Chromosome Damage in Relation to Recent Radiation Exposure and Radiation Quality in Nuclear Power Plant Workers

Abstract

Ionizing radiation is a well-known carcinogen that causes genomic instability. However, the biological and carcinogenetic effects of occupational radiation exposure at low doses have not been extensively studied. The aim of this study was to assess chromosomal instability in power plant workers exposed to occupational radiation at low doses in South Korea. Chromosomal aberrations in the lymphocytes of 201 nuclear power plant workers and 59 sex-matched controls were measured. Chromosomal aberrations in the lymphocytes of 201 nuclear power plant workers (mean age: 41.4 ± 10.0 years) and 59 sex-matched controls (mean age: 47.2 ± 6.0 years) were measured. A total of 500 metaphases for each subject were scored randomly. The means of recent 1.5-year, recent 5.5-year, and cumulative exposed radiation doses among workers were 8.22 ± 7.0 mSv, 30.7 ± 22.0 mSv, and 158.8 ± 86.1 mSv, respectively. The frequency of chromosome-type and chromatid-type aberrations was significantly higher in workers than that in the control group (p < 0.001), and the frequency of chromosome-type aberrations among workers increased in a radiation dose-dependent manner (τ = 0.16, p = 0.005). Poisson regression analyses revealed that chromosome-type aberrations were significantly associated with recent 1.5-year dose after adjusting for confounding variables such as age, smoking, and alcohol intake, even when only the exposed worker was considered. Frequency of multi-aberrant cells (two or more chromosome aberrations within a cell) increased according to cumulative neutron exposure. Our study demonstrates that chromosome damage can be induced in nuclear power plant workers occupationally exposed to ionizing radiation at low doses below the occupational permissible dose limit. Furthermore, an increase in multi-aberrant cells may provide evidence for chronic neutron exposure in nuclear power plant workers. This study was performed to obtain baseline data for a surveillance program of workers occupationally exposed to ionizing radiation long-term.

Gametocidal genes: from a discovery to the application in wheat breeding

“…Ionizing irradiation and chemical agents causing chromosomal breaks (clastogenes) affect a broad range of cells by directly damaging DNA in both somatic and germ cells, causing various forms of DNA damage, including single- and double-strand breaks, and nucleotide base modifications ( Schubert et al., 2004 ; Durante and Formenti, 2018 ; Kim et al., 2020 , 2022 ; Guo et al., 2021 ). Ionizing irradiation and clastogens induce chromosomal rearrangements, encompassing duplications, and inversions, among others, causing more infertility.…”

“…Ionizing irradiation and clastogens induce chromosomal rearrangements, encompassing duplications, and inversions, among others, causing more infertility. Chromosomal aberrations can be heritable if arising in germ cells but not if occurring in somatic cells ( Durante and Formenti, 2018 ; Kim et al., 2020 , 2022 ; Guo et al., 2021 ). Furthermore, the irradiation method generally poses greater safety concerns due to its non-specificity and potential for widespread genetic damage.…”

“…Furthermore, the irradiation method generally poses greater safety concerns due to its non-specificity and potential for widespread genetic damage. It is crucial to mention that the outcomes of irradiation and chemicals are unpredictable, constituting a completely random process ( Schubert et al., 2004 ; Durante and Formenti, 2018 ; Kim et al., 2022 ).…”

“…Further challenges include linkage drag and insufficient compensation for substituted wheat chromatin. Hence, the integration of alien chromosome segments into the wheat genome necessitates induced chromosome rearrangements, achievable through methods such as meiotic manipulation ( Copete-Parada et al., 2021 ; Türkösi et al., 2022 ; Liu et al., 2023 ), ionizing irradiation ( Schubert et al., 2004 ; Guo et al., 2021 ; Kim et al., 2022 ), tissue culture ( Lapitan et al., 1984 ; Li et al., 2000 ; Zhang et al., 2016 ), CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) ( Kosicki et al., 2018 ; Schmidt et al., 2020 ) or the Gc system ( Endo, 1985 ; Farkas et al., 2023 ; Türkösi et al., 2024 ). An approach that utilizes the Gc system enables the identification of alien chromosomal regions containing target genes and facilitates the analysis of their homoeologous relationships to overcome non-collinearity between donor and wheat chromosomes.…”