Genotoxicity of ionizing radiation in occupationally exposed individuals: comparison between oral and conjunctival mucosal cells

Abstract Objective To evaluate genotoxic effects associated with occupational exposure to ionizing radiation using the micronucleus test in exfoliated cells from the oral and conjunctival mucosa of healthcare workers. Methods This pilot cross-sectional study included 22 participants (11 exposed and 11 controls). Micronuclei were quantified in 1000 epithelial cells from the oral and conjunctival mucosa of each participant. Between-group comparisons were performed using Student’s t -test or the Mann–Whitney U test, with effect size estimation. Negative binomial regression models with a log link function were fitted to assess whether the association between occupational exposure and oral micronucleus frequency remained after adjustment for age, alcohol consumption, and comorbidities. Results Oral micronucleus frequency was markedly higher in the exposed group than in controls (67.64 ± 39.80 vs. 1.91 ± 2.81; U = 0; p < .001; r = − 1.00). Occupational exposure remained significantly associated with oral micronucleus frequency after adjustment for age ( β = 3.373, SE = 0.438, p < .001; IRR = 29.16, 95% CI [12.36, 68.83]) and after additional adjustment for social alcohol consumption and comorbidities ( β = 3.767, SE = 0.562, p < .001; IRR = 43.24, 95% CI [14.38, 130.06]). No significant between-group differences were observed for oral binucleated cells or conjunctival micronuclei. Conclusion Occupational exposure to ionizing radiation was associated with a substantially higher frequency of micronuclei in oral mucosal cells, even after adjustment for potential confounders. These findings support the use of the oral micronucleus test as a practical biomonitoring tool in occupational health surveillance. Larger prospective and multicenter studies integrating biological biomarkers with individual dosimetry are warranted to confirm these results and further explore the conjunctival mucosa as a complementary biomatrix.