Biodosimetry and physical dosimetry tools in radiation exposure assessment

Abstract

Occupational exposure to ionizing radiation (IR) involves operations with unsealed or sealed sources. Nuclear medicine staff using unsealed sources is of particular interest for dosimetry research because they are exposed to extremely inhomogeneous fields of ionizing radiation with an increased risk of internal contamination. The findings for two technicians who were unintentionally exposed to IR while operating unsealed sources in the Nuclear Medicine Department are presented here. Exposure evaluation was conducted at the Radiation Protection Center of the Serbian Institute of Occupational Health (SIOH). Values for the personal dose equivalent at a body depth of 10 mm at the point of application of the personal dosimeter [Hp(10)], the dose equivalent at a body depth 0.07 mm at the application point of the personal dosimeter [Hp(0.07)], and the results for chromosomal aberrations (CA) and micronuclei (MN) analysis after the first and control examinations at the Cytogenetic Laboratory (SIOH) are presented. The case report for Technician 1 (T1) is an example of agreement between the findings obtained by physical dosimetry and cytogenetic analysis in detecting unintentional exposure and internal contamination with high doses of radionuclides. The results also show that the cytokinesis block micronucleus (CBMN) test is a more sensitive technique in detecting internal contamination than CA analysis. Multiple MN are an unequivocal indicator of genetic damage. Since radiation is a strong inducer of MN, these genetic changes may be a certain biomarker of internal contamination. © 2019 RAD Association. All rights reserved.