Lausanne, Switzerland – As director of the Institute of Radiophysics in Lausanne, Dr Francois Bochud lead a team of scientists whose tests revealed in 2012 that biological samples on Arafat's final personal effects - his clothes, toothbrush, a hospital cap and underwear - contained abnormal levels of the radioactive element polonium.
The institute is affiliated with the city’s University Hospital and the Centre of Legal Medicine, and is considered one of the best forensic pathology labs in the world.
It has studied evidence for the UN in East Timor and the International Criminal Court in the former Yugoslavia. It investigated the death of Princess Diana, among other cases.
In January 2012, Al Jazeera's manager of investigative journalism, Clayton Swisher, contacted the labs on behalf of Arafat’s widow, Ms Suha Arafat, to initiate a forensic review of her late husband's death. In February 2012, the labs were given Arafat’s medical files and a bag containing the personal effects that accompanied him to a French military hospital, where he died.
Following the broadcast of What Killed Arafat in July 2012, French authorities opened a murder investigation into Arafat’s death. This paved the way to Arafat’s exhumation on November 27, 2012.
Once again, Professor Bochud and his team were asked to investigate, this time by the Palestinian Authority. The Swiss, along with French and Russian scientists, received 20 of a total of 60 samples taken from Arafat’s flesh and bones.
Speaking to Al Jazeera’s David Poort in Lausanne, Bochud elaborated on the outcome of his investigation.
David Poort: How would you explain the findings in your report to someone who is not a scientist?
Francois Bochud: We preformed quite a lot of measurements and we observed higher than expected levels of polonium and lead. We ruled out that the origin of what we measured was coming from radon, which is a natural gas.
We took great care of measuring different parts of the body and different parts of the tomb and we arrived to the conclusion that it was not possible to explain what we did measure. The polonium that we did measure is actually the supported kind of polonium, the same kind of polonium that you would find naturally. The difference is the level; we observed a much higher level than what we were expecting to see normally.
DP: Based on the measurements by your team, Al Jazeera reported that Yasser Arafat had 18 times the expected level of polonium in his bones. How would you qualify that estimate?
FB: I think this is conservative, because the normal levels are actually between 25 and 50 [mBq/g Ca], depending on the literature. And the maximum level that we measured was 900, so you can make the calculations quite easily. But we have to point out that this is supported polonium; the kind of polonium that is supported by lead.
DP: A conclusion that could be derived from the report is that you are confident up to an 83 percent level that Yasser Arafat died of polonium poisoning. Could you explain where that percentage is coming from?
FB: We tried to estimate as much as possible how we could see the coherence of our data with the hypothesis of “being poisoned” or “not being poisoned” and we arrived to a six level scale. We still want to stick by this scale – we say that our observations “moderately support” the hypothesis of Arafat being poisoned. The number that you obtained of 83 percent is actually a simple division of this six level scale. While this is explainable and understandable, this is not the way I would like to pronounce it. I don’t want to give a figure. I prefer to say “moderately support” because we do not have enough evidence to give a figure.
DP: How significant are these unnatural levels of polonium that you measured if you also look at all other evidence?
FB: I think this is really significant because if we compare all the measurements that we performed over the last 10 years and when we compare it with general literature, we see that all the values that have been published in the past are clearly below what we observed in Arafat’s bones.
DP: What should a reasonable person conclude from seeing these results?
FB: If I would go into the body of someone who is asked to interpret these results, I would say that our conclusion pushes towards the hypothesis that Arafat was poisoned. But I cannot say that there is an X or Y percentage level. I can just analyse my data and see how coherent it is with one of the two hypotheses.
DP: The levels of polonium measured in the pelvis and ribs were much higher than in other bones. What is the explanation for that?
FB: We didn’t take any samples from - for example - the skull because we thought that this would not be the best kind of bone sample to measure. It is not as vascularised as other bones and therefore not the bone that would collect the highest quantity of polonium. So we decided not to collect any skull samples when were in the tomb in Ramallah.
DP: Is there any clarity on where the polonium that you found came from?
FB: We did not find the “passport” of the polonium. The only thing that we could tell from our measurements was the quantity of the polonium and the quantity of lead and we tried to fit this in the landscape of all our measurements and try to analyse everything globally and conclude that our observations “moderately support” the poisoning hypothesis.
DP: Would you have found that passport if an autopsy was done right after Arafat’s death?
FB: I don’t think it would have been possible to find it. For this we would’ve needed samples from different reactors and this information is usually quite secret. We don’t even know anything about the case of [former Russian spy Alexander] Litvinenko. So I think it would have been difficult to find that signature.
DP: So, if Arafat was indeed poisoned, it was a job well done from the culprit’s point of view?
FB: I think it was well done if it was poisoning. But I think we managed to find some evidence that is coherent with poisoning.