Persistent unstable chromosomal aberrations in lymphocytes of radiotherapy workers after 1[st] mitotic divison in Tehran, Iran

ABSTRACT

Studies indicate that ionizing radiation can induce persistent genetic instability in a high proportion of exposed cells. It has also been reported that exposure of radiotherapy workers to ionizing radiation causes chromosomal damages. Some of the damaged cells show a large number of aberrations such as dicentrics, polycentrics, rings, and numerous acentric fragments.To determine, whether chromosomal damages can be used as a biomarker of possible radiation in occupational exposure in a hospital setting. In this study, chromosome abnormalities were evaluated in peripheral blood lymphocytes from fifty medical radiotherapy workers who handled ionizing radiation for an average of twelve years, and forty three control individuals who did not knowingly come in contact with any radiation source. Chromosome aberrations were evaluated by the conventional solid stain technique. Dicentrics, fragments, followed by ring chromosomes, as well as total chromosome aberrations were elevated in the experimental group. We did not observe any aneuploidy chromosome in the present study. Although the level of exposure was below the annual permissible limit of twenty mSv/y recommended by the International Commission for Radiation Protection for whole body exposure, the mean frequencies of different chromosomal aberrations were higher in radiotherapy workers compared with controls [P=0.041]. Although the mean frequencies of chromosomal aberrations in the female workers [3.5 +/- 1.42] was slightly higher than in males [3.28 +/- 0.95], there was no significant differences [P=0.74] in the frequency of chromosome aberration between males and females of ionizing radiotherapy workers. The results of this study underscore the need of adopting measures to avoid or minimize overexposure to radiation in hospital settings