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DEPLETED SCIENCE: HEALTH CONSEQUENCES AND MECHANISMS OF EXPOSURE TO FALLOUT FROM DEPLETED URANIUM WEAPONS
CONTRIBUTION TO INTERNATIONAL DU CONFERENCE HAMBURG OCT 16-19TH 2003
CHRIS BUSBY PhD
Occasional paper 2003/06; July 2003 Aberystwyth: Green Audit
1. The DU story is part of a wider concern
For there is nothing hid that shall not be manifested; neither was anything kept secret, but that it should come abroad Mark 4,22
Why is there concern about the health effects of Depleted Uranium? Would there be equivalent argument about the health effects following the use of Tungsten in tank shells or lead in bullets? The answer is straightforward: everybody knows that Uranium is radioactive and everyone knows that radiation exposure leads to cancer, leukaemia and genetic damage. No one wants to be exposed to ionising radiation. So why is such a weapon being used, if this is the case? The answer is tied to a much larger and more serious issue. This is the issue of the health consequences of exposure to low doses of radiation from nuclear pollution of the planet, a subject which I have studied for more than fourteen years. The reason that DU is employed is that the weapons are astoundingly successful and have revolutionised warfare, rendering the tank and its armour useless. In addition, its use represents a route for the nuclear industry to rid itself of a waste product which would otherwise be expensive to dispose of. But the downside is that the material clearly represents a radiation hazard which is indiscriminate: battlefields are going to be contaminated and civilian populations are going to be exposed. There is an up-side and a down-side. The war will be won but the method will be illegal within contemporary accepted moral arguments. Human rights will be infringed by a randomly dispersed and thus indiscriminate radioactive weapon of mass destruction. Since 1945, these arguments have been endlessly rehearsed for man-made nuclear pollution. First there were atmospheric nuclear weapons tests which caused global contamination with fallout, followed by pollution from the civilian/military nuclear power cycle which in the UK means pollution from Sellafield. The European Committee on Radiation Risk have recently calculated that more than 60million people have died from cancer as a result of these exposures (ECRR2003) yet Sellafield continues to operate, and nuclear power stations continue to release radioactivity to the environment. Owing to the application of false scientific models, this behaviour is sanctioned legally, and the situation is getting worse. In May 2000, the European Union adopted the 1996/29 Euratom Basic Safety Standards Directive which explicitly permits the re-cycling of radioactive substances into consumer goods. Let us try to fit the dispersion of Depleted Uranium into this perspective. In terms of disintegrating atoms, radioactivity is measured in Bequerels. One Bequerel represents one disintegration per second. This is a reasonable way of quantifying amounts of radioactivity. The average Natural Uranium content of soil is about 10-20 Bequerels per kilogram, including all the Uranium isotopes. Most people excrete as much as 0.1mBq (0.0001Bq) per litre of Urine as a result of absorption of natural Uranium in food they eat. Pure Depleted Uranium contains about 12,400,000Bq of U-238 per kilogram and in Kosovo, some soil samples analysed by the United Nations Environment Program (UNEP) contained 250,000Bq/kg (UNEP 2001, Annex). The 350 tonnes of DU used in the first Gulf War represents 4.3 TBq (4.3 x 1012 Bq) of Uranium alpha activity (13.0 x 1012 if the radioactive beta emitting daughter isotopes are included-more of these below). If Dai Williams (2003) is correct and about 1700 tonnes were used in the latest war, then that represents 63 TBq of activity dispersed mainly into a populated area of perhaps 100km2 . This gives a mean density of deposition of radioactivity of 630,000Bq/m2. These sums are instructive and are collected together in Table 1. These activity comparisons are given just to get some feel for the amounts of radioactivity involved, and to show that the dispersion of Uranium in various recent battlefields is not trivial, as the military and some politicians regularly imply. But the comparisons are slightly misleading because we are not dealing with the same isotopes as were released by weapons fallout which is composed of alpha beta and gamma emitters. Battlefield DU fallout is in the form of microscopic alpha and beta emitting particles. U-238 is an alpha emitter. The U-238 daughters, Protoactinium-234m and Thorium-234 are beta emitters. Having short half-lives, they are in equilibrium and therefore have the same level of activity in a sample of DU. In an area contaminated by DU it is the beta radiation that is detected because it has a range in air of about 30cm unlike the alpha particles which are very short range. We can find a better comparison for DU. As an alpha emitter and long lived environmental particle DU is more comparable with Plutonium-239, a substance released by Sellafield and a major contaminant of the Irish Sea. Plutonium in the environment is also in the form of micron sized oxide particles.
Table 1. Mean density of deposition of radioactivity from DU in the two Gulf Wars and Kosovo including decays from U-238 and beta daughters Pa-234m and Th-234 compared with other radioactive contamination.
* I measured 4000Bq/kg in Gjakove, Western Kosovo, in Jan 2001 in a car park, but these values are averages based on an assumption about the area into which the material has been dispersed.
Like DU, these Plutonium Oxide particles are also long lived and mobile. Plutonium from Sellafield has been measured in autopsy specimens across the UK, in sheep droppings on the east coast of England 100 km from Sellafield at the same latitude and even in the teeth of children up to 200 km from the site in south east England. Both Uranium-238 and Plutonium-239 are alpha emitters, although Plutonium has no beta emitting daughter isotopes in SECULAR equilibrium. U-238 has a very long half life, 4500 million years, so owing to its much shorter half life of 24,100 years, the specific activity of Pu-239 is far greater. It is 2.3TBq/kg. But this means that 350 tons of DU (or 4.30TBq of U-238) is equivalent in activity to about 2 kg of Plutonium-239. What would governments of the world say to a war in which one army caused the intentional scattering of 2kg of Plutonium-239 over a populated area? What would the ethicists and moral philosophers say? Or ordinary members of the public? What would happen in New York or in London if 2kg of Plutonium-239 was dispersed among the public? The emergency services are geared up in the UK to evacuate whole cities if such a 'dirty bomb' was exploded by terrorists. Actually, for reasons which I shall enlarge on, in terms of health deficit, what has been done in Iraq and Kosovo, possibly also in Afghanistan is much worse. Yet nothing is said by the regulatory authorities. Worse than this: they develop models and enrol scientists in an attempt to minimise any perception of harm and routinely deny or marginalize evidence that shows that the use of DU has had major and serious effects. I compare U-238 and Pu-239 in Table 2.
Table 2 Comparing Plutonium-239 and Uranium-238 in the environment
I have compared Plutonium and weapons fallout with DU to demonstrate that we are dealing with the same problem, the health effects of low level exposure to radioactive substances that irradiate our bodies from the inside. The weapons fallout, and other pollution from nuclear sites like Sellafield has been responsible for the present cancer epidemic, the one that everyone has experienced. It has been a major project of the nuclear military complex, and for governments who have been involved in releases of radioactivity, to cover up the link between these exposures and cancer or other ill health. This is why all these committees are controlled and steered by the same people. Recognition that DU caused cancer, leukaemia or lymphoma at the doses experienced by those who were contaminated after its use would lead to inevitable recognition that the weapons fallout substances, the Strontiums and Plutoniums and Caesiums also caused cancer, leukaemia and lymphoma. The reverse is also true. Recognition of the cause of the Sellafield lukemia/lymphoma cluster would lead to reassessing the risk models to the point where it would be clear that DU would have serious health effects. This is the origin of a massive cover up which extends to the cancer registries and the cancer research organisations.
2. Green Activists First they laugh at you, then they attack you, then you win. Gandhi The truth about the health effects of low level radiation has been covered up by the nuclear /military lobby in many ways for about 50 years. I wrote about this in Wings of Death (Busby 1995) and there I explained how different levels of control and bias had been employed to keep the public from realising that they were being systematically poisoned by radioactivity. Others have made this point. John Gofman, once a very senior figure in the nuclear establishment put it well: the nuclear industry is conducting a war against humanity. Part of the reason behind the success of this cover-up has been that the process has been tied in with Military and State security in the countries that have nuclear weapons. The process extends to the highest levels. The World Health Organisation (WHO) is tied to the International Atomic Energy Agency by a 1959 agreement which prohibits them from researching the health effects of radiation. This is why we hear that there have been no increases of cancer due to Chernobyl. This is why the WHO take the view that DU is not a health problem. This why the European Commission adopt the EURATOM safety standards and the radiation safety laws are predicated on the advice of the ICRP, a self selected and unaccountable organisation that is part of a network of revolving doors in which the same people pass in and out saying the same things and agreeing with one another. From very early on I felt that to change this situation a scientific analysis was not enough. There had to be a political analysis as well, and particularly an analysis of power. The power of the nuclear/ military establishment lies in institutions rather than in money. It is these institutions that lend credibility to their position. Increasingly, though the liberalisation of universities and their research funding, it is the grants that drive the direction of science and formulates its current 'Truths'. It is not the quality of the research that decides whether it is published and eventually influences policy. It is the acceptance of the research results into the required institutional view. If you write a scientific paper and the editors or their referees don’t like it, they reject it. You are not told who the referees are. For the Green Activist, who wishes to change this, the answer then is to ignore these institutions and create new ones. What is the point of sending rigorously argued manuscripts to scientific journals if these journals are controlled by the nuclear industry scientists, those they support with research grants and money?. What is the point of sending out Press Releases to the media if they are put in the waste bin? As a result of the Green Activist approach, the Low Level Radiation Campaign has persuaded the UK government to set up a new committee to examine these effects. We pointed out, following the 'Mad Cow Disease' committee failings that the only way to get to the truth in science advice was to fund both sides and have them argue the case out in committee. The first committee of this kind is this new Committee Examining Radiation Risk form Internal Emitters (CERRIE, www.cerrie.org). Here, there are scientists from both sides of the debate on low-level internal radiation arguing out the various pieces of evidence that the ICRP risk model is in error and that internal radiation exposure, like that from fallout, from Plutonium, or DU represents a serious health hazard. CERRIE reports finally in 2004, but its preliminary report was considered at an international workshop in Oxford in July 2003. The report drew attention, for the first time, to the existence of major scientific uncertainties in the area of risk from internal radioisotopes. There is one other independent institution which I helped to set up. This is the European Committee on Radiation Risk, based in Brussels (www.euradcom.org). This committee was intended as an alternative ICRP. It has over 40 independent experts in radiation risk, mainly from Europe and the ex-Soviet Union but some from the USA also. It includes ethicists, doctors, physicists, geneticists, biologists, politicians and philosophers. Together with Prof. Inge Schmitz-Feuerhake and Prof Alexey Yablokov, I launched the ECRRs new radiation risk model in Brussels on 30th June [ECRR2003]. The model incorporates weightings factors for internal radiation exposure. These are based on arguments and evidence which I shall examine now. For DU the weightings are as high as 1000-fold Let me now concentrate on reviewing where we are in the investigation of Depleted Uranium.
3. The health effects of internal irradiation by man-made radioisotopes and new forms of natural isotopes. I will summarise briefly here the theoretical and epidemiological evidence that the ICRP external model is in error by orders of magnitude when used to predict or explain the consequences of internal irradiation. A fuller explanation is given in ECRR2003. 3.1 Theoretical considerations External radiation produces ionization tracks in tissue that are uniformly distributed. Thus each cell receives on average one track per year and the linear dose response used by the ICRP to predict cancer from the Hiroshima survivors breaks down if there is more than one track intercepting a cell in the time it takes for the cell to repair damage, about ten hours. For internal sequentially decaying isotopes and for internal long lived, hot (or warm) particles the probability of a cell local to the internal decay receiving two or more hits is very much higher than the equivalent probability for the same dose delivered externally. There are two consequences. The first is that the cell response is in the 'dose squared' region of the accepted ICRP model and the dose response in no longer linear. This is because the probability of a DNA double strand break occurring increases sharply for two or more hits to the cell. Such a lesion carries a high degree of certainty that a fixed mutation will follow. The second possible consequence is that the first hit to the cell will either induce a repair replication cycle in the hit cell, or if the cell is killed, in local cells which will begin to replicate to supply a replacement. Whilst replicating and repairing the initial lesion, a second hit at the critical point in the replication process will cause a fixed unrepairable mutation. This is the second Event Theory. There are further problems with internal isotopes which relate to their chemical affinity for DNA. Both Strontium (e.g. Sr-90, Sr-89) (Sr++), Barium (Ba-140, an Auger emitter) and Uranyl UO2++ ions bind strongly to DNA (Wu et al, 1996) and so their decays will be extremely hazardous since they are localised near the target of interest. Work with the covalently bound Auger emitter Iodine-129, and also manmade Auger emitters like Cr-59 with bind to DNA show that these localisation effects carry very high risks which are not modelled by their apparent average doses. U-238 itself is an Auger emitter (31 % decay 10keV) and the high concentration gradient of of UO2++ ions near the surface of a UO2 particle would result in a high level of DNA localisation near the particle. Particles are, of course, highly likely to cause second event and multiple hit effects to nearby cells and the local doses from DU particles are considered below. In the last ten years, evidence has emerged that low doses of radiation cause genomic instability in cells that are hot, but also in cells that are near the cells that are hit, up to about a 300 cells radius. Using computer controlled microbeams, individual cells can be targeted and the effects in nearby cells counted using various endpoints. In all these experiments, the dose response is very clearly non linear and increases sharply up to two or three hits per cell when it saturates. Miller et al (1999) have shown that cancerous transformation is almost exclusively caused by two hits rather than by one hit/ the effect for chromosome aberration as an end point seems to saturate after three hits (Prise et al, 2002). The cell volumes around damaged cells respond to the damage through a communication field, and therefore it is the location of radiation doses and ionisation effects within this field that is important in establishing future effects in the tissue like cancer. It is clear that physics no longer informs us of the effects of radiation at the cellular level. The key problem is that the evidence shows that concentration of ionization in a small volume of cells, or inside a single cell results in very high yields of mutations. It is high local ionisation density that is important, not dose; but this fact has been obscured by experiments with such high densities of ionisation that cell killing is the result. This is why the hot particle experiments show such equivocal results. These new discoveries in biology make a nonsense of the basic science underpinning the ICRP averaging models and therefore we have to look to appropriate epidemiology to see what the health consequences of exposure to these novel isotopes and forms are. To use epidemiology of externally irradiated groups to inform on internally irradiated groups is not using scientific method (Busby 2001 RS, Busby 2002 BNES).
3.2 Epidemiological considerations If we cannot extrapolate from external radiation and Hiroshima, and we cannot use linear no threshold dose responses to mathematically model health effects where does that leave risk assessment? The scientific answer is that we have to look at the effects themselves and use them to define risk. This is done by epidemiology of populations exposed to the radiation sources we are interested in. It is not good enough to say that the model does not predict the cancers, as the risk agencies said about the Sellafield leukaemia cluster. If the models is theoretically unsound, we must re-examine the issue and consider whether the cancers were caused by the radiation. When we do this for the famous Sellafield child leukaemia cluster, we find that the error in the ICRP risk model needed to account for the cancers is about 300-fold. Looking at the other leukaemia clusters the error needed to explain the cancers is between 300-fold and 2000-fold. This may seem like an enormous error, but if it consistently turns up, we should as scientists begin to look at how it can occur. Tamplin in 1972 examined hot particles of plutonium and concluded on the basis of theoretical assumptions that they, were more hazardous that the ICRP model suggested by a factor of 115,000, so these large numbers are not as silly as they may seem. They essentially represent the difference between local dose to tissue and averaged dose to body from a hot particle. And since it is the tissue that develops the cancer over a long period by amplification through cell division of various DNA lesions, it is not surprising that it is the tissue dose that is important, and not the whole body or whole organ dose. Although many studies of nuclear sites, downwinders, and other contaminated individuals have pointed to large errors in the ICRP model (see Busby 1995 and the web site: www.llrc.org) it was only after Chernobyl that we were able to obtain sufficiently unequivocal evidence. Despite the cover-ups in the ex-Soviet territories and the efforts of the cancer agencies (e.g. IARC, IAEA, WHO ) to deny any effects two sets of evidence emerged which falsified the conventional position that the only effects of Chernobyl were the deaths of a few liquidators and some thyroid cancers. There were two pieces of evidence that forced the UK government into a reappraisal of the issue of internal radiation. The first was the Chernobyl infants and the second was the minisatelite DNA mutations.
3.3 The Chernobyl infants Following the Chernobyl accident in 1986, the cohort of children who were exposed in their mother’s womb to radioisotopes from the releases suffered an excess risk of developing leukaemia in their first year of life. This ‘infant leukaemia’ cohort effect was observed in six different countries. It was first reported in Scotland [Gibson et al., 1988], and then in Greece [Petridou et al., 1996], in the United States [Mangano, 1997] and in Germany [Michaelis, et al.. 1997]. Busby and Scott Cato examined the relationship between the observed numbers of cases and those predicted by the ICRP model. For the first time, the specificity of the cohort enabled them to argue that the effect could only be a consequence of exposure to the Chernobyl fallout. There could be no alternative explanation. Because the National Radiological Protection Board had measured and assessed the doses to the populations of Wales and Scotland and because they themselves had also published risk factors for radiogenic leukaemia based on ICRP models it was a simple matter to compare their predictions with the observations and test the contemporary risk model. The method simply assumed that infants born in the periods 1980-85 and 1990-92 were unexposed and defined the Poisson expectation of numbers of infant leukaemia cases in the children who were in utero over the 18 month period following the Chernobyl fallout. This 18 month period was chosen because it was shown that the in utero dose was due to radioactive isotopes which were ingested or inhaled by the mothers. Whole-body monitoring had shown that this material remained in the bodies of the mothers until Spring 1987 because silage cut in the Summer of 1986 had been fed to cattle in the following winter. The result showed a statistically significant 3.8-fold excess of infant leukaemia in the combined Wales and Scotland cohort (p = 0.0002). The leukaemia yield in the exposed in utero cohort was about 100 times the yield predicted by the ICRP model. Table 3 compares the effect in the three main studies. In this table, the B cohort were those children exposed to the internal exposure from Chernobyl in utero in the 18 month period following the event and born between June 1987 and January 1988. These exposure periods were defined by the whole body monitoring results. The control periods A and C were the ten years before (1975-85) and the four years after 1988 for which data was available. The possibility of the effect being due to chance may be obtained by multiplying the p-values for the null hypothesis that the effect was due to chance in each of the separate countries to give an overall p-value less than 0.0000000001. Thus it was not a chance occurrence: it was a consequence of the exposure to low-level radiation from Chernobyl. The infant leukaemia results represent unequivocal evidence that the ICRP risk model is in error by a factor of between 100-fold and 2000-fold for the type of exposure and dose, the latter figure allowing for a continued excess risk in the cohort being studied.
Table 3 Unequivocal evidence of ICRP risk factor errors: comparison between infant leukaemia rates after Chernobyl in Wales and Scotland and similar data from Greece and from the former Federal Republic of Germany
a See text for A B and C periodsb Petridou et al..(1996)c Michaelis et al..(1997)
3.3 Minisatellite mutation rates in Chernobyl children The ICRP model of genetic mutation after irradiation is based, like ICRP's cancer risk model, on the Hiroshima lifespan study yield of gross genetic effects and also studies of radiation effects in mice. Although subtle genetic effects on sex ratio were apparent in the LSS offspring, the RERF researchers excluded them from the study because they did not accord with their notions of the expected direction of such an effect [Padmanabhan, 1997]. Neels’s exclusion of the sex ratio effects resulted in the belief that the genetic effects of 10mSv in the first generation would be unmeasurable. Thus BEIR V gives the incidence of total genetic effects including chromosomal effects (unbalanced translocations and trisomies) at 6 per million offspring compared with the natural rate of 4,200. It predicts a 10mSv excess risk of 10 cases of congenital malformation in a natural rate of 25,000 per million offspring and similar vanishingly small increases are given for autosomal dominant, X-linked and recessive disorders. Using a combination of mouse studies and the epidemiology of the LSS, the doubling dose for spontaneous genetic burden has been estimated to be 1 Sievert. [e.g.BEIR V, 1990 p 70] However, the development of molecular techniques has enabled objective measurements of the consequences of irradiation to be investigated in human populations. There have been several studies of minisatellite DNA mutation in children living in parts of the ex-Soviet Union and exposed to radiation from Chernobyl. Using the technological development of ‘DNA testing’ in which minisatellite DNA is separated into bands which are characteristic of its genetic identity, it has been possible to show that children living in Belarus and exposed to radiation from fission-product isotopes and particle fission fragments which contaminated their environment suffered a doubling in genetic mutation. [Dubrova, 1996, 1997]. Similar work with barn swallows exposed in Belarus showed that these genetic changes were also present in these birds and were associated with phenotypic changes in their plumage patterns as well as reduced survival, therefore underlining the potential importance of such mutations. [Ellegren et al. 1997]. Most recently, the minisatellite DNA tests have been applied to the children of Chernobyl liquidators who were born after the accident compared with siblings born before the accident. [Weinberg et al. 2001] There was a seven-fold increase in genetic damage found in the post-exposure children. By comparison with mutation rates for the loci measured, this finding defined an error of between 700-fold and 2000-fold in the ICRP model for heritable genetic damage. In addition, the research results could be stratified by dose range and this resulted in a biphasic non linear response. It is remarkable that studies of the children of those exposed to external radiation at Hiroshima show little or no such effect, suggesting a fundamental difference in mechanism between the exposures. [Satoh and Kodaira, 1996]. The most likely difference is that it was the internal exposure to the Chernobyl liquidators that caused the effects. These results follow the use of a new objective analytical method fro examining individuals who have been exposed. In this sense they cannot be subject to the arguments used against epidemiological studies. The mutations are there and are measurable so there can be little argument. The doses are known and the comparison is safe. It shows a large error in the ICRP model and raises many issues relating to the overall outcome of irradiating human populations. I will now turn to the effects of DU.
4. The health effects of Depleted Uranium I want to consider the DU case under four headings. They are:
3.1 Particle doses and hot coals To recapitulate, the ICRP model is the presently accepted risk model for radiation and health. It is based on the idea that radiation is external to the body. Examples of external radiation exposures are medical X-rays and gamma rays from atom bombs. The ICRP model bases the amount of ill health produced by doses of radiation of different sizes on a large study of the Hiroshima survivors. These people received a very large dose and some of them were incinerated. But among those that were not, some of them developed cancer much later on. The ICRP model relates the numbers of cancer to the large dose they received and argues that at half this dose there should be half the cancers and so forth. So if the dose is very small, there are very few cancers. The problem is, that this model is not strictly applicable to internal radiation. Absorbed dose, in Grays or Sieverts or rads or rems is measured as energy per unit mass. Therefore it would not distinguish between a man warming himself in front of a fire or the same man eating a hot coal. The average energy per unit mass is the same. This a good analogy for why the DU or plutonium situation is wrongly modelled. In the case of DU particles the decay energy is all absorbed in the local cells. So one single particle will give a big dose to the local cells and no dose to the rest of the body. The ICRP will say that the dose is very small, but because the alpha decay range is small, the dose to the cells nearby, is very large. This is a trick and I show how it is done for a 2 micron diameter particle of DU trapped in the lymphatic system of a person who inhaled it. The calculation in Table 4 shows the dose to the tissue within range of the particle alpha decays and the dose to (a) the whole body and (b) the lymphatic system that NRPB and ICRP would calculate. [see e.g. NRPB, R-276 p 86 1995) The NRPB reference is to actual calculations made by NRPB on the doses from Plutonium particles to the public near Sellafield. Two things are immediately apparent. The cells close to the particle receive a significant dose and they also suffer an enhanced risk of receiving multiple tracks. The dose calculated by the ICRP model is vanishingly small, so it is easy to see how the Royal Society, the Ministry of Defence, the United Nations, the IAEA/ WHO say that DU cannot cause any cancer.
Table 4. Doses to local tissue within range of a 2 micrometer particle of DU compared with doses calculated using the ICRP model and an NRPB version of it.
*for lymphatic system modelled as lymph nodes, liver, spleen, kidneys, pancreas, uterus, thymus, thyroid, stomach, both intestines, colon, red bone marrow and cells on bone surfaces [NRPB, 1995] ** values from ICRP standard man [ICRP23, 1975]
3.2 Borrowing radiation energy from background: second order scattering There may be a second source of error here although it is difficult to quantify. Uranium is very dense and the particles have an enormous combined surface area. It is possible to calculate that for the smaller particles of 0.2m diameter a 5mg inhalation loading represents some 1011 particles with a combined surface area of about 250cm2. Now small particles smaller than the wavelength of incident scatter incident radiation so that the particles act as secondary scatterers for the gamma rays from natural background radiation or medical X-rays or other internal emitters including other local particles. In addition, the lower energy component of this radiation, below 100keV photon energy will quantitatively be converted into photoelectrons from the particle surfaces. These are short-range highly ionising electrons which will increase the ionisation density in the immediate vicinity of the particles. This effect is increased because Uranium happens to have a very low photoelectron work function and even releases electrons when irradiated by UV and visible light so that Uranium salts are light sensitive and can be used for photography. In addition the release of photoelectrons from the particle surface will cause it to acquire an electric charge and attract negative ions which will perturb the biochemistry taking place close to the particle with unknown consequences. None of these considerations are included in the ICRP model.
3.3 Particle environmental dispersion The military and other authorities have dismissed the possibility of widespread dispersion of DU particles. The US Department of Defense papers make this claim but have not been able to justify it. The particles of less than 2m diameter are easily resuspended by wind or by electrostatic repulsion in the earth's electric field. In addition they become charged by photoelectric effects owing to the low Uranium work function (see above) and these charges would assist their resuspension although no experiments have been done to my knowledge. I discovered DU dust in western Kosovo one year after the war. It was in road dust at several sites under conditions where it was clear that the material had been washed out by snow. In addition the ratio of activity of the beta emitting daughter isotopes to the parent Uranium-238 showed that the U-238 was being preferentially resuspended. I gave this information to the Royal Society but their experts said that mathematical models showed that DU particles could not be resuspended and would remain where the targets were a few metres from the site of impact. I also gave a paper on this at a meeting organised in the European Parliament on DU. At this meeting I asked the head of UNEP, Dr Snihs why UNEP had not examined air filters in their November 2001 survey of Kosovo. He stated that the DU would not widely disperse and would not be found in the air so there was no need. However, I note that UNEP did deploy air measuring equipment later in Bosnia and Montenegro. This equipment detected DU in the air. The UNEP response was that the material had been resuspended by their disturbing of the soil. The UNEP Kosovo report tabulated the presence of DU in 46% of all the samples they measured but the tables were not given to the Press at the launch of the report in Geneva and the executive summary says there is no widespread dispersion of DU. If you read the report closely, their definition of widespread dispersion is of DU which would be a cause for concern in health terms, a qualification that was lost on the journalists. Here again is an example of spinning a report . Since the results tables were not given out (and have since disappeared from the report on the website) no one was able to argue the point. For those who are interested, I have a copy of the UNEP Kosovo tables and have written a critique of the whole way the results were presented. The study also showed the presence of DU particles larger than 0.2m in a rainwater pond in Vranovac (Busby 2001). I also found widespread DU in southern Iraq when I visited there in September 2000, or rather, I found areas of high beta counts on the ground in the area of the 'Mother of All Battles' and saw a few A10 penetrators lying on the ground also. In Iraq, I found significantly higher alpha activity in the air in this area. Unfortunately the Iraqi authorities would not let me remove any samples.
3.4 Human contamination and biokinetics Shortly after my visit to Kosovo in January 2001, Prof Nic Priest visited the same region with BBC Scotland and took urine samples from some 20 people including his BBC cameraman. Priest has access to sophisticated mass spectrometry equipment and can measure Uranium isotope ratios in urine. He found that all the urin |
