Joseph H. Abraham

Potential health implications associated with particulate matter exposure in deployed settings in southwest Asia.

There is a recognized need to identify the potential impact of air pollution exposure on the health of military personnel deployed to Southwest Asia (SWA). The exposure characterization reported by Engelbrecht et al. in this issue summarizes the results of a remarkable effort to conduct environmental sampling at locations where US military personnel are deployed in support of Operation Enduring Freedom and Operation Iraqi Freedom. This is an important first step in better understanding the relationship between the health of soldiers deployed in SWA and air pollution in the area of operations. We discuss here what is currently known about the effects of particulate matter (PM) on human health, focusing on the limited evidence specific to US military personnel, and outline current and planned efforts to utilize sampling data to assess health outcomes in deployed military populations.

A Retrospective Cohort Study of Military Deployment and Postdeployment Medical Encounters for Respiratory Conditions

Deployed military personnel are exposed to inhalational hazards that may increase their risk of chronic lung conditions. This evaluation assessed associations between Operation Iraqi Freedom (OIF) deployment and postdeployment medical encounters for respiratory symptoms and medical conditions. This retrospective cohort study was conducted among military personnel who, between January 2005 and June 2007, were deployed to either of two locations with burn pits in Iraq, or to either of two locations without burn pits in Kuwait. Incidence rate ratios (IRRs) were estimated using two nondeployed reference groups. Rates among personnel deployed to burn pit locations were also compared directly to those among personnel deployed to locations without burn pits. Significantly elevated rates of encounters for respiratory symptoms (IRR = 1.25; 95% confidence interval [CI]: 1.20-1.30) and asthma (IRR = 1.54; 95% CI: 1.33-1.78) were observed among the formerly deployed personnel relative to U.S.-stationed personnel. Personnel deployed to burn pit locations did not have significantly elevated rates for any of the outcomes relative to personnel deployed to locations without burn pits. These results are consistent with the hypothesis that OIF deployment is associated with subsequent risk of respiratory conditions. Elevated medical encounter rates were not uniquely associated with burn pits.

Overview and recommendations for medical screening and diagnostic evaluation for postdeployment lung disease in returning US warfighters.

Objective: To review inhalational exposures and respiratory disease risks in US military personnel deployed to Iraq and Afghanistan and to develop consensus recommendations for medical screening and diagnostic referral. Methods: A Working Group of physicians and exposure scientists from academia and from the Departments of Defense and Veterans Affairs was convened in February 2010. Results: Despite uncertainty about the number of people affected and risk factors for adverse pulmonary outcomes in this occupational setting, the Working Group recommended: (1) standardized approaches to pre- and postdeployment medical surveillance; (2) criteria for medical referral and diagnosis; and (3) case definitions for major deployment-related lung diseases. Conclusions: There is a need for targeted, practical medical surveillance for lung diseases and for a standardized diagnostic approach for all symptomatic deployed personnel.

Does deployment to Iraq and Afghanistan affect respiratory health of US military personnel

Objective: To evaluate the association between postdeployment respiratory conditions and deployment to Iraq or Afghanistan. Methods: We linked deployment history of US military personnel with postdeployment medical records. We then conducted a nested case–control study. Results: Relative to a single deployment, multiple deployments were not significantly associated with obstructive pulmonary disease (odds ratio, 1.08; 95% confidence interval, 0.82 to 1.42). Cumulative time deployed was also not significantly associated with obstructive pulmonary disease. Nevertheless, we did note that the rate of respiratory symptoms and encounters for obstructive pulmonary diseases (predominantly asthma and bronchitis) increased from before to after deployment. Conclusions: In a population of active duty US military personnel, we observed an increase in postdeployment respiratory symptoms and medical encounters for obstructive pulmonary diseases, relative to predeployment rates, in the absence of an association with cumulative deployment duration or total number of deployments.

Respiratory Health Status of Us Army Personnel Potentially Exposed to Smoke From 2003 Al-mishraq Sulfur Plant Fire

Objective: To assess the impact of exposure to a 2003 sulfur plant fire on the health of deployed US Army personnel. Methods: The authors identified a small firefighter group known to be at the fire source and a larger, more dispersed population. Self-reported health status and respiratory health outcomes for these two groups were reviewed compared with two unexposed groups. Results: Self-reported health concerns, difficulty breathing, and shortness of breath were common in the exposed. Rates for chronic respiratory conditions increased in all groups from before to after deployment. Postdeployment medical encounters for chronic respiratory conditions among the exposed did not differ significantly from the unexposed comparison groups. Conclusion: Potential exposure to the sulfur fire was positively associated with self-reported health concerns and symptoms but not with clinical encounters for chronic respiratory health conditions.

A case-crossover study of ambient particulate matter and cardiovascular and respiratory medical encounters among US military personnel deployed to southwest Asia.

Objective: To evaluate the impact of ambient particulate matter (PM) on acute cardiorespiratory morbidity among US military personnel in southwest Asia. Methods: We linked ambient PM data collected between December 2005 and June 2007 with personnel, medical, and meteorological data. We implemented a case-crossover analysis to estimate base-specific associations and pooled those estimates using meta-analytic methods. Results: The adjusted odds ratios for a 10-&mgr;g/m3 increase in ambient PM2.5 and a qualifying medical encounter were 0.92 (95% confidence interval [CI]: 0.77 to 1.11) and 1.01 (95% CI: 0.95 to 1.07) for the current (lag_0) and previous (lag_1) days. The estimates for a 10-&mgr;g/m3 increase in PM10 were 0.99 (95% CI: 0.97 to 1.03) at lag_0, and 1.00 (95% CI: 0.97 to 1.02) at lag_1. Conclusions: No statistically significant associations between PM and cardiorespiratory outcomes were observed in this young, relatively healthy, deployed military population.

Postdeployment Respiratory Health Care Encounters Following Deployment to Kabul, Afghanistan: A Retrospective Cohort Study

Inhalational hazards are numerous in operational environments. A retrospective cohort study was conducted to investigate associations between deployment to Kabul, Afghanistan and subsequent respiratory health among U.S. military personnel. The study population consisted of personnel who deployed to Kabul, select Operation Enduring Freedom locations, personnel stationed in the Republic of Korea, and U.S.-stationed personnel. Incidence rate ratios (IRRs) were estimated for respiratory symptoms, signs, and ill-defined conditions, asthma, and chronic obstructive pulmonary disease. A significantly elevated rate of symptoms, signs, and ill-defined conditions was observed among Kabul-deployed personnel compared to personnel deployed or stationed in Bagram (IRR 1.12; 95% confidence interval [CI], 1.05-1.19), Republic of Korea (IRR 1.20; 95% CI, 1.10-1.31), and the United States (IRR 1.52; 95% CI, 1.43-1.62). A statistically elevated rate of asthma was observed among personnel deployed to Kabul, relative to U.S.-stationed personnel (IRR 1.61; 95% CI, 1.22-2.12). Statistically significant rates were not observed for chronic obstructive pulmonary disease among Kabul-deployed personnel compared to other study groups. These findings suggest that deployment to Kabul is associated with an elevated risk of postdeployment respiratory symptoms and new-onset asthma.

Bronchodilator Responsiveness and Airflow Limitation Are Associated With Deployment Length in Iraq and Afghanistan Veterans.

Objective: The aim of this study was to determine the relationship between deployment length and indices of airflow obstruction in Iraq and Afghanistan veterans with airborne hazards exposure. Methods: One hundred twenty-four post-9/11 veterans completed pulmonary function testing and questionnaires. We examined the association of airflow limitation [forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC)] and bronchodilator responsiveness (&Dgr;FEV1 and &Dgr;FVC) with deployment length, adjusting for smoking. Results: Longer deployment length was associated with lower FEV1/FVC [&bgr; = −0.19; 95% confidence interval (95% CI), −0.39 to 0.01], greater &Dgr;FEV1 (&bgr; = 0.27; 95% CI, 0.09 to 0.45) and &Dgr;FVC (&bgr; = 0.19; 95% CI, 0.05 to 0.33). In our model adjusted for smoking history, longer deployment length remained associated with greater &Dgr;FEV1 and &Dgr;FVC (P < 0.01), but not with FEV1/FVC (P = 0.059). Conclusion: In our sample of post-9/11 veterans, longer deployment lengths were associated with significant bronchodilator responsiveness and a trend toward airflow limitation independent of tobacco use.

The Impact of Deployment on COPD in Active Duty Military Personnel

PURPOSE To identify trends in chronic obstructive pulmonary disease (COPD) diagnoses among active duty U.S. military personnel based on deployment history and whether International Classification of Disease, 9th edition (ICD-9) coding meet criteria for the diagnosis of COPD. METHODS A retrospective chart review using the electronic medical system was conducted for military personnel diagnosed with COPD based on ICD-9 codes for emphysema or chronic obstructive lung disease with at least three qualifying outpatient COPD-coded encounters. Clinical symptoms, smoking history, pulmonary function testing, and radiographs obtained during the diagnostic workup were reviewed. The established diagnosis of COPD was analyzed in relation to deployment. RESULTS A total of 371 patients were identified during the study period (2005-2009). Of these patients, 194 (52.3%) deployed, whereas 177 (47.7%) did not deploy to Southwest Asia since 2003. Thirty-four percent had no documented smoking history despite the diagnosis of COPD. Airway obstruction was identified by spirometry in only 67% of individuals diagnosed with COPD. No statistically significant differences in pulmonary function testing values were identified between those deployed and nondeployed individuals. CONCLUSION Despite evidence of increased respiratory symptoms in deployed military personnel, the impact of deployment on increased diagnosis of COPD or severity of disease appears minimal.