Study links long-term health risks to burn pit exposure in military veterans

Study links long-term health risks to burn pit exposure in military veterans

In a recent study published inJAMA network openedResearchers examined the relationship between length of deployment at military bases that used open burn pits and the likelihood of diagnosing veterans with respiratory or cardiovascular disease.

The study found that prolonged deployment to bases with open burn pits is associated with a slightly increased risk of developing chronic obstructive pulmonary disease (COPD), asthma, ischemic stroke and hypertension, suggesting possible adverse health consequences related to environmental factors during military service.

Study: Use on military bases with open burn pits and respiratory and cardiovascular diseases. Senior Airman Julianne Showalter, Public Domain, via Wikimedia Commons, en.wikipedia.org/wiki/Burn_pit. Accessed April 29, 2024.

background

The United States military has used open burn pits for the disposal of various materials, including medical, hazardous and solid waste, during multiple deployments in Iraq and Afghanistan.

Despite restrictions imposed by the Department of Defense (DOD) in 2009 and efforts to adopt alternative waste disposal methods, incineration pits remained in operation until more sustainable options were implemented.

Despite concerns expressed by the public and veterans themselves, few studies have examined the lasting health effects of exposure to burn pits.

While deployment during Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF) is associated with an increased risk of respiratory illnesses, it is difficult to isolate the effects of burn pit exposure due to the complex mix of emissions and other air pollutants that occur during military service.

About the study

The aim of this study was to assess how deployment to bases with open burn pits affects veterans' long-term cardiovascular and respiratory health outcomes.

The cohort study examined Air Force and Army veterans who were stationed at OIF or OEF from 2001 to 2011 and enrolled in the Veterans Health Administration (VHA) to receive medical care after their deployment.

The study used declassified military deployment records linked to VHA health data to assess the association between deployment to bases that use open burn pits and veterans' long-term cardiovascular and respiratory health outcomes.

A cohort of veterans who met inclusion criteria was created, excluding Navy and Navy veterans due to unavailability of data and those with incomplete deployment records prior to 2005.

Burn pit exposure and deployment history were determined using Department of Defense records, with health outcomes assessed using health records maintained by VHA through 2020.

The analysis considered covariates including obesity, smoking status, demographic factors, service industry and income level.

Statistical analysis included multivariable logistic regressions to examine associations between burn pit exposure and disease outcomes, controlling for covariates.

Sensitivity analyzes addressed methodological concerns, including exclusions and potential sources of confounding.

Results

The study included 459,381 Air Force and Army veterans stationed at OIF or OEF between 2001 and 2011. Follow-up data was collected by the VHA through the end of 2020.

The cohort, predominantly male (87%) and racially diverse (white veterans comprised 67% of the population), was on average 31.6 years old when they entered VHA care. Over 94% of veterans had a history of military service.

Participants had varying socioeconomic indicators, including high rates of obesity (34%) and cigarette smoking (43%).

Most cohort members (86%) had deployed to bases with burn pits at least once, with a median exposure duration of 244 days.

Analysis of the association between duration of burn pit exposure and various health outcomes revealed a slight increase in the odds of asthma (1%) and COPD (4%) per 100 days of exposure, with moderate dose-response relationships across exposure tertiles.

Hypertension was also associated with burn exposure, with a slight increase in the likelihood of ischemic stroke observed, but the accuracy was limited. No associations were observed for interstitial lung disease.

Sensitivity analyzes showed minimal effects on association measures after exclusions and adjustments for covariates.

Adjusting the model for duration of use accounted for most of the difference in associations between adjusted and unadjusted outcomes, with the exception of hypertension, which showed an increased association only after adjusting for all covariates.

Conclusions

The cohort study found that longer periods of exposure to open burn pits were associated with modest increases in COPD, hypertension, and asthma in OIF and OEF veterans.

These associations were modest; However, given the large number of veterans potentially affected, the authors argue that even small increases in risk should be considered clinically important.

Previous studies have had limitations in assessing the effects of exposure to burn pits. This study, with a longer median follow-up of 10.9 years and a larger sample size, provided important insights.

Although there were limitations, including potential biases and the lack of detailed data on burn pit exposure, these results highlight the need for continued assessment of the health risks associated with burn pit exposure in veterans.

These results highlight the importance of considering potential long-term health impacts when providing health care and benefits to veterans and the value of shared deployment data for research on military-related health outcomes.

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