Deployment-related Cigarette Smoking Behaviors and Pulmonary Function Among U.S. Veterans.

INTRODUCTION: The effects of smoking on lung function among post-9/11 Veterans deployed to environments with high levels of ambient particulate matter are incompletely understood. MATERIALS AND METHODS: We analyzed interim data (04/2018-03/2020) from the Veterans Affairs (VA) Cooperative Studies Program #595, "Service and Health Among Deployed Veterans". Veterans with ≥1 land-based deployments enrolled at 1 of 6 regional Veterans Affairs sites completed questionnaires and spirometry. Multivariable linear regression models assessed associations between cigarette smoking (cumulative, deployment-related and non-deployment-related) with pulmonary function. RESULTS: Among 1,836 participants (mean age 40.7 ± 9.6, 88.6% male), 44.8% (n = 822) were ever-smokers (mean age 39.5 ± 9.5; 91.2% male). Among ever-smokers, 86% (n = 710) initiated smoking before deployment, while 11% (n = 90) initiated smoking during deployment(s). Smoking intensity was 50% greater during deployment than other periods (0.75 versus 0.50 packs-per-day; P < .05), and those with multiple deployments (40.4%) were more likely to smoke during deployment relative to those with single deployments (82% versus 74%). Total cumulative pack-years (median [IQR] = 3.8 [1, 10]) was inversely associated with post-bronchodilator FEV1%-predicted (-0.82; [95% CI] = [-1.25, -0.50] %-predicted per 4 pack-years) and FEV1/FVC%-predicted (-0.54; [95% CI] = [-0.78, -0.43] %-predicted per 4 pack-years). Deployment-related pack-years demonstrated similar point estimates of associations with FEV1%-predicted (-0.61; [95% CI] = [-2.28, 1.09]) and FEV1/FVC%-predicted (-1.09; [95% CI] = [-2.52, 0.50]) as non-deployment-related pack-years (-0.83; [95% CI] = [-1.26, -0.50] for FEV1%-predicted; -0.52; [95% CI] = [-0.73, -0.36] for FEV1/FVC%-predicted). CONCLUSIONS: Although cumulative pack-years smoking was modest in this cohort, an inverse association with pulmonary function was detectable. Deployment-related pack-years had a similar association with pulmonary function compared to non-deployment-related pack-years.

Chronic respiratory symptoms following deployment-related occupational and environmental exposures among US veterans.

OBJECTIVES: Characterise inhalational exposures during deployment to Afghanistan and Southwest Asia and associations with postdeployment respiratory symptoms. METHODS: Participants (n=1960) in this cross-sectional study of US Veterans (Veterans Affairs Cooperative Study 'Service and Health Among Deployed Veterans') completed an interviewer-administered questionnaire regarding 32 deployment exposures, grouped a priori into six categories: burn pit smoke; other combustion sources; engine exhaust; mechanical and desert dusts; toxicants; and military job-related vapours gas, dusts or fumes (VGDF). Responses were scored ordinally (0, 1, 2) according to exposure frequency. Factor analysis supported item reduction and category consolidation yielding 28 exposure items in 5 categories. Generalised linear models with a logit link tested associations with symptoms (by respiratory health questionnaire) adjusting for other covariates. OR were scaled per 20-point score increment (normalised maximum=100). RESULTS: The cohort mean age was 40.7 years with a median deployment duration of 11.7 months. Heavy exposures to multiple inhalational exposures were commonly reported, including burn pit smoke (72.7%) and VGDF (72.0%). The prevalence of dyspnoea, chronic bronchitis and wheeze in the past 12 months was 7.3%, 8.2% and 15.6%, respectively. Burn pit smoke exposure was associated with dyspnoea (OR 1.22; 95% CI 1.06 to 1.47) and chronic bronchitis (OR 1.22; 95% CI 1.13 to 1.44). Exposure to VGDF was associated with dyspnoea (OR 1.29; 95% CI 1.14 to 1.58) and wheeze (OR 1.18; 95% CI 1.02 to 1.35). CONCLUSION: Exposures to burn pit smoke and military occupational VGDF during deployment were associated with an increased odds of chronic respiratory symptoms among US Veterans.

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

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.

Introduction to Department of Defense Research on Burn Pits, Biomarkers, and Health Outcomes Related to Deployment in Iraq and Afghanistan.

OBJECTIVE: This paper provides an overview of our study that was designed to assess the health impact of environmental exposures to open pit burning in deployed troops. METHODS: The rationale for the study and the structure of the research plan was laid out. An overview of each article in the supplement was provided. The cohort of deployed Service members was assessed for airborne exposure, relevant biomarkers, and health outcomes following deployment to Balad, Iraq, and/or Bagram, Afghanistan. RESULTS: Polycyclic aromatic hydrocarbon (PAH) exposures were elevated, and serum biomarkers were statistically different postdeployment. Associations were noted between PAHs and dioxins and microRNAs. Some health outcomes were evident in deployers compared with nondeployers. CONCLUSIONS: Future research will examine the associations between demographic variables, smoking status, biomarker levels, and related health outcomes.

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.

Maximizing the Utility of the Serum Repository With Current Technologies and Recommendations to Meet Future Needs: Report of the Technical Panel.

The Department of Defense Serum Repository (DoDSR) of the Armed Forces Health Surveillance Center (AFHSC), Silver Spring, Maryland, has over 55 million specimens. Over 80% of these specimens are linked to individual health data. In response to Congressional and Department of Defense (DoD) concern about toxic exposures of deployed Service members and rapidly developing laboratory capabilities that may identify those exposed, the AFHSC hosted two panels in 2013. The first, the Needs Panel, focused on assessing the needs of the DoD that may be met using the current DoDSR and an enhanced repository. The second panel, the Technical Panel, focused on identifying the emerging laboratory technologies that are or will be available to DoD public health workers and researchers. This report summarizes the recommendations of the Technical Panel, to include identified gaps in the ability of the current DoDSR to address questions of interest to the DoD, the availability of laboratory technology to address these needs, and the types and quality of specimens required from Service members possibly exposed.

Trends in rates of chronic obstructive respiratory conditions among US military personnel, 2001-2013.

BACKGROUND: The US military has been continuously engaged in combat operations since 2001. Assessing trends in respiratory health diagnoses during this time of prolonged military conflict can provide insight into associated changes in the burden of pulmonary conditions in the US military population. PURPOSE: To estimate and evaluate trends in rates of chronic obstructive pulmonary diseases in the active duty US military population from 2001 through 2013. METHODS: A retrospective analysis of ambulatory medical encounter diagnosis data corresponding to a study base of over 18 million personnel-years was performed to estimate average rates and evaluate temporal trends in rates of chronic obstructive lung conditions. Differences in rates and the time trends of those rates were evaluated by branch of military service, military occupation, and military rank. RESULTS: During the 13-year period, we observed 482,670 encounters for chronic obstructive pulmonary disease and allied conditions (ICD-9 490-496) among active duty military personnel. Over half (57%) of the medical encounters in this category were for a diagnosis of bronchitis, not specified as acute or chronic. There was a statistically significant 17.2% average increase in the annual rates of this nonspecific bronchitis diagnosis from 2001-2009 (95% CI: 13.5% to 21.1%), followed by a 23.6% annual decline in the rates from 2009 through 2013 (95% CI: 8.6% to 36.2%). Statistically significant declines were observed in the rates of chronic bronchitis over time (annual percentage decline: 3.1%; 95% CI: 0.5% to 6.6%) and asthma (annual percentage decline: 5.9%; 95% CI: 2.5% to 9.2%). A 1.6% annual increase in the rate of emphysema and a 0.1% increase in the rate of chronic airways obstruction (not elsewhere classified) over the study period were not statistically significant (P>.05). The magnitude of the estimated rates of these chronic obstructive lung conditions, and, to a lesser extent, the temporal trends in these rates, were sensitive to the requirement that there be persistence of the diagnosis evidenced in the medical record in order qualify as an incident case. CONCLUSIONS: We observed decreases in the rates of asthma and chronic bronchitis over the 13-year study period. The increase, and then decrease, over time in rates of bronchitis that has not been specified as acute or chronic drives the overall trends in chronic respiratory disease trends.

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.

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-µg/m 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-µg/m 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.