WASHINGTON—With no published reports on spirometric restriction in herbicide-exposed Vietnam War veterans serving in the U.S. Army Chemical Corps, a group of researchers decided to examine the issue.
The review in the International Journal of Environmental Research & Public Health reported that spirometry was conducted on 468 veterans who served in chemical operations. VA and University of Maryland authors said that information was based on a 2013 study assessing the association between chronic obstructive pulmonary disease and herbicide exposure.1
In that study, exposure was verified based on blood serum values of 2,3,7,8-tetrachlorodibenzo-p-dioxin. After adjustment for military characteristics, selected anthropometrics and other predictors using multivariable regression, the association between herbicide exposure and spirometry restriction (forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) ≥ lower limit of normal (LLN) and FVC < LLN) was tested.
Results indicated that spirometric restriction in herbicide sprayers (15.7%, 95% CI: 10.6, 20.9) was almost twice that of nonsprayers (9.91%, 95% CI: 5.9, 13.9) (p = 0.081).
Interestingly, the authors wrote, spirometric restriction was not significantly associated with herbicide exposure (adjusted odds ratio (aOR) = 1.64, 95% CI: 0.82, 3.29) despite the greater prevalence of restriction in sprayers vs. nonsprayers. They determined, however, that spirometric restriction was significantly associated with race/ethnicity (aOR = 3.04, 95% CI: 1.36, 6.79) and waist circumference (aOR = 2.46, 95% CI: 1.25, 4.85).
“Because restrictive pulmonary disease may result from chemically-induced inflammation or sensitivity, research on chemical exposures and restriction in veterans should continue,” the researchers concluded. “Future study should include full pulmonary function testing, targeted research designs, and a wider set of explanatory variables in analysis, such as other determinants of health.”
- Cypel Y, Hines SE, Davey VJ, Eber SM, et. Al. Spirometric Pulmonary Restriction in Herbicide-Exposed U.S. Vietnam War Veterans. Int J Environ Res Public Health. 2019 Aug 28;16(17). pii: E3131. doi: 10.3390/ijerph16173131.PubMed PMID: 31466319; PubMed Central PMCID: PMC6747381.
