At present, a possible radiation effect is estimated as a function of dose irradiation although it is strongly dependent more on the environmental factors. The consequences of low doses of internal irradiation linked to chronic soil contamination and of external irradiation associated with short or prolonged atmospheric impacts for plant populations in nature are analysed in this paper. The results revealed that the internal and external lab short and prolonged irradiations showed the same effects. In nature, soil contamination (~30 Bq/kg) limited survival of seeds to ~50% and increased their resistance to heat stress, whereas atmospheric impact (~0.12 μSv/h) combined with high summer temperature decreased viability to 20–30%. External atmospheric irradiations compared with background originate sporadically synergic radiation-heat effect which can be lethal for populations from time to time, whereas low-chronic internal soil contamination decreases seed survival significantly but increases resistance caused by adaptation processes continued in lifespan and over generations.
Keywords: low radiation, soil contamination, atmospheric impact, plant populations, environmental conditions, statistical modelling