HPLC Links Burn Pit Smoke to Vascular and Other Organ Damage

A significant number of U.S. troops and support staff have been stationed at military bases across the Middle East, where many were exposed to smoke and fumes from burn pit (BP) sites (large areas where waste of all kinds was set on fire). Long-term exposure to this smoke has been linked to a wide range of health problems, now grouped under the term chronic multisymptom illness (CMI). Pinning down exactly how many veterans are affected is difficult, given how much locations, conditions, and missions varied, but estimates suggest somewhere between 40 and 60%. Despite how widespread the problem is, what exactly causes CMI is still not well understood. In response, researchers set out to replicate BP combustion and deliver these representative emissions to a whole-body inhalation exposure chamber with Sprague Dawley rats, with plasma samples from the subjects analyzed using high performance liquid chromatography (HPLC). A paper based on this work was published in the journal Particle and Fibre Technology.¹

What is a Burn Pit?

Burn pits became the go-to solution for dealing with the enormous amounts of trash produced on military bases. By some estimates, a single American soldier generates around 10 pounds of waste every day while deployed; on larger bases, that adds up to as much as 85,000 pounds of waste per day.² In addition, everyday base activities (such asvehicle maintenance, construction, and general operations) added even more to the waste pile. All of this was dealt with by dumping it into open pits in the ground and setting it alight, often with jet fuel to keep the fires going. The burning was rarely clean or complete, meaning a thick mix of harmful smoke and fumes was constantly being released into the air. Since 1990, an estimated 250 or so of these burn pits have been in use across the conflicts in Afghanistan and Iraq, with some covering as much as 10 acres.^2-4

What Does Burn Pit Smoke Actually Do to the Body?

The researchers suspected that burn pit smoke might interfere with the body's tiny blood vessels (the microscopic network that plays a crucial role in keeping us healthy). To test this, they built a device that mimicked burn pit conditions, burning a mix of wood, rubber, plastic, and jet fuel. The smoke this produced was a complex cocktail of harmful chemicals and microscopic particles small enough to be inhaled deep into the lungs. Rats were then exposed to this smoke for about 4 hours a day over 2, 3, or 6 days. A day after the last exposure, the researchers examined the rats' blood vessels and collected tissue samples for further analysis. After 3 to 6 days of exposure, the small blood vessels had lost their normal ability to widen in response to the body's signals, a key function for regulating blood flow. On top of that, the vessels became up to 50% more sensitive to signals that cause them to constrict, meaning blood flow could be more easily restricted than normal. Examination of fluid from the lungs also revealed significant inflammation and an influx of immune cells, pointing to serious respiratory damage.

The HPLC analysis showed a greater than 50% rise in levels of a substance called xanthine oxidase, which is known to damage cells through oxidative stress and to interfere with the blood vessels' ability to function properly by disrupting nitric oxide, a molecule that helps keep blood vessels relaxed and healthy. After just 3 days of burn pit smoke exposure, genetic analysis of tissue samples revealed signs of lung inflammation and a disrupted immune response in both the lungs and spleen. The smoke exposure also triggered changes in the brain (specifically in the hippocampus) where genes linked to blood vessel growth and immune cell movement showed unusually high activity.

“These initial microvascular observations,” write the authors of the paper,¹ “demonstrate disruption of typical function and mechanisms that may link pulmonary insult with diverse systemic syndromes characteristic with CMI in veterans.”

The researchers state that future studies must continue to identify the full scope of biologic impacts of military burn pit emission inhalation exposures, their interactions, and contributions to the development of CMI.¹

Read More on Similar Topics
LC-MS/MS Profiling Links PFAS Exposure to Reduced Cognitive Processing Speed in Firefighters

References

1. Nguyen, V.; Ranpara, A.; Goldsmith, W. T. et al. Inhalation Exposure to Surrogate Military Burn Pit Emissions Impairs Systemic Microvascular Function: Linking Pulmonary Insult and Diverse Peripheral Responses. Part Fibre Toxicol. 2026. DOI: 10.1186/s12989-026-00691-8
2. Institute of Medicine. Long-term Health Consequences of Exposure to Burn Pits in Iraq and Afghanistan; The National Academies Press, 2011.
3. Woskie, S. R.; Bello, A.; Rennix, C. et al. Burn Pit Exposure Assessment to Support a Cohort Study of US Veterans of the Wars in Iraq and Afghanistan. J. Occup. Environ. Med. 2023, 65 (6), 449-457.DOI: 10.1097/JOM.0000000000002788
4. Penuelas, V. L.; Lo, D. D. Burn Pit Exposure in Military Personnel and the Potential Resulting Lung and Neurological Pathologies. Front. Environ. Health 2024, 3. DOI: 10.3389/fenvh.2024.1364812