Genotoxic risk in health-care professionals occupationally exposed to low doses of ionizing radiation

Abstract

<jats:p> The purpose of this study was to evaluate the potential influence of occupational ionizing radiation (IR) exposure on health professionals, assessing DNA damage using the comet and micronucleus (MN) assays and analyzing relative risks, correlations, and associated factors between outcomes and socioeconomic and lifestyle factors. Blood and buccal samples were collected from 36 workers, who actively participated in an imaging sector of a hospital, who were either exposed to IR directly or indirectly (9 internal control and 27 exposed), and 27 individuals living in the same city but with no occupational exposure (external control, unexposed/healthy). All radiation dosages performed on the 36 workers were less than 20 mSv/y, not exceeding the effective dose limit for occupational exposure. A questionnaire identified socioeconomic and lifestyle factors associated with the outcomes. The results of the MN assay showed a significant difference between both internal control and the exposed group when compared to the external control. For the comet assay, there were significant differences between the percent of tail DNA of the exposed group and external controls, but no difference was found between the exposed group and internal controls. Relative risk associations were found in time of exposure, hours worked per week, and perceived stress. Correlations were found between the outcomes and age, consumption of alcohol, and frequencies of X-rays during life. Variables that showed to be significant in the adjusted analysis were skin color and recent exposure to radiation. Albeit limited, the findings of this study suggest genotoxicity in both blood and buccal mucosa cells of workers exposed directly or indirectly to IR and that lifestyle and socioeconomic factors are associated and correlated with the risk of developing these outcomes. </jats:p>

Response to letter to the editor “Genetic biomonitoring of professionals occupationally exposed to ionizing radiation: Theoretical concepts for scientific debate”

“…The micronucleus average found in this group was consistent with values found in other studies, such as Bonassi et al (2011) and Holland et al (2008). Moreover, the micronucleus averages found in the study by da Silva Júnior et al (2020) are even less than the values reported by Holland et al (2008) in subjects exposed to ionizing radiation, and with values closer to those reported by Aguiar Torres et al (2019) among workers exposed to low doses of ionizing radiation.…”

“…In this regard, it should be noted that we neither explored nor discussed the variables that were significant for any of the statistical analyses performed between the independent variables and the genotoxic outcomes: Pearson’s correlation analysis and Poisson regression analysis (bi- and multivariate). In this sense, although we are aware that these variables are commonly reported and discussed in studies with micronucleus evaluations, in the study by da Silva Júnior et al (2020) they were not among the independent variables significantly related to the number of micronuclei. To exemplify, we point out the results from the most robust analysis made: the Poisson regression analysis (bi- and multivariate).…”

“…Even so, recent studies, as mentioned by Antoniazzi et al (2018) and other studies (Vilas Boas et al, 2018), showed promising and reliable results with the Giemsa staining technique. The staining procedure used in the study by da Silva Júnior et al (2020), a solution of eosin methylene blue according to Leishman, is an appropriate cocktail for differential visualization of both cytoplasm and cell nucleus. Korsakov et al (2015) used the solution of eosin methylene blue according to Leishman for staining oral cells in their study that recommended the use of oral epithelium cells as an environmental indicator.…”

Micronucleus in oral exfoliated cells and associated factors among young adults in the far south of Brazil

“…Aging effect negatively DNA repair mechanisms and cytosolic DNA removal, with a steady build-up of DNA damage, increasing chronic proinflammatory signals and reactive oxygen and nitrogen species (RONS) production, increasing induction of chromosomal lesions, including MN, leading into a vicious cycle where MN induces inflammation and inflammation induces MN. Thus, the most of studies target older population, while, studies that evaluated with young population have been restricted to environment or occupational exposure groups (14)(15)(16)(17)(18) , being neglected the mutagenic damage risks on young populations. Therefore, the present study aimed in investigate the MN presence in young adults and its associated factors in a population residing in the extreme south of Brazil.…”

Genetic biomonitoring of professionals occupationally exposed to ionizing radiation: Theoretical concepts for scientific debate

“…I read the recent paper accepted for publication in Toxicology and Industrial Health titled “Genotoxic risk in health-care professionals occupationally exposed to low doses of ionizing radiation” by Silva-Junior et al (2020) with much enthusiasm. In the manuscript, the authors found DNA damage followed by increased number of micronucleated cells in peripheral blood and buccal mucosa cells, respectively, of professionals occupationally exposed to ionizing radiation.…”