Depleted intelligence, not uranium, the problem in Kosovo

By Zbigniew Jaworowski and Roger Bate
Copyright 2001 Junkscience.com
January 10, 2001

The practitioners of voodoo science and opportunistic epidemiology are at it again. They argue that radioactive dust from the explosion of shells tipped with uranium elevated the risk to service men in Kosovo. Concern has spread to all European military testing grounds using depleted uranium, and even to the civilian population close to such facilities.

The British Ministry of Defence initially said there is nothing to be alarmed about, since the risk of harm is negligible. Its tune changed when Armed Forces Minister John Spellar told the house of commons on Tuesday that soldiers who served in the Balkans would be offered screening.

But it's unlikely that the scientific facts changed from the previous day. There is no significant risk from using depleted uranium. So a political decision to succumb to media demands is the only rational explanation.

During March-June 1999 thousands of 35 millimeter caliber rounds stuffed with depleted-uranium were fired over Kosovo, mainly by the American A-10 aircraft. The core of each round contained about 0.82 kilograms of almost pure uranium-238, from which its 14 radioactive daughters and uranium-235 were separated. This depleted uranium is much less radioactive than natural uranium normally present in the soil and rock.

Natural uranium is in equilibrium with radioactive isotopes of radium, radon, thorium, protoactine, polonium, lead and bismuth. During its decay it emits energetic alpha particles and very weak beta and gamma radiation. Alpha particles have little penetrative power in the air and in human tissues.

The total mass of depleted uranium dispersed over Kosovo was at most 25 tons. The radioactivity of one round was about 10 megabecquerels (MBq). Assuming that 30,000 rounds were fired, about 300,000 MBq of uranium-238 activity were dispersed in Kosovo's environment (10,887 square kilometers). Yet, the natural uranium-238 in a one-centimeter layer of Kosovo soil emits about 100,000,000 MBq. Thus, the surface layer of soil in Kosovo contains about 300 times more natural uranium than was dispersed there by NATO weaponry.

Local concentrations of depleted uranium may be higher than the average concentration of natural uranium in the soil at the target sites. From these patches of activity depleted uranium may be re-suspended into the air, and may also enter the food chain. This, however, should not lead to any observable medical consequences.

The weak beta and gamma radiation does not pose a serious radiation protection problem. In fact, the radiation protection standards for depleted uranium are based on its chemical toxicity, not radiotoxicity. It is similar to other heavy metals (such lead, cadmium, or mercury), and like these other metals at high doses uranium is toxic stuff.

Experimental and epidemiological studies carried out over the past 50 years suggest that the main adverse effect of uranium-238 is a chemical impairment of the renal function. Secondary protection standards for uranium-238 (for example concentration limits in air and food) are based on a limit of 3 micrograms of uranium per gram of kidney.

In epidemiological studies of more than 32,000 nuclear workers exposed to uranium between 1943 and 1986, no other health impairment other than renal problems was observed. Among these workers the general mortality was lower than in general population, and mortality due to all cancers and leukemia was also lower.

Among about 150,000 soldiers, who for various periods of time were in Kosovo between March 1999 and the end of 2000, 17 have so far died due to leukemia. This corresponds to about 11 deaths per 100,000 soldiers. The annual leukemia death rate in the United Kingdom is 11 per 100,000. Thus, the rate of soldiers dying due to leukemia seems to fit the European norm.

A few years ago "clusters" of leukemia were found in several countries, in which morbidity of leukemia was up to 10-fold higher than the general population. The first such cluster was discovered in the village of Seascale, near the Sellafield nuclear fuel reprocessing plant in the UK. The excess was reported in a television program in November 1983 and similar clusters were later found in few other places in Europe, Canada and the US. Initially, radioactive emissions from nuclear installations were suspected to be the cause of the clusters. However, it was realized quite quickly that clusters appear at other non-nuclear sites, where migration of large number of people occurred.

In an extensive review of the issue the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) concluded that a possible explanation for the cluster was the spread of infection resulting from the mixing of populations from urban and rural areas. One might expect such a phenomenon to occur among large military formations. But it seems that this in not the case in Kosovo, where incidence of leukemia rather fits the European norm.

The shortest latency time for leukemia induced by ionizing radiation is two years. As this disease started to appear among the soldiers much earlier, and there were no reports on a dramatic increase of renal problems, the cause of leukemias in Kosovo, does not seem to be radiation of depleted uranium, but rather a natural one.

Once again another nuclear concern is really much ado about nothing.

Zbigniew Jaworowski is a professor with the Central Laboratory for Radiological Protection in Warsaw, Poland. Dr. Roger Bate is with Wolfson College, Cambridge University, England.