Swiss scientists discovered unexpectedly high levels of polonium despite fears body would not yield much evidence
When Palestinian officials opened up Yasser Arafat‘s grave in November last year, the international scientists standing by were not sure whether the naturally decayed corpse would yield many secrets. The Swiss team present had already found that biological samples on Arafat’s final belongings, including urine-stained underwear and blood from a hospital hat, showed “significant quantities” of polonium-210, the lethal substance used to assassinate the Russian dissident Alexander Litvinenko.
The scientists now wanted to test Arafat’s remains for traces of the radioactive substance to establish whether he might have been poisoned by polonium, which he would have to have ingested – perhaps administered to him in food or drink. But polonium decays rapidly. Eight years after burial, it was unclear what state the corpse was in. Certainly, the soft tissue of the liver and kidneys – which would have been best able to show any alleged polonium poisoning had there been an autopsy at the time of death – would now have decomposed. So the teams would have to rely on bone fragments and scraps of tissue still present around bones and on the death shroud.
Despite worries about decomposition, the Swiss team’s report, which was obtained by al-Jazeera and shared with the Guardian prior to publication, found the bone and tissue fragments from the corpse showed “unexpectedly high” levels of radioactive polonium-210. David Barclay, a British forensic scientist who had studied the report, said it contained strong evidence of levels of polonium at least 18 times higher than the norm in Arafat’s ribs, pelvis and in soil that absorbed his leaked bodily fluids. Barclay called the report’s findings “a smoking gun”.
The 108-page report describes how Arafat’s corpse was located at a depth of around four metres below his mausoleum in Ramallah. With high relative humidity of 70% and temperatures of 17C, the body, which was lying facing upwards, with the left lower leg slightly bent over the right, was “almost skeletonised”. All the bones showed a dark-brown discolouration but there were remnants of some soft tissue material, such from the abdominal cavity, as well as some hair in the cranial area. A Palestinian medical investigator collected 20 specimens from Arafat’s corpse and grave during the exhumation and handed samples of each to three international teams – Swiss, French and Russian – in the presence of additional representatives from the French justice system which is conducting a murder inquiry. The specimens included a tooth, fragments from the scalp, bones such as rib and pelvis bones and remnants of the death shroud. Also collected was soil from the grave, some of which bore a black stain where bodily fluid had seeped. Some tissue matter was able to be scraped from bones.
The Swiss report concluded that even taking into account the eight years since Arafat’s death and the quality of specimens taken from bone fragments and tissue scraped from his decayed corpse and shroud, the results “moderately support the proposition that the death was the consequence of poisoning with polonium-210”.
The scientists examined at the length what they called the “pros and cons” of the theory that Arafat’s death was caused by polonium-210 poisoning. They list a number of points that support the notion that Arafat could have been poisoned by polonium, especially the “sudden and brutal onset” of his stomach complaints following a meal “in a patient who was otherwise in general good health”.
First, the scientists felt that the acute onset of gastro-intestinal symptoms in Arafat, who first fell ill four hours after eating dinner in October 2004, as well as the progressive deterioration of his state in the following weeks were “compatible with ingestion of a large quantity of radioactivity”. That Arafat died one month after the onset of symptoms also supported the idea of an acute intoxication. Similarly, the development of Arafat’s final symptoms, and his death from a blood condition known as disseminated intravascular coagulation, or DIC, was “compatible with an acute toxin pathology, possibly the radiosotope polonium-210”.
The scientists first found “significant” quantities of polonium-210 on Arafat’s final clothing and belongings which they analysed in early 2012. They then found “unexpectedly high” polonium-210 activity in the specimens collected during the exhumation in November 2012.
The team also pointed out and analysed in depth the presence of lead in the specimens from the corpse. They said this was likely to be compatible with lead impurities measured in sources of polonium-210. Barclay, after studying the report, explained that lead may be present when polonium is made in a reactor. The report found that the presence and distribution of the lead and polonium were compatible with “an acute intake” occurring just before Arafat’s clinical symptoms began, four hours after his dinner on 12 October. The scientists stated: “No other cause to explain the onset of the symptoms could be identified.” The negative results of initial toxicology tests three weeks after Arafat first fell ill and shortly before he died could be explained by “metabolism or elimination of some toxic agents” over the course of those weeks, they said. They also pointed out that those tests could not have eliminated every possible toxic substance. They added that at the time of those tests in 2004, polonium-210 poisoning was not documented except that it was known to be toxic.
Examining the case against the theory of possible polonium poisoning, the team said that the “acute radiation syndrome” that polonium poisoning would have caused often includes hair-loss and decreased bone marrow activity, while Arafat had not lost his hair or displayed the bone marrow symptoms. But the team said those two factors were not always found in poisoning cases. They were more often associated with external radiation exposure, not always with internal exposure. For Arafat to have been killed by polonium-210, he would have need to have ingested the poison and would have been exposed internally.