NEW INFORMATION ON AGENT ORANGE:
A study has increased
the estimate of how much Agent Orange and other dioxin-tainted defoliants the
U.S. military sprayed during the Vietnam War. But it remains unclear whether
the increased amount raises the illness risk of those exposed, scientists say.
Re-examining
military records, researchers at the Columbia University School of Public
Health determined that about 21 million gallons of the herbicides were sprayed
from 1961 to 1971 - 1.84 million gallons, or 10 percent, more than previously
believed.
About
55 percent of the defoliant was Agent Orange - nicknamed for the color of the
identification band on its storage containers. Scientists said the other herbicides,
such as Agent Pink, were closely related to Agent Orange but even more potent.
Two-thirds
of the herbicides were contaminated with the most dangerous form of dioxin,
TCDD, which is associated with cancers, neurological disorders, miscarriages
and birth defects.
Details
of the study appear in the current issue of the journal Nature.
Agent
Orange toxins persist in soil and water in parts of the southern half of
Vietnam. Tree cover has re-grown in many locations, but chemicals have migrated
into the tissues of fish and fowl that local residents eat.
Studies
by U.S. scientists show that blood samples from residents in exposed
communities contain dioxin at levels 135 times higher than blood from areas
that were not sprayed.
In
1999, Vietnam conducted its own Agent Orange survey, but details were not made
public.
``Cancer,
miscarriages and birth defects in the sprayed areas are always higher than in
the areas not sprayed,'' said Tran Manh Hung of the special committee on Agent
Orange in Vietnam's Ministry of Health. ``It might take another 50 years before
those rates become equal.''
The
Columbia researchers suggest 2.1 million to 4.8 million people were living in
3,181 villages that were directly sprayed.
But
other scientists said the work ``does little'' to determine the health
consequences of the campaign to deny jungle cover along supply trails used by
communist forces.
``What
is important from a health perspective is what gets into humans, not what is
sprayed,'' said Arnold Schecter of the University of Texas School of Public
Health. Schecter has conducted dioxin research in Vietnam since 1984.
``Whether
the amount of herbicides is a bit higher and the TCDD content a bit heavier,''
Schecter said, ``what counts for health purposes is the dose the person receives.''
Last
year, U.S. and Vietnam conducted their first joint conference on Agent Orange
exposure.
In
January, the Department of Veterans Affairs extended extra benefits to U.S.
veterans suffering from a form of leukemia after researchers found a link to Agent
Orange. About 10,000 Vietnam vets receive disability benefits related to the
herbicide.
Joseph
B. Verrengia, Associated Press
Published
April 16, 2003
Those involved in the
Vietnam War, including Australian troops, were exposed to twice the amount of
dioxin in Agent Orange than previously thought, according to the journal Nature.
The total amount of
the herbicide sprayed was underestimated by between seven and nine million
liters, said US researchers who revised US military documents and corrected
their errors.
About 10 per cent of
the herbicide was used, but the missing inventory contained some of the most
dioxin-rich herbicides - dioxin being the toxic active ingredient blamed for
diseases and birth defects suffered by millions of Vietnamese and war veterans
and their children.
The researchers, from
New York's Colombia University and the Institute for Cancer, said the data
revealed that "millions of Vietnamese were likely to have been sprayed
upon directly" .
Agents Orange, Pink,
Green, Purple, White and Blue were sprayed by US planes in Vietnam between 1962
and 1971 to defoliate jungle cover for communist troops, and ruin the crops
needed to feed them.
The researchers
tracked down US Defense Department documents, including the HERBS file - the
flight paths of air force spraying missions between 1965 and 1971.
"The HERBS file
error rate was about 10 per cent, attributable largely to transcription, data
entry and pilot-recording errors," wrote the researchers.
One of the paper's
co-authors, Dr Jeanne Stellman, said: "It's difficult to say who bore the
brunt of the increased dioxin.
"The Aussies were
in the Rung Sat area, which was the most heavily sprayed area of Vietnam over
the course of the war. No-one knows the extent to which presence of dioxin in
the soil could have affected troops serving there.
"Hopefully, in a
few years (before all the veterans are dead) we will be able to know these
overdue answer ... I am certain that Australian researchers will be very
interested in our methodology - we've had lots of contact with them."
The HERBS file were
first assessed in 1974 by the National Academy of Sciences.
"We have
re-estimated the volume and type of herbicides sprayed between 1961 and 1971 to
have 7,131,907 more liters than the 'uncorrected' NAS-1974 inventory and
9,440,028 liters more than NAS-1974's 'corrected' inventory, in which about 10
per cent of all missions had been discarded because of obvious recording
errors," wrote the researchers.
The national president
of the Vietnam Veterans' Association of Australia, Brian McKenzie, questioned
whether the original data was wrong by accident or by purpose.
"The whole thing
[Agent Orange] has been a series of cover-ups during the war and ever
since."
A 1998 Department of
Veterans Affairs survey of Vietnam War veterans' health found that among
veterans' children:
·
Spina Bifida was 10 times the expected rate.
·
Cleft palates were more than four times higher.
·
Absent body parts 10 times higher.
·
Suicide rates three times the rate of the
general population.
·
Cancers, anxiety, psychiatric disorders,
accidental death were significantly elevated.
By Stephen
Cauchi
April 17 2003
