ECRR Risk Model and radiation from Fukushima
Chris Busby
Scientific Secretary
European Committee on Radiation Risk
March 19th 2011
Radioactivity from the Fukushima Catastrophe is now reaching centres of population
like Tokyo and will appear in the USA. Authorities are downplaying the risk on thebasis of absorbed dose levels using the dose coefficients of the International
Commission on Radiological Protection the ICRP. These dose coefficients and theICRP radiation risk model are unsafe for this purpose. This is clear from hundreds ofresearch studies of the Chernobyl accident outcomes. It has also been conceded by theeditor of the ICRP risk model, Dr Jack Valentin, in a discussion with Chris Busby inStockholm, Sweden in April 2009. Valentin specifically stated in a videoed interview(available on www.llrc.org and vimeo.com) that the ICRP model could not be used toadvise politicians of the health consequences of a nuclear release like the one from
Fukushima. Valentin agreed that for certain internal exposures the risk model wasinsecure by 2 orders of magnitude. The CERRIE committee stated that the range ofinsecurity was between 10 and members of the committee put the error at nearer to1000, a factor which would be necessary to explain the nuclear site child leukemia
clusters. The ECRR risk model was developed for situations like Fukushima.
Since the ECRR 2003 Radiation Risk Model, updated in 2010, was developed for justthis situation it can be employed to assess the risk in terms of cancer and other ill
health. See www.euradcom.org. It has been checked against many situations where
the public has been exposed to internal radioactivity and shown to be accurate.
Using the ECRR 2010 radiation risk model the following guide to the health effects ofexposure can be employed.
Take the dose which is published by the Japanese authorities. Multiply it by 600. Thisis the approximate ECRR dose for the mixture of internal radionuclides released fromFukushima. Then multiply this number by 0.1. This is the ECRR 2010 cancer risk.
Example 1: According to Japanese chief cabinet secretary Yukio Edano, the dosefrom exposure to radioactive milk from Fukushima is so low that you would have todrink milk for a year to get the equivalent of a CT scan dose. A CT scan dose is about
10 milliSieverts (mSv) Assuming you drink 500ml a day, the annual intake is180litres so the dose per litre is 0.055mSv. The ECRR dose per litre is at maximum
0.055 x 600 = 33mSv. Thus the lifetime risk of cancer following drinking a litre ofsuch contaminated milk is 0.0033 or 0.33%. Thus 1000 people each drinking 1 litre ofmilk will result in 3.3 cancers in the 50 years following the intake.
From the results in Sweden and elsewhere following Chernobyl, these cancers willprobably appear in the 10 years following the exposure.
Example 2: External doses measured by a Geiger counter increased from 100nSv/h to500nSv/h. What is the risk from a week's exposure? Because the external dose is only
a flag for the internal dose we assume that this is the internal ICRP dose from therange of radionuclides released which include radiodines, radiocaesium, plutonium
and uranium particles, tritium etc. A week's exposure is thus 400 x 10-9 x 24 x 7days
or 6.72 x 10-5 Sv . We multiply by 600 to get the ECRR dose which is 0.04Sv andthen by 0.1 to get the lifetime cancer risk which is 0.4%. Thus in this case, in 1000
individuals exposed for a week at this level, 4 will develop cancer because of thisexposure. In 30 million, the population of Tokyo, this would result in 120,000 cancers
in the next 50 years. The ICRP risk model would predict 100 cancers from the sameexposure. Again we should expect to see a rise in cancer in the 10 years following theexposure. This is due to early clinical expression of pre-cancerous genomes.
Other health effects are predicted, including birth effects, heart disease and a range ofother conditions and diseases. For details see ECRR2010.
These calculations have been shown to be accurate in the case of the population of
Northern Sweden exposed to fallout for the Chernobyl accident, and also are accurate
for the increased in cancer in northern hemisphere countries following the 1960s
weapons testing fallout (the cancer epidemic). The public and the Japanese and otherauthorities would do well to calculate exposure risks on the basis of theseapproximations and to abandon the ICRP model which does not protect the public.
This was the conclusion of a group of international experts who signed the 2009
Lesvos Declaration (this can be found on
http://www.euradcom.org/2009/lesvosdeclaration.htm)
Reference:
ECRR 2010. The 2010 Recommendations of the European Committee on Radiation
Risk. The health effects of exposure to low doses of ionizing radiation. Regulators'
Edition. Eds: Chris Busby, Alexey V Yablokov, Rosalie Bertell, Molly Scott Cato,Inge Schmitz Feuerhake, Brussels: ECRR.