Desastre nuclear de Fukushima (XIX)

No increased risk of cancer for children living near Sellafield or Dounreay | University of Oxford

No aumenta el riesgo de cáncer para los niños que viven cerca de Sellafield o Dounreay

El equipo de investigación estudió las tasas de cáncer entre 1963 y 2006, entre los que eran menores de 25 años y que viven cerca de Sellafield en Cumbria o Dounreay, en la costa norte de Escocia cuando se diagnostica.

Los científicos de la Universidad de Oxford, junto con colegas de la Universidad de Newcastle, no encontraron diferencias en la incidencia de cáncer a partir de 1991-2006 entre los que viven cerca de estas plantas de energía nuclear y la población en general. Sin embargo, el estudio confirmó los riesgos elevados de cáncer, particularmente la leucemia, ya se ha informado por períodos de tiempo anteriores antes de 1990.

"Durante muchos años, ha habido preocupaciones sobre el potencial planteado el riesgo de cáncer entre las personas - especialmente los niños - que viven cerca de las instalaciones nucleares", dice Kathryn Bunch, quien dirigió la investigación. 'Este estudio encontró que los niños, adolescentes y adultos jóvenes que viven cerca de Sellafield y Dounreay ya no tienen un mayor riesgo de desarrollar cáncer.

'Por otra parte, no hay evidencia de ningún aumento del riesgo de cáncer en el futuro para los que nacieron cerca de estas plantas de energía.'

El número de cánceres observados alrededor de Sellafield y Dounreay se compararon con los que se espera de las tasas nacionales de registro de cáncer. Los hallazgos aparecen en la Investigación del Cáncer del Reino Unido British Journal of Cancer .

British Journal of Cancer , (22 July 2014) | doi:10.1038/bjc.2014.357
Updated investigations of cancer excesses in individuals born or resident in the vicinity of Sellafield and Dounreay

http://www.nature.com/bjc/journal/vaop/ncurrent/pdf/bjc2014357a.pdf

La doctora Julie Sharp jefe de información de salud de Cancer Research UK, dijo: "Ha habido mucha preocupación que las centrales nucleares podrían aumentar el riesgo de cáncer, especialmente leucemia. Este estudio es tranquilizador para cualquier persona que pasa a vivir cerca de una planta de energía, ya que no muestra ningún aumento en el riesgo entre los niños, adolescentes o adultos jóvenes en los últimos años. '

CIENTIFICOS MANIPULANDO LA CIENCIA ((Bithell) : HA MANIPULADO LOS DATOS DEL ESTUDIO SOBRE SELLFIELD PARA CONCLUIR QUE NO HAY AUMENTO DE LEUCEMIAS ALREDEDOR DE LAS PLANTAS NUCLEARES:

Sin embargo, una lectura atenta de los datos reales de la tabla del informe 3, de hecho revela que el cáncer aumenta estadísticamente significativamente en todos los años y edades. La disposición de los datos en la tabla 3 esconden cuidadosamente estos aumentos ...

Comments on another BJC article | Dr Ian Fairlie

In 2013, the British Journal of Cancer published an article (Bithell et al, 2013) (for references see below) purporting to show there were no leukemia increases in young children near UK nuclear power plants (NPPs). I published a post criticising this article stating that it should not have been published. The BJC has now printed a similar article (Bunch et al, 2014) which, if anything, is even worse than the 2013 one. The new article also should never have been published.

The new report concludes, first, that children, teenagers and young adults currently living close to Sellafield and Dounreay are not at an increased risk of developing cancer. Second, it concludes there is no evidence of any increased cancer risk later in life among those resident in these areas at birth.

However a close reading of the actual data in the report’s table 3 in fact reveals statistically significant cancer increases measured across all years and ages. The data layout in their table 3 carefully hides these increases so the data are more clearly laid out below (for Seascale ward), together with p values kindly added by Dr Alfred Körblein.

The very low p values in Seascale ward show that the cancer increases there are statistically significant, ie are not due to chance. It is notable that these increases and their accompanying p values are NOT discussed in the new report.

Total leukaemias (0-24 y)

Obs Exp SIR P value* RR P value**
study region 6 0.91 6.59 0.0004
control region 68 76.33 0.89 0.8442 7.40 0.0002
All malignancies (0-24 y)

Obs Exp SIR P value* RR P value**
study region 12 3.66 3.28 0.0004
control region 321 322.27 1.00 0.5356 3.29 0.0005
Obs= observed, Exp= expected, SIR= standardised incidence ratio, RR= relative risk

*one-sided P value (Poisson test), **one-sided P value (Binomial test) both calculated by Dr Alfred Körblein

So, at Seascale, the leukemia risk is 7.4-times greater than the control area (RR=7.4, P=0.0002), and for all malignancies, the risk is 3.3 times greater than the control area (RR= 3.3, P=0.0005).

The new article should therefore have reported that statistically significant cancer increases occurred across all ages and cancers in Seascale, about 4 km from Sellafield. Instead, the printed conclusions refrain from this and make misleading inferences in selected analyses which appear to show the opposite. This is poor science.

Let’s unpack that first conclusion that “children, teenagers and young adults currently living near Sellafield are not at an increased risk of developing cancer”. This is presumably based on the most recent data (1991-2006) which show 1 observed case (0-14 yr olds) and 1 observed case (15-24 yr olds). In fact, these are increases over the expected numbers, but you can’t say anything definite one way or the other as the numbers are far too small for meaningful conclusions. Also these data are now eight years old: can we really say that young people currently living near Sellafield are not running risks?

Let’s unpack the second conclusion that “there is no evidence of any increased cancer risk later in life among those resident in these areas at birth”. This is presumably based on the data for those aged 15-24, but in fact, these again show actual increases (Observed 4, Expected 1.43 for all cases). Again you can’t be definite from such small numbers as the increases are still not statistically significant, but to say there was no increased risk when in fact the numbers show the opposite is perverse and misleading.

Given the lack of statistical power in their chosen analyses and given the fact that increases were actually found, the report should not have concluded that people were not at risk. Instead it should have reported the cancer increases but added that the results of its chosen analyses were not statistically significant as they were underpowered. However, it should also have added that, over all cancers and all years, the observed cancer increases in fact were highly statistically significant.

There is a second major flaw in this study. Leukemia incidences vary a great deal depending on age at detection. Grouping babies and infants with other ages may mask increases among them, as any increase could be diluted by the numbers at older ages. This problem is well known and it’s for this reason that almost all studies in this area have focussed on under 5 year olds. This study should have done the same: it didn’t.

Another problem is that the leukemia data from 1963 to 1990 at Seascale only shows 5 cases. But the famous study by Gardner et al (1990) revealed 10 such cases. Where have the other 5 cases gone? Were they all detected before 1963?

Fourth, the study refrains from discussing the huge amount of evidence world-wide on childhood leukemias near NPPs as discussed by myself (Fairlie, 2013) and many others. It hardly mentions the important German KiKK study (Kaatsch et al, 2008) and ignores the meta-analysis of four European studies by Körblein and Fairlie (2012) which conclusively showed increased leukemia risks among under fives, living within five km of almost all NPPs in France, Germany, Switzerland and the UK.

In sum, like the similar study of leukemias the BJC published in 2013, this study should also not have been published as it is misleading and contains no scientifically useful information.

(PS This post concentrates on Sellafield but similar considerations and criticisms apply to the Dounreay data.)

I wish to thank Dr Körblein for his invaluable help in writing this post.


El artículo previo en el que se analiza la manipulación de los datos sobre el estudio de la leucemia alrededor de Shellfield, :Leukemias near Nuclear Power stations: new study by Bithell et al September 2013. | Dr Ian Fairlie

El estudio manipulado es el que ha colgado en un post previo el CM InAudito