engleski

Biological indicators in risk assessment of occuaptional exposure to ionizing radiation

Currently, the most fully developed biological indicator of exposure to ionizing radiation is the study of chromosomal aberrations in the peripheral lymphocytes of exposed persons. Chromosome aberration analysis is recognised as a valuable dose-assessment method, which fills a gap in dosimetric technology, particularly when there are difficulties in interpreting the data, in cases where there is reason to believe that persons not wearing dosimeters have been exposed to radiation, when the injured person have not worn personal dosimeter as well as when the physical dosimeter was irradiated tentatively or accidentally without the exposure of its owner. Laboratory for mutagenesis, Institute for Medical Research and Occupational Health (Zagreb, Croatia) carry out cytogenetic monitoring of persons occupationaly exposed to any source of ionizing radiation. Protocol for producing and processing lymphocyte cultures, slide preparation and staining is based on IAEA (International Atomic Energy Agency) recommended technical report no. 260, 1986 (Biological dosimetry: Chromosomal Aberration Analysis for Dose Assessment). For the efficient interpretation of the results the practice in Laboratory is to analyse and score 200 metaphase cells per subject. Types of aberrations scored include chromatid breaks, chromosome breaks, acentric fragments, dicentric and ring chromosomes. Considering data collected from subjects of the general population of the Republic of Croatia who served as controls and were never occupationally exposed to ionizing radiation background values for each type of chromosomal aberrations were estimated. The number and type of aberrations observed in ocupationally exposed subject can deviate from baseline values of control. More then one dicentric chromosome, ring chromosome as well as more then five acentric fragments observed on 200 analysed cells are clearly biological indicators for exposure to ionizing radiation.

biological indicators; ionizong radiation; occupational exposure

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