It is often quoted that Fukushima will produce “No discernible changes in future cancer rates and hereditary diseases”. This quote is from the UNSCEAR report on the Fukushima1. While other reports2 go into various criticisms of the UNSCEAR report, this post is about what that phrase actually means. This post is not about whether this statement from UNSCEAR are correct or not.
“No discernible changes” does not mean that there will be no changes or those changes are not important. UNSCEAR actually states:
“the Committee has used the phrase “no discernible increase” to express the idea that currently available methods would most likely not be able to demonstrate an increased incidence in disease statistics due to radiation exposure. This does not rule out the possibility of future excess cases or disregard the suffering associated with any such cases should they occur.”
However, this is not clear in much press coverage of the report and many people (including several comments left on this blog) mistakenly believe that ‘No discernible changes’ means that there is no effect.
To explain this matter a bit more, let us have a look at the murder rate in the UK – does it have a ‘discernible’ effect on the UK death rate?
I have used the murder rate, since we actually do know have a reasonable idea of the number of people murdered in the UK each year. However, if we did not, then would we be able to notice any change in the murder rate from the death rate? In the graph below, I have plotted the number of thousands of deaths3 against the number of murder in the UK4,5. Please note that the number and the variation of the number of deaths is 1000 times larger than those seen on the graph.
So do we see any correlation between the death rate and homicides – no we don’t.
That there is no ‘discernible’ relationship – statistically speaking – does not mean that the relationship does not exist. Even if hundreds or even of thousands of people were killed every year, it would still be difficult to see any correlation. Yet with the murders we do know that people have been killed.
With murder, a knife in the back or a bullet through the head may be a bit of a give-away. However, cancer and other health effects associated with radiation are not so clear-cut. Various factors including background radiation (see Is Natural Background Radiation is Safe?) can also produce these effects. There is no direct casual link between say getting cancer and being exposed to radiation, the same way that there is no direct casual link between smoking and cancer.ย No single cancer death can be attributed to radiation, the same way as no single cancer death can be attributed to smoking. Radiation and smoking both increase the risk of getting cancer.
So with nuclear accidents such as Chernobyl or Fukushima we will never be able to directly attribute a death to radiation exposure. However, we do know that such radiation exposure will cause deaths – more on that in a future post.
1 Sources, Effects and Risks of Ionising Radiation, UNSCEAR 2013 (http://www.unscear.org/docs/reports/2013/13-85418_Report_2013_Annex_A.pdf)
2 Critical Analysis of the UNSCREAR Report, International Physicians for the Prevention of Nuclear War (IPPNW), (http://www.psr.org/assets/pdfs/2014-unscear-full-critique.pdf)
3 Demography of the United Kingdom, Wikipedia (https://en.wikipedia.org/wiki/Demography_of_the_United_Kingdom)
4 Recorded Crime Statistics For England And Wales 1898 – 2001/02, UK Office of National Statistics (https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/116649/rec-crime-1898-2002.xls)
5 Recorded Crime Statistics For England And Wales 2002/03 – 2013/14, UK Office of National Statistics (https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/329801/rec-crime-2003-2014.ods)
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