Vietnam veterans who served from
1962-1971 have double the rate of chronic lymphatic leukemia compared to the
general population according to a new study by the University of Otago’s
Department of Preventive and Social Medicine.
Nearly
3400 New Zealand military personnel served in Vietnam and the study examined
the health records of 2752 men from 1988 to 2008. This is the first cohort
study of New Zealand Vietnam veterans which assesses long-term health effects
of serving in a combat zone.
The
study says most veterans deployed in the Nui Dat area of Phuoc Tuy province,
experienced a ‘toxic environment’ because of the widespread use of 2,4,5-T and
2,4-D as defoliant herbicides.
This
mixture is more commonly known as Agent Orange and was contaminated with the
carcinogen 2,3,7,8,TCDD, or ‘dioxin’. However the study does not have specific
data on herbicide exposure of individual soldiers.
The US
Institute of Medicine, in their report ‘Veterans and Agent Orange: Health
Effects of Herbicides Used in Vietnam’ first classified chronic lymphatic leukemia
on their ‘sufficient evidence for cancer’ list in 2002, based on dioxin
toxicity and studies of farm workers exposed to herbicides. The cohorts of
Australian and New Zealand soldiers are the only group of Vietnam veterans to
show an actual excess of the disease.
The
results also show that although 407 veterans died over the study period the
overall rate of death from all causes was 15% lower than the general population
suggesting lower incidence of mortality and morbidity. Mortality from cancer
was not significantly lower or higher however than the general population, and
there was no decrease in ‘all cancer’ incidence.
“The
pattern of lower overall mortality is known as the ‘healthy soldier effect’
which is related to the fact that this cohort would have been selected for its
health and fitness,” says lead author Dr David McBride.
“However
the study shows 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.”
Dr McBride and colleagues say
the findings are not at odds with evidence needed for compensation from
Veterans Affairs New Zealand for ill-health caused by service in the Vietnam
War.
The researchers say that
further work is still needed, including the selection of a non-deployed
comparison group to reduce the ‘healthy soldier effect.’ As some of the cancers
are also associated with smoking and alcohol consumption there is a need to
collect further information on confounding factors such as ethnicity, smoking
and alcohol use.
The
current study will shortly appear in the international journal BMJ Open and
was funded by the War Pensions Medical Research Trust Fund. A copy of the paper
is available on request to Dr McBride.
The
University of Otago Research Theme ‘Health of Veterans, Serving Personnel and
their Families’ is holding its annual two-day colloquium on Tuesday the 3rd and
Wednesday the 4th of September, hosted by the Dunedin Club.
Unfortunately this study was based on the premise that the percentage of Maori that served in the New Zealand Army was the same as the general population which this study was based on. The percentage of Maori that served in Vietnam was in the region of twice the national percentage...............Maori males have twice the mortality rate of caucasians (Statistics NZ). In fact we, the veterans, mirror the 2003 Australian study of having a 7% better mortality rate than the general male population,
ReplyDeleteDue to the trickle reinforcement system the US military used it is difficult to trace exposure whereas the the Australian and New Zealand forces moved and were replaced as entire units. So far there is no evidence increased health effects outside of those that were evident from past wars ie, difficulty in maintaining relationships and on going PTSD. which lead to life style cancers from excessive use of alcohol, tobacco and fast food,,,