Deployment-Related Lung Disorders

Agent Orange

The herbicide Agent Orange is commonly contaminated with dioxin, which has been demonstrated to be a tumor promoter in animal studies. Agent Orange was used widely in the Vietnam War. The National Academy of Sciences issued a report in 2001 reviewing evidence for a link between Agent Orange and various neoplasms. Evidence was strongest for Hodgkin lymphoma and soft tissue sarcoma. The evidence of an association between Agent Orange exposure and lung cancer was deemed only suggestive.¹⁶

Respiratory Disease Associated With Southwest Asia Deployment

Over the past 14 years, > 2.5 million U.S. military personnel and civilian contractors have been deployed as part of 3 major military operations: OEF in Afghanistan (2001 to present), OIF in Iraq (2003 to 2010), and OND in Iraq (2010 to present).^17,18 Deployed personnel encounter a wide variety of inhalational exposures that include desert dust particulate matter, burn pit combustion products, environmental tobacco smoke, vehicular diesel exhaust, debris from detonations and explosions, and other unique or specific job-related exposures (Table 1).^19,20

A number of recent studies have helped identify and characterize an emerging spectrum of deployment-related lung disorders, including asthma, rhinosinusitis, emphysema, bronchiolitis, granulomatous pneumonitis, and less common conditions such as acute eosinophilic pneumonia and rapidly progressive pulmonary fibrosis (Table 2).^20-30 Still, diagnosis of these conditions is often challenging, and traditional diagnostic tools such as PFT and chest radiography may be normal or mildly abnormal despite significant histopathologic abnormalities on surgical lung biopsy.^24,30,31

Deployment-Related Exposures

As listed in Table 1, there are a number of other exposures that may be encountered during deployment. Environmental air sampling was conducted in several locations in Iraq, Afghanistan, and sites in SWA as part of the Enhanced Particulate Matter Survey. All sites were notable for air pollutant levels that exceeded 15 μg/m³, the military exposure guideline for fine particulate matter (PM2.5). The PM2.5 fraction comprised geologic dust, burn pit emissions, and the heavy metals aluminum, cadmium, and lead.^32,33

Respiratory Disorders

Reports of deployers with respiratory symptoms during and after deployment surfaced as early as 2004.³⁴ The Millennium Cohort study reported a 1.7-fold higher rate of new-onset respiratory symptoms that was independent of smoking status, such as cough and shortness of breath, in deployers compared with nondeployers. These increased symptom rates were associated with land-based deployment and longer deployment duration.³⁵ A number of epidemiologic studies also demonstrated an association between respiratory symptoms and environmental exposures encountered during deployment.^36-39

Respiratory diseases such as asthma, acute eosinophilic pneumonia, and constrictive bronchiolitis have been reported following deployment to SWA, but a review of the literature supports a more expansive list of deployment-related respiratory diseases (Table 2).^20-30 The following case examples describe findings in veterans referred to the authors’ clinic for evaluation of chest symptoms associated with deployment.

OEF/OIF/OND Case Studies

Case Study 1

A 42-year-old male never smoker presented to his VA PCP for evaluation of nonproductive cough, dyspnea on exertion, chest tightness, and recurrent episodes of bronchitis since 2004 when he was deployed to Afghanistan. He had no history of asthma or other chronic respiratory disease in childhood or adolescence.

The patient served as a Civil Affairs officer in the U.S. Army and was deployed to Bosnia in 1997, Afghanistan in 2004, and Camp Arif-Jan in Kuwait as well as Mosul, Iraq, in 2005. He was exposed to depleted uranium while serving in Bosnia. He also had exposures to sandstorms, desert dust, and burn pit combustion products while deployed to Afghanistan and Iraq. He developed symptoms of chest tightness and dyspnea on exertion during his 2004 deployment, with these symptoms persisting after returning home from deployment. His symptoms occurred frequently while running and limited his ability to pass his military physical fitness test requirements and train for marathons as he had done previously. He also had symptoms of chest tightness and excessive coughing at rest, which were treated with antibiotics by his medical provider as recurrent acute infectious/viral bronchitis.

The patient was medically discharged from the U.S. Army in July 2005, primarily due to musculoskeletal injuries. His past medical history was notable for PTSD, recurrent allergic rhinosinusitis, and lumbosacral back pain. Given persistent respiratory symptoms of dyspnea after walking 1 block, the patient presented to his VA PCP in early 2006.

The patient’s vital signs and physical examination were normal. Spirometry showed a mixed restrictive and obstructive pattern, prompting referral for pulmonary consultation. Full PFT demonstrated an abnormally increased residual volume and mildly decreased diffusion capacity (Table 3). Laryngoscopy was negative for vocal cord dysfunction. A chest X-ray showed mild airway wall thickening bilaterally in the lower lung fields. Subsequent high-resolution CT of the chest demonstrated diffuse centrilobular nodularity (Figure 1). Serial spirometry measurements over 8 months showed severe and worsening airflow limitation despite treatment with inhaled bronchodilator and corticosteroid therapy. Seeking diagnostic clarity, the patient was referred for surgical lung biopsy via video-assisted thorascopic surgery (VATS) within 6 months of initial consultation.