Effects of Radiation Contamination on Human Genome Stability and Health

Background: Environmental radiation exposure is a well-recognized risk factor for genomic instability and adverse health outcomes. Kazakhstan hosts multiple legacy radioactive waste disposal sites, including settlements in Western Kazakhstan located in close proximity to solid radioactive waste. While the health effects of the Semipalatinsk Nuclear Test Site have been studied extensively, the long-term cytogenetic and molecular genetic consequences of chronic low-dose exposure from radioactive waste storage remain poorly characterized. This study aimed to investigate the impact of chronic radiation exposure on genome stability and population health in residents of contaminated areas compared with non-exposed controls. Results: Peripheral blood samples were collected from residents living near a radioactive waste disposal site and from controls residing in non-contaminated regions. Cytogenetic analyses, including the micronucleus test and metaphase chromosome analysis, revealed significantly elevated frequencies of micronuclei and chromosomal aberrations among exposed individuals. Mutant allele distributions of DNA repair genes (XRCC1, XRCC3, and XPD) also differed between exposed and control groups. Correlation analysis demonstrated strong associations between chromosomal instability and increased prevalence of endocrine disorders, congenital anomalies, and nervous system diseases in the exposed population. These findings are consistent with international reports on chronic low-dose exposure and highlight the potential contribution of both genetic and environmental factors to population health risks. Conclusions: Residents living in close proximity to radioactive waste disposal sites in Western Kazakhstan exhibit measurable genomic instability and altered DNA repair gene profiles. These biological effects are associated with higher rates of specific health disorders, underscoring the urgent need for systematic medical-genetic monitoring, public health interventions, and environmental remediation. This study provides one of the first integrated analyses of chronic low-dose radiation exposure in Central Asia and contributes to global understanding of radiation-induced genomic instability.