COPD mortality elevated in Vietnam veterans exposed to herbicides
MedWire News: Results from a US study show that mortality due to chronic obstructive pulmonary disease (COPD) and other respiratory conditions is significantly elevated among Vietnam veterans from the Army Chemical Corps (ACC).
“The members of the ACC were responsible for handling and spraying herbicides around the perimeters of military base camps in Vietnam. They may constitute the largest cohort of Vietnam-era veterans… who were directly exposed to Agent Orange,” explain Yasmin Cypel (Department of Veterans Affairs, Washington, DC) and colleagues.
The researchers studied data on 2872 ACC veterans who served in Vietnam between 1965 and 1973, and 2737 military veterans who did not serve in South East Asia during the same period.
By 2005, 593 of the Vietnam veterans and 355 of the non-Vietnam veterans had died.
After accounting for smoking and other factors, the researchers found that the risk for excess mortality due to COPD was significantly higher among Vietnam veterans than non-Vietnam veterans, at an adjusted relative risk of 4.82.
Among the Vietnam veterans, those who had been herbicide sprayers (n=662) had non-significant increased risks for all-cause, non-malignant respiratory disease, and respiratory cancer mortality compared with those who had not been herbicide sprayers (n=811).
The researchers also found that, compared with men of similar age in the US population, the Vietnam veterans had significant excess mortality due to all-causes (standardized mortality ratio [SMR]=1.13), respiratory cancers (SMR=1.35), nonmalignant respiratory diseases (SMR=1.58), and other cancers (SMR=1.77).
Cypel and team conclude in the Annals of Epidemiology: “ACC Vietnam veterans who were occupationally exposed to herbicides experienced a significant excess in mortality from diseases of the respiratory system (COPD) in comparison with their non-Vietnam veteran peers, and all causes, respiratory cancer, miscellaneous cancers, and nonmalignant respiratory disease as compared with US males.”
They add: “Our findings are consistent with the results from several studies of workers who were occupationally exposed to herbicides and dioxin.”
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By Mark Cowen