Burmese Army Chemical Weapon used ---Yellow Rain (acid rain) in Mai Ja Yang Photos (20-11-2011
1. Featured Articles Archive
A Note from History: Yellow Rain
Photo From Web site Photo From Mai Ja Yang
T-2 mycotoxin
1975, following the Vietnam War, the communist governments of Vietnam and Laos launched a retaliatory
campaign against Hmong tribesmen in northern Laos, who had sided with the United States during the war and
continued to resist communist rule. That summer, reports came from Laos claiming that government forces
were using Soviet-supplied chemical weapons to drive the Hmong out of their mountain hideaways. Refugees
reported that toxic agents were being delivered by low-flying aircraft; most described an oily, yellow liquid that
sounded like rain when it struck leaves or roofs, earning it the nickname "yellow rain."
Many people exposed to yellow rain suffered physical and neurological symptoms, including seizures,
blindness, and bleeding. Similar attacks were reported during the Vietnamese invasion of Cambodia in 1978,
and in Afghanistan in 1979. Reports from Chinese analysts suggest that nearly 10,000 people died from these
incidents between 1975 and 1982. The similarities between the descriptions of the attacks and subsequent
symptoms raised suspicions that the same agent had been used in all three locations.
2. Initially, U.S. chemical weapons experts were baffled by yellow rain. The symptoms described by refugees did
not match the effects of any known chemical weapon agent. However, in July 1981, a U.S. Army toxicologist
noted a striking similarity between the symptoms of yellow rain exposure and those resulting from exposure to
fungal toxins called trichothecene mycotoxins. Mycotoxins are naturally occurring substances produced by
fungi, many of which can be harmful to animals and humans. Trichothecene mycotoxins comprise a group of
more than 40 compounds found in common grain mold. Laboratory analysis of a yellow rain sample taken from
an alleged attack site in Laos identified three different trichothecenes present in concentrations and
combinations not known to occur in nature.
Trichothecene mycotoxins are believed to have been discovered accidentally by the Soviet military during
World War II. During that time, thousands of Soviet civilians were afflicted with alimentary toxic aleukia, a
highly lethal disease with symptoms resembling radiation poisoning. The disease was caused by the ingestion of
bread made with flour contaminated by fusarium mold, which had grown on wheat left in fields all winter long,
due to the war. This outbreak spurred intensive Soviet research on mycotoxin poisoning as a public health threat.
The Soviet Union also had some manner of ties to each of the locations where yellow rain had been reported:
the Soviets supported the Communist Vietnamese forces and the Pathet Lao political movement in Laos and
Cambodia, and were directly involved in the war in Afghanistan. U.S. intelligence hypothesized that the Soviets
had recognized the military potential of trichothecenes and developed them as weapons. In 1981, based on this
hypothesis and the laboratory findings, then U.S. Secretary of State Alexander Haig announced that physical
evidence had been found, proving that mycotoxins supplied by the Soviet Union were being used as a weapon
against civilians and insurgents in Southeast Asia and Afghanistan.
The U. S. allegation was not universally accepted. Some nations were unsuccessful in identifying mycotoxins in
yellow rain samples, and the United Nations found the evidence to be inconclusive. In 1987, a group of
academic scientists, led by Harvard molecular biologist Matthew Meselson, traveled to Laos to conduct an
investigation. The team noted that some trichothecene mycotoxins occurred naturally in the region. Based on
this and the presence of pollen in some yellow rain samples, the team offered an alternative hypothesis that the
yellow rain phenomenon was not a chemical attack, but the result of massive swarms of bees depositing feces
over the areas. Such swarms have been documented before and since the yellow rain incidents—although mass
casualties did not result from these swarms. An example of one such swarm occurred in India in 2002. This
incident is cited by proponents of the bee feces hypothesis as supporting evidence. At that time, a yellow-green
rain fell from the sky on the town of Sangrampur, near Calcutta. Fears arose that the rain might be contaminated
with toxins or chemical warfare agents, but scientists confirmed that the yellow-green droplets were, in fact, bee
feces containing pollen from local mangoes and coconuts. The scientists concluded that the colored rain could
have been caused by the migration of a giant swarm of Asian honeybees.
The U.S. government has never retracted the yellow rain allegations, and the controversy has never been fully
resolved. A declassified CIA intelligence document written in 1983, suggests that the Soviet Union developed
weapons based on trichothecene mycotoxins as early as 1941 and may have tested them on political prisoners.
The Soviet Union never declared any stockpiles of trichothecene mycotoxins among their stores of chemical
and biological weapons, however, and no trace of a trichothecene-containing weapon was ever found in the
areas affected by yellow rain. Their use may never be unequivocally proved.