Archive for September 6th, 2009

On the socalled Greiser-study

Sunday, September 6th, 2009


According to Spiegel a new study by Eberhard Greiser on the correlation between living in the vicinity of a nuclear power plant and children Leukemia had been brought forward.

randform reported recently in a blog post about an earlier study (the socalled KIKK-study, see also: Kaatsch P, Spix C, Schulze-Rath R, Schmiedel S, Blettner M. Leukemia in young children living in the vicinity of German nuclear power plants. Int J Cancer 2008; 122 (4): 721-726) in which a correlation between living next to a german nuclear power plant and childhood leukemia was asserted. This very comprehensive study gave way to many discussions about nuclear power, however although the study established a correlation between children getting sick of Leukemia and living next to a nuclear power plant the KIKK-study could not identify a cause for that correlation. May be this was the reason why no political measures, like sending out warnings for those living close to a nuclear power plant were enforced. In particular it was argued that the measured radiation in the vicinity of a nuclear power plant could – due to its low value – not be accounted for an increased risk of developping Leukemia. However as pointed out earlier the KIKK-study doesn’t rule out this possibility either and there may be other risk factors, which could (and should) in principle be investigated.

The study by Eberhard Greiser (shortly called Greiser-study) is interesting. It is however of a different kind than the KIKK-study. First of all the KIKK study had been commissioned by the german Ministry of Environment and the Federal Office for Radiation Protection. The Greiser-Study had been commisioned by the german green party (which is against nuclear power generation). This shall put the neutrality of the Greiser-study under strong scrutiny. The KIKK study had been undertaken by the Institut for Medical Biometry, Epidemiology and Informatics at the University of Mainz and the German Childhood Cancer Registry (Kinderkrebsregister), the study by Greiser had been performed by him as a consultant at a consultant company called epi.consult, a company of which I couldn’t find a website. Nevertheless Eberhard Greiser seems to be a distinguished scholar (Biomedexperts link1,link2?), in particular he is mentioned as the founder of the Bremen Institute for Prevention Research and Social Medicine, given his publications on Biomedexperts and e.g. this book he seems to be an expert for epidemiological investigations. So in short – the academic reputation of this person could in principle reinforce some trust in the neutrality of the study.

Greisers study investigates given data in journal articles and cancer registries (in particular he includes the KIKK study). So Eberhard Greiser used more or less open accessible data (see also here in this randform post about cancer in Marine county) in order to perform a statistical analysis. He analyzed data of 80 nuclear power plants in the five countries: Germany, France, Great Britain, USA and Canada.

Main result of Greiser-study:

The Greiser-study displayed a statistically increased risk for children (up to age 24) to develop Leukemia due to living next to a nuclear power plant. The risk was increased by 13% to 24% with respect to the respective national average risk of developping Leukemia.

E. Greiser lists all his data sources, in particular he lists which source was used for investigating each of the 80 nuclear power plants. The data from each facility is then weighted in a socalled meta-analysis (a method which seems to be described in DerSimonean R., Laird N. Meta-analysis in clinical trials, 1986;7:177-188 and Greenland S. Quantitative Methods in the review of epidemiologic literature, Epidemiol Rev 1987; 9:1-30). This method was used in order to gain a statistically relevant evidence for the international comparision.

In order to understand the implications of the main result Eberhard Greiser mentions that passive smoking increases the risk of lung cancer by 13% to 19%.

Concluding it can be said that there is plenty of data about cancer occurrences available, especially on an international level. The Greiser-study displays this already at the example of only 5 countries. This data however should be analysed in a more neutral (and international) setting than in the Greiser-study in order to obtain a neutral matter-of-fact scientifically sound analysis of the health risks of nuclear energy. The above mentioned studies strongly indicate that such a health risk seems to exist. Moreover the risk seems to be high enough so that political measures may be necessary as they were e.g. undertaken in the case of passive smoking.