Burn pits are open-air sites the U.S. military used to incinerate waste at bases in Iraq, Afghanistan, and other deployment zones from the 1990s through the 2010s. They burned nearly everything a base produced, from food scraps and wood to plastics, medical waste, chemicals, munitions, and human waste, often in trenches or pits doused with jet fuel. Hundreds of thousands of service members lived and worked near these pits, sometimes for months or years, breathing smoke that carried a toxic mix of particulates and chemical compounds now linked to cancers, chronic lung disease, and other serious conditions.
What Was Burned and Why
Military bases in combat zones generate enormous volumes of waste with no access to municipal landfills or commercial incinerators. Burn pits became the default solution. Materials thrown into the pits included chemicals, paint, petroleum and lubricant products, plastics, Styrofoam, rubber, metal and aluminum cans, medical and human waste, munitions and unexploded ordnance, wood, and food waste. Essentially, anything a base needed to get rid of went into the pit.
The pits operated around the clock at many locations, producing thick smoke that drifted across living quarters, dining areas, and workspaces. Unlike a controlled industrial incinerator that reaches high, consistent temperatures and filters exhaust, an open-air pit burns unevenly. Much of the material smolders rather than fully combusting.
Why Open-Air Burning Is So Toxic
The health danger of burn pits comes down to incomplete combustion. When waste smolders at lower temperatures instead of burning cleanly, it releases far higher concentrations of harmful byproducts. Lab research simulating burn pit conditions found that smoldering combustion (around 510°C) produced roughly 10 times more particulate matter and 5 times more volatile organic compounds than flaming combustion at higher temperatures (around 640°C). That means the thick, slow-burning smoke drifting across a military base carried dramatically more pollutants than a hotter, more efficient fire would have.
Lung biopsies from soldiers who were healthy before deployment but developed breathing problems afterward revealed burned oxidized metals, carbonaceous materials, and polycyclic aromatic hydrocarbons, all compounds found in burn pit smoke, embedded in their lung tissue. The biopsies also showed scarring and a condition called constrictive bronchiolitis, where the smallest airways become permanently narrowed.
Where Burn Pits Were Used
Burn pits operated across a wide geographic footprint tied to U.S. military operations from 1990 through 2021. Countries and regions where service members may have been exposed include Iraq, Afghanistan, Kuwait, Saudi Arabia, Bahrain, Oman, Qatar, the United Arab Emirates, Somalia, Djibouti, Jordan, Lebanon, Syria, Uzbekistan, Yemen, and Egypt. The broader Southwest Asia theater of operations and associated airspaces and waterways, including the Persian Gulf, Arabian Sea, Red Sea, Gulf of Aden, and Gulf of Oman, are also covered under the VA’s registry. Joint Base Balad in Iraq operated one of the largest known burn pits, but hundreds of smaller sites existed across these regions.
Respiratory Disease Linked to Exposure
The strongest evidence ties burn pit exposure to chronic lung and airway disease. A study tracking over 75,000 military personnel from 2001 to 2013 found that up to 5% developed new-onset asthma, and combat deployment increased that risk by 24 to 30%. Among veterans deployed specifically to Iraq and Afghanistan, the incidence of new-onset asthma reached as high as 14%.
The trend showed up at a population level too. Between 2003 and 2011, asthma prevalence among more than 760,000 veterans nearly tripled, rising from 1.1% to 3.1%. That increase outpaced the rise in COPD and interstitial lung disease in the same population. A smaller study of 31 non-smoking soldiers who developed respiratory symptoms during or after deployment found that 21 of them showed measurable airway hyperresponsiveness, meaning their airways reacted abnormally to irritants and constricted more easily than healthy airways would.
Cancers Linked to Burn Pit Exposure
The VA now recognizes a long list of cancers as “presumptive” conditions for veterans exposed to burn pits, meaning the government assumes the exposure caused the cancer rather than requiring the veteran to prove a direct link. The list spans multiple organ systems:
- Head, neck, and brain: glioblastoma and other brain cancers, plus cancers of the scalp, face, mouth, throat, and larynx
- Gastrointestinal: cancers of the esophagus, stomach, small intestine, colon, liver, pancreas, spleen, and salivary glands
- Kidney and urinary tract: renal cell carcinoma, bladder cancer, and ureter cancer
- Blood and lymphatic system: acute and chronic leukemias, multiple myeloma, lymphomas (including Hodgkin’s and non-Hodgkin’s), and myelodysplastic syndromes
- Reproductive cancers of any type
- Respiratory cancers of any type
- Melanoma, including melanomas of the eye
The PACT Act and VA Benefits
For years, veterans exposed to burn pits struggled to get their health conditions recognized by the VA. That changed in 2022 with the PACT Act (Promise to Address Comprehensive Toxics Act), the most significant expansion of VA toxic exposure benefits in decades. The law established presumptive status for burn pit-related conditions, removing the burden on individual veterans to prove their illness was caused by their service.
Beyond the cancers listed above, the PACT Act covers a range of respiratory and pulmonary illnesses as presumptive conditions: asthma diagnosed after service, chronic bronchitis, COPD, emphysema, constrictive bronchiolitis, interstitial lung disease, pulmonary fibrosis, sarcoidosis, granulomatous disease, chronic rhinitis, chronic sinusitis, and pleuritis. Veterans who served in the covered locations and time periods can file claims for these conditions without needing to establish a direct connection between their specific deployment and their diagnosis.
The VA also maintains an Airborne Hazards and Open Burn Pit Registry where veterans and service members can document their exposures and health concerns, which helps track long-term patterns across the exposed population.