Analysis of Postdeployment Serum Samples Identifies Potential Biomarkers of Exposure to Burn Pits and Other Environmental Hazards

Military and occupational exposures among Veterans in the Million Veteran Program by survey self-report: a descriptive study

OBJECTIVE

We aimed to characterise self-reported military and occupational exposures including Agent Orange, chemical/biological warfare agents, solvents, fuels, pesticides, metals and burn pits among Veterans in the Department of Veterans Affairs Million Veteran Program (MVP).

METHODS

MVP is an ongoing longitudinal cohort and mega-biobank of over one million US Veterans. Over 500 000 MVP participants reported military exposures on the baseline survey, and over 300 000 reported occupational exposures on the lifestyle survey. We determined frequencies of selected self-reported occupational exposures by service era, specific deployment operation (1990-1991 Gulf War, Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF)), service in a combat zone and occupational categories. We also explored differences in self-reported exposures by sex and race.

RESULTS

Agent Orange exposure was mainly reported by Vietnam-era Veterans. Gulf War and OEF/OIF Veterans deployed to a combat zone were more likely to report exposures to burn pits, chemical/biological weapons, anthrax vaccination and pyridostigmine bromide pill intake as compared with non-combat deployers and those not deployed. Occupational categories related to combat (infantry, combat engineer and helicopter pilot) often had the highest percentages of self-reported exposures, whereas those in healthcare-related occupations (dentists, physicians and occupational therapists) tended to report exposures much less often. Self-reported exposures also varied by race and sex.

CONCLUSIONS

Our results demonstrate that the distribution of self-reported exposures varied by service era, demographics, deployment, combat experience and military occupation in MVP. Overall, the pattern of findings was consistent with previous population-based studies of US military Veterans.

Metabolomics and proteomics in occupational medicine: a comprehensive systematic review

BACKGROUND

Occupational biomonitoring is essential for assessing health risks linked to workplace exposures. The use of 'omics' technologies, such as metabolomics and proteomics, has become crucial in detecting subtle biological alterations induced by occupational hazards, thereby opening novel avenues for biomarker discovery.

AIMS

This systematic review aims to evaluate the application of metabolomics and proteomics in occupational health.

METHODS

Following the PRISMA guidelines, we conducted a comprehensive search on PubMed, Scopus, and Web of Science for original human studies that use metabolomics or proteomics to assess occupational exposure biomarkers. The risk of bias was assessed by adapting the Cochrane Collaboration tool and the Newcastle-Ottawa Quality Assessment Scale.

RESULTS

Of 2311 initially identified articles, 85 met the eligibility criteria. These studies were mainly conducted in China, Europe, and the United States of America, covering a wide range of occupational exposures. The findings revealed that metabolomics and proteomics approaches effectively identified biomarkers related to chemical, physical, biomechanical, and psychosocial hazards. Analytical methods varied, with mass spectrometry-based techniques emerging as the most prevalent. The risk of bias was generally low to moderate, with specific concerns about exposure measurement and confounding factors.

CONCLUSIONS

Integrating metabolomics and proteomics in occupational health biomonitoring significantly advances our understanding of exposure effects and facilitates the development of personalized preventive interventions. However, challenges remain regarding the complexity of data analysis, biomarker specificity, and the translation of findings into preventive measures. Future research should focus on longitudinal studies and biomarker validation across diverse populations to improve the reliability and applicability of occupational health interventions.

Burn pit-related smoke causes developmental and behavioral toxicity in zebrafish: Influence of material type and emissions chemistry

Combustion of mixed materials during open air burning of refuse or structural fires in the wildland urban interface produces emissions that worsen air quality, contaminate rivers and streams, and cause poor health outcomes including developmental effects. The zebrafish, a freshwater fish, is a useful model for quickly screening the toxicological and developmental effects of agents in such species and elicits biological responses that are often analogous and predictive of responses in mammals. The purpose of this study was to compare the developmental toxicity of smoke derived from the burning of 5 different burn pit-related material types (plywood, cardboard, plastic, a mixture of the three, and the mixture plus diesel fuel as an accelerant) in zebrafish larvae. Larvae were exposed to organic extracts of increasing concentrations of each smoke 6-to-8-hr post fertilization and assessed for morphological and behavioral toxicity at 5 days post fertilization. To examine chemical and biological determinants of toxicity, responses were related to emissions concentrations of polycyclic hydrocarbons (PAH). Emissions from plastic and the mixture containing plastic caused the most pronounced developmental effects, including mortality, impaired swim bladder inflation, pericardial edema, spinal curvature, tail kinks, and/or craniofacial deformities, although all extracts caused concentration-dependent effects. Plywood, by contrast, altered locomotor responsiveness to light changes to the greatest extent. Some morphological and behavioral responses correlated strongly with smoke extract levels of PAHs including 9-fluorenone. Overall, the findings suggest that material type and emissions chemistry impact the severity of zebrafish developmental toxicity responses to burn pit-related smoke.

Military burn pit exposure and airway disease: Implications for our Veteran population

Millions of veterans have been exposed to burn pit smoke during combat deployments throughout the last three decades. Toxic compounds present in burn pit fumes that may cause or exacerbate upper and lower airway diseases include dioxins, polyaromatic hydrocarbons, and particulate matter, among others. There have been several observational studies evaluating the potential role of burn pit exposure in the development of a multitude chronic health conditions, and the veterans Administration has established the Airborne Hazards and Open Burn Pit Registry in 2014. However, specific causality of airway disease from burn pits has been difficult to prove, and there are multiple barriers toward etiologic research. Preclinical models have demonstrated airway dysfunction and inflammation but modeling human exposures remains challenging. Here, we review the current literature on the potential impact of burn pit exposure on chronic airway disease.

Impact of gulf war toxic exposures after mild traumatic brain injury

Chemical and pharmaceutical exposures have been associated with the development of Gulf War Illness (GWI), but how these factors interact with the pathophysiology of traumatic brain injury (TBI) remains an area of study that has received little attention thus far. We studied the effects of pyridostigmine bromide (an anti-nerve agent) and permethrin (a pesticide) exposure in a mouse model of repetitive mild TBI (r-mTBI), with 5 impacts over a 9-day period, followed by Gulf War (GW) toxicant exposure for 10 days beginning 30 days after the last head injury. We then assessed the chronic behavioral and pathological sequelae 5 months after GW agent exposure. We observed that r-mTBI and GWI cumulatively affect the spatial memory of mice in the Barnes maze and result in a shift of search strategies employed by r-mTBI/GW exposed mice. GW exposure also produced anxiety-like behavior in sham animals, but r-mTBI produced disinhibition in both the vehicle and GW treated mice. Pathologically, GW exposure worsened r-mTBI dependent axonal degeneration and neuroinflammation, increased oligodendrocyte cell counts, and increased r-mTBI dependent phosphorylated tau, which was found to colocalize with oligodendrocytes in the corpus callosum. These results suggest that GW exposures may worsen TBI-related deficits. Veterans with a history of both GW chemical exposures as well as TBI may be at higher risk for worse symptoms and outcomes. Subsequent exposure to various toxic substances can influence the chronic nature of mTBI and should be considered as an etiological factor influencing mTBI recovery.

Approaches for assessing performance of high-resolution mass spectrometry-based non-targeted analysis methods

Non-targeted analysis (NTA) using high-resolution mass spectrometry has enabled the detection and identification of unknown and unexpected compounds of interest in a wide range of sample matrices. Despite these benefits of NTA methods, standardized procedures do not yet exist for assessing performance, limiting stakeholders’ abilities to suitably interpret and utilize NTA results. Herein, we first summarize existing performance assessment metrics for targeted analyses to provide context and clarify terminology that may be shared between targeted and NTA methods (e.g., terms such as accuracy, precision, sensitivity, and selectivity). We then discuss promising approaches for assessing NTA method performance, listing strengths and key caveats for each approach, and highlighting areas in need of further development. To structure the discussion, we define three types of NTA study objectives: sample classification, chemical identification, and chemical quantitation. Qualitative study performance (i.e., focusing on sample classification and/or chemical identification) can be assessed using the traditional confusion matrix, with some challenges and limitations. Quantitative study performance can be assessed using estimation procedures developed for targeted methods with consideration for additional sources of uncontrolled experimental error. This article is intended to stimulate discussion and further efforts to develop and improve procedures for assessing NTA method performance. Ultimately, improved performance assessments will enable accurate communication and effective utilization of NTA results by stakeholders.

Use of Biomarkers to Assess Environmental Exposures and Health Outcomes in Deployed Troops

OBJECTIVE

This paper provides an overview of our Military Biomarkers Research Study (MBRS) designed to assess whether biomarkers can be used to retrospectively assess deployment exposures and health impacts related to deployment environmental exposures.

METHODS

The MBRS consists of four phases. Phase I was a feasibility study of stored sera. Phase II looks at associations between exposures and biomarkers. Phase III examines relationships of biomarkers and health outcomes, and Phase IV investigates in vitro biomarker changes associated with exposures to chemicals of interest. This paper briefly summarizes work already published and introduces the new reports contained in this supplement.

RESULTS

Novel biomarkers were identified. These were associated with deployment exposures.

CONCLUSIONS

Significant associations were noted between deployment exposures, microRNA biomarkers and metabolomic biomarkers, and deployment health outcomes.