Studies tonen meer kinderkanker rond kerncentrales

[Turkje]

Oorspronkelijk geplaatst door Johan Bollen

SCK CEN is een instituut dat de nucleaire industrie in België ondersteund. Hun brochure leest als een geschiedenis van de nucleaire industrie in België. Mijlpalen zijn voor hen de opening van kerncentrales en andere technologische nucleaire hoogstandjes.

Maw ze MOETEN wel de resultaten VERVALSEN.

Tot zover de argumentatie van de heer Bollen, die zich zelden laat afschrikken door stemmingmakerij allerhande.

[Turkje]

Nog een schone quote over dat verschil tussen two-sided tests (die vroeger gebeurd zijn), en one-side tests (degene waar Bollen naar verwijst):

One sided tests should never be used simply as a device to make a conventionally non-significant difference significant.

Bron: J M Bland, D G Bland, Statistics Notes: One and two sided tests of significance, BMJ 1994;309:248

Reden genoeg om de huidige studie eerst eens deftig te vergelijken met de vroegere studies...

[Johan Bollen]

Voorspelbare reakties Turkje. De boodschapper heeft geen zin daarop te reageren.

Dit is een Engelstalige samenvatting van de KIKK studie. Misschien kan u uw kritiek specifiek maken door an te duiden waar de studie faalt volgens u.

Epidemiological Study on Childhood Cancer in the Vicinity of Nuclear Power Plants (KiKK-Study)
Summary
Background
The German Childhood Cancer Registry (Deutsches Kinderkrebsregister, DKKR) carried out an epidemiological case-control study which started in 2003 and was intended to find out whether cancer in children under 5 years of age is more frequent in the immediate vicinity of nuclear power plants (NPP) than further away. This study was motivated by a series of exploratory evaluations of former studies conducted by the DKKR using a different method estimating the cancer incidence of children near German NPPs. This was followed by exploratory analyses of data from the DKKR carried out by third parties based on data sets used and published by the Federal Office for Radiation Protection (BfS) for their studies, mainly for the purpose of environmental health reports. The present study consists of two parts: Part 1 is a case-control study without case or control contact, whereas for Part 2 interviews were carried out in a subgroup of cases and controls from Part 1. The study design was defined in consultation with an Expert Committee assembled by the BfS. The hypothesis of the study (in terms of the statistical null hypothesis) is: "There is no relation between the vicinity of a residence to a NPP and the risk of cancer up to the
5th
year of life. There is no negative trend of the disease risk with distance".
Material and Methods
A case-control study was carried out. Part 1 includes all cases of children reported to the German Childhood Cancer Registry, diagnosed with cancer between 1980 and 2003, who were under 5 years of age at the time and living in preassigned regions around 16 German nuclear power plants (1,592 cases). Controls of equal sex and age in the year of the diagnosis of the disease were chosen randomly for each case (4,735 controls). The individual distance of the residence was determined on the day of diagnosis for the cases, and on a corresponding reference date for the controls.
For Part 2 of the study, a subgroup of cases and controls from Part 1 was questioned about potential risk factors which might act as confounders and about their residence history. For this purpose, the cases diagnosed between 1993 and 2003 who were less than 5 years of age, affected by leukaemia, lymphoma or a CNS tumour, and living in the study region at the time of the diagnosis were selected. The controls assigned to theses cases in Study Part 1 were also used in Part 2.
Results
Data
The appropriation of the addresses of cases and controls and their geological coding could largely be carried out as scheduled. There was only very little missing or inaccurate information. The predefined accuracy of at least 100 m for the distance
to be determined between dwellings and the nearest NPP was fulfilled to an estimated average accuracy of approximately 25 m.
Control recruitment showed that communities in the vicinity of NPPs were less cooperative in providing control addresses (84 per cent control addresses provided, compared to 90 per cent elsewhere) than those further away.
78 per cent of the cases and 61 per cent of the controls were willing to participate in the survey in Part 2. The case-control relationship of 1:2 which had been targeted was achieved.
For a random sample of participants the information given was validated by comparing it with copies of medical records (maternity card, check-up pass, vaccination pass). The statements concerning vaccinations and data relevant to childbirth (body weight and height at birth, week of pregnancy at birth) proved to be consistent with the records.
A comparison of survey participants and non-participants revealed that participation of families was less frequent when the specific day in question (time of diagnosis for case children, corresponding reference day for control children) was longer ago (1993-1995, i.e. about 10 years before the interview). The most obvious influence on the willingness to participate proved to be the distance from the nearest NPP: within the inner 5-km area the willingness to participate was considerably lower, and this was even more pronounced in controls (46 per cent within the area compared to 62 per cent outside of it) than in cases (63 per cent compared to 79 per cent outside). We conclude that families living in the immediate vicinity of a NPP are very well aware of this fact and, therefore, tend to be more reticent when questioned.
A short questionnaire was sent to all potential participants in the survey of Part 2. Families of higher social status appeared to be more willing to participate, especially in controls. This phenomenon is known from other epidemiological and empirical studies (in Germany and internationally).
Confirmatory analysis
The main hypothesis for Part 1, i.e. that no monotonic decreasing relation exists between the distance of the dwelling from the next NPP and the risk of disease, was rejected at the one-sided level � = 5 per cent. 1/r was predefined as a distance measure, whereby r is the distance between the home address and the nearest NPP. Regression analysis resulted in an estimate for the regression coefficient of
βˆ = 1.18 (lower one-sided 95-per-cent confidence limit = 0.46, i.e. statistically significant different from zero). Evaluation of the secondary question, for which the distance is considered as a categorical variable, also shows a statistically significant result (estimated Odds Ratio (OR) = 1.61, lower one-sided 95-per-cent limit =1.26) for the 5-km area around the NPPs.
In the diagnostic subgroups, leukaemia (593 cases, 1,766 controls) showed a statistically significant estimate of the regression coefficient of βˆ =1.75 (lower one-sided 95-per-cent confidence limit = 0.65). The effect observed in the subgroup of all
leukaemias is stronger than that of all malignancies. The leukaemia subgroups in
the study each exhibited similar values. However, this is only statistically significant in the case of acute lymphatic leukaemia. The number of cases of acute myeloid leukaemia was too small (75 cases, 225 controls). In the other predefined diagnostic subgroups (CNS-tumours, embryonal tumours) there was no evidence of distance dependency. It may be concluded that the effect observed in all malignancies is mainly due to the results of the relatively large subgroup of leukaemias.
There is no statistically significant difference between the regression coefficients in the predefined subperiods (first half of the prevailing reactor life span compared to the second half) (p=0.1265).
The members of the subgroup of cases and controls contacted in Part 2 of the study (471 cases, 1,402 controls) show no relevant difference with respect to the regression parameter determined for the whole group in Part 1 (estimated coefficient 11 per cent less than overall model). However, the group of people participating in the interview differs considerably from the complete group.
A statistical criterion was defined in the analysis plan to determine whether the participants in the telephone interview (Part 2) were possibly a non-representative selection of the cases with corresponding diagnoses from Part 1 and the controls related to them. In which case the results of Part 2 could not be used to interpret the results of Part 1. This criterion was fulfilled, i.e. the data from the interviews in Part 2 of the study cannot be used to check whether the results of Part 1 have been biased by potential confounders. The reason is mainly based on reluctance to participate within the inner 5-km-area.
Sensitivity analyses and explorative analyses
A series of sensitivity analyses and exploratory analyses was carried out, some of which were planned whereas others resulted from the data situation. On the whole there was no evidence of any relevant influence on the results. Most of the sensitivity analyses tend to show a slight overestimation of the effect reported.
The planned exploratory analyses of the shape of the regression curve using fractional polynomials and a Box-Tidwell-Model showed no evidence of a basic difference of the shape of the regression curve to that intended in the analysis plan.
Since the provision of control addresses by the communities in the vicinity of NPPs was less exhaustive than by the more remote communities, a sensitivity analysis was carried out in addition to the specifications of the analysis plan. The potential bias due to this problem of control recruitment is minimal.
Interviews on residence history (Part 2) revealed that some of the control families had only lived at the originally registered addresses after the day of reference and at no time before it. This is because incorrect control addresses had been provided by the registration offices. Simulations, an extended evaluation of control recruitment data, and verification in a random sample of community registration offices showed that this was of only marginal influence on the result of the study.
be noted, with regard to the heated discussion in Germany on the increased incidence of leukaemia in children living near the NPP Krümmel (as a result of 17 cases of leukaemia between 1990 and 2006 in two neighbouring communities), that 8 of these cases are within the inner 5-km study area. As regards leukaemia, the NPP Krümmel has the biggest influence on the result of the study. If these cases and the corresponding controls are omitted, the estimate for the regression coefficient in the
subgroup of leukaemias is βˆ =1.39 (lower one-sided 95 per-cent confidence limit=0.14).
Confounder Analyses
The results of Part 2 cannot be used to interpret the results of Part 1, because a selection occurred, as willingness to participate depended on the distance between the home and the NPP. Nevertheless, a multivariate regression analysis was carried out on the request of the BfS and the Expert Commission using the data collected (confounder analysis). The question of whether allowance for potential confounders would change the estimated regression coefficient of the distance measure was looked into (change-in-estimate principle), as originally intended. Thishad been the motivation for conducting Part 2 of the study. None of the variables led to changes in the estimate which exceeded the preset range ( ±1 standard deviation).
An exploratory evaluation of the confounders which this study, however, was not designed for, revealed correlations which largely confirmed the results known from literature.
Attributable Risks
The risk attributable to living within a 5-km area of one of the 16 nuclear power plants in Germany between 1980-2003, and for the number of cases observed in the 5-km area under study (n=77) is 0.2 per cent. This means that under the model assumptions, 29 of the 13,373 cases diagnosed with cancer at less than 5 years of age from 1980 to 2003 in Germany, i.e. 1.2 cases per year, could be attributed to living within the 5-km area of a German NPP. In relation to the cases of leukaemia, of which 37 were observed at up to 5 years of age between 1980 and 2003 within the inner 5-km area, a 0.3 per-cent population attributable risk was calculated, i.e. 20 of 5,893 cases under 5 years of age in Germany which were diagnosed between 1980 and 2003, making 0.8 cases per year. These estimates are rather inconclusive because they are based on a very small number of cases.
Discussion
Study design
This Study is a case control study on children of less than 5 years of age who were diagnosed with cancer between 1980 and 2003. The study investigated the question of whether there is a relationship between the distance from the residence to the nearest NPP and the risk of developing cancer. The strength of this study is its application of an individual distance measure, based on the distance between homes and the nearest NPP. It thus complements the NPP studies which have been
conducted in Germany up to now based on aggregated incidence rates in vicinity regions.
The interviews of a preselected subgroup of parents of case and control children integrated into the study were intended to take potential confounders into consideration in order to use this information for the evaluation of the study result. This analysis was unfortunately not possible, or rather could not be evaluated because of the paticipants’ response behaviour. There are, however, hardly any risk factors known in present literature which could act as sufficiently strong confounders.
Radiation epidemiological aspects
The present study considers the distance from the nearest NPP. Data on radiation exposures due to environmental conditions were not used because they are not available, nor can they be collected retrospectively. Neither was it taken into consideration that individuals do not stay in the same place constantly and that beyond the natural radiation background they are also exposed to other sources of radiation (e.g. terrestrial radiation, medical diagnostics, air travel). Varying topographic or meteorological conditions (e.g. precipitation, wind direction) could not be allowed for either.
The distance applied was that of each individual’s home from the nearest NPP at the time of diagnosis (control: date of diagnosis of matched case). Taking into account home moves during the time from conception to diagnosis would have necessitated the interviewing of the families under study and was, therefore, not possible for most of the families involved.
A distance measure based on a predefined model was decided on and a regression curve was estimated for it. The distance measure was based on theoretical dispersion models, and the regression model corresponds to the standard linear model for the low-dose range. This model however is based on studies evaluating the cancer risk in adults in relation to ionising radiation. Adults predominantly develop solid tumours, whereas systemic diseases are relatively more frequent in children. It has not so far been clarified in international literature as to what extent models describing low-dose radiation effects can be transferred to leukaemia incidence in children of pre-school age.
The estimates of low-dose radiation effects presently used on the international level are based on the assumption of a linear no-threshold extrapolation, an additional option for leukaemia is a quadratic model. Other authors suggest that these models considerably overestimate the effects in the dose range < 0.01 Sv (Sievert). Special statements about children are not made in the relevant reports, or the data is described as insufficient for this purpose. The models for example specify an excess relative risk, which could be compared with the dimension OR-1 in the current report, of 0.5 per Gy per year (one Gray (Gy) corresponds to 1 Sievert). The limit of exposure for persons in the “proximity” of nuclear technical plants in Germany is 0.3 mSv (milliSievert) per year. The effective exposure is much lower. For example, a 50-year-old living at a distance of 5 km from a NPP is expected to accumulate from 0.0000019 mSv (milli Sievert)(Obrigheim) to 0.0003200 mSv(Grundremmingen) through exposure to airborne emissions from Obrigheim and Grundremmingen,
respectively. Annual exposure in Germany to the natural radiation background is approximately 1.4 mSv and the annual average exposure through medical examinations is approximately 1.8 mSv. Compared to these values, the exposure to ionising radiation in the vicinity of German NPPs is lower by a factor of 1,000 to 100,000. In the light of these facts, and based on the present status of scientific knowledge, the result of our study cannot be explained radiobiologically.
Comparison with previous German NPP-studies
Before the present study was carried out, the German Childhood Cancer Registry had conducted two studies involving incidence comparisons in connection with NPPs. The first study (“Study 1”) considered the incidence of all the cancer cases diagnosed from 1980 to 1990 of individuals under 15, living within 15 kilometres of any of 20 German NPPs as compared to demographically similar comparison regions. The study was motivated by the conspicuous findings within a range of 10 miles of British NPPs (Sellafield, Windscale) and the main issue was to examine all children diagnosed at 0-14 years of age within a 15-km area. No increased risk was found (RR 0.97; 95-per-cent CI [0.87;1.08]). Age subgroups, vicinity regions, and diagnosis subgroups were examined by way of exploratory analysis.
The exploratory additional results were verified in a subsequent study (“Study 2”) based on the same design and using independent, updated data from 1991-1995. The central question (all diagnoses, age 0-14, 15-km area) remained the same, the corresponding result was unremarkable (RR 1.05; 95 per cent CI [0.92; 1.20]). The significant exploratory results from the first study , especially those pertaining to the question of leukaemia in children of less than 5 years of age living within the 5-km area, then revealed slightly lower relative risks and were statistically insignificant. Consequently, this was regarded as non-confirmation of the exploratory results.
The previous studies and the present study overlap with respect to the cases and the regions examined, especially in the vicinity of the NPPs. In contrast to the previous studies the BfS Expert Committee excluded the nuclear plants Kahl, Jülich, Hamm, Mühlheim-Kärlich, and Karlsruhe. These are essentially research reactors or nuclear power plants with short operating times. About 70 per cent of the cases of children under 5 years of age living within the inner 5-km area included in the present study had already been included in the previous studies 1 and 2, and 80 per cent of cases in the previous studies are included in the current study. The discrepancy is due to the exclusion of a number of nuclear plants and also to the additional time span considered (1996-2003) and the modified definition of “vicinity”. In the previous studies, communities were assigned a 5,10 or 15 km zone according to the location of most of their area, and no individual house coordinates were used.
Similar to the result of the main question of the previous study (age up to 15 years, 15-km area), the consideration of all malignancies in children of less than 5 living within the inner 5-km areas in the first studies did not lead to the conclusion that an increased risk existed because the effect estimates were not statistically significant (two-sided tests). However, using the approach of the present study, a statistically significant increase of risk was found (one-sided test).
age living within the 5-km area) is confirmed to a similar order of magnitude by the present study and on the basis of the extended time span of 1980-2003. As regards leukaemia, the influence of the previous results on the present results is very obvious. The risk estimate obtained in Study 1 for the period of 1980 to 1990 is nearly identical with that obtained for the same period in the present study. The odds ratio for the period after the two previous studies (1996-2003) is lower than that obtained for the preceding periods.
The former had been an exploratory result within Study 1 which was, therefore, less relevant than the confirmatory analyses within the same study. In the study which was intended to check this (Study 2) the significant result was not confirmed however the relative risk was increased. In the latest study the same question was examined as a secondary question, and this time a statistically significant result was obtained.
Conclusions
The present study confirms that in Germany there is a correlation between the distance of the home from the nearest NPP at the time of diagnosis and the risk of developing cancer (respectively leukaemia) before the 5th birthday. This study is not able to state which biological risk factors could explain this relationship. Exposure to ionising radiation was neither measured nor modelled. Although previous results could be reproduced by the current study, the present status of radiobiologic and epidemiologic knowledge does not allow the conclusion that the ionising radiation emitted by German NPPs during normal operation is the cause. This study can not conclusively clarify whether confounders, selection or randomness play a role in the distance trend observed.

P.S. Dit document is een omzetting van PDF naar DOC. Niet alle symbolen zijn juist weergegeven.

[Turkje]

Oorspronkelijk geplaatst door Johan Bollen

Voorspelbare reakties Turkje. De boodschapper heeft geen zin daarop te reageren.

Dat is normaal. Wanneer ge eerst hoog van den toren blaast, en daarna blijkt dat ge enkel een asthmatisch gehijg kunt uitbrengen, is het beter u in stilte terug te trekken.

Dit is een Engelstalige samenvatting van de KIKK studie. Misschien kan u uw kritiek specifiek maken door an te duiden waar de studie faalt volgens u.

Ik val in herhaling, maar dus:
1) statistiek op kleine getallen
2) one sided vs two sided tests

Er staat daar geen jota kritische bemerking over in die Engelstalige tekst, daarom dus mijn vraag (aan u) over de bespreking ervan in de Duitse teksten (die u -zo laat u toch uitschijnen- van voor naar achter hebt gelezen).

[Johan Bollen]

Oorspronkelijk geplaatst door Turkje

Dat is normaal. Wanneer ge eerst hoog van den toren blaast, en daarna blijkt dat ge enkel een asthmatisch gehijg kunt uitbrengen, is het beter u in stilte terug te trekken.

Ik bedoel dat het aanvallen van de boodschapper tot nu toe niet gebeurd was in deze draad, wel het verkeerd voorstellen van conclusies uit andere studies.

Ik ben geen leek op het gebied van statistiek, maar ik heb geen zin die discussie met u hier aan te gaan. Misschien kan u uw kritiek op de methode uiten tegen het European Journal of Cancer (Volume 44, Issue 2, Pages 275 - 284, Authors Spix C., Schmiedel S., Kaatsch P., Schulze-Rath R. and Blettner N.)

Andere Engelstalige publikaties van de studie zijn hier te vinden

http://www.ejcancer.info/article/S09...855-6/abstract

http://www.ejcancer.info/article/S09...855-6/fulltext

http://download.journals.elsevierhea...4907008556.pdf

Een andere geschikte plaats om de studie te bekritizeren is bij de makers ervan, namelijk het “Bundesamt für Strahlenschutz”, het Duitse Federale bureau voor radiatie protectie (http://www.bfs.de/en/bfs) en de 'International Physicians for the Prevention of Nuclear War' (www.ippnw.org)
De geschikte persoon bij deze laatste hier om uw kritiek op de methode naar te richten is Dr. med. Angelika Claussen (voorzitter van het IPPNW). Deze persoon schreef "Given these massive findings at every German nuclear power station location, a radiation-linked cause is highly likely in every case. Anyone who now still talks of coincidence is making himself ridiculous".

De KIKK studie door het BFS is er gekomen onder druk van de bevolking (meer als 10000 protestbrieven) nadat eerdere studies van bv. Dr. Alfred Körblein (Environment Institute Munich), significant hogere incidentie van kinderkanker vonden rond Beierse nucleaire energiecentrales.

Voor zover ik het begrijp is de KIKK studie juist betrouwbaarder dan eerdere studies, onder andere omdat het de eerste maal is dat de effectieve afstand tot de kerncentrale in rekening gebracht werd in een studie, en wat blijkt:

But more importantly, and controvertially, the study found an inverse distance - effect relationship linking the cancers directly to the nuclear facilities. The study tested this relationship by examining whether other risk factors (confounders) could have had an appreciable effect on the result. This proved not to be the case: the proximity of residence to the nuclear power plant remained the most likely explanation.

Ik denk dat in plaats van de methode te bekritizeren we verder komen indien we zoeken naar de oorzaken van de resultaten van de studie. De studie stelt namelijk niet dat radiatie de oorzaak zou zijn van de vastgestelde correlatie. Maar wat zou het dan wel zijn, indien niet 'iets' dat gelinkt is met de centrale. Om dit duidelijker vast te stellen is het incorporeren van de windrichting in een studie van belang.

[Johan Bollen]

Hier een meer algemeen artikel over de problematiek van deze draad

Childhood Leukemias Near Nuclear Power Stations

Article for MEDACT Communique

In the late1980s and early 1990s, a number of UK studies revealed increased incidences of childhood leukemias near the nuclear facilities at Windscale (now Sellafield), Burghfield and Dounreay. The official reaction to these increases was that the estimated radiation doses from intakes of nuclides released by these facilities were too low (by 2 to 3 orders of magnitude) to explain the increased leukemias. Various explanations were offered for the increases, including population mixing, however these increases are still occurring despite the existence of long-stabilised populations.

The UK Government’s Committee on the Medical Aspects of Radiation in the Environment (COMARE) then concluded that the explanation for the increased leukemias remained unknown but was unlikely to be radiation. In 2004, the CERRIE Committee discussed the matter and its Report (www.cerrie.org) stated that there could be very large cumulative uncertainties in internal dose estimates because of uncertainties in the biokinetic and dosimetric models used – which had to be multiplied together. From the examples discussed by the CERRIE Committee, net uncertainties in dose could be large enough to explain the increased leukemias in populations near the UK facilities.

Three recent epidemiological studies have, somewhat startlingly, rekindled the childhood leukemia debate. In June 2007, a study by Baker and Hoel (2007) at the Medical University of South Carolina lent new support to the idea that increased leukemias were linked to nuclear facilities. The authors carried out a sophisticated meta-analysis of 17 research papers covering 136 nuclear sites in the UK, Canada, France, US, Germany, Japan and Spain. They found that death rates for children up to the age of 9 were elevated by 5 to 24 per cent, depending on their proximity to nuclear facilities, and by 2 to 18 per cent in children and young people up to the age of 25. Incidence rates were increased by 14 to 21 per cent in 0 to 9 year-olds and 7 to 10 percent in 0 to 25 year-olds.

But it is two very recent German studies which have dramatically re-opened the matter. They provide much stronger evidence of an association between increased incidences of childhood leukemias and nuclear installations than previous studies. They are also significant because of their unequivocal establishment of an inverse distance- effect relationship and because of the involvement of the German Government’s BfS – the equivalent of the UK’s HPA in the KiKK study.

The first German study was published in June 2007 by Hoffmann et al. The authors found 14 cases of leukemia between 1990 and 2005 in children living within 5 km of the Krümmel nuclear plant in Geesthacht and a neighbouring nuclear research facility in northern Germany. The 14 observed leukemia cases significantly exceeded the 0.45 predicted cases based on county and national incidence rates. The team concluded that the Geesthacht cluster was (then) the largest series of childhood leukemia cases among the various leukemia clusters near other European nuclear facilities, including Dounreay and Sellafield, UK and La Hague, France.

However the second German study is the most important of the three. This is the KiKK study published in two articles by Spix et al in January 2008 and by Kaatsch et al in February 2008. (KiKK = Epidemiologische Studie zu Kinderkrebs in der Umgebung von Kernkraftwerken = Childhood Cancer in the Vicinity of Nuclear Power Plants).

The study covered 16 (out of 20) large nuclear reactor locations in Germany between 1980 and 2003, and examined 1,592 under-fives with cancer with a control group of 4,735 children. The KiKK study’s main findings were a 0.60 fold increase in solid cancers and a 1.17 fold increase in leukaemias among young children living near German nuclear reactors. These increases are very large compared with the increases near other nuclear facilities (see Baker and Hoel above).

But more importantly, and controvertially, the study found an inverse distance - effect relationship linking the cancers directly to the nuclear facilities. The study tested this relationship by examining whether other risk factors (confounders) could have had an appreciable effect on the result. This proved not to be the case: the proximity of residence to the nuclear power plant remained the most likely explanation.

The KiKK study had been commissioned in 2003 by the Bundesampt fur Strahlenshutz (the German Federal Office for Radiation Protection, the equivalent of the UK’s HPA) following prolonged pressure by IPPNW Germany and other citizen groups. The publication of the KiKK study in December 2007 resulted in a public outcry and considerable public debate in Germany which continues to this day and which has been unreported in the UK.

The KiKK authors stated they were surprised by their results, but as a result of the furore, they issued a further report to allay public fears (BfS, 2007). The authors stated that study “only” found a small number of cases of cancer: 37 observed cases where 17 would have been expected statistically. This meant that less than one additional leukaemia case occurred per year. However the authors failed to explain that leukemia is a rare disease and that the cancers had occurred in a sparsely populated region. The authors said that the 20 additional cases were “only” found within a 5 km radius. However they did not consider that the reciprocal distance rule would add many more cases if applied to the whole region.

With a touch of déj�* vu for UK readers, the KiKK authors then alleged that the raised levels of childhood cancer could not be explained by radioactive emissions from the nuclear power plants because the estimated radiation doses were too low. The authors, seemingly, were unable to countenance the possibility that their estimated doses could contain the large uncertainties discussed in the CERRIE Report www.cerrie.org.

What is the cause of the increased cancers?

In both studies, the authors explained that population mixing was unlikely to account for the leukemia incidence because the populations had remained stable over the years studied. Coincidence as an explanatory model for these raised incidences was held improbable by the External Expert Group commissioned by the German Government’s Bundesampt fur Strahlenschutz to supervise the drafting, the execution and evaluation of the KiKK study. Instead, it is now officially accepted in Germany (Weiss, 2007) that children living near nuclear power plants develop cancer and leukaemia more frequently than those living further away.

If nuclide emissions have been correctly measured (as claimed by the nuclear operators and regulatory authorities), then current environmental transport models may be wrong, or current biokinetic models for determining radiation doses to local residents may be incorrect, or the biological effects of incorporated radionuclides may have been underestimated. Or, more likely, all three.

An interesting aspect is that many of the reactors in the KiKK study are boiling water reactors (BWRs) notable for their relatively high tritium emissions. Tritium is the radioactive isotope of hydrogen and its most common form is radioactive water. Recently, the UK Government’s AGIR group published a report (AGIR, 2007) which examined a number of unusual aspects of tritium and discussed questions surrounding its biokinetic and dosimetric models. The report concluded that tritium’s hazards (ie its dose coefficient) should be doubled.

These 3 new studies (Baker and Hoel, Hoffmann et al, KiKK) are important in radiation protection terms, as they provide good evidence of strong associations between increased cancers and closeness to nuclear facilities. They raise questions about the wisdom of the UK Government’s recent decision to build more nuclear reactors in the UK.

For more information, please refer to www.ippnw.de www.bfs.de

[Mahalingam]

They raise questions about the wisdom of the UK Government’s recent decision to build more nuclear reactors in the UK.

Hoezo? Als het rapport gelijk heeft dan zorgt men ervoor dat er geen kinderen binnen de gevarenzone leven. (5 km als ik het wel heb?) Dus zet die dingen ergens op het weinig bevolkte platteland neer. No problemo.

[Johan Bollen]

5 km is de onderzoekszone. De bedoeling in duitsland is/was om de bevolking binnen een straal van 50 km op de hoogte te brengen van de resultaten.

The authors said that the 20 additional cases were “only” found within a 5 km radius. However they did not consider that the reciprocal distance rule would add many more cases if applied to the whole region.

De Duitse kerncentrales staan in het algemeen al op relatief onbewoonde stukken land.

Vergeet ook niet dat Leukemie een betrekkelijk zeldzame ziekte is. Andere ziektes dienen ook onderzocht te worden mijns inziens.

[Turkje]

Bon, Bollen. Als ge dan toch geen discussie wilt, zeg het dan gewoon. Dat maakt het leven simpeler.

Ik zal het eens voordoen: "Ik ben Johan Bollen en dit is de enige studie die ik serieus neem. Andere studies zijn gemanipuleerd of slecht. Waarom weet ik niet, maar ik wil er niet over discussiëren. Ik ga enkel een stuk of drie links zetten naar telkens hetzelfde artikel, en als ge het daarover wilt hebben, dan moet ge maar rechtstreeks uw kritiek uiten bij de auteurs van dit artikel."

Daarmee zou je mijn kostbare tijd een pak minder verspeeld hebben.

[Turkje]

Voor degenen die toch nog wat meer willen lezen, dan de uitspraken van de "dokters tegen nucleaire oorlog" en hun forum-accolieten, hier een aantal links:

http://cebp.aacrjournals.org/cgi/con...tract/8/10/925
http://www.pubmedcentral.nih.gov/art...?artid=1892120
http://www.evacuationplans.org/Is-th...ear-power.html

Met het lezen van zulke artikels, wordt het duidelijk dat de opzet van de KNIKK studie inderdaad wel eens gebiased kan zijn, door het werken met "one-sided tests".

Zo blijkt dat kanker mortality rates dichtbij een NPP lager (kunnen) liggen dan het landelijk gemiddelde, maar dat leukemie meer voorkomt (maar niet consistent statistisch hoger ligt, er is eerder sprake van clustervorming rond maar enkele NPPs). De redenen daarvoor zijn onbekend (alhoewel Bollen zegt dat het niet aan straling ligt, terwijl hij mensen quote die zeggen dat het wel aan straling ligt ); één factor die misschien van belang is -naast eventuele links met de NPPs zelf natuurlijk-, betreft het zogenaamde "population mixing". Voor meer uitleg over dit laatste, zie o.a.:

http://aje.oxfordjournals.org/cgi/co...full/159/7/716
http://pediatrics.aappublications.or...ll/114/1/330-a

[Zwitser]

Oorspronkelijk geplaatst door Johan Bollen

Ik bedoel dat het aanvallen van de boodschapper tot nu toe niet gebeurd was in deze draad, wel het verkeerd voorstellen van conclusies uit andere studies.

De eerste die die in deze draad "de boodschapper" aanviel was wel toevallig jijzelf...

[Zwitser]

Oorspronkelijk geplaatst door Johan Bollen

Vergeet ook niet dat Leukemie een betrekkelijk zeldzame ziekte is. Andere ziektes dienen ook onderzocht te worden mijns inziens.

En men moet dat voor elke activiteit doen. Ik zou wel eens een studie willen zien die ook andere vormen van energieopwekking mee neemt.

En men moet dan ook eens nadenken over de logika die achter we eis een activiteit die een extra leukemiegeval per jaar oplevert in de ban te doen, terwijl een andere activiteit die jaarlijks tienduizenden kinderen doodt wel door mag gaan...

[Johan Bollen]

Oorspronkelijk geplaatst door Turkje

Met het lezen van zulke artikels, wordt het duidelijk dat de opzet van de KNIKK studie inderdaad wel eens gebiased kan zijn, door het werken met "one-sided tests".

U heeft niet uitgelegd waarom een one-sided studie in het geval vande KIKK studie een probleem zou zijn. Die artikels waarnaar u verwijst brengen niets bij in dit opzicht. De KIKK studie stelt een statistisch significant verband vast tussen afstand tot kerncentrale (en niet slechts 'straal') en leukemie. Wat precies vindt u niet kunnen in de methode? Liefst geen algemene statistische uitleg over het verschil tussen one-sided en two-sided, want dan staan we nog geen stap verder.

alhoewel Bollen zegt dat het niet aan straling ligt, terwijl hij mensen quote die zeggen dat het wel aan straling ligt

Ik heb gezegd dat de studie die conclusie niet trekt, dat het aan de straling ligt. Straling werd niet gemeten. Ik vraag me af, wat is het anders als het niet straling is, dat dit verband verklaard tussen Leukemie en nabijheid van kerncentrales? Voor sommigen is er niet veel andere optie dan 'straling'.

De geciteerde metastudie van Baker en Hoel (2007) is trouwens ook interessant.

één factor die misschien van belang is -naast eventuele links met de NPPs zelf natuurlijk-, betreft het zogenaamde "population mixing"

Bij de KiKK studie werd vastgesteld dat het om stabiele polulaties ging.

Voor degenen die toch nog wat meer willen lezen, dan de uitspraken van de "dokters tegen nucleaire oorlog"

Vergeet niet dat het om een federale studie gaat van het BFS. Des te meer opmerkelijk, omdat die geen problemen willen voor de nucleaire industrie, net zoals dat instituut in Mol waarnaar u eerder verwees. Niet verwonderlijk ook de houding van dat instituut na de verrassende resultaten van de KIKK studie.

De eerste die die in deze draad "de boodschapper" aanviel was wel toevallig jijzelf...

Ik herinner me geschreven te hebben dat ik aanraad de studie eens te lezen vooraleer te oordelen. Is het daar dat u op doelt? Ik ben in ieder geval niet beginnen schelden.

Oorspronkelijk geplaatst door Zwitser

En men moet dan ook eens nadenken over de logika die achter we eis een activiteit die een extra leukemiegeval per jaar oplevert in de ban te doen, terwijl een andere activiteit die jaarlijks tienduizenden kinderen doodt wel door mag gaan...

Het is niet duidelijk om hoeveel gevallen van Leukemie het eigenlijk gaat. De studie beperkte zich tot een radius van 5 km. rond centrales. Indien er sprake is van straling is het ook niet duidelijk wat het effect is op andere ziektes. Ik ben wel akkoord met u dat de problemen van kernenergie moeten vergeleken worden met andere problemen, zonder daarbij één probleem te gebruiken als excuus om een ander probleem niet te willen aanpakken. Wat we kunnen missen is een houding die wetenschappelijke resultaten naast zich neerlegt vanuit een ideologsiche houding.

[Zwitser]

Oorspronkelijk geplaatst door Johan Bollen

Ik herinner me geschreven te hebben dat ik aanraad de studie eens te lezen vooraleer te oordelen. Is het daar dat u op doelt? Ik ben in ieder geval niet beginnen schelden.

Dat niet, maar jou eerste reactie op het aanhalen van een onderzoek van het SCK door een andere poster was:

SCK CEN is een instituut dat de nucleaire industrie in België ondersteund. Hun brochure leest als een geschiedenis van de nucleaire industrie in België. Mijlpalen zijn voor hen de opening van kerncentrales en andere technologische nucleaire hoogstandjes.

Dat is op de boodschapper schieten, en niet op de boodschap.

Het is niet duidelijk om hoeveel gevallen van Leukemie het eigenlijk gaat. De studie beperkte zich tot een radius van 5 km. rond centrales. Indien er sprake is van straling is het ook niet duidelijk wat het effect is op andere ziektes. Ik ben wel akkoord met u dat de problemen van kernenergie moeten vergeleken worden met andere problemen, zonder daarbij één probleem te gebruiken als excuus om een ander probleem niet te willen aanpakken. Wat we kunnen missen is een houding die wetenschappelijke resultaten naast zich neerlegt vanuit een ideologsiche houding.

Wetenschappelijke studies naar de gevolgen van kernenergie voor de volksgezondheid vallen grofweg uiteen in twee groepen:
- Onderzoeken die geen verband vinden.
- Onderzoeken die een heel erg kleine effect vinden.

Ik vind meer onderzoek om een erg klein effect met een paar cijfers achter de komma te precizeren weggegooid geld.

We weten dat kernenergie een negatieve invloed heeft op de volksgezondheid. Kernenergie is niet de enige menselijke activiteit met die eigenschap. Echter al nemen we de meest pessimistische aannames voor waar aan, dan nog is kernenergie gezonder dan vrijwel elke andere vorm van electriciteitsopwekking.

[AdrianHealey]

Mooi, ik stel voor dat we ouders zwaar bestraffen indien ze in de buurt van een kerncentrale wonen.

Kids first.

[Johan Bollen]

Oorspronkelijk geplaatst door Zwitser

Dat is op de boodschapper schieten, en niet op de boodschap.

Toen ik schreef over het 'op de boodschapper schieten' vanwege Turkje, doelde ik op mezelf. De makers van de studie en degene die de draad opent werden als onbekaam voorgesteld, en de studie werd bekritizeerd zonder concrete argumenten tot nu toe. Nochthans bekritizeert het BSF zelf de studie, maar de resultaten zijn te duidelijk om veel belang te hechten aan deze kritiek. Het enigste wat het BSF hiermee verwerzenlijkt is het etaleren van een partijdigheid.

Echter al nemen we de meest pessimistische aannames voor waar aan, dan nog is kernenergie gezonder dan vrijwel elke andere vorm van electriciteitsopwekking.

Zolang er geen ramp gebeurd, en we niet de mogelijke toekomstige problemen met nucleair afval in rekening brengen kan dat waar zijn. Maar dat is geen reden om te doenalsof er helemaal geen probleem zou zijn met bv. straling op dit moment. Het mag onderzocht worden,en het mag geweten zijn. U vindt het misschien weggegooid geld, maar op deze studie hebben meer als 10000 mensen aangedrongen. Er bestaat dus wel een behoefte aan informatie hieromtrend.

[Johan Bollen]

Oorspronkelijk geplaatst door AdrianHealey

Mooi, ik stel voor dat we ouders zwaar bestraffen indien ze in de buurt van een kerncentrale wonen.

Kids first.

Je kan ouders niet verantwoordelijk stellen indien ze niet geïnformeerd zijn. Het niet bekend maken van de resultaten van deze studie door de overheid zoals oorspronkelijk gepland, kan je de ouders niet verwijten.

[Erw]

Oorspronkelijk geplaatst door Johan Bollen

Je kan ouders niet verantwoordelijk stellen indien ze niet geïnformeerd zijn. Het niet bekend maken van de resultaten van deze studie door de overheid zoals oorspronkelijk gepland, kan je de ouders niet verwijten.

De bal was: ouders die hun woonplaats kiezen in de buurt van een amai-atoomcentrale.

[Zwitser]

Oorspronkelijk geplaatst door Johan Bollen

Zolang er geen ramp gebeurd, en we niet de mogelijke toekomstige problemen met nucleair afval in rekening brengen kan dat waar zijn.

Bij de beoordeling van kernenergie worden reeds gebeurde en eventueel in de toekomst mogelijk rampen wel degelijk meegenomen, net als de gevolgen die het opslaan van radioactief afval voor de toekomstige volksgezondheid kunnen hebben.
Dat allemaal meegerekend is kernnergie nog steeds de schoonste vorm van energieproductie.

[vlijmscherp]

Oorspronkelijk geplaatst door AdrianHealey

Mooi, ik stel voor dat we ouders zwaar bestraffen indien ze in de buurt van een kerncentrale wonen.

Kids first.

hey ja, laten we de onwetenden eerst straffen!