Similar incidents were reported in Democratic Kampuchea Cambodia in , after the Vietnamese Army invaded that country to topple the dictator Pol Pot and his murderous Khmer Rouge regime.
Put on a yellow rain slicker, climb aboard a rail car and rumble into the heart of a mountain. Five must-see small towns," 13 Oct. First Known Use of yellow rain , in the meaning defined above. Learn More about yellow rain. Resources for yellow rain Time Traveler! Explore the year a word first appeared. Dictionary Entries near yellow rain yellow pyrites yellow rabbitbrush yellow rail yellow rain yellow rain lily yellow rattle yellow redpoll.
Statistics for yellow rain Look-up Popularity. Time Traveler for yellow rain The first known use of yellow rain was in See more words from the same year. More Definitions for yellow rain. More from Merriam-Webster on yellow rain See words that rhyme with yellow rain. Comments on yellow rain What made you want to look up yellow rain? Secretary of State Alexander Haig announced in September that:.
The Soviet Union described these accusations as a "big lie" and in turn accused the US government of using chemical weapons during the Vietnam War. This involved five doctors and scientists who interviewed alleged witnesses and collected samples that were purported to come from Afghanistan and Cambodia.
However, the interviews produced conflicting testimony and the analyses of the samples were inconclusive. The UN experts also examined two refugees who claimed to be suffering from the after-effects of a chemical attack, but the refugees were instead diagnosed as having fungal skin infections. The team reported that they were unable to verify that chemical weapons had been used but noted that circumstantial evidence "suggestive of the possible use of some sort of toxic chemical substance in some instances.
The US mycotoxin analyses were reported in the scientific literature in and and reported small amounts of mycotoxins called trichothecenes , ranging from the parts per million to traces in the parts per billion range. Mirocha at the University of Minnesota conducted a biochemical investigation, looking for the presence of trichothecene mycotoxins, including T-2 toxin, diacetoxyscirpenol DAS , and deoxynivalenol DON.
The most compelling evidence is the presence of T-2 and DAS in the yellow powder. Both toxins are infrequently found in nature and rarely occur together. In our experience, copious producers of T-2 toxin F. In , these charges were disputed by Harvard biologist and biological weapons opponent Matthew Meselson and his team, who traveled to Laos and conducted a separate investigation. Meselson's team noted that trichothecene mycotoxins occur naturally in the region and questioned the witness testimony.
He suggested an alternate hypothesis that the yellow rain was the harmless fecal matter of honeybees. The US government responded to these findings by arguing that the pollen was added deliberately, in order to make a substance that could be easily inhaled and "ensure the retention of toxins in the human body".
After the honeybee hypothesis was made public, a literature search turned up an earlier Chinese paper  on the phenomenon of yellow droppings in Jiangsu Province in September Strikingly, the Chinese villagers had also used the term "yellow rain" to describe this phenomenon. Many villagers believed that the yellow droppings were portents of imminent earthquake activity. Others believed that the droppings were chemical weapons sprayed by the Soviet Union or Taiwan.
However, the Chinese scientists also concluded that the droppings came from bees. Analyses of putative "yellow rain" samples by the British, French and Swedish governments confirmed the presence of pollen and failed to find any trace of mycotoxins. Surveys also showed that both mycotoxin-producing fungi and mycotoxin contamination were common in Southeast Asia, casting doubt on the assertion that detecting these compounds was an unusual occurrence.
In , the New York Times reported that Freedom of Information requests showed that field investigations in —85 by US government teams had produced no evidence to substantiate the initial allegations and instead cast doubt on the reliability of the initial reports, but these critical reports were not released to the public.
These issues included the US Army team only interviewing those people who claimed to have knowledge of attacks with chemical weapons and the investigators asking leading questions during interviews. The authors noted that individuals' stories changed over time, were inconsistent with other accounts, and that the people who claimed to have been eyewitnesses when first interviewed later stated that they had been relaying the accounts of others.
In , Meselson had visited a Hmong refugee camp with samples of bee droppings that he had collected in Thailand. Most of the Hmong he interviewed claimed that these were samples of the chemical weapons that they had been attacked with. One man accurately identified them as insect droppings, but switched to the chemical weapons story after discussion with fellow Hmong.
Australian military scientist Rod Barton visited Thailand in , and discovered that Thai villagers were blaming yellow rain for a variety of ailments, including scabies. An American doctor in Bangkok explained that the United States had been taking a special interest in yellow rain, and was providing medical care to alleged victims. Most of the Hmong he interviewed claimed that these were samples of the chemical weapons that they had been attacked with.
One man accurately identified them as insect droppings, but switched to the chemical weapons story after discussion with fellow Hmong. Australian military scientist Rod Barton visited Thailand in , and discovered that Thai villagers were blaming yellow rain for a variety of ailments, including scabies. An American doctor in Bangkok explained that the United States had been taking a special interest in yellow rain, and was providing medical care to alleged victims.
A CIA report from the s reported allegations by the Cambodian government that their forces had been attacked with chemical weapons, leaving behind a yellow powder. The Cambodians blamed the United States for these alleged chemical attacks. Some of the samples of "yellow rain" collected from Cambodia in tested positive for CS , which the United States had used during the Vietnam War.
CS is a form of tear gas and is not toxic, but may account for some of the milder symptoms reported by the Hmong villagers. Currently, two main viewpoints exist on the yellow rain controversy. One viewpoint sees these allegations as supported by insufficient evidence, or as having been completely refuted. For instance, a review published in Politics and the Life Sciences described the idea of yellow rain as a biological agent as conclusively disproved and called for an assessment by the US government of the mistakes made in this episode, stating that "the present approach of sweeping the matter under the rug and hoping people will forget about it could be counterproductive.
In contrast, as of the US Army maintains that some experts believe that "trichothecenes were used as biological weapons in Southeast Asia and Afghanistan" although they write that "it has not been possible for the United States to prove unequivocally that trichothecene mycotoxins were used as biological weapons.
An episode of mass pollen release from bees in in Sangrampur, India , prompted unfounded fears of a chemical weapons attack, although this was in fact due to a mass migration of giant Asian honeybees.
This event revived memories of what New Scientist described as "cold war paranoia", and the article noted that the Wall Street Journal had covered these s yellow rain allegations in particular detail. In the build-up to the invasion of Iraq the Wall Street Journal alleged that Saddam Hussein possessed a chemical weapon called "yellow rain". Henry Wilde, a retired US Foreign Service Officer, has drawn parallels between the use of yellow rain allegations by the US government against the Soviet Union and the later exaggerated allegations on the topic of Iraq and weapons of mass destruction.
In the science-themed show Radiolab aired an interview with Hmong refugee Eng Yang and his niece, author Kao Kalia Yang , to discuss Eng Yang's experience with yellow rain.
The hosts took the position that yellow rain was unlikely to have been a chemical agent. The episode prompted a backlash among listeners, who criticized the hosts for insensitivity, racism, and their disregard for Yang's personal experience with the region in question. Sign In Don't have an account? T-2 mycotoxin Yellow rain was the subject of a political incident in which the United States Secretary of State Alexander Haig accused the Soviet Union of supplying T-2 mycotoxin to the Communist states in Vietnam and Laos for use in counterinsurgency warfare.
Lessons for Arms Control Compliance". It's yellow from digested pollen grains, and it rains down from swarms of bees too high to be seen. His theory turns out to be exactly right.
The Government's own studies, still unpublished, prove that the source is bees, not bombs.
Yellow rain was the subject of a political incident in which the United States Secretary of State Alexander Haig accused the Soviet Union of supplying T-2 mycotoxin to the Communist states in Vietnam, Laos and Cambodia for use in counterinsurgency warfare. Yellow rain, airborne substance that was alleged to have been used in biological attacks in Southeast Asia from the mids to the mids. Yellow rain definition is - a yellow substance that has occurred in southeastern Asia as a mist or as spots on rocks and vegetation and has been held to be a biological warfare agent used in the Vietnam War but appears upon scientific examination to be identical to pollen-laden bee feces.