Biological Effects of Low-Dose Radiation: Dna Damage, Cellular Repair and Stochastic Effects

This scientific review examines the biological effects of low-dose ionizing radiation, with particular emphasis on DNA damage, cellular repair mechanisms, genomic stability, and stochastic health effects. It explores the molecular pathways through which radiation interacts with biological tissues, potentially inducing DNA single-strand and double-strand breaks, oxidative stress, chromosomal abnormalities, and other cellular alterations. The publication provides an overview of major DNA repair mechanisms, including base excision repair (BER), nucleotide excision repair (NER), homologous recombination (HR), and non-homologous end joining (NHEJ). It also discusses apoptosis, cellular senescence, adaptive responses, genomic instability, and radiation-induced bystander effects. Special attention is given to stochastic effects, particularly radiation-induced cancer, and to the scientific basis of the Linear No-Threshold (LNT) model. The review considers current evidence, epidemiological findings, and uncertainties associated with estimating health risks from low-dose and low-dose-rate radiation exposure. By integrating molecular radiobiology, cellular biology, radiation protection, and risk assessment, this publication provides a comprehensive scientific perspective on the mechanisms and potential long-term consequences of low-dose radiation exposure.