Chapter 5: Scientific examination of Alexander Litvinenko's body

¶3.151 Many scientific investigations and tests have been conducted on Mr Litvinenko's body,

and on samples taken from it. This process started before Mr Litvinenko's death with the array of tests that were commissioned by the treating clinicians. At the same time, frequent observations were taken and recorded in Mr Litvinenko's medical notes. I have referred to some of the tests and observations above. I have also referred to the tests conducted on samples of Mr Litvinenko's blood and urine at AWE, which revealed for the first time excess levels of polonium in his body.

¶3.152 The process of testing and investigation continued after Mr Litvinenko's death, first

with a post mortem examination and thereafter with a series of tests on samples taken from his body. This process has generated a considerable quantity of data, which has been set out and analysed in a series of statements and reports written by a variety of experts. All this material has been in evidence before me.

¶3.153 This scientific material has not been put into the public domain prior to these

proceedings (although some of it was used as the basis for a paper published in a scientific journal in 2007).188

¶3.154 I am aware that some commentators have suggested that there may be something

sinister about the fact that this material has not so far been presented publicly – for example, that it may be part of a cover up orchestrated by the British government. I would simply observe that it is normal in this jurisdiction for medical and scientific reports and records of this type not to be made public until they have been used in court proceedings relating to the death. In Mr Litvinenko's case, this Inquiry is the first substantive set of proceedings that has taken place with regard to his death. I would not therefore have expected this material to have been published prior to my Inquiry. I should add that my team and I have studied thousands of government documents that relate to Mr Litvinenko's death. They do not contain anything to suggest that there has been deliberate concealment of relevant material. The fact that this material has not hitherto been put into the public domain is simply a consequence of normal procedures being followed, albeit that in this case – given its exceptional features – it has taken longer than normal for those procedures to run their course.

¶3.155 Further and in any event, all this material has now been published by the Inquiry.

Anyone who wishes to refer to the detail of the scientific investigation that has taken place may now access the underlying documents by means of the Inquiry website. The key documents are tabulated at Appendix 8.

¶3.156 What I propose to do in the remainder of this section of the Report is to identify

the more important conclusions that the scientists have reached as a result of their analysis, and to consider the evidence that I received in respect of those conclusions.

¶The raised levels of polonium 210 in Mr Litvinenko's body 3.157 As I have already noted, the first tests that identified raised levels of polonium 210 in

Mr Litvinenko's body were the tests conducted at the AWE in Aldermaston on 21 and 22 November 2006 – i.e. very shortly before Mr Litvinenko's death.189

¶The Litvinenko Inquiry

¶3.158 Following Mr Litvinenko's death, measurements of polonium 210 were taken using

tissue samples from Mr Litvinenko's lung, spleen, kidneys and liver, using gamma ray spectrometry. These tests showed raised levels in each of the organs, with the highest result (49,000Bq per g of tissue) in the kidney sample and the lowest (3,500Bq per g of tissue) in the lung sample. These findings are recorded in Dr Harrison's statement dated 26 April 2007.190

¶3.159 In a further statement dated 27 October 2010,191 Dr Harrison reported the results of

similar gamma spectrometry tests on other samples taken from Mr Litvinenko's body after his death, namely samples of mesentery, testicle, muscle, brain, bile, heart, skin and blood. The results of these tests appear to have been consistent with those of the earlier tests.

¶The total intake of polonium 210 3.160 Dr Harrison used the results of the gamma ray spectrometry tests on tissue samples

to estimate Mr Litvinenko's likely total intake of polonium 210. He described his calculations, and the assumptions that he made in performing this exercise, in his statement of 26 April 2007.192 He stated that the best estimate of intake was 4.4Gbq of polonium 210.

¶3.161 The further testing reported in 2010 broadly supported the earlier estimate, although

the test on the blood sample indicated that the intake might have been slightly lower at 4.1Gbq.

¶3.162 This analysis is also discussed at paragraphs 5 to 9 of the experts' joint report dated

¶February 2014.193

¶The route of intake: ingestion or inhalation? 3.163 I have already referred to the fact that Dr Harrison's gamma ray spectrometry testing

in 2007 indicated a relatively low concentration of polonium 210 in lung tissue. Dr Harrison calculated that, given these values, only about 5 per cent of the total amount of polonium 210 in Mr Litvinenko's body could have been inhaled.

¶3.164 On this basis, Dr Harrison explained that he, "dismissed inhalation as a route of intake

and concentrated on ingestion as a route of intake."¹⁹⁴¹⁹⁴ Harrison 19/26 Mascall 30/83-92 The fact that polonium 210 was discovered in the lung tissue, albeit in relatively low quantities, did not require a conclusion that any polonium had been inhaled: the finding was equally consistent with polonium being distributed through blood following ingestion.195

¶3.165 The formal conclusion expressed by Dr Harrison on this point in his report dated

26 April 2007 was that, "The low concentration of polonium-210 in lung tissue is consistent with inhalation being a minor route of intake." He then proceeded to calculate the likely total intake on the basis of intake solely by ingestion. In his oral evidence, Dr Harrison stated that the low value for retention in lung tissue, "indicates that inhalation wasn't an important route of intake".196

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¶3.166 As I understand Dr Harrison's evidence on this point, his view is that in this case there

was certainly a major intake of polonium 210 by ingestion. There may have been an additional, but minor, intake by inhalation, or there may in fact have been no intake by inhalation at all.

¶3.167 I also note in this regard an observation made in the course of oral evidence by

Dr Swift, one of the two pathologists who conducted the post mortem. He stated that, whilst it was not possible to state with certainty the route by which the polonium 210 had entered Mr Litvinenko's body; "given the clinically recognised severe pharyngeal, so the back of the throat, and oesophageal, the food pipe or gullet, inflammation, it has most likely entered the body through oral means."¹⁹⁷¹⁹⁷ Swift 2/90-91 INQ021208 (page 11)

¶3.168 The conclusion that most if not all of the polonium 210 found in Mr Litvinenko's

body had been ingested rather than inhaled is relevant, amongst other things, to the question of whether Mr Litvinenko's death could have been an accident. Put shortly, it seems less likely that he could have accidentally eaten something than that he accidentally inhaled something. I shall return to this point in due course.

¶The medical cause of Mr Litvinenko's death 3.169 The evidence on this issue comprised two lines of scientific investigation and analysis, which were, to an extent at least, interdependent.

¶The pathologists 3.170 First, there was the evidence of the two pathologists, Dr Cary and Dr Swift, who

conducted Mr Litvinenko's post mortem.198 The post mortem took place at the Royal London Hospital on 1 December 2006. Special safety precautions were taken because of the radioactivity that was then still present in Mr Litvinenko's body. Even so, Dr Cary stated that the procedure had been: "one of the most dangerous post- mortem examinations ever undertaken in the Western world".199

¶3.171 Dr Cary summarised his findings in the form of six conclusions, with which Dr Swift agreed. I shall record those conclusions here.

¶3.172 First, Dr Cary stated that:

"the changes in the internal organs are typical of those seen at the end stage of multi-organ failure in an intensive care setting. There is no macroscopic evidence, and by that I mean to the naked eye, of any underlying natural disease process that would have preceded the presentation with an acute illness on 3 November 2006."²⁰⁰²⁰⁰ Cary 2/64 Mascall 30/150-151

¶3.173 Second, Dr Cary noted that due to the hazardous nature of the tissue samples that he

had taken from Mr Litvinenko's body, he was unable to follow what would otherwise have been the routine procedure of examining these samples under the microscope to try to obtain further information about the cause of death. That said, Dr Cary observed that the medical records from Mr Litvinenko's time in hospital provided useful information in this regard – there was clear documentation, for example, of

¶The Litvinenko Inquiry

bone marrow failure, multi-organ failure and the development of alopecia. Dr Cary stated; "when you look at all these together, they provide clinical corroboration for the fact that the deceased suffered acute radiation exposure due to ingestion of polonium 210".201

¶3.174 Third, Dr Cary noted the findings, made through analysis of samples taken both before and after Mr Litvinenko's death, that he had ingested a quantity of polonium 210.202

¶3.175 Fourth, Dr Cary noted the findings of Dr Harrison and his colleagues (to which I shall

refer further below), to the effect that Mr Litvinenko had ingested a quantity of polonium 210 that was far in excess of known survivability limits.

¶3.176 Fifth, Dr Cary concluded:

"I am entirely satisfied that on the basis of both the calculated exposure of the internal organs to radiation and the deceased's downhill clinical course a cause of death of acute radiation syndrome may be recorded."²⁰³²⁰³ INQ003002 (page 7); Cary 2/67 Quirke 11/98-99

¶3.177 Sixth, Dr Cary listed a number of possibilities in relation to the final mode of death, namely:

"(i) Due to bone marrow failure there was a final episode of sepsis, including as a possibility due to fungal infection with this sepsis resulting in cardiorespiratory arrest.

(ii) Due to metabolic consequences of organ failure (particularly the liver and kidney) cardiorespiratory arrest occurred.

(iii) Due to primary effects of radiation on the heart itself an ultimately fatal heart rhythm disturbance developed resulting in cardiorespiratory arrest.

¶(iv) A combination of some or all of the above."²⁰⁴²⁰⁴ INQ003002 (page 7); Cary 2/67-68 Mascall 13/168-173

¶Dr Harrison and his colleagues 3.178 In one of his written reports, Dr Harrison explained the mechanism by which the alpha particles emitted by polonium 210 cause damage within the human body. He said:

"Ionizing radiations, including gamma rays and alpha particles can kill cells by damaging biological molecules within them, including DNA. Alpha particles are particularly effective at killing cells because, although they only travel short distances (a few cell widths), they deposit a lot of energy along their paths. They can be thought of as atomic bullets, capable of killing at a cellular level. Enough alpha particles will kill enough cells to cause gross tissue damage, organ failure and death."²⁰⁵²⁰⁵ INQ007633 (page 5) Mascall 13/191

¶3.179 Having ascertained (see above) that Mr Litvinenko had ingested approximately 4.4Gbq

of polonium 210, Dr Harrison was able to calculate the quantity of radiation that would have been generated within Mr Litvinenko's body, and to compare those figures with

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scientific tables giving expected survival periods following exposure to radiation. Dr Harrison explained this analysis in detail in both his written and oral evidence.206

¶3.180 The conclusion that Dr Harrison drew from this analysis was clear. He stated:

"Death is the inevitable outcome of the radiation doses estimated to have been received by Mr Litvinenko's red bone marrow, kidneys and liver. Bone marrow failure is likely to be an important contributory cause of death occurring within a few weeks of intake, as a component of multiple organ failure."²⁰⁷²⁰⁷ INQ007633 (page 7) Mascall 13/185-187

¶3.181 The experts' joint statement comments, at paragraph 25:208

"It can be stated with certainty that Mr Litvinenko died as a consequence of an intake of polonium 210."

¶The number and timing of the doses of polonium 210 ingested by Mr Litvinenko 3.182 Scientific analysis of samples of Mr Litvinenko's hair was consistent with there having

been more than one intake of polonium 210. The hair analysis suggested that there had been two intakes, the earlier being about a hundred times smaller than the later.209

¶3.183 The scientific evidence did not produce a definitive timing for the second and larger

intake of polonium. That said, I heard that Mr Litvinenko's medical records, and in particular the rise in levels of circulating neutrophils (white blood cells) recorded on 3 November and 5 November, were consistent with the fatal intake having taken place on 1 November.210 As we shall see, there is independent evidence which strongly indicates that that is when the second intake occurred.

¶3.184 As to the timing of the earlier intake, the scientific evidence may be summarised as follows:

a. It was common ground that it was not possible to determine the precise date upon which the earlier intake had occurred. As the experts put it in their joint report:

"[the] evidence does not enable precise interpretation in terms of relative times of intake because of uncertainties over the rate of hair growth and the possible effect of radiation exposure on hair growth."

b. Accordingly, the scientists estimated a period during which the earlier intake had taken place, assuming that the later intake had occurred on 1 November

c. Dr Harrrison, Dr Gent and A1 concluded that the earlier intake had probably taken place between 18 October and 23 October 211

d. Dr Black, who conducted his analysis on a different basis, estimated that the earlier intake had taken place between 14 and 18 October 212

¶The Litvinenko Inquiry

e. The evidence that Mr Litvinenko vomited and was feeling unwell on the evening of 16 October should not be taken as a strong indication that the first intake of polonium had occurred on that day. The scientists were cautious as to whether the similar 'prodromal' symptoms that Mr Litvinenko suffered on the evening of 1 November had been caused by the very much higher intake of polonium on that day.213 The symptoms that Mr Litvinenko suffered on 16 October must, therefore, be an even less reliable indicator of a postulated weaker intake of polonium on that day