Deployment to Military Bases With Open Burn Pits and Respiratory and Cardiovascular Disease

Abstract

Importance: Many veterans who served in Afghanistan and Iraq during Operations Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) were deployed to military bases with open burn pits and exposed to their emissions, with limited understanding of the long-term health consequences.

Objective: To determine the association between deployment to military bases where open burn pits were used for waste disposal and the subsequent risk of developing respiratory and cardiovascular diseases.

Design, setting, and participants: This retrospective observational cohort study used Veterans Health Administration medical records and declassified deployment records from the Department of Defense to assess Army and Air Force veterans who were deployed between 2001 and 2011 and subsequently received health care from the Veterans Health Administration, with follow-up through December 2020. Data were analyzed from January 2023 through February 2024.

Exposure: Duration of deployment to military bases with open burn pits.

Main outcomes and measures: Diagnosis of asthma, chronic obstructive pulmonary disease, interstitial lung disease, hypertension, myocardial infarction, congestive heart failure, ischemic stroke, and hemorrhagic stroke.

Results: The study population included 459 381 OEF and OIF veterans (mean [SD] age, 31.6 [8.7] years; 399 754 [87.0%] male). Median (IQR) follow-up from end of deployment was 10.9 (9.4-12.7) years. For every 100 days of deployment to bases with burn pits, veterans experienced increased adjusted odds for asthma (adjusted odds ratio [aOR], 1.01; 95% CI, 1.01-1.02), chronic obstructive pulmonary disease (aOR, 1.04; 95% CI, 1.02-1.07), hypertension (aOR, 1.02; 95% CI, 1.02-1.03), and ischemic stroke (aOR, 1.06; 95% CI, 0.97-1.14). Odds of interstitial lung disease, myocardial infarction, congestive heart failure, or hemorrhagic stroke were not increased. Results based on tertiles of duration of burn pit exposures were consistent with those from the continuous exposure measures.

Conclusions and relevance: In this cohort study, prolonged deployment to military bases with open burn pits was associated with increased risk of developing asthma, COPD, and hypertension. The results also point to a possible increased risk in ischemic stroke. The novel ability to use integrated data on deployment and health outcomes provides a model for additional studies of the health impact of environmental exposures during military service.

Figure 1.. Cohort Enrollment Flowchart

DOD indicates Department of Defense; OEF, Operation Enduring Freedom; OIF, Operation Iraqi Freedom; VHA, Veterans Health Administration.

Figure 2.. Associations of Open Burn Pit Exposure With Respiratory and Cardiovascular Disease Outcomes in a Cohort of US Military Veterans (N = 459 381)

All odds ratios (ORs) are adjusted for age at Veterans Health Administration enrollment, sex (male or female), race and ethnicity (Black or not Black), region (Northeast, Midwest, South, West), median income of Census tract, percentage with a bachelor’s degree in Census tract, body mass index (calculated as weight in kilograms divided by height in meters squared; >30 or ≤30), cigarette smoking (never, always, or mixed), Veterans Health Administration enrollment priority (service connected or disability, low income, low priority or high copay), branch of service (Army or Air Force), rank (officer, enlisted, or unknown), year of entry for Veterans Health Administration care, deployment duration, square of deployment duration, and cube of deployment duration.