Whole-body inhalation of nano-sized carbon black: a surrogate model of military burn pit exposure

Neuroinflammation and Brain Health Risks in Veterans Exposed to Burn Pit Toxins

Military burn pits, used for waste disposal in combat zones, involve the open-air burning of waste materials, including plastics, metals, chemicals, and medical waste. The pits release a complex mixture of occupational toxic substances, including particulate matter (PM), volatile organic compounds (VOCs), heavy metals, dioxins, and polycyclic aromatic hydrocarbons (PAHs). Air pollution significantly impacts brain health through mechanisms involving neuroinflammation. Pollutants penetrate the respiratory system, enter the bloodstream, and cross the blood-brain barrier (BBB), triggering inflammatory responses in the central nervous system (CNS). Chronic environmental exposures result in sustained inflammation, oxidative stress, and neuronal damage, contributing to neurodegenerative diseases and cognitive impairment. Veterans exposed to burn pit toxins are particularly at risk, reporting higher rates of respiratory issues, neurological conditions, cognitive impairments, and mental health disorders. Studies demonstrate that Veterans exposed to these toxins have higher rates of neuroinflammatory markers, accelerated cognitive decline, and increased risks of neurodegenerative diseases. This narrative review synthesizes the research linking airborne pollutants such as PM, VOCs, and heavy metals to neuroinflammatory processes and cognitive effects. There is a need for targeted interventions to mitigate the harmful and escalating effects of environmental air pollution exposures on the CNS, improving public health outcomes for vulnerable populations, especially for Veterans exposed to military burn pit toxins.

Risk of myeloproliferative neoplasms among U.S. Veterans from Korean, Vietnam, and Persian Gulf War eras

The Promise to Address Comprehensive Toxics (PACT) Act expanded U.S. Veterans' health care and benefits for conditions linked to service-connected exposures (e.g., Burn Pits, Agent Orange). However, myeloproliferative neoplasms (MPN) are not recognized as presumptive conditions for Veterans exposed to these toxic substances. This study evaluated the development of MPN among U.S. Veterans from the Korean, Vietnam, and Persian Gulf War eras. This retrospective cohort study included 65 425 Korean War era Veterans; 211 927 Vietnam War era Veterans; and 214 007 Persian Gulf War era Veterans from January 1, 2006, to January 26, 2023. Veterans with MPN, thrombosis, bleeding, and cardiovascular risk factors were identified through ICD-9 and -10 codes. Veterans from the Persian Gulf War era had the highest risk of developing MPN compared with Veterans from the Korean and Vietnam War eras, hazard ratio (HR) 4.92, 95% confidence interval (CI) 4.20-5.75 and HR 2.49, 95% CI 2.20-2.82, both p < .0001, respectively. Vietnam War era Veterans also had a higher risk of MPN development compared with Korean War era Veterans, HR 1.97, 95% CI 1.77-2.21, p < .0001. Persian Gulf War era Veterans were diagnosed with MPN at an earlier age, had higher risks of thrombosis and bleeding, and had lower survival rates compared with Korean War and Vietnam War era Veterans. This study reinforces evidence that environmental and occupational hazards increase the risk of clonal myeloid disorders and related complications, impacting overall survival with MPN. Limitations include the inability to confirm clonality and fully verify deployment and exposure status.

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.