([Formula: see text]), heart rate (HR), perceived exertion (RPE; 6-20 scale), and dyspnea (Borg Breathlessness Scale; 0-10 scale). A repeated measures analysis of variance (RM-ANOVA) model (2 groups: deployed vs non-deployed X 6 timepoints: 0%, 20%, 40%, 60%, 80%, and 100% [Formula: see text]) was conducted for participants meeting valid effort criteria (deployed = 25; non-deployed = 11).

RESULTS

Significant group (η2partial = 0.26) and interaction (η2partial = 0.10) effects were observed such that deployed Veterans exhibited reduced f R and a greater change over time relative to non-deployed controls. There was also a significant group effect for dyspnea ratings (η2partial = 0.18) showing higher values in deployed participants. Exploratory correlational analyses revealed significant associations between dyspnea ratings and fR at 80% (R2 = 0.34) and 100% (R2 = 0.17) of [Formula: see text], but only in deployed Veterans.

CONCLUSION

Relative to non-deployed controls, Veterans deployed to SWA exhibited reduced fR and greater dyspnea during maximal exercise. Further, associations between these parameters occurred only in deployed Veterans. These findings support an association between SWA deployment and affected respiratory health, and also highlight the utility of CPET in the clinical evaluation of deployment-related dyspnea in Veterans.

Repetitive Sulfur Dioxide Exposure in Mice Models Post-Deployment Respiratory Syndrome

Soldiers deployed to Iraq and Afghanistan have a higher prevalence of respiratory symptoms than non-deployed military personnel and some have been shown to have a constellation of findings on lung biopsy termed post-deployment respiratory syndrome (PDRS). Since many of the deployers in this cohort reported exposure to sulfur dioxide (SO 2 ), we developed a model of repetitive exposure to SO 2 in mice that phenocopies many aspects of PDRS, including adaptive immune activation, airway wall remodeling, and pulmonary vascular disease (PVD). Although abnormalities in small airways were not sufficient to alter lung mechanics, PVD was associated with the development of pulmonary hypertension and reduced exercise tolerance in SO 2 exposed mice. Further, we used pharmacologic and genetic approaches to demonstrate a critical role for oxidative stress and isolevuglandins in mediating PVD in this model. In summary, our results indicate that repetitive SO 2 exposure recapitulates many aspects of PDRS and that oxidative stress may mediate PVD in this model, which may be helpful for future mechanistic studies examining the relationship between inhaled irritants, PVD, and PDRS.

Institutional Courage in Healthcare: An Improvement Project Exploring the Perspectives of Veterans Exposed to Airborne Hazards

BACKGROUND

Military environmental exposures and care for subsequent health concerns have been associated with institutional betrayal, or a perception on the part of veterans that the US government has failed to adequately prevent, acknowledge, and treat these conditions and in doing so has betrayed its promise to veterans. Institutional courage is a term developed to describe organizations that proactively protect and care for their members. While institutional courage may be useful in mitigating institutional betrayal, there is a lack of definitions of institutional courage in healthcare from the patient perspective.

METHODS

Using qualitative methods, we sought to explore the notions of institutional betrayal and institutional courage among veterans exposed to airborne hazards (i.e., airborne particulate matter such as open burn pits; N = 13) to inform and improve clinical practice. We performed initial interviews and follow-up interviews with veterans.

RESULTS

Veterans' depictions of courageous institutions contained key themes of being accountable, proactive, and mindful of unique experiences, supporting advocacy, addressing stigma related to public benefits, and offering safety. Veterans described institutional courage as including both individual-level traits and systems or organizational-level characteristics.

CONCLUSIONS

Several existing VA initiatives already address many themes identified in describing courageous institutions (e.g., accountability and advocacy). Other themes, especially views of public benefits and being proactive, hold particular value for building trauma-informed healthcare.

Contributions of particulate and gas phases of simulated burn pit smoke exposures to impairment of respiratory function

OBJECTIVE

Inhalation of smoke from the burning of waste materials on military bases is associated with increased incidences of cardiopulmonary diseases. This study examined the respiratory and inflammatory effects of acute inhalation exposures in mice to smoke generated by military burn pit-related materials including plywood (PW), cardboard (CB), mixed plastics (PL), and a mixture of these three materials (MX) under smoldering (0.84 MCE) and flaming (0.97 MCE) burn conditions.

METHODS

Mice were exposed nose-only for one hour on two consecutive days to whole or filtered smoke or clean air alone. Smoldering combustion emissions had greater concentrations of PM (∼40 mg/m3) and VOCs (∼5-12 ppmv) than flaming emissions (∼4 mg/m3 and ∼1-2 ppmv, respectively); filtered emissions had equivalent levels of VOCs with negligible PM. Breathing parameters were assessed during exposure by head-out plethysmography.

RESULTS

All four smoldering burn pit emission types reduced breathing frequency (F) and minute volumes (MV) compared with baseline exposures to clean air, and HEPA filtration significantly reduced the effects of all smoldering materials except CB. Flaming emissions had significantly less suppression of F and MV compared with smoldering conditions. No acute effects on lung inflammatory cells, cytokines, lung injury markers, or hematology parameters were noted in smoke-exposed mice compared with air controls, likely due to reduced respiration and upper respiratory scrubbing to reduce the total deposited PM dose in this short-term exposure.

CONCLUSION

Our data suggest that material and combustion type influences respiratory responses to burn pit combustion emissions. Furthermore, PM filtration provides significant protective effects only for certain material types.

Short-term PM exposure and social stress cause pulmonary and cardiac dysfunction

Ambient particulate matter (PM) exposure increases risk for cardiopulmonary health problems which may be exacerbated in a stressful environment. Co-exposure to PM and stress characterizes the experience of many deployed military personnel and first responders but has not been thoroughly investigated. This is especially relevant to military personnel who have been exposed to high PM levels in conjunction with stressful military conflict situations. To understand the mechanisms and time-course of the health consequences following burn pit exposure, we exposed mice to moderate levels of ambient PM less than 2.5 μM in diameter (PM_2.5) alone or in combination with psychological stress. We found male mice exposed to PM_2.5 alone or in combination with stress had significantly reduced pulmonary function when subjected to methacholine, indicating increased airway hyperreactivity. These mice experienced increased goblet cell hyperplasia in their lungs, with no change in alveolar density. Mice exposed to PM_2.5 and/or stress also exhibited reduced cardiac contractility, right ventricular (RV) output, and changes in RV capillary density and cardiac inflammatory markers. Taken together, these data indicate that short-term exposure to PM_2.5 with or without stress causes a clear reduction in pulmonary and cardiac function. We believe that this model is well-suited for the study of military and other occupational exposures, and future work will identify potential mechanisms, including the inflammatory progression of these co-exposures.

Characterization of Immunopathology and Small Airway Remodeling in Constrictive Bronchiolitis

Rationale: Constrictive bronchiolitis (ConB) is a relatively rare and understudied form of lung disease whose underlying immunopathology remains incompletely defined. Objectives: Our objectives were to quantify specific pathological features that differentiate ConB from other diseases that affect the small airways and to investigate the underlying immune and inflammatory phenotype present in ConB. Methods: We performed a comparative histomorphometric analysis of small airways in lung biopsy samples collected from 50 soldiers with postdeployment ConB, 8 patients with sporadic ConB, 55 patients with chronic obstructive pulmonary disease, and 25 nondiseased control subjects. We measured immune and inflammatory gene expression in lung tissue using the NanoString nCounter Immunology Panel from six control subjects, six soldiers with ConB, and six patients with sporadic ConB. Measurements and Main Results: Compared with control subjects, we found shared pathological changes in small airways from soldiers with postdeployment ConB and patients with sporadic ConB, including increased thickness of the smooth muscle layer, increased collagen deposition in the subepithelium, and lymphocyte infiltration. Using principal-component analysis, we showed that ConB pathology was clearly separable both from control lungs and from small airway disease associated with chronic obstructive pulmonary disease. NanoString gene expression analysis from lung tissue revealed T-cell activation in both groups of patients with ConB with upregulation of proinflammatory pathways, including cytokine-cytokine receptor interactions, NF-κB (nuclear factor-κB) signaling, TLR (Toll-like receptor) signaling, T-cell receptor signaling, and antigen processing and presentation. Conclusions: These findings indicate shared immunopathology among different forms of ConB and suggest that an ongoing T-helper cell type 1-type adaptive immune response underlies airway wall remodeling in ConB.

Postdeployment Respiratory Health: The Roles of the Airborne Hazards and Open Burn Pit Registry and the Post-Deployment Cardiopulmonary Evaluation Network

Background

Following deployment to the Southwest Asia theater of operations and Afghanistan, many service members and veterans report respiratory symptoms and concerns about their military and environmental exposures. The US Department of Veterans Affairs (VA) established the national Airborne Hazards and Open Burn Pit Registry (AHOBPR) in 2014 to help better understand long-term health conditions that may be related to these exposures.

Observations

The AHOBPR provides an online questionnaire and optional health evaluation performed by a primary care or environmental health clinician. The clinical evaluation provides an opportunity for the service member or veteran to talk with a health care professional about their symptoms, exposures, and potential treatment. Data derived from questionnaire responses and health evaluations facilitate medical surveillance and research. The VA also established a network of specialists, referred to as the Post-Deployment Cardiopulmonary Evaluation Network (PDCEN). The PDCEN identifies veterans within the AHOBPR who self-report certain conditions or have unexplained dyspnea and conducts comprehensive diagnostic evaluations. Primary objectives of PDCEN evaluations are to define respiratory and related conditions that are present, determine whether conditions are related to deployment, and work with the veteran's clinician to identify treatments and/or follow-up care to improve their health. We utilize a case example to illustrate the role of the primary care practitioner in connecting veterans to PDCEN clinical evaluations.

Conclusions

AHOBPR clinical evaluations represent an initial step to better understand postdeployment health conditions. The PDCEN clinical evaluation extends the AHOBPR evaluation by providing specialty care for certain veterans requiring more comprehensive evaluation while systematically collecting and analyzing clinical data to advance the field.

Burn Pit Exposure Is Associated With Increased Sinonasal Disease

OBJECTIVE

The aim of this study was to determine whether self-reported burn pit exposure is associated with increased subjective and objective sinus disease.

DESIGN

A cross-sectional study was performed evaluating consecutive adult patients presenting to a US Military rhinology clinic. Demographics, medical histories, sinonasal quality-of-life scores, and nasal endoscopy examinations were obtained. Participants were divided into three cohorts based on self-reported exposure histories and outcomes compared.

RESULTS

One hundred eighty-six patients met the inclusion criteria, the majority of whom were male. Patients with burn pit exposure had worse Sinonasal Outcome Test-22 scores (49.9) compared with those deployed without burn pit exposure (31.8) or never deployed (31.5). Endoscopic findings demonstrated worse disease within those exposed (Lund-Kennedy score, 3.3) compared with the other cohorts (1.8 and 1.7, respectively).

CONCLUSIONS

These novel findings suggest that deployment-related burn pit exposure is associated with increased subjective and objective sinus disease.

Chemistry, lung toxicity and mutagenicity of burn pit smoke-related particulate matter

BACKGROUND

Open burning of anthropogenic sources can release hazardous emissions and has been associated with increased prevalence of cardiopulmonary health outcomes. Exposure to smoke emitted from burn pits in military bases has been linked with respiratory illness among military and civilian personnel returning from war zones. Although the composition of the materials being burned is well studied, the resulting chemistry and potential toxicity of the emissions are not.

METHODS

Smoke emission condensates from either flaming or smoldering combustion of five different types of burn pit-related waste: cardboard; plywood; plastic; mixture; and mixture/diesel, were obtained from a laboratory-scale furnace coupled to a multistage cryotrap system. The primary emissions and smoke condensates were analyzed for a standardized suite of chemical species, and the condensates were studied for pulmonary toxicity in female CD-1 mice and mutagenic activity in Salmonella (Ames) mutagenicity assay using the frameshift strain TA98 and the base-substitution strain TA100 with and without metabolic activation (S9 from rat liver).

RESULTS

Most of the particles in the smoke emitted from flaming and smoldering combustion were less than 2.5 µm in diameter. Burning of plastic containing wastes (plastic, mixture, or mixture/diesel) emitted larger amounts of particulate matter (PM) compared to other types of waste. On an equal mass basis, the smoke PM from flaming combustion of plastic containing wastes caused more inflammation and lung injury and was more mutagenic than other samples, and the biological responses were associated with elevated polycyclic aromatic hydrocarbon levels.

CONCLUSIONS

This study suggests that adverse health effects of burn pit smoke exposure vary depending on waste type and combustion temperature; however, burning plastic at high temperature was the most significant contributor to the toxicity outcomes. These findings will provide a better understanding of the complex chemical and combustion temperature factors that determine toxicity of burn pit smoke and its potential health risks at military bases.

Postdeployment Respiratory Syndrome in Soldiers With Chronic Exertional Dyspnea

After deployment to Southwest Asia, some soldiers develop persistent respiratory symptoms, including exercise intolerance and exertional dyspnea. We identified 50 soldiers with a history of deployment to Southwest Asia who presented with unexplained dyspnea and underwent an unrevealing clinical evaluation followed by surgical lung biopsy. Lung tissue specimens from 17 age-matched, nonsmoking subjects were used as controls. Quantitative histomorphometry was performed for evaluation of inflammation and pathologic remodeling of small airways, pulmonary vasculature, alveolar tissue and visceral pleura. Compared with control subjects, lung biopsies from affected soldiers revealed a variety of pathologic changes involving their distal lungs, particularly related to bronchovascular bundles. Bronchioles from soldiers had increased thickness of the lamina propria, smooth muscle hypertrophy, and increased collagen content. In adjacent arteries, smooth muscle hypertrophy and adventitial thickening resulted in increased wall-to-lumen ratio in affected soldiers. Infiltration of CD4 and CD8 T lymphocytes was noted within airway walls, along with increased formation of lymphoid follicles. In alveolar parenchyma, collagen and elastin content were increased and capillary density was reduced in interalveolar septa from soldiers compared to control subjects. In addition, pleural involvement with inflammation and/or fibrosis was present in the majority (92%) of soldiers. Clinical follow-up of 29 soldiers (ranging from 1 to 15 y) showed persistence of exertional dyspnea in all individuals and a decline in total lung capacity. Susceptible soldiers develop a postdeployment respiratory syndrome that includes exertional dyspnea and complex pathologic changes affecting small airways, pulmonary vasculature, alveolar tissue, and visceral pleura.

Brain cancer incidence: a comparison of active-duty military and general populations

BACKGROUND

In the USA, brain cancer disproportionately affects young adults. The US military has a younger age structure than the general population and may have differential exposures related to brain cancer. This study aimed to compare the incidence rates of brain cancer in the active-duty military and general populations to provide clues for future etiologic research. The rates between military service branches were also compared.

METHODS

The data for this study were from the Department of Defense's Automated Central Tumor Registry (ACTUR) and the National Cancer Institute's Surveillance, Epidemiology, and End Results 9 (SEER-9) registries. Age- and sex-adjusted incidence rates of malignant neuroepithelial brain cancer among adults 20-54 years of age from 1990-2013 were calculated and compared between the two populations, given as incidence rate ratios (IRRs) with 95% confidence intervals (CIs).

RESULTS

The age and sex-adjusted incidence rate for malignant neuroepithelial brain cancer was significantly lower in the active-duty population than in the US general population (IRR = 0.62, 95% CI,  0.56-0.68). The reduced incidence rate in the active-duty population was observed in men, all races, individuals 20-44 of age, and for all histological subtypes and time periods assessed. There were no significant differences in rates between the military service branches.

CONCLUSION

The incidence rates of neuroepithelial brain cancer were lower in the active-duty military population than the US general population. This study highlights the need for more research to enhance our understanding of variations in brain cancer incidence between these two populations.

Utilization of 19F MRI for Identification of Iraq-Afghanistan War Lung Injury

INTRODUCTION

There is mounting evidence of respiratory problems related to military service in the Middle East in the past two decades due to environmental exposures during deployment (eg, sand storms and burn pits). This pilot study tests the hypothesis that regional lung function in subjects with prior deployment in Iraq and/or Afghanistan with suspected War Lung Injury (WLI) would be worse than subjects with normal lung function.

MATERIALS AND METHODS

Five subjects meeting the inclusion and exclusion criteria were recruited for this pilot study. All subjects underwent spirometry, high-resolution chest computed tomography imaging, and 19F MRI.

RESULTS

While the WLI subjects had normal pulmonary function tests and normal high-resolution chest computed tomography evaluations, their regional lung function from 19F MRI was abnormal with compartments with poor function showing slower filling time constants for ventilation. The scans of suspected WLI subjects show higher fractional lung volume with slow filling compartments similar to patients with chronic obstructive pulmonary disease in contrast to normal subjects.

CONCLUSIONS

This is consistent with our premise that WLI results in abnormal lung function and reflects small airways dysfunction and suggests that we may be able to provide a more sensitive tool for evaluation of WLI suspected cases.

Non-necrotizing granulomatous pneumonitis and chronic pleuritis in soldiers deployed to Southwest Asia

AIMS

Reports of respiratory illnesses among soldiers returning from Southwest Asia have been described. During deployment to Southwest Asia, soldiers are exposed to various respiratory hazards, including dust storms, smoke from burn pits and industrial air pollutants. A few studies have reported increased rates of constrictive bronchiolitis and asthma in these patients. We sought to expand upon the pathological findings in this cohort.

METHODS AND RESULTS

Lung biopsies from veterans of Southwest Asia were identified and re-reviewed. All patients had undergone pulmonary function tests and chest high-resolution CT imaging with no significant findings. Overall, 59 patients with a history of inhalational exposure to at least one of the following were identified: smoke from burn pit, dust storm and sulphur plant fire. Samples included video-assisted thoracoscopic lung biopsies (57 of 59, 96.6%) and cryobiopsies (two of 59, 3.4%). Patients were predominantly male (54 of 59, 91.5%) with an age range of 24-55 years (mean and median = 35). Non-necrotising, poorly formed granulomas were identified in 22 cases (22 of 59, 37.2%). The granulomas were mainly bronchiolocentric and were associated with chronic lymphoplasmacytic bronchiolitis, similar to hypersensitivity pneumonitis (HP). Pleural reaction in the form of focal chronic lymphocytic pleuritis and/or focal pleural adhesions were seen in 43 of 57 (75.4%) biopsies.

CONCLUSIONS

To our knowledge, this is the first study to report pleural reaction as well as features of HP in this population, suggesting that pleural reaction and HP may be part of the spectrum of Southwest Asia deployment-related lung diseases.

A Pilot Study of Airborne Hazards and Other Toxic Exposures in Iraq War Veterans

During their deployment to Iraq in support of Operation Iraqi Freedom (OIF), many Veterans were exposed to a wide array of toxic substances and psychologic stressors, most notably airborne/environmental pollutants from open burn pits. Service members do not deploy whilst unhealthy, but often they return with a multitude of acute and chronic symptoms, some of which only begin to manifest years after their deployment. Our findings, while preliminary in nature, suggest that Iraq War Veterans who participated in our survey reported a decrease in overall physical fitness and increased respiratory clinical symptoms compared with pre-deployment periods. The objective of this report is to provide information that will benefit how combat Veterans are cared for post-deployment. Strategies for a wider and more comprehensive assessment and medical screening process post-deployment are recommended.

Machine Learning Approach for Predicting Past Environmental Exposures From Molecular Profiling of Post-Exposure Human Serum Samples

OBJECTIVE

To develop an approach for a retrospective analysis of post-exposure serum samples using diverse molecular profiles.

METHODS

The 236 molecular profiles from 800 de-identified human serum samples from the Department of Defense Serum Repository were classified as smokers or non-smokers based on direct measurement of serum cotinine levels. A machine-learning pipeline was used to classify smokers and non-smokers from their molecular profiles.

RESULTS

The refined supervised support vector machines with recursive feature elimination predicted smokers and non-smokers with 78% accuracy on the independent held-out set. Several of the identified classifiers of smoking status have previously been reported and four additional miRNAs were validated with experimental tobacco smoke exposure in mice, supporting the computational approach.

CONCLUSIONS

We developed and validated a pipeline that shows retrospective analysis of post-exposure serum samples can identify environmental exposures.

Burden of Cancer Mortality in the Canadian Armed Forces, 1976-2012: A Retrospective Cohort Study

BACKGROUND

Military personnel may have potential exposures to carcinogens during their military careers. However, the generalizability of causal evidence between occupational exposures and cancer outcomes in military personnel is limited. This study aims to describe the epidemiology cause-specific cancer mortality in still serving and released Canadian Armed Forces (CAF) personnel recruited between 1976 and 2012.

METHODS

Data came from the Canadian Forces Cancer and Mortality Study II (CF CAMS II), a record-linkage study of approximately 228,685 CAF Regular Force personnel and Reservists. Sex-stratified standardized mortality ratios (SMR) were calculated for each neoplasm subcategory, with the Canadian general population (CGP) as the reference.

RESULTS

Approximately 1,450 deaths were attributable to neoplasms. Cancer mortality was lower in both men and women with military service (SMR = 0.77 and 0.78, respectively) versus CGP. Females had a significantly lower risk of breast cancer. Males in the cohort had a significantly lower risk of lip, oral cavity and pharynx, digestive organs, respiratory and intrathoracic organs, bone and articular cartilage, and mesothelial and soft-tissue cancers. However, males also had a significantly increased risk for neoplasms of the central nervous system and lymphoid cells, as well as for certain specific cancer diagnoses.

CONCLUSIONS

Current and former CAF personnel were at comparable, or lower risk than, the CGP for cancer-related deaths. However, there was an increased risk for certain neoplasm subcategories and specific cancers.

IMPACT

These findings contribute to the limited body of evidence investigating the link between military service and cancer mortality.

Surfactant Dysfunction in ARDS and Bronchiolitis is Repaired with Cyclodextrins

Objectives

Acute respiratory distress syndrome (ARDS) is caused by many factors including inhalation of toxicants, acute barotrauma, acid aspiration, and burns. Surfactant function is impaired in ARDS and acute airway injury resulting in high surface tension with alveolar and small airway collapse, edema, hypoxemia, and death. In this study, we explore the mechanisms whereby surfactant becomes dysfunctional in ARDS and bronchiolitis and its repair with a cyclodextrin drug that sequesters cholesterol.

Methods

We used in vitro model systems, a mouse model of ARDS, and samples from patients with acute bronchiolitis. Surface tension was measured by captive bubble surfactometry.

Results

Patient samples showed severe surfactant inhibition even in the absence of elevated cholesterol levels. Surfactant was also impaired in ARDS mice where the cholesterol to phospholipid ratio (W/W%) was increased. Methyl-β-cyclodextrin (MβCD) restored surfactant function to normal in both human and animal samples. Model studies showed that the inhibition of surfactant was due to both elevated cholesterol and an interaction between cholesterol and oxidized phospholipids. MβCD was also shown to have anti-inflammatory effects.

Conclusions

Inhaled cyclodextrins have potential for the treatment of ARDS. They could be delivered in a portable device carried in combat and used following exposure to toxic gases and fumes or shock secondary to hemorrhage and burns.

Effects of Psychological, Environmental and Physical Stressors on the Gut Microbiota

Stress, a ubiquitous part of daily human life, has varied biological effects which are increasingly recognized as including modulation of commensal microorganisms residing in the gastrointestinal tract, the gut microbiota. In turn, the gut microbiota influences the host stress response and associated sequelae, thereby implicating the gut microbiota as an important mediator of host health. This narrative review aims to summarize evidence concerning the impact of psychological, environmental, and physical stressors on gut microbiota composition and function. The stressors reviewed include psychological stress, circadian disruption, sleep deprivation, environmental extremes (high altitude, heat, and cold), environmental pathogens, toxicants, pollutants, and noise, physical activity, and diet (nutrient composition and food restriction). Stressors were selected for their direct relevance to military personnel, a population that is commonly exposed to these stressors, often at extremes, and in combination. However, the selected stressors are also common, alone or in combination, in some civilian populations. Evidence from preclinical studies collectively indicates that the reviewed stressors alter the composition, function and metabolic activity of the gut microbiota, but that effects vary across stressors, and can include effects that may be beneficial or detrimental to host health. Translation of these findings to humans is largely lacking at present. This gap precludes concluding with certainty that transient or cumulative exposures to psychological, environmental, and physical stressors have any consistent, meaningful impact on the human gut microbiota. However, provocative preclinical evidence highlights a need for translational research aiming to elucidate the impact of stressors on the human gut microbiota, and how the gut microbiota can be manipulated, for example by using nutrition, to mitigate adverse stress responses.

An Analysis of Reported Dangerous Incidents, Exposures, and Near Misses amongst Army Soldiers

Occupational health and safety incidents occurring in the military context are of great concern to personnel and commanders. Incidents such as "dangerous incidents", "exposures", and "near misses" (as distinct from injuries, illnesses, and fatalities) indicate serious health and safety risks faced by military personnel, even if they do not cause immediate harm. These risks may give rise to harm in the future, if not adequately addressed, and in some cases the incidents may cause latent harm. The purpose of this study was to ascertain the rates and patterns of incidents of these types reported by full time (ARA) and part time (ARES) Australian Army personnel. A retrospective cohort study was performed using self-reported incident data from the Workplace Health, Safety, Compensation and Reporting (WHSCAR) database over a two-year period. Data were analysed descriptively. Of 3791 such incidents, 3636 (96 percent) occurred in ARA and 155 (4 percent) in ARES personnel, somewhat consistent with the proportions of total army person-years served in each (ARA 93 percent; ARES 7 percent). In ARA, 84 percent of these incident types were exposures, 14 percent near misses, and 2 percent dangerous incidents. In ARES, 55 percent of incidents were exposures, 38 percent near misses, and 7 percent dangerous incidents. Soldiers at the rank of 'private' experienced the highest rates of these incident types, in both ARA and ARES. Driving gave rise to more near misses than any other activity, in both populations. Exposures to chemicals and sounds were more common in the ARA than ARES. The ARES reported higher proportions of vehicle near misses and multiple mechanism dangerous incidents than the ARA. The findings of this study can usefully inform development of risk mitigation strategies for dangerous incidents, exposures, and near misses in army personnel.

Lifetime Prevalence of Respiratory Diseases and Exposures Among Veterans of Operation Enduring Freedom and Operation Iraqi Freedom Veterans: Results From the National Health Study for a New Generation of U.S. Veterans

OBJECTIVE

The objective of this study was to determine the prevalence of respiratory exposures and the association between respiratory exposures and respiratory disease among veterans deployed to Operation Enduring Freedom and Operation Iraqi Freedom (OEF/OIF) compared with nondeployed veterans of this era.

METHODS

Data come from a national health survey of 20,563 deployed and nondeployed OEF/OIF era veterans. Prevalence estimates and adjusted odds ratios were calculated. Results were weighted to represent the population.

RESULTS

Prevalence of at least one respiratory exposure was high among both deployed and nondeployed groups (95% and 70%, respectively). In both groups, those with any respiratory exposure were at an increased risk for reporting a respiratory disease.

CONCLUSION

Respiratory exposures are highly prevalent and are associated with increased odds of respiratory diseases among the OEF/OIF era population.

The Unique Health Needs of Post-9/11 U.S. Veterans

This article applies a hazard-based approach to the identification of physical, mental, and psychosocial health needs of post-9/11 veterans. The weaponry, survival, and population of servicemen and women by the military have evolved over time, particularly during the post-9/11 era. It is evident that military hazards and potential exposures vary depending on not only the deployment era but also the specific location and role. Many individual factors may affect the development of health problems. Recent evidence-based literature about post-9/11 veterans' long-term complex health issues is summarized, so occupational health nurses can advocate for the provision of veteran-sensitive care.

MicroRNAs as Novel Biomarkers of Deployment Status and Exposure to Polychlorinated Dibenzo-p-Dioxins/Dibenzofurans

OBJECTIVE

To determine if service members deployed to locations with open air burn pits have different serum microRNA (miRNA) profiles after deployment compared with length-of-service matched, non-deployed individuals. We also tested for correlations between miRNA and serum levels of Polychlorinated Dibenzo-p-Dioxins/Dibenzofurans (PCDD/PCDFs).

METHODS

MiRNAs were isolated and quantified by PCR array. Groups were analyzed for differences in miRNA expression. Correlations between serum miRNA and PCDD/PCDFs were assessed with a linear regression model.

RESULTS

Several miRNAs were differentially expressed after deployment and a partially overlapping set of miRNAs were identified between deployed and non-deployed individuals. Significant correlations between miRNAs and PCDD/PCDFs were identified.

CONCLUSIONS

Serum miRNA levels show a link between deployment to locations with open burn pits and environmental exposures that can take place during deployment.

Detection of Serum microRNAs From Department of Defense Serum Repository: Correlation With Cotinine, Cytokine, and Polycyclic Aromatic Hydrocarbon Levels

OBJECTIVE

The aim of this study was to investigate whether serum samples from the Department of Defense Serum Repository (DoDSR) are of sufficient quality to detect microRNAs (miRNAs), cytokines, immunoglobulin E (IgE), and polycyclic aromatic hydrocarbons (PAHs).

METHODS

MiRNAs were isolated and quantified by polymerase chain reaction (PCR) array. Cytokines and chemokines related to inflammation were measured using multiplex immunoassays. Cotinine and IgE were detected by enzyme-linked immunoassay (ELISA) and PAHs were detected by Liquid Chromatography/Mass Spectroscopy.

RESULTS

We detected miRNAs, cytokines, IgE, and PAHs with high sensitivity. Eleven of 30 samples tested positive for cotinine suggesting tobacco exposure. Significant associations between serum cotinine, cytokine, IgE, PAHs, and miRNA were discovered.

CONCLUSION

We successfully quantified over 200 potential biomarkers of occupational exposure from DoDSR samples. The stored serum samples were not affected by hemolysis and represent a powerful tool for biomarker discovery and analysis in retrospective studies.

Burn Pit Emissions Exposure and Respiratory and Cardiovascular Conditions Among Airborne Hazards and Open Burn Pit Registry Participants

OBJECTIVE

The aim of this study was to determine how burn pit emissions exposure is associated with the incidence of respiratory and cardiovascular conditions.

METHODS

We examined the associations between assumed geographic and self-reported burn pit emissions exposure and respiratory and cardiovascular outcomes in participants of the Airborne Hazards and Open Burn Pit Registry.

RESULTS

We found significant dose-response associations for higher risk of self-reported emphysema, chronic bronchitis, or chronic obstructive pulmonary disease with increased days of deployment within 2 miles of selected burn pits (P-trend = 0.01) and self-reported burn pit smoke exposure (P-trend = 0.0005).

CONCLUSIONS

We found associations between burn pit emissions exposure and higher incidence of post-deployment self-reported respiratory and cardiovascular conditions, but these findings should be interpreted with caution because the surrogate measurements of burn pit emissions exposure in this analysis may not reflect individual exposure levels.

The Role of Iraqi Dust in Inducing Lung Injury in United States Soldiers-An Interdisciplinary Study

United States soldiers are returning from the Greater Middle East with respiratory illnesses ranging from new onset asthma to constrictive bronchiolitis. The etiology of the diseases is 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, (CVD) was characterized both chemically and mineralogically. For comparison, a dust sample from Fort Irwin, California, (FID) 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 comprised 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 contribute extensively to pathogenesis.

Respiratory symptoms among Swedish soldiers after military service abroad: association with time spent in a desert environment

Introduction: The aim of this paper was to study whether Swedish soldiers who have served abroad had a higher prevalence of respiratory symptoms than the general population and, if this was the case, also to study whether this was associated with time spent in a desert environment. Methods:The prevalence of respiratory symptoms among 1,080 veterans from Kosovo and Afghanistan was compared with that in almost 27,000 subjects from a general population sample, using propensity score matching and logistic regression. Results:The prevalence of wheeze (16.3 vs. 12.3%), wheeze without a cold (11.1 vs. 8.0%), nocturnal coughing (26.6 vs. 20.1%) and chronic bronchitis (12.3 vs. 6.8%) was significantly higher among soldiers than controls (p < 0.05). A dose-response-related association was found between time spent in a desert environment and wheeze, wheeze with breathlessness and wheeze when not having a cold. Having been exposed to desert storms was related to nocturnal cough and chronic bronchitis. Conclusion:Swedish soldiers who had served abroad had a higher prevalence of wheeze and cough than a control group from the general population. The association between being exposed to a desert environment and respiratory symptoms indicates that further protective measures should be introduced for military personnel serving in a desert environment.

Ultrafine Particle Distribution and Chemical Composition Assessment during Military Operative Trainings

(1) Background: The assessment of airborne particulate matter (PM) and ultrafine particles (UFPs) in battlefield scenarios is a topic of particular concern; (2) Methods: Size distribution, concentration, and chemical composition of UFPs during operative military training activities (target drone launches, ammunition blasting, and inert bomb impact) were investigated using an electric low-pressure impactor (ELPI+) and a scanning electron microscope (SEM), equipped with energy-dispersive spectroscopy (EDS); (3) Results: The median of UFPs, measured for all sampling periods and at variable distance from sources, was between 1.02 × 10³ and 3.75 × 10³ particles/cm³ for drone launches, between 3.32 × 10³ and 15.4 × 10³ particles/cm³ for the ammunition blasting and from 7.9 × 10³ to 1.3 × 10⁴ particles/cm³ for inert launches. Maximum peak concentrations, during emitting sources starting, were 75.5 × 10⁶ and 17.9 × 10⁶ particles/cm³, respectively. Particles from the drone launches were predominantly composed of silicon (Si), iron (Fe) and calcium (Ca), and those from the blasting campaigns by magnesium (Mg), sulphur (S), aluminum (Al), iron (Fe), barium (Ba) and silicon (Si); (4) Conclusions: The investigated sources produced UFPs with median values lower than other anthropogenic sources, and with a similar chemical composition.

Military small arms fire in association with acute decrements in lung function

OBJECTIVE

After introduction of unleaded ammunition, Norwegian Armed Forces received reports of acute respiratory symptoms in soldiers after exposure to fumes from firing the standard weapon, HK416. The aim of the present study was to examine lung function before and after exposure to fumes from HK416 in a double-blinded standardised study design using three different types of ammunition.

METHODS

Fifty-four healthy, non-smoking male volunteers (19-62 years) fired the weapons for 60 min with either leaded, unleaded or 'modified' unleaded ammunition. Gaseous and particulate emissions were monitored. Spirometry and exhaled nitric oxide (eNO) were performed within 14 days before (T0), shortly after (T1) and 24 hours after (T2) shooting. Methacholine provocation and diffusing capacity of carbon monoxide (DLCO) were carried out at T0 and T2.

RESULTS

The mean forced expiratory volume in 1 s on a group level was significantly reduced both at T1 and T2 compared with T0, with means and 95% CI of 226 mL (158 to 294 mL) and 285 mL (218 to 351 mL), respectively. The same significant pattern was seen for DLCO, forced vital capacity and eNO. The methacholine test indicated a slight increase in bronchial hyper-reactivity. However, there were no significant differences between types of ammunition used.

CONCLUSION

Exposure to fumes from military weapons might be a respiratory hazard for soldiers who do live-fire training regularly or are in a closed combat environment.

Iraq and Afghanistan Veterans report symptoms consistent with chronic multisymptom illness one year after deployment

Many Veterans returning from service in Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) experience chronic pain. What is not known is whether for some OIF/OEF Veterans this pain is part of a larger condition of diffuse multisystem symptoms consistent with chronic multisymptom illness (CMI). We use data from a prospective longitudinal study of OIF/OEF Veterans to determine the frequency of CMI. We found that 1 yr after deployment, 49.5% of OIF/OEF Veterans met criteria for mild to moderate CMI and 10.8% met criteria for severe CMI. Over 90% of Veterans with chronic pain met criteria for CMI. CMI was not completely accounted for either by posttraumatic stress disorder or by predeployment levels of physical symptoms. Veterans with symptoms consistent with CMI reported significantly worse physical health function than Veterans who did not report symptoms consistent with CMI. This study suggests that the presence of CMI should be considered in the evaluation of OIF/OEF Veterans. Further, it suggests the pain management for these Veterans may need to be tailored to take CMI into consideration.

Airborne Dioxins, Furans, and Polycyclic Aromatic Hydrocarbons Exposure to Military Personnel in Iraq

OBJECTIVES

The objective of this study was to use ambient polycyclic aromatic hydrocarbon (PAH), polychlorinated dibenzo-p-dioxins (PCDD), and polychlorinated dibenzofurans (PCDF) concentrations measured at Joint Base Balad in Iraq in 2007 to identify the sources of these species and their spatial patterns.

METHODS

The ratios of the measured species were compared with literature data for likely emission sources. Using the multiple site measurements on specific days, contour maps have been drawn using inverse distance weighting (IDW).

RESULTS

These analyses suggest multiple sources, including the burn pit (primarily a source of PCDD/PCDFs), the transportation field (primarily as source of PAHs), and other sources of PAHs that include aircraft, space heating, and diesel power generation.

CONCLUSIONS

The nature and locations of the sources were identified. PCDD/PCDFs were emitted by the burn pit. Multiple PAH sources exist across the base.

Proposed Iraq/Afghanistan War-Lung Injury (IAW-LI) Clinical Practice Recommendations: National Academy of Sciences' Institute of Medicine Burn Pits Workshop

High rates of respiratory symptoms (14%) and new-onset asthma in previously healthy soldiers (6.6%) have been reported among military personnel post-deployment to Iraq and Afghanistan. The term Iraq/Afghanistan War-Lung Injury (IAW-LI) is used to describe the constellation of respiratory diseases related to hazards of war, such as exposure to burning trash in burn pits, improvised explosive devices, and sandstorms. Burnpits360.org is a nonprofit civilian website which voluntarily tracks medical symptoms among soldiers post-deployment to the Middle East. Subsequent to initiation of the Burnpits360.org website, the Department of Veterans Affairs started the Airborne Hazards and Open Burn Pit registry. This paper: (a) analyzes the latest 38 patients in the Burnpits360.org registry, validated by DD214 Forms; (b) compares strengths and weaknesses of both registries as outlined at the National Academy of Sciences Institute of Medicine Burn Pits Workshop;

Biological monitoring of Italian soldiers deployed in Iraq. Results of the SIGNUM project

BACKGROUND

Leukemia/lymphoma cases reported in 2001 among United Nation soldiers or peacekeepers deployed to the Balkans aroused alert on the exposure to depleted uranium. Recent epidemiological studies carried out in different European countries among peacekeepers who served in the Balkans failed to demonstrate a higher than expected risk of all cancers but, mostly due to their limitations in size and follow up time, leave open the debate on health risk of depleted uranium. The aim of SIGNUM (Study of the Genotoxic Impact in Military Units) was to identify potential genotoxic risk associated with the exposure to depleted uranium or other pollutants in the Italian Army military personnel deployed in Iraq.

METHODS

Blood and urine samples were collected before and after the deployment from 981 Italian soldiers operating in Iraq in 2004-2005. As, Cd, Mo, Ni, Pb, U, V, W, and Zr were determined in urine and serum. DNA-adducts, 8-hydroxy-2'-deoxyguanine and micronuclei frequency were evaluated in blood lymphocytes. Three different genetic polymorphisms, GSTM1, XRCC1, OGG1 were analyzed.

RESULTS

Significant T0-T1 reduction in the total concentration of uranium, increases for Cd, Mo, Ni, Zr, and decreases for As, Pb, W, and V in urine and plasma were observed. Increases in oxidative alterations and in micronuclei frequency, included in the range of values of non-occupationally exposed populations, were observed at the end of the period of employment.

CONCLUSIONS

Our results did not detect any toxicologically relevant variation of DNA-damage biomarkers related to the deployment in the operational theater.