Date of Award

January 2023

Document Type

Thesis

Degree Name

Master of Public Health (MPH)

Department

School of Public Health

First Advisor

Carrie Redlich

Abstract

Background: The deployment of military personnel to Afghanistan and Southwest Asia has raised concerns about the adverse respiratory effects of inhalational exposures rom burn pits, dust storms, and other deployment-related exposures. However, military personnel can also have substantial occupational and environmental inhalational exposures during non-deployment periods of military service. Such exposures and potential health effects have received limited attention. For this project we hypothesize that non-deployment related military exposures contribute to respiratory health outcomes. To address this hypothesis, we aimed to better characterize non-deployment inhalational exposures and assess their association with chronic respiratory symptoms.

Methods: As part of the Veterans Affairs (VA) Cooperative Study 595, “Service and Health Among Deployed Veterans,” 1,712 participants were randomly selected and recruited from the Defense Manpower Data Center roster. All participants completed in-person visits for an interviewer-administered multi-item questionnaire consisting of 29 items regarding occupational and environmental exposures during their non-deployment active-duty military service. Using exploratory factor analysis (EFA), we categorized the above exposures into 5 final exposure categories. We used the median of the person-months duration of each exposure to assign a three-level scoring system (0, 1, 2) to each exposure. Factor loadings (weighted exposure scores) from the factor analysis were used for the final models; summed and normalized to 100 for each exposure category. We used multivariable logistic regression to explore associations between each respiratory outcomes (dyspnea, wheeze in the past 12 months, and chronic bronchitis) and exposure score categories, while adjusting for covariates.

Results: A total of 1,712 veterans were included in this study, with the majority being middle-aged, male, and White. The median duration of military service was 8 years. Most reported a single deployment with a median duration of 1 year. The prevalence of dyspnea, chronic bronchitis, and wheezing in the past 12 months was 3.7%, 6.8%, and 15.2%, respectively. In the multivariable analysis, Heavy Equipment exposure category was significantly associated with increased odds of dyspnea (OR 1.29; 95% CI 1.03 – 5.58), wheeze (OR 1.24; 95% CI 1.08 – 1.43), and chronic bronchitis (OR 1.35; 95% CI 1.02 – 1.74). The Combustion exposure category was significantly linked to increased odds of dyspnea (OR 1.27; 95% CI 1.04 – 1.58) and wheeze (OR 1.20; 95% CI 1.02 – 1.40). The Aircraft exposure category showed a significantly increased odds of wheeze (OR 1.15; 95% CI 1.00 – 1.35). The Burn Pit and Construction exposure categories were not associated with increased odds of chronic respiratory symptoms.

Conclusion: This study reveals that military exposures during non-deployment active-duty service, are associated with adverse chronic respiratory health outcomes among veterans. Research on the effects of deployment-related exposures often overlooks non-deployment exposures. Our findings emphasize the need to better characterize inhalational exposures in military settings during non-deployment periods and to assess the potential adverse effects of such exposures.

Comments

This thesis is restricted to Yale network users only. This thesis is permanently embargoed from public release.

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