Objective: cytogenetic control of the staff radiation exposure level during the construction of the protective shell for a new confinement at the ChNPP site.
Materials and methods: A cytogenetic examination was carried out for 32 staff persons from the contracting organ izations involved into construction of the protective shell for a new confinement. Additionally, for the goal of com parison, 28 persons who did not have professional contacts with the radiation factors were inspected. The analyti cal method of the aberrations on preparations of uniformly stained chromosomes of the peripheral blood lympho cytes has been used. The frequency has been determined for the dicentrics and centric rings with an accompanying pair fragment for 100 analyzed metaphases. The staff chronic exposure absorbed doses are estimated by means of the linear part of the linear quadratic equations, which describe the calibration dose dependence of the unstable chromosomal exchanges yield in the acute irradiated blood samples in vitro.
Results: Six staff persons from 32 investigated ones have the individual frequency of the recent exposure specific markers (unstable chromosomal exchanges with accompanying pair fragments) significantly higher than those for the comparison group and the population average spontaneous level. It indicates on the possibility of their exces sive irradiation during the work execution in the ChNPP zone. Single cells with two chromosomal exchanges were registered for three persons, while such cells were absent in the comparison group. This is the result of the incorpo ration of radionuclides, which are available in the air at the workplaces. The calculated averaged individual absorbed doses caused by the recent exposure of six staff persons lies in the range from 102.5 to 371.0 mGy.
Conclusion: The doses calculated from the frequency of unstable chromosomal exchanges with the accompanying pair fragment caused by the recent exposure of six staff persons are exceeding significantly the doses determined by the methods of physical dosimetry and the occupational exposure dose limits.
Meta: tsytogenetychnyy̆ kontrol' rivnia radiatsiy̆nogo vplyvu na personal pid chas budivnytstva zakhysnogo konturu novogo konfay̆nmentu v zoni DSP ChAES.Materialy i metody. Provedeno tsytogenetychne obstezhennia 32 osib iz chysla personalu pidriadnykh organizatsiy̆, iakyy̆ vykonuvav roboty zi sporudzhennia zakhysnogo konturu novogo konfay̆nmentu. Dlia porivniannia obstezheno osib, iaki ne maly profesiy̆nykh kontaktiv z radiatsiy̆nym chynnykom. Vykorystano metod analizu aberatsiy̆ na pre paratakh rivnomirno zabarvlenykh khromosom limfotsytiv peryferiy̆noï krovi. Vyznacheno chastotu dytsentrychnykh i kil'tsevykh khromosom iz suprovodzhuiuchym parnym fragmentom na 100 proanalizovanykh metafaz. Poglyneni dozy khronichnogo oprominennia personalu otsineno, vykorystovuiuchy liniy̆ni chastyny liniy̆no kvadratychnykh rivnian', shcho opysuiut' kalibruval'ni dozovi zalezhnosti vykhodu nestabil'nykh khromosomnykh obminiv pry gostromu oprominenni zrazkiv krovi in vitro.Rezul'taty. U shesty iz 32 osib personalu indyvidual'na chastota spetsyfichnykh markeriv nedavn'ogo oprominen nia – nestabil'nykh khromosomnykh obminiv iz suprovodzhuiuchym parnym fragmentom, virogidno perevyshchuvala ïkh chastotu u osib grupy porivniannia i seredn'opopuliatsiy̆nyy̆ spontannyy̆ riven', shcho svidchyt' pro y̆movirnist' ïkh nadnormatyvnogo oprominennia pry vykonanni robit v zoni ChAES. U tr'okh z nykh zareiestrovano poodynoki klity ny z dvoma khromosomnymy obminamy za vidsutnosti takykh u osib grupy porivniannia. Tse ie naslidkom inkorporatsiï radionuklidiv, shcho prysutni v povitri na robochykh mistsiakh. Rozrakhovani indyvidual'ni useredneni poglyneni dozy vidnosno nedavn'ogo oprominennia shesty osib personalu skladaly vid 102,5 do 371,0 mGr.Vysnovok. Rozrakhovani za chastotoiu nestabil'nykh khromosomnykh obminiv iz suprovodzhuiuchym parnym fragmen tom dozy vidnosno nedavn'ogo oprominennia shesty osib personalu znachno perevyshchuiut' dozy, vyznacheni metoda my fizychnoï dozymetriï i limit dozy profesiy̆nogo oprominennia.
Keywords: Chornobyl NPP; chromosomal aberrations; culture of blood lymphocytes; cytogenetic dosimetry; new confinement; personnel.
L. K. Bezdrobna, L. V. Tarasenko, T. V. Tsyganok, V. A. Kurochkina, V. O. Sushko, L. I. Shvayko.