Work

Chronic Obstructive Pulmonary Disease and Herbicide Exposure in Vietnam-Era U.S. Army Chemical Corps Veterans

Year: 2018

Type: conference-abstract

Abstract: Rationale Past research demonstrates a possible association between herbicide exposure and respiratory health. Biologic plausibility and inhalation as a mode of exposure further support the contention that herbicides may act as adverse contributors to respiratory status, especially in military personnel who were responsible for chemical maintenance and distribution during the Vietnam War. Objectives This study examines the association between chronic obstructive pulmonary disease and herbicide exposure among Vietnam-era U.S. Army Chemical Corps veterans. Methods A 2013 three-phase health study was conducted that included a survey (mail or telephone), in-home physical examinations, and medical record reviews/abstractions. Living, eligible veterans (n = 4,027) were identified using an existing cohort of men (n = 5,609) who either served in Vietnam (n = 2,872) or never served in Southeast Asia (n = 2,737). The health survey collected self-reported data on physician-diagnosed pulmonary conditions (chronic obstructive pulmonary disease, emphysema, and chronic bronchitis), service-related herbicide spraying history, cigarette smoking status, alcohol use, and demographics. Data from service personnel files confirmed chemical operations involvement and service status, whereas serum samples analyzed for 2,3,7,8-tetrachlorodibenzo-p-dioxin supported self-reported herbicide exposure. National Institute for Occupational Safety and Health quality-assured spirometry was performed during the physical examinations on a subset of survey respondents (n = 468 of 733 selected for participation and who provided consent) to determine mainly spirometric obstructive respiratory disease (forced expiratory volume in 1 second [FEV1]/forced vital capacity [FVC] < lower limit of normal [LLN], FVC ≥ LLN, and FEV1 < LLN; and FEV1/FVC < LLN and FEV1 ≥ LLN). Associations between chronic obstructive pulmonary disease and veteran characteristics were examined (n = 403) using multivariable models. Results Reporting here specifically on spirometrically diagnosed disease, prevalence of obstructive disease was 8.4%. No significant differences in mean values of FEV1/FVC or mean percentage of predicted for FEV1 and FVC between herbicide sprayers and nonsprayers were found. The odds of spirometric obstructive disease among sprayers were 0.65 times the odds among nonsprayers (adjusted odds ratio, 0.65; 95% confidence interval, 0.28–1.47), although elevated odds for spirometric restrictive disease were observed for sprayers versus nonsprayers (adjusted odds ratio, 1.61; 95% confidence interval, 0.85–3.06). Race/ethnicity, anthropometric measures, and cigarette smoking status accounted for differences among veterans’ respiratory patterns. Conclusions No significant association between herbicide exposure and spirometry-determined chronic obstructive pulmonary disease was found. Greater focus is required on confirming diagnoses of respiratory disease through spirometry in epidemiological research.

Source: Annals of the American Thoracic Society

DOI: 10.1513/annalsats.201706-483mg

Authors: Yasmin Cypel, Stella E. Hines, Victoria J. Davey, Stephanie M. Eber, Aaron I. Schneiderman