BIOLOGICAL EFFECTS OF LOW DOSE AND/OR PROTRACTED EXPOSURES TO IONIZING RADIATION
In diagnostic examinations ionizing radiation plays a key role. There is an increased concern with the effects induced from the exposure to low doses of ionizing radiation. Orthopantomography, using low doses, is a radiological exam used very often for the evaluation of oral diseases, especially in youth groups. The evaluation of micronuclei formation in the oral mucosa exfoliated cells is a non-invasive procedure that can give an idea of the damage caused by ionizing radiation, since they are biomarkers of genotoxic events and chromosomal instability.
This study was performed in collaboration with the Hospital de São José, Centro Hospitalar de Lisboa Central, EPE. Exfoliated oral mucosa cells were collected, with a non-invasive method, immediately before the orthopantomografy and approximately 10 days after. To evaluate the lesion induced by the exam, the micronucleus assay in the exfoliated oral mucosa cells was implemented and validated in our laboratory. This procedure can give an idea of the damage induced by ionizing radiation, since micronuclei are biomarkers of genotoxicity. The mononucleated cells were analyzed in terms of micronuclei frequency. Statistically significant differences were observed between micronuclei yields obtained before and after 10 days of the exposure.
Mononucleated cells with 1 micronucleus (a) and with 3 micronuclei (b).
Contact person: Octávia Monteiro Gil