Occupational exposure to ionizing radiation (IR) can cause systemic acute and chronic effects on human health, including genetic instability that may be etiology of various diseases, including cancer. The aim of this study was to evaluate the possible toxicogenetic changes in haematological and biochemical parameters, and cytogenetic biomarkers (micronuclei and nuclear abnormalities) indicators of mutagenicity and apoptosis, as well as seek their correlation with lifestyle, age and gender. In accordance with the ethical aspects, 45 professionals (technicians and technologists in radiology) occupationally exposed to low doses of IR participated in this study. For control, 45 healthy individuals were not exposed to IR and/or genotoxic chemicals were included. Peripheral blood and oral epithelium samples were used in the toxic evaluations. The results suggested unchanged hematological biomarkers but a significant (P < 0.05) increases in the frequency of micronuclei, sprouts, binucleate cells and bridges, as well as karyolysis and karyorrhexis in professional radiology sector. Hepatic and nephritic toxicity were not observed. Without protection, a significant (P < 0.01) correlation (P < 0.05) was observed between toxicogenetic biomarkers with age, smoking, alcohol consumption, time and place of work. In conclusion, IR may be associated with genetic instability in health diseases, like cancer.