Keywords: radiation hormesis, adaptive response, human health, radon, epidemiology, ionising radiation, low dose, low radiation, beneficial effects, radiation exposure, dose response, radiation protection
Radiation hormesis: the validity of the linear no-threshold hypothesis
Through various researches and investigations it has been established that high doses of ionising radiation are harmful to health. There is substantial controversy regarding the effects of low doses of ionising radiation despite the large amount of work carried out (both laboratory and epidemiological). According to the linear no-threshold hypothesis, any amount, however small, of radiation is potentially harmful, even down to zero levels. The threshold hypothesis, on the other hand, emphasises that below a certain threshold level of radiation exposure, any deleterious effects are absent. At the same time, there are strong arguments, both experimental and epidemiological, which support the radiation hormesis (beneficial effects of low-level ionising radiation). The choice of the approximate dose-response model for use in estimating the health effects of small doses of ionising radiation remains controversial. In the present work, a comprehensive study of the available literature, data and reports of various radiation exposure and protection studies is presented.