Respiratory Health after Military Service in Southwest Asia and Afghanistan. An Official American Thoracic Society Workshop Report

Abstract

Since 2001, more than 2.7 million U.S. military personnel have been deployed in support of operations in Southwest Asia and Afghanistan. Land-based personnel experienced elevated exposures to particulate matter and other inhalational exposures from multiple sources, including desert dust, burn pit combustion, and other industrial, mobile, or military sources. A workshop conducted at the 2018 American Thoracic Society International Conference had the goals of: 1) identifying key studies assessing postdeployment respiratory health, 2) describing emerging research, and 3) highlighting knowledge gaps. The workshop reviewed epidemiologic studies that demonstrated more frequent encounters for respiratory symptoms postdeployment compared with nondeployers and for airway disease, predominantly asthma, as well as case series describing postdeployment dyspnea, asthma, and a range of other respiratory tract findings. On the basis of particulate matter effects in other populations, it also is possible that deployers experienced reductions in pulmonary function as a result of such exposure. The workshop also gave particular attention to constrictive bronchiolitis, which has been reported in lung biopsies of selected deployers. Workshop participants had heterogeneous views regarding the definition and frequency of constrictive bronchiolitis and other small airway pathologic findings in deployed populations. The workshop concluded that the relationship of airway disease, including constrictive bronchiolitis, to exposures experienced during deployment remains to be better defined. Future clinical and epidemiologic research efforts should address better characterization of deployment exposures; carry out longitudinal assessment of potentially related adverse health conditions, including lung function and other physiologic changes; and use rigorous histologic, exposure, and clinical characterization of patients with respiratory tract abnormalities.

Keywords: constrictive bronchiolitis; deployment; particulate matter.

Figure 1.

Mean particulate matter with an aerodynamic diameter less than or equal to 2.5 μm (PM_2.5) concentrations at 15 sites in Iraq, Afghanistan, Kuwait, and other sites in 2006 and 2007 (28). MEG = military exposure guideline; NAAQS = National Ambient Air Quality Standards; USEPA = U.S. Environmental Protection Agency.

Figure 2.

Monthly predictions of particulate matter with an aerodynamic diameter less than or equal to 2.5 μm in μg/m³ (y-axis) by year (2000–2012) for sites in Afghanistan, Iraq, Kuwait, Kyrgyzstan, United Arab Emirates, Djibouti, and Qatar, based on military airport visibility data. Reprinted from Reference by permission of Air & Waste Management Association, www.awma.org.