Re: Assuming LNT
Of course LNT is well on the way to being thoroughly debunked as a PREDICTOR of cancer rates. It is a REGULATORY limit, and its predictions have failed to live up to expectation in every single case where people are exposed to long term chronic low level radiation.
But then that's not surprising: It was developed by drawing a straight line from where data did exist - people dying after massive exposure to high level radiation in the A-bomb attacks on Japan, and a few 'lab accidents' - to the origin.
Thus giving rise to the myth that 'there is no safe level for radiation - even the government thinks so'.
100msV/year is not unknown in a few places on earth. Ramsar for example. There are no detectable cancer increases there.
What cancers do occur from radiation appear to be intimately connected with the biological activity of the radionuclide responsible, and whether or not particles get lodged inside the body to act as hot spots.
In short its very much a threshold. And indeed some cell research suggest that DNA contains two copies of itself, and unless both match, the cell dies. Like digital transmission, it is 'parity checked' . So mutations are normally killed. Which would lead to the situation that seems to match reality, that the rate of 'successful' mutation requires strong PEAK doses and will exhibit strong non linearity around a threshold value.
Whether or not you believe the results or the logic, Wade Allisons 'radiation and reason' raises some interesting points.
There are a few other papers out there on cell division and mutation under mild chronic radiation that also seem to support the non-linear with threshold type models.
And the most significant long term result from Chernobyl, is not how many people died, but how many did not die.The LNT adherents were predicting hundreds of thousands of deaths. They simply never showed up in the data. The official death toll IIRC by the WHO stands at 78. Mostly those involved firefighting at the plant itself who received massive peak doses.
The simple fact is that as Wade says,
"Although the public accepts moderate to high doses of radiation when used benignly for their own health, non-medical international safety standards are set extremely low to appease popular concerns - these specify levels found in nature or as low as reasonably achievable (ALARA). Yet modern biology and medicine confirm that no harm comes from radiation levels up to 1000 times higher and realistic safety levels could be set as high as relatively safe (AHARS). Indeed the local damage to public health and the social economy caused by ALARA regulations imposed at Chernobyl and Fukushima has been extremely serious and without benefit."
I.e. that the level at which a detectable increase in radiation induced cancer occurs is about 100-1000 times higher than the LNT guidelines currently in force.
You may not choose to believe that: but the evidence is slowly rolling in that LNT is almost useless at predicting cancer death rates. Although it is a laudable standard (the regulatory limits) to aim for.