LNT The LNT hypothesis has the benefit of simplifying radiation risk assessments but it has also led to the alarmist mantra, “There is no safe dose of radiation.” This, in turn, has resulted in political pressures that have exacerbated the difficulties of conducting activities involving even minor uses of radiation and radioactive materials. Another issue is that it flies in the face of common understanding. Mankind lives equally healthily in a range of background radiation (say 1.5-15 mSv/y) to the extent that people ordinarily have no concern about such levels of radiation and its variability (nor do authorities say they should). Thus for minor changes in exposure within the proven healthy range attempts to regulate such exposures and efforts to comply would generally be regarded as a waste of resources. JR Fredsall, 17/3/05