Low levels of ionizing radiation exposure and cytogenetic effects in radiopharmacists

Abstract

Radiopharmaceuticals are unique medicinal formulations containing radioisotopes which are used in major clinical areas for diagnosis and/or therapy. The aim of this study was to assess occupationally induced DNA damage in workers of a radiopharmaceutical facility who are at risk of exposure to low levels of external ionizing radiation and internal contamination. Cytokinesis-block micronucleus (CBMN) assay used as an important biological indicator of ionizing radiation exposure in the peripheral blood lymphocytes of 35 exposed workers compared with 35 controls matched for gender, age and smoking habits. Occupational dosimetry records were collected over the last year (ranged from 1.05 to 30.73 mSv) and last 5 years exposure (ranged from 2.56 to 70.24 mSv). The results showed a 2.5 fold increase in the chromosomal damage leading to micronucleated lymphocytes in the workers of the radiopharmaceutical facility compared to the controls (25.82±8.67 vs. 10.52±6.83 micronuclei per 1000 binucleated cells, p < 0.0005). The nuclear division index as a parameter of cytostasis, in the workers was signifi cantly lower than that in the controls. The mean frequency of nucleoplasmic bridges was higher in the radiation workers compared to the controls without statistical signifi cant difference (p > 0.05). Taking all the confounding factors into account, no obvious trend of increased micronuclei as a function of either duration of employment, exposed dose, smoking or age was observed. The present study showed that occupationally exposed individuals have higher frequencies of DNA damage, despite the very low levels of ionizing radiation exposure.

A New Insight on the Radioprotective Potential of Epsilon-Aminocaproic Acid

“…Damaging impact of low-dose ionizing radiation on DNA of human and animal cells has been a topic of many studies [38][39][40][41][42][43][44][45]. It was found out that in animals, chromosomal aberrations were detected between 50 mGy and 0.1 Gy of low linear energy transfer radiation, while in humans, DNA damage was detected in children who underwent CT scans with an estimated radiation dose as low as 0.15 mGy shortly after CT examination [41].…”