Jet Fuel Exposures in the Military

Abstract

This article introduces a comprehensive collection examining the health effects of jet fuels, highlighting the application of rigorous assessment methods in a military environmental exposure context. It provides a clinically relevant foundation of the state of the science to clinicians, researchers, and policymakers aiming to advance and improve Veteran care.

LEARNING OUTCOMES

• Upon reviewing this manuscript, readers will be able to understand how the Department of Veterans Affairs' (VA) prioritization of military environmental exposure evaluation directly supports improved veteran care.

• Upon reviewing this manuscript, readers will be able to describe the historical progress of the VA's response to military environmental exposure concerns.

The 2020 US Census identified approximately 15.8 million US veterans, representing about 6.1% of this country's adult population.¹ Veterans represent a unique health care population, often requiring specialized care due to the circumstances of their service.^2–4 For many veterans, it is difficult to understand how their service may have impacted their long-term health, especially in the absence of immediate signs or symptoms during their service that may indicate the possibility of chronic health effects. Indeed, veterans' knowledge of harms caused by physical and psychosocial stressors inherent to combat and other duties has been apparent in trends of compensation awarded by the Department of Veterans Affairs (VA), as musculoskeletal injuries, scarring, hearing decrements, and posttraumatic stress disorder (PTSD) are among the most prevalent service-connected conditions.⁵ Further, VA has historically commissioned consensus studies by the National Academies of Science, Engineering, and Medicine to independently assess health effects related to some well-known, deployment-related hazards, such as Agent Orange^6–16 and burn pits,^17,18 to address concerns expressed by veterans and other key stakeholders. However, the potential impact of other military environmental exposures (MEE) has not been fully explored, limiting VA's ability to provide adequate preventive care for veterans.

The Evolution of MEE Concerns

Veteran concerns related to MEE have evolved over time. Historically, media and stakeholder interest in potential deployment-related exposures have led to legislative actions requiring the maintenance of cohort registries and, in some cases, the presumptive service connection of disabilities with established relationships to hazards present in deployed settings. An important example of this was the potential exposure to the tactical herbicide Agent Orange while serving during the Vietnam War. As a result of widespread concern about the potential toxic consequences of Agent Orange and other “Rainbow Herbicides,” the United States passed “The Agent Orange Act of 1991,” requiring the VA to cover various conditions for Vietnam veterans.¹⁹ The legislation also required ongoing, independent review of the scientific and medical literature to determine additional conditions that may be related to the components and contaminants of tactical herbicides.^6–16 These independent reviews were considered by VA in the extension of presumptions of service connection related to service in Vietnam.

In recent years, with the advancement of technology and information sharing, there has been a shift in concerns related to MEE. With improved understanding that exposures can occur as a result of regular military duties, both during deployments and in garrison, increased attention has been given to potential risks of exposures that are inherently tied to military service, not just those that are experienced during combat or in austere environments. For instance, the discovery that drinking water at Camp Lejeune had been contaminated for decades with chlorinated chemicals from drycleaning waste and fuel that leaked from underground storage tanks led to a public outcry that got the attention of US lawmakers. In 2012, President Barack Obama signed into law the “Honoring America's Veterans and Caring for Camp Lejeune Families Act.”²⁰ This legislation was precedence setting in that it not only required VA to provide health care for a number of conditions for those with eligible service at Camp Lejeune but also required last-payer reimbursement for their family members for the covered conditions if they also resided at the base. This scenario brought to the forefront the reality that environmental contamination on military bases can also provide the opportunity for exposures to service members.²¹

The landscape of investigating and providing care and compensation related to MEE changed with the passing of the “Sergeant First Class Heath Robinson Honoring our Promise to Address Comprehensive Toxics (PACT) Act of 2022.”²² The law represented the most comprehensive expansion of care and benefits for veterans in at least three decades.²¹ Specifically, service connection for several diseases related to exposures potentially encountered during deployments were addressed, and requirements to improve the ability to declare connections between MEE and service in the future were outlined. Section 510 of the PACT Act pushed jet fuels to the forefront as a MEE issue, requiring VA to report to Congress on “(1) a discussion of the effect of various different types of jet fuels used by the Armed Forces on the health of individuals by length of exposure,” “(2) an identification of the immediate symptoms of jet fuel exposure that may indicate future health risks,” “(3) a chronology of health safeguards implemented by the Armed Forces intended to reduce the exposure of members of the Armed Forces to jet fuel,” and “(4) an identification of any areas relating to jet fuel exposure about which new research needs to be conducted.”²² This request for information was the first mandated, comprehensive evaluation of the potential impact of this MEE on the health of veterans that Congress has issued to VA.

Defining the Health Impact of Jet Fuel Exposures

Jet fuel exposure is a common concern that VA has tried to address in numerous ways over the years. Although some components of jets fuels, such as benzene,^23–25 toluene,²⁶ and xylenes,²⁷ and combustion products,²⁸ have known toxicities, less is known about the potential long-term health effects related to exposure to these components in mixtures of liquid jet fuels or fuel vapors. In a report by the Institute of Medicine that was commissioned by VA (2005), the independent expert committee was not able to identify any studies of health effects related to exposure to jet fuels that veterans may have been exposed to during the Gulf War.²⁸ The Agency for Toxic Substances and Disease Registry has conducted toxicological assessments on some military jet fuels^26,29 and also noted the lack of epidemiological data with adequate follow-up to observe effects long after the exposures ceased. As interagency collaboration is leveraged for all investigations on MEE, VA has also consulted with DoD on the matter, reviewing limited monitoring data and technical reports to try to glean the best way to inform its providers and claims adjudicators on the adverse outcomes that impacted veterans may face, but in the absence of dedicated resources, these efforts have stopped short of comprehensive evaluation and synthesis of all available data.

The PACT Act has empowered VA to take a more aggressive approach to address concerns related to jet fuel exposure in the military. To fulfill the requirement of submitting the initial report to Congress required under Section 510, VA conducted a systematic review of the occupational jet fuel exposure literature,³⁰ which leveraged existing, peer-reviewed methodology from the US Environmental Protection Agency's Integrated Risk Information System (IRIS) assessments.³¹ To our knowledge, this was the first systematic review of epidemiologic studies examining the health effects related to occupational jet fuel exposures in military and nonmilitary settings that offers weight-of-evidence conclusions about health hazards. Overall, the low quality and sparseness of the available evidence from epidemiologic studies on occupational jet fuel exposure limited our ability to confidently make conclusions about associations for certain health outcomes above the level of slight, which indicates that the data were limited to low-quality studies, and although a consistent link could be observed, significant uncertainty remained. The effects determined to have slight evidence of an association with occupational jet fuel exposure were neurologic, cognitive and behavioral, respiratory, and cancer outcomes. The evidence for all other outcomes was deemed indeterminate.

Because a focused review on studies of military and civilian occupational populations resulted in a limited ability to determine the relationship between jet fuel exposure and specific health outcomes, it was then necessary to consider incorporating other evidence streams. Indeed, it may be possible to gain additional insight by also assessing evidence of human environmental exposures, toxicological data from animal studies, and mechanistic data. Therefore, VA performed an expanded systematic review that integrated data across these evidence streams for multiple health outcomes prioritized based on amount of evidence and potential level of disability. The following supplement published by the Journal of Occupational and Environmental Medicine includes this collection of work, describing the evaluation of the available evidence on neurological and behavioral,³² respiratory,³³ hepatic and renal,³⁴ cardiovascular and hematological,³⁵ immunological,³⁶ reproductive and endocrine,³⁷ and cancer outcomes³⁸ as of March 2025, along with a detailed accounting of the methodology.³⁹

In addition to conducting systematic reviews to best utilize existing evidence, VA is also leading pioneering research to address current gaps identified in the epidemiological studies, specifically in military veterans and service members. The Long-term Impact of Fuel Exposure (LIFE) Study is the largest cohort study to date to investigate the health consequences of occupational jet fuel exposure in the military. This retrospective, tri-service study has two phases. The first phase leverages administrative data from both the VA and the DoD to comprehensively evaluate the health of veterans with certain jet fuel–related occupations compared to those with other duties.⁴⁰ The second phase of the study seeks to identify signature changes in microRNA that result from exposures to jet fuels to better understand some of the mechanisms involved with disease progression. Analyses for the LIFE Study are ongoing, and its findings will be used to shape VA's health care guidance and compensation policies for veterans who were exposed to jet fuels during their service.

Taken together, these efforts illustrate VA's commitment to learning more about MEE and improving the health of impacted veterans long-term. This is a special population with unique exposure potential and complex health care needs. Only through continued collaboration and the incorporation of cutting-edge methods and interdisciplinary research can we meet these needs and achieve VA's mission to fulfill President Lincoln's promise “to care for him who shall have borne the battle, and for his widow, and his orphan” by serving and honoring the nation's veterans and their families.