A statement by participants to the 6th Citizen-Scientist International Symposium on Radiation Protection （7–10 October 2016）in Nihonmatsu, Japan
Over recent years, some interested parties have claimed that human exposure to low doses（100 mSv/mGy or less）of ionising radiation does not confer an increased risk of cancer, or that the risk is so small that it cannot be estimated.
Our understanding of the risks of ionising radiation leads us to conclude that:
The accrued epidemiological data do not support there being a threshold of risk at 100 mSv for the induction of cancer. [1-11] [12-14]. Most of the available evidence together with mechanistic considerations, point to linearity of dose response at both high and low dose-rates.
Direct measurement of risk below 100 mSv [1-5, 7, 9] and extrapolation from higher doses [3, 5, 6, 10, 11, 15], support the use of the linear dose response model for doses less than 100 mSv and for the estimation of risks for the protection of public health after nuclear accidents.
The INWORKS study of workers is particularly important because the mode of exposure is similar to that which will be experienced by returning evacuees. It provides important information in re- lation to the risks in the dose range 0 to 100 mGy. Over this range the risk（0.8 per Gy）is higher, but not significantly so, than the overall estimate of 0.48 per Gy.This estimate is not influenced by the slope at higher doses.The paper states: “INWORKS thus provides supportive evidence for a positive association between radiation dose and all cancer other than leukaemia, even if less precise when analyses are restricted to data for the 0-100 mGy dose range.”
This position is consistent with:
The 2000 report of the United Nations Scientific Committee on the Effects of Ionising Radiation  （UNSCEAR, subsequently endorsed in their 2012 White Paper  and the 2012 analysis of the 2006 BEIR VII report from the US National Academy of Sciences  the Japanese bomb survivor data .
The World Health Organisation report of 2013  on the Fukushima accident.
We conclude that a recommended “reference level” of 20 mSv/year for returning evacuees from areas adjacent to the Fukushima Daiichi accident will entail an increased lifetime risk of cancer, par- ticularly for those exposed as children.
Keith Baverstock, Department of Environmental and Biological Sciences, University of Eastern Fin- land, Kuopio, Finland.
Iuliia Davydova, Institute of Paediatrics, Obstetrics and Gynaecology, National Academy of Medical Science of Ukraine, Kiev, Ukraine.
John Mathews, School of Population and Global Health, University of Melbourne, Carlton,Australia Sebastian Pflugbeil, Society for Radiation Protection, Berlin, Germany
Ben Spycher, Institute of Social and Preventive Medicine（ISPM）, University of Bern, Bern, Switzer- land.
Wolfgang Hoffmann, Institute für Community Medicine, Urnst-Moritz-Arndt-Universität, Greifswald, Germany
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