New evidence of childhood leukaemias near nuclear power stations

The risk of leukaemia in young children from exposure to tritium and carbon-14 in the discharges of German nuclear power stations and in the fallout from atmospheric nuclear weapons testing

Towards the end of 2007, the results were published from a case-control study (the "KiKK Study") of cancer in young children, diagnosed <5 years of age during 1980-2003 while resident near nuclear power stations in western Germany. The study found a tendency for cases of leukaemia to live closer to the nearest nuclear power station than their matched controls, producing an odds ratio that was raised to a statistically significant extent for residence within 5 km of a nuclear power station. The findings of the study received much publicity, but a detailed radiological risk assessment demonstrated that the radiation doses received by young children from discharges of radioactive material from the nuclear reactors were much lower than those received from natural background radiation and far too small to be responsible for the statistical association reported in the KiKK Study. This has led to speculation that conventional radiological risk assessments have grossly underestimated the risk of leukaemia in young children posed by exposure to man-made radionuclides, and particular attention has been drawn to the possible role of tritium and carbon-14 discharges in this supposedly severe underestimation of risk. Both (3)H and (14)C are generated naturally in the upper atmosphere, and substantial increases in these radionuclides in the environment occurred as a result of their production by atmospheric testing of nuclear weapons during the late 1950s and early 1960s. If the leukaemogenic effect of these radionuclides has been seriously underestimated to the degree necessary to explain the KiKK Study findings, then a pronounced increase in the worldwide incidence of leukaemia among young children should have followed the notably elevated exposure to (3)H and (14)C from nuclear weapons testing fallout. To investigate this hypothesis, the time series of incidence rates of leukaemia among young children <5 years of age at diagnosis has been examined from ten cancer registries from three continents and both hemispheres, which include registration data from the early 1960s or before. No evidence of a markedly increased risk of leukaemia in young children following the peak of above-ground nuclear weapons testing, or that incidence rates are related to level of exposure to fallout, is apparent from these registration rates, providing strong grounds for discounting the idea that the risk of leukaemia in young children from (3)H or (14)C (or any other radionuclide present in both nuclear weapons testing fallout and discharges from nuclear installations) has been grossly underestimated and that such exposure can account for the findings of the KiKK Study.

Childhood cancers near German nuclear power stations: hypothesis to explain the cancer increases

In early 2008, the very large Kinderkrebs in der Umgebung von Kernkraftwerken [Childhood Cancer near Nuclear Power Plants] (KiKK) study in Germany reported increases in leukaemias and solid cancers among children living near all German nuclear power plants (NPPs). This study, previously described in Medicine, Conflict and Survival, has triggered debates in many countries as to the cause or causes of these increased cancers. An accompanying article reports on the recent developments on the KiKK study including the responses by German radiation agencies, and the results of recent epidemiological studies near United Kingdom and French nuclear installations. This article outlines a possible explanation for the increased cancers. In essence, doses from environmental NPP emissions to embryos/foetuses in pregnant women near NPPs may be larger than suspected, and haematopoietic tissues may be considerably more radiosensitive in embryos/foetuses than in newborn babies. The article concludes with recommendations for further research.

Childhood cancers near German nuclear power stations: the ongoing debate

In late 2007, the significant KiKK study (Kinderkrebs in der Umgebung von KernKraftwerken = Childhood Cancer in the Vicinity of Nuclear Power Plants) in Germany reported a 1.6-fold increase in all cancers and a 2.2-fold increase in leukaemias, among children living within 5 km of all German nuclear power stations. The KiKK study by Kaatsch et al. was extensively described in a recent edition of Medicine Conflict and Survival. It has triggered much discussion as to the cause(s) of these increased cancers. This article reports on recent developments on the KiKK study, including responses by German radiation agencies, and recent epidemiological studies near United Kingdom and French nuclear installations. It reflects the current debate and concludes with advice to policy-makers on radiation risks on the relative merits of the KiKK study. An accompanying article outlines a possible explanation for the increased cancers and makes recommendations for future research.

Childhood leukemia and cancers near German nuclear reactors: significance, context, and ramifications of recent studies

A government-sponsored study of childhood cancer in the proximity of German nuclear power plants (German acronym KiKK) found that children < 5 years living < 5 km from plant exhaust stacks had twice the risk for contracting leukemia as those residing > 5 km. The researchers concluded that since "this result was not to be expected under current radiation-epidemiological knowledge" and confounders could not be identified, the observed association of leukemia incidence with residential proximity to nuclear plants "remains unexplained." This unjustified conclusion illustrates the dissonance between evidence and assumptions. There exist serious flaws and gaps in the knowledge on which accepted models for population exposure and radiation risk are based. Studies with results contradictory to those of KiKK lack statistical power to invalidate its findings. The KiKK study's ramifications add to the urgency for a public policy debate regarding the health impact of nuclear power generation.

The hazards of tritium--revisited

Tritium (3H) is the radioactive isotope of hydrogen, with a half-life of 12.3 years. It is created naturally in the atmosphere, and in higher annual rates in nuclear reactors and in nuclear weapon tests. This article surveys the properties of tritium, its biokinetics and its biological effectiveness. The safety levels of tritium have been a subject of dispute for many years, as many scientists consider that its doses and risks, as promulgated by the International Commission on Radiological Protection are, too low and should be at least doubled. Recent reports and evidence of increased cancer risks near nuclear installations that release tritium are discussed; these are of interest in view of new proposals to expand civil nuclear power.