The present work encompasses some key aspects of a 3-year long research project (INTRANOR) where the main focus has been specifically on environmental assessments for radiation exposure through application of existing methodologies and their adaptation to quantify transfer, exposure and effects in Boreal/Arctic ecosystems. Non-parametric statistical methods have been applied in order to estimate the threshold dose rates above which radiation effects can be expected in vertebrate organisms. In addition, industrial areas contaminated by uranium mill tailings and radium production wastes, in the Komi Republic, Russia, were selected as suitable sites to study further the effects of exposure to radiation under boreal conditions. Dose–effect relationships have been established for a few natural populations inhabiting this area. Analyses of data have allowed benchmarks to be established below which no decrease in reproductive capacity could be observed. Other work performed within the project includes the collation of data in relation to naturally occurring radionuclides and application of existing methodologies to characterise background radiation exposures. These dose-rates may be a suitable means of contextualising the exposure attributable to enhanced dose-rates arising from human activities. Finally, combined action of ionizing radiation and low temperature has been analyzed and mathematically modelled.