Agent Orange was an herbicide employed during the Second Indochina War
commonly referred to as the Viet Nam War. Agent Orange was not the only
herbicide sprayed in Vietnam although, due to its intensified usage,
it is the herbicide most commonly mentioned and blamed for health problems
in connection with that period in history. There were two other herbicides,
an insecticide and a chemical irritant used during the Second Indochina War.
They each were called by code names: Agent Blue, Agent Orange, Agent White,
CS and Malathion.
Agent Blue: code name for cacodylic acid (dimethyl arsenic acid; 371.5 km/m3)
Agent Orange: code name for mixture of 2,4,5-T (2,4,5.-trichlorophenoxyacetic
acid; 545.4 Kg/m3) and 2,4-D (2,4-dichlorophenoxyacetic acid;
485.1 kg/m3), altogether weighing 1 285 kg/m3; a herbicide;
associated with the (2,4,5-T moiety is the impurity dioxin
(2,3,7,8-tetrachlorodibenzo-p- dioxin).
Agent White: code name for a mixture of an approximate ratio of 4:1 of 2,4-D
(2,4-dichlorophenoxyacetic acid; 239.7 kg/m3) and picloram
(4-amino-3,5,6-trichloropicolinic acid; 64.7 kg/m3)
CS (o -chlorobenzalmalonitrile), an anti-personnel (harassing) agent,
was used as an irritant from 1964 to 1970.
Malathion (S-(1,2-dicarbethoxyethyl)-0, 0-dimethyldithiophosphate), an
insecticide, was sprayed from 1967 to 1972.
Agent Orange (A-O) and Agent White (A-W) contain mixtures of plant hormone
mimicking compounds which destroy plants by interfering with their normal
metabolism. Agent Blue (A-B) destroys vegetation by preventing plants from
retaining moisture. These chemical products were used in Viet Nam during the
years 1961 to 1971. The three year period from 1967 to 1969 herbicide usage
was at its heaviest. A-O (61% usage) and A-W were effective against
dicotyledonous plants (two leaves emerging from seed) and A-B (11% usage)
was used for monocotyledonous plants (single leaf emerging from seed). A-W
and A-O were used to destroy the forests of South Viet Nam while A-B was
mainly used for the destruction of grain crops, particularly the staple crop
of rice. The levels of usage for military operations was 20 to 40 times
greater than for normal agricultural usages. These chemicals were dispensed
by fixed-wing aircraft and ground troops.
Loss of foliage, flower and fruit occurred within two to three weeks after
spraying. Not all of the trees died and a large percentage of those surviving
trees were permanently damaged. Environmentally, because it was in a tropical
area, there was an increase in soil nutrient loss and an acceleration in soil
erosion. Dioxin has an environmental half life of about three years or more
and has shown up in the food chain. The effect of A-O on humans has been an
area of intense debate for the past two decades. It has now been thoroughly
established that dioxin is a very potent poison. It can cause a wide range
of organ and metabolic dysfunctions. In laboratory animals dioxin has shown
to be carcinogenic (causing cancer ) and teratogenic (causing birth defects)
and mutagenic (causing genetic damage). I have listed a summary of reported
Agent Orange symptoms and effects at the end of this article.
--
原來agent orange是橘劑.. 我現在才知道.. ><
--
"They say that dreams always end"
- Ian Curtis
"Dreams never end..."
- New Order
--
※ 發信站: 批踢踢實業坊(ptt.twbbs.org)
◆ From: 211.21.92.219