New take on impacts of low dose radiation

[Marlin]

Researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab), through a combination of time-lapse live imaging and mathematical modeling of a special line of human breast cells, have found evidence to suggest that for low dose levels of ionizing radiation, cancer risks may not be directly proportional to dose. This contradicts the standard model for predicting biological damage from ionizing radiation - the linear-no-threshold hypothesis or LNT - which holds that risk is directly proportional to dose at all levels of irradiation.

http://www.eurekalert.org/pub_releases/2011-12/dbnl-nto122011.php

[RDTroja]

Researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab), through a combination of time-lapse live imaging and mathematical modeling of a special line of human breast cells, have found evidence to suggest that for low dose levels of ionizing radiation, cancer risks may not be directly proportional to dose. This contradicts the standard model for predicting biological damage from ionizing radiation - the linear-no-threshold hypothesis or LNT - which holds that risk is directly proportional to dose at all levels of irradiation.

http://www.eurekalert.org/pub_releases/2011-12/dbnl-nto122011.php

Fascinating -- and well written. Thanks.

[Chimera]

Makes one kind of wonder just how much money the DoE wasted on the study.  As the dictionary says, Stochastic - proceeding by guesswork.  The linear-no-threshhold (LNT) theory has always been a statistical compromise based on inferring information where no data existed. 

There have been many discussion over the decades as to the real effects of radiation from dose-rates less than 10 R (or so) acute dose.  Figure 1 in Reg Guide 8.29 shows these differences of opinion rather well.  The levels that are set by regulation - 5 R/year - are so low that any possible real data is pretty much lost in the statistical variables that come with normal living.

"Risk" has never been "directly proportional" to dose at these low levels.  There has been a presumption of proportionality as a means to establish regulations but the risk has always only been judged to increase with increasing exposure up to the point where actual harm can be actually determined . . . ergo, Stochastic and non-Stochastic exposures.