Military burn pits were large, open-air garbage fires used by the U.S. armed forces to dispose of waste at bases in Iraq, Afghanistan, and other conflict zones. The largest, at Joint Base Balad in Iraq, covered more than 25 acres and burned through 100 to 200 tons of solid waste every day. Millions of service members breathed in the toxic smoke these fires produced, and the health consequences have shaped veterans’ policy for a generation.
How Burn Pits Worked
Without reliable waste management infrastructure in combat zones, the military defaulted to the simplest option: digging a large pit near a base, filling it with trash, and setting it on fire. Jet fuel was commonly used as an accelerant. The fires burned at relatively low temperatures, which is a critical detail. High-temperature incineration can break down many toxic compounds, but low-temperature, open-air burning does the opposite. It creates a denser, more chemically complex smoke.
Nearly everything a military base generated went into these pits. That included chemicals, paints, medical and human waste, computers and electronics, plastic water bottles, munitions, uniforms, tires, batteries, and even vehicles. The result was a thick, toxic smog that blanketed surrounding areas, often drifting directly into living and working quarters where troops spent months or years of their deployments.
What Was in the Smoke
Because so many different materials burned together at low temperatures, the smoke contained a cocktail of dangerous compounds. Researchers have identified cancer-causing chemicals, volatile organic compounds, dioxins, furans, formaldehyde, hydrogen cyanide, carbon monoxide, sulfur dioxide, and nitrogen dioxide in burn pit emissions. Heavy metals, including lead, were measured at concentrations far exceeding the EPA’s air quality safety limits.
Lung tissue samples taken from exposed veterans tell a more granular story. Biopsies have revealed not just particulate dust but also residues of burned jet fuel and oxidized metals like titanium lodged deep in lung tissue. These particles trigger inflammation and scarring in the small airways, a process that can continue long after the original exposure ends.
Health Conditions Linked to Exposure
The health effects of burn pit exposure span the respiratory and cardiovascular systems, and likely extend further. A large cohort study found that for every 100 days a veteran spent deployed to a base with burn pits, the odds of developing asthma, chronic obstructive pulmonary disease (COPD), and high blood pressure all increased. There was also a possible elevated risk of ischemic stroke, though the data on that connection is still emerging.
One of the most distinctive conditions tied to burn pit exposure is constrictive bronchiolitis, a disease where the smallest airways in the lungs become scarred and narrowed. It’s rare, serious, and notoriously difficult to diagnose. Soldiers with the condition typically report being unable to keep up with physical fitness standards due to shortness of breath during exertion, yet their standard lung function tests often come back normal or only mildly abnormal. Chest X-rays are almost always clean. Even CT scans catch abnormalities in only about a quarter of cases. In many patients, the disease is only confirmed through a surgical lung biopsy, which reveals fibrous thickening and narrowing in the majority of small airways examined.
This diagnostic difficulty has been a major source of frustration. Veterans who feel genuinely sick but whose routine tests look fine have historically faced skepticism from both military and civilian doctors. The disease doesn’t show up on the tests most physicians would order first, which delayed recognition of the problem for years.
The Scale of Exposure
The number of people affected is enormous. As of early 2025, nearly 4.4 million veterans and service members have signed up for the VA’s Airborne Hazards and Open Burn Pit Registry. That figure reflects both the widespread use of burn pits across multiple theaters of war and growing awareness among veterans that their deployments may have caused lasting health damage.
Isolating the specific contribution of burn pits to any individual veteran’s health problems remains a scientific challenge. Service members in Iraq and Afghanistan were simultaneously exposed to ambient desert dust, diesel exhaust, and other airborne hazards. Many also used tobacco. Researchers have noted that the chemical mixture in burn pit smoke differs from typical urban air pollution, containing toxicants not normally present in civilian environments, but untangling these overlapping exposures in any single person’s medical history is difficult.
The PACT Act and Presumptive Coverage
For years, veterans exposed to burn pits had to individually prove that their illness was connected to their service, a burden of proof that was often impossible to meet. The PACT Act, signed into law in 2022, changed this by establishing a list of “presumptive” conditions. If you served in a qualifying location and later develop one of these conditions, the VA presumes it was caused by your service. You no longer have to prove the link yourself.
The presumptive cancers include brain cancer, glioblastoma, gastrointestinal cancers, kidney cancer, lymphoma, melanoma, pancreatic cancer, reproductive cancers, respiratory cancers, and cancers of the head and neck. The presumptive respiratory illnesses include asthma diagnosed after service, COPD, chronic bronchitis, emphysema, constrictive bronchiolitis, interstitial lung disease, pulmonary fibrosis, sarcoidosis, chronic sinusitis, chronic rhinitis, and granulomatous disease.
This legislation was the result of years of advocacy by veterans like Army Reserve Captain Le Roy Torres, who was exposed to the burn pit at Joint Base Balad during a deployment in late 2007 and spent years struggling to get the VA to acknowledge his resulting health problems. His experience was shared by thousands of others who encountered the same bureaucratic resistance.
What Screening Looks Like
If you’re a veteran concerned about burn pit exposure, the first practical step is enrolling in the Airborne Hazards and Open Burn Pit Registry through the VA. This creates a record of your service locations and health concerns. From there, you can apply for VA health care and file a disability claim.
The clinical evaluation process can be involved, particularly for conditions like constrictive bronchiolitis that don’t appear on standard tests. A normal chest X-ray or spirometry result does not rule out burn pit-related lung disease. If you have persistent shortness of breath during exercise that seems out of proportion to your test results, that pattern itself is a recognized feature of burn pit lung injury. High-resolution CT scanning, cardiopulmonary exercise testing, and in some cases lung biopsy may be needed to reach a diagnosis. Veterans who feel dismissed by initial normal results should be aware that this gap between symptoms and standard test findings is well documented in the medical literature.