Is micronucleus assay a suitable method for biomonitoring children exposed to X-ray? A systematic review with meta-analysis

Purpose: The aim of this study was to evaluate if the micronucleus test using oral epithelial cells is a suitable biomarker for biomonitoring children exposed to X-ray. Material and methods: A search was performed through the electronic databases PubMed/Medline, Scopus, and Web of Science, all studies published up to February 2022 that examined the relationship between exposure of children to radiographic examinations and micronucleus. Results: A total of 17 full-text manuscripts were screened for eligibility. Only two studies found a difference in micronucleus labeling. On the other hand, all studies showed that X-ray was able to induce cellular death in oral mucosa cells. Following the parameters of the Effective Practices in Public Health Project (EPHPP), five manuscripts reached moderate and strong scores, and four studies were categorized as weak at final rating. In the meta-analysis, statistically significant difference was detected in micronucleated cells in children before and after radiographic examinations (SMD = 0.96, 95% CI, 0.07–1.84, p =.04), with τ2=1.09; χ2=53.37, and p <.001. Conclusion: Radiographic examinations in children can cause genotoxic and cytotoxic damage in the oral epithelium with a large effect size.