The Nature of Morbidity and Mitochondrial Disorders in the Context of Radiation Exposure. The Mechanism of Low Doses

Abstract

Purpose: To identify pathogenetic links explaining the systemic nature of the effects of low-dose radiation exposure. Material and methods: The analysis was based on a review of available scientific literature and original data on the morbidity rates among nuclear industry workers. Results: The International Commission on Radiological Protection (Publication 103, 2007) acknowledges the association between radiation exposure and somatic pathology, while noting that the contribution of low doses to overall morbidity is not fully understood. It is currently recognized that the stochastic effects of low-dose radiation include oncological diseases and heritable effects. This underscores the relevance of investigating the pathogenetic mechanisms of systemic health impairments under chronic low-dose radiation exposure. The analysis of the relationship between morbidity indices and occupational factors in personnel involved in mixed uranium-plutonium fuel production revealed polysystemic health impairments, interpreted as a decrease in general resistance under chronic low-dose irradiation. Mitochondria are one of the targets of radiation; their dysfunction can lead to the development of a significant number of pathologies. Mitochondrial DNA is not protected by histones and has a less efficient repair system. Possible pathogenetic mechanisms of mitochondrial dysfunction were considered: direct radiation damage, oxidative stress, disruption of ionic homeostasis, the impact of nanoparticles, and the synergy between radiation and chemical exposures, which creates a multiplicative, rather than additive, damaging effect. This analysis allows for the following conclusions. Conclusions: 1. The increase in overall morbidity is an integral indicator of reduced general body resistance under low-dose radiation exposure. This is pathogenetically linked to mitochondrial dysfunction, which can be considered a universal mechanism of the action of low-dose radiation. 2. Under combined exposure to low-dose radiation and chemical factors (e.g., heavy metals), the body’s response is characterized by a multiplicative enhancement of damage to the mitochondrial system, which exhausts the organelle’s reparative and adaptive potential.