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Frequently Asked
Questions
about Agent
Orange/Dioxin
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Agent Orange Fact Sheet
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Efforts to Address
Agent Orange
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Overview
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Hotspot Clean-up
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Health Effects
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Clarity on Two Terms
Agent orange—was
one of a class of color-coded herbicides that US forces
sprayed over the rural landscape in Vietnam to kill trees,
shrubs and food crops over large areas. Agent orange was a
50/50 mixture of two individual herbicides, 2,4-D and
2,4,5-T. It remained toxic over a short period--a scale of
days or weeks-- and then degraded. The production of agent
orange was halted in the 1970s, existing stocks were
destroyed and it is no longer used. The effects of agent
orange do however persist in the form of ecologically
degraded landscapes in parts of the hilly and mountainous
areas of Vietnam. The pre-war forests that existed in most
of these areas took hundreds of years to reach an
ecologically-balanced mixture of large numbers of species of
flora and fauna. Natural regeneration would take centuries
to reproduce those landscapes. In addition, in some of the
sprayed areas soil erosion and landslides have sharply
lowered soil nutrient levels and altered the topographical
features of the landscape. These changes have encouraged a
few species of invasive grasses of low value. Active
replanting with species of trees and shrubs which are
ecologically viable and have economic value will require
substantial and sustained long term investment.
Dioxin—
is a member of the class of persistent organic pollutants
which resulted from the deliberately accelerated production
of 2,4,5-T, one of the components of agent orange. Dioxin
can shorten the life of humans exposed to it and is
associated with severe degradation of health in this and,
potentially, future generations. Dioxin is toxic over a long
period--a scale of many decades-- and does not degrade
readily. Dioxin is not absorbed by plants nor is it water
soluble. It can attach to fine soil particles or sediment,
which are then carried by water downstream and settle in the
bottoms of ponds and lakes. It continues to adversely affect
people who eat dioxin-contaminated fish, molluscs and fowl
produced around a handful of point sources of dioxin called
dioxin "hot spots." Dioxin's continuing impact can be slowed
or halted by genetic counselling, cutting the dioxin
exposure pathways in the human food chain and by
environmental remediation of contaminated sites. The adverse
effects of dioxin on human health can be ameliorated in most
cases if detected early, but they cannot be fully corrected
in some cases by any amount of time or money. If dioxin
permanently alters the intricate internal cellular and
chemical balances involved in maintaining good human health,
there is serious risk of life-long health problems which may
ultimately lead to mortality.
(Written by Wayne Dwernychuk, Hatfield Consultants and
Charles Bailey, Director, Ford Foundation Special Initiative
on Agent Orange)
References:
Institute of Medicine, 2001. Veterans and Agent Orange
update 2000. National Academy Press, Washington, DC.
Dwernychuk, L. Wayne, Cau, H.D., Hatfield, C.T., Boivin, T.G.,
Hung, T.M., Dung, P.T., Thai, N.D. 2002. Dioxin reservoirs
in southern Viet Nam - A legacy of Agent Orange. Chemosphere
47, 117-137.
Stellman Jeanne Mager, Steven D. Stellman, Richard
Christian, Tracy Weber & Carrie Tomasallo, 2003. The extent
and patterns of usage of Agent Orange and other herbicides
in Vietnam. Nature 422: 686-687.
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