New Zealand Vietnam war veterans, some of whom were exposed
to Agent Orange defoliant, have double the rate of chronic
lymphatic leukemia compared to the general population, an
Otago University study has found.
The study, by the university's Department of Preventive and
Social Medicine, looked at the medical records of many of the
nearly 3400 New Zealanders who served in Vietnam from 1962 to
The cohort study, which looked at the records of 2752 men
between 1988 to 2008, is the first to look at New Zealand
Vietnam veterans to assess the long-term health effects of
serving in a combat zone.
The researchers found while 407 veterans died over the study
period, the overall death rate from all causes was 15 per
cent lower than the general population.
They also found mortality from cancer was not significantly
lower or higher however than the general population.
However, lead author Dr David McBride said the study showed a
doubling of the risk of mortality from cancers of the head
and neck, as well as an increase in oral cancers of the
pharynx and larynx.
"Lung cancer contributed the greatest burden of deaths in
both New Zealand and Australian veterans,'' he said.
The study noted veterans deployed in the Nui Dat area of
Phuoc Tuy province experienced a toxic environment because of
the widespread use Agent Orange, which contained the
carcinogen dioxin. However, the study did not have specific
data on herbicide exposure of individual soldiers.
Dr. McBride said the findings were not at odds with evidence
needed for compensation from Veterans Affairs New Zealand for
ill-health caused by service in the Vietnam War.
He said the pattern of lower overall mortality was known as
the 'healthy soldier effect' which was related to the fact
the soldiers would have been selected for health and fitness.
Further work was still needed, including the selection of a
non-deployed comparison group to reduce the 'healthy soldier
The study, funded by the War Pensions Medical Research Trust
Fund, is due to appear shortly in the international journal