Chromosomal Aberrations in Workers Occupationally Exposed to Chronic Low-Level Ionizing Radiation

Farideh Zakeri, Reza Assaei, and Roshan Varzegar

Radiobiology and Biodosimetry Group, Medical Care and Biodosimetry Division, National Radiation Protection Department, Iranian Nuclear Regulatory Authority, Tehran, Iran

Corresponding author: Farideh Zakeri
    Head of Radiobiology and Biodosimetry Group
    National Radiation Protection Department,
    P.O. Box: 14155-4494
    Tehran, Iran
    Telephone: +98 21 61384154
    Fax number: +98 21 8009502
    E-mail: fzakeri@seai.neda.net.ir

CEJOEM 2003, Vol.9. No.1.: 33–38

Key words:
Chromosomal aberrations, human lymphocytes, cytogenetics, occupational radiation exposure

Abstract:
To reveal whether prolonged or repeated low-level ionizing radiation can induce chromosomal aberrations (CAs), which is a fairly reliable indicator of damages induced by ionizing radiation, a large scale cytogenetic study of 450 radiation-exposed workers (industrial radiographers, personnel of nuclear research, medical X-ray diagnostic and nuclear medicine centers) was undertaken using the yield of CAs analyzed in peripheral blood lymphocyte cultures. All subjects were routinely monitored with film badge. None of them had ever been exposed to radiation exceeding the permitted limit for occupational exposure recommended by the International Commission on Radiological Protection (ICRP). At least 200 metaphases for each person were scored. The frequencies of acentric fragments and dicentrics were determined and compared to those obtained in a matched healthy group that had had no radiation history. The results showed that the incidence of all types of CAs, were significantly higher in all exposed groups than in the controls (P<0.05). The highest rate of aberrations was found in the industrial radiographers and the lowest one was obtained in the personnel of medical X-ray diagnostic centers. Although the mean frequency of CAs in the male workers was slightly higher than in the females, no obvious trend of increased aberrations as a function of either duration of employment or age was observed. The results suggest that education and retraining of staff concerning radiation safety guidelines and regulations and the use of up-to-date equipment are major considerations in reducing the workers’ radiation exposure. As the risks to low doses of radiation are not fully known, the best policy is to follow the principle of “As Low As is Reasonably Achievable (ALARA)” in setting the level of exposure.

Received: 28 April 2003
Accepted: 24 July 2003

| Back |