INPO - WANO News and Report
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Posted: 16 Aug 2012 09:45 AM PDT
The
latest Life Span Study (LSS-Report 14) of A-bomb survivors by Dr Kotaro
Ozasa, Radiation Effects Research Foundation (RERF), and others,
published in Radiation Research Journal this year, noted
that the risk of all causes of death among the survivors increased with
radiation dose over the entire range of doses with no threshold
observed. The RERF study supported the Linear No Threshold (LNT) concept
which is basic to radiation protection.
This
means that harmful effects of radiation increase with radiation dose and
even small radiation doses can cause some finite harm. Some scientists
challenge the validity of LNT concept.
Writing in Radiation Research (on-line
July 20, 2012) Mohan Doss, Brian L. Egleston and Samuel Litwin, Fox
Chase Cancer Centre, Philadelphia argued that the functional forms the
RERF authors chose for dose dependence, were not flexible enough and
might have led them to the conclusion of a zero-dose threshold.
They showed that there is too much variability in the data used by the
RERF authors to suggest that the threshold for the harmful effect of
radiation is zero.
RERF researchers observed
that the radiation risk estimates for intermediate doses were lower than
those for the linear model. Professor Doss argued that this observation
is consistent with radiation hormesis or ‘beneficial’ effect of
radiation (Dose-Response, 2012).
He
noted that RERF’s formalism ignored the potential for a large systematic
bias in the measured baseline cancer mortality rate. He showed that if
we correct the bias, the excess relative risk for intermediate doses can
lower to negative values.
Whether low dose of
radiation will cause harm or not remains controversial. The U.S.
National Academy of Sciences and The French Academy of Sciences do not
agree on the matter.http://inpowano.blogspot.com/2012/08/scientists-question-basic-conclusion-of.html?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+Inpo-WanoNewsAndReport+%28INPO+-+WANO+News+and+Report%29
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