Military exposures research: A state-of-the-art review

Abstract: INTRODUCTION: Military personnel encounter a wide range of environmental and occupational exposures during their service such as burn pit smoke, chemical warfare agents, depleted uranium, jet fuel, radiation, and pesticides. The field of military exposures research seeks to better understand the nature of these exposures and their effects on Veteran and service member health. This state-of-the-art review assesses the breadth and depth of published military exposures research so that stakeholders can identify trends and gaps in this growing field. MATERIALS AND METHODS: An evidence mapping approach was used to perform a literature review of military exposures research published from 1962 to 2024. The search strategy was developed around exposed cohorts: groups of military personnel with a shared potential for exposure to toxic agents. Publications were included if they directly addressed exposures or related health outcomes in military cohorts. Publications were then further categorized by the type of research, and the results were analyzed to build a map of the current military exposures research landscape. RESULTS: Thirty-six exposed cohorts were identified in the literature which were then grouped based on the nature of the exposure event: Wars and Operations (4 cohorts), Occupational Exposures (5), Combat and Combat Training (2), Across Military (2), Ship Exposures (2), Defense Testing (2), Base/Garrison Exposures (9), Toxic Substance Clean-Up and Disposal (5), and Isolated Exposure Events (5). The search identified 2,321 publications that fit the review inclusion criteria. The exposed cohort with the highest number of publications was Gulf War (940, 40.5% of all publications) followed by Vietnam War (277, 11.9%), Post-9/11 Operations in Iraq and Afghanistan (191, 8.2%), Aircraft Mechanics and Ground Support (176, 7.6%), and Munition Emissions and Embedded Fragments (164, 7.1%). Each remaining cohort individually represented < 4% of the literature. Six cohorts appeared only in non-peer-reviewed reports. The type of research best represented was Epidemiology (34.0%) followed by Animal and In Vitro Models (18.8%), Sequelae and Management (17.1%), Reviews and Meta-Analyses (11.7%), Exposure Assessment (9.5%), Toxic Agent Sampling and Analysis (4.3%), and publications from the National Academy of Sciences, Engineering, and Medicine (4.6%). The volume of military exposures research has increased steadily since the early public reports of Gulf War Illness in 1994, with 50% of articles being published after 2008. CONCLUSION: Military exposures research published since 1962 has focused on cohorts from large, high-profile deployments, particularly the Gulf War. Underrepresented cohorts with potential exposures on bases or from military occupations present opportunities for future research. The lack of meaningful exposure assessment data that has been published also points to further research opportunities to specifically improve collection and accessibility of exposure data. This work should be done with a focus on cohorts where research can directly impact Veterans access to benefits and exposure-informed care.