A cytogenetic study of hospital workers occupationally exposed to radionuclides in Serbia: premature centromere division as novel biomarker of exposure?

Abstract

Identification of other phenomena related to radionuclide exposure, beside well known, may clarify recent problems in radiobiology concerning the biological response to low doses of ionizing radiation and its consequences.

Biomarkers of Genotoxicity in Medical Workers Exposed to Low-Dose Ionizing Radiation: Systematic Review and Meta-Analyses

“…Additionally, among the 32 MN studies, 23 evaluated the relationship (correlation or dose-response) between IR exposure and MN frequencies using two alternative indicators of exposure (using one or both indicators): cumulative dose from personal dosimeters (14 studies) and/or duration of exposure in years (16 studies). Among those, a significant association/correlation between cumulative dose or duration of exposure and MN frequencies were reported in 5/14 and 9/16 studies, respectively [ 23 , 32 , 38 , 61 , 64 , 65 , 74 , 77 , 82 ]. Additionally, in professionals working in a nuclear medicine department, both MN and SCE levels were significantly higher during their occupational exposure compared to levels immediately after vacation period [ 70 ].…”

“…Lastly, the only two studies that focused on PCD reported significantly higher frequencies in IR-exposed workers compared to unexposed, regardless of a specific PCD readout used [ 49 , 64 ].…”

“…Indeed, most of the occupational exposures are below the lowest resolution power observed in ex vivo cytogenetic assays [ 92 , 93 , 94 ], but previous studies did show a significant increase in cytogenetic endpoints in patients who received radiation exposure during a single medical examination, such as a CT scan or catheterization procedure, where the radiation dose is far lower than 100 mSv [ 95 , 96 , 97 ]. Similarly the effect of confounding factors on CA frequencies was inconsistent between studies, with some authors reporting the effect of certain factors such as age, smoking and gender [ 54 , 57 , 60 , 72 ], while others showing no influence [ 62 , 64 , 76 , 87 ]. Furthermore, statistically significant differences in CA frequencies were reported between cohorts employed at different working places, with specificity of certain types of CA depending on the job.…”

“…Unfortunately, our systematic review showed a limited number of studies assessing dose-responses, resulting in inability to carry out quantitative dose-response meta-analysis. Furthermore, given that non-significant results are less likely to be reported [ 114 ], it can be assumed that the dose–response relationship between occupational medical IR exposure and cancer biomarkers is poorly understood [ 27 , 64 , 71 , 74 ]. Issues associated with dose records include for example underestimation of dose when personal badges are not properly worn as observed in cardiologists studies [ 115 ], which could affect corresponding dose-response estimates [ 116 ].…”

Correlation between γ -H2AX, micronucleus and annual occupational dose in medical radiation workers

“…Micronuclei are acentric chromosomal fragments, or whole chromosomes, lost during cell division because due to DNA damage. Formation is dependent on the capacity for DNA repair and the accumulation of DNA damage (41,42) .…”