[Pro and contra regarding the threshold/non-threshold mutagenic (carcinogenic) action of low-level ionizing radiation].

According to the analysis of epidemiological and experimental data there are evidences in threshold on criterion of mutagenic (in broad sense) ionising radiation action. A threshold takes place in the region of about 20-200 mGy concerning a dose in case of an acute exposure and in the region of the third order above a background level regarding a dose rate in case of chronic or prolonged exposure. Evidences in favour of linear non-threshold conception are based on primitive mathematical extrapolations and approximations of the study results, mainly, in the region of intermediate doses/dose rates. Besides real data in region of low doses are ignored. The latter has a reason in paradigm of stochastic damage action of ionising radiation and in underestimation of cell and organism protection-reparation systems action. Regarding axiomatic bases of ionising radiation action it is possible to conclude more reliable substantiation of the dual (positive-negative) nature and the threshold conception concerning ionising radiation action in comparison with the non-threshold one.