The bell should toll for the linear no-threshold model**This is an amended version of a paper which was accepted for presentation at the IRPA-11International Congress in Madrid, Spain, 23–28 May 2004. It was not presented because theauthor was unable to attend the Congress.

Abstract

The linear no-threshold (LNT) model has been a convenient tool in thepractice of radiation protection but it is not supported by scientific dataat doses less than about 100 mSv or at chronic dose rates up to at least200 mSv yr−1. Radiation protection practices based on the LNT model yield no demonstrable benefits tohealth when applied at lower annual doses. The assumption that such exposures areharmful may not even be conservative and has helped to foster an unwarranted fear oflow-level radiation.For its new recommendations, to be issued probably in 2005, the ICRP has said that itexpects to continue the application of the LNT model ‘above a few millisieverts per year’.National societies for radiation protection may wish to consider the need to lobbythe ICRP, through the auspices of IRPA, to further relax adherence to the LNTassumption—up to ‘a few tens of millisieverts per year’.