Physics of auroral phenomena : proceedings of the 35th Annual seminar, Apatity, 28 Februaru – 02 March, 2012 / [ed. board: A. G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2012. - 187 с. : ил., табл.

CYTOGENOTOXIC EFFECTS OF EXPOSURE TO IONIZING RADIATION IN THE MINERS BUCCAL CELLS D.A. Petrashova N.K. Belisheva N.A. M eln ik2 'Kola Science Centre o f the Russian Academy o f Sciences, Apatity, Department o fMedical and Biological Problems o f human adaptation in the Arctic, Apatity, e-mail: petrashova@admksc.apatity.ru, natalybelisheva@mail.ru 2Institute o f Chemistry Technology o f Rare Elements and Mineral Raw Materials, Kola Science Centre the Russian Academy o f Sciences, Apatity, e-mail: melnik@chemy.kolasc.net.ru Abstract The study results of the cytogenetic damages in the buccal cells of miners working in conditions of the natural ionizing radiation exposure are presented. It is shown that genotoxic effects in the buccal cells of the miners are manifested in the reducing of the normal cell frequency, in the increase of the necrotic cells and in the increase of the binuclear cells. Introduction Underground mining of ores containing of the natural radionuclides such as uranium, thorium, radium is dangerous to the health of workers due to mixed irradiation of the different types of ionizing radiation. The micronucleus test is the most widely used to evaluate the genotoxic effects of ionizing radiation sources. It is used in the cultivation of peripheral blood cells in the cytokinetyc block (Пелевина и др., 2011). However, in certain cases, such effects are preferable to study on buccal epithelium allowing to obtain information about the genetic changes in human cells with minimal invasive procedures (Holland et al, 2008). This method was first used in 1983 (Stich et al., 1983) and have been used when monitoring of the environment genotoxicity. The aim of our study was to determine the genotoxic effects of the natural ionizing radiation sources formed during underground mining on the health of miners by using micronucleus test on buccal epithelial cells. Materials and Methods Loparite ore, along with precious metals (Ti, Та, Nb, etc.), contains impurities of natural radionuclides (238U, 232Th, 226Ra), which are a source of mixed types of ionizing radiation. Buccal cells are the first barrier (Holland et al., 2008) arising in the way of carcinogens entering the body by breathing, with water and food. The consent of the donors was obtained. The donors were questioned about they age, time of exposure, habits such as smoking, drinking, and consumption of drugs. The all donors were male, smokers and they were age varieties between 25 and 40 with addiction to smoking. The exposed group consisted have been included of 10 miners who had been working on the loparite ore minning (Revda, Murmanskaya oblast’). The unexposed group consisted of 8 individuals (Apatity, Murmanskya oblast’). They were selected because they had socioeconomic characteristics similar to those of the exposed group but they were not in direct contact with environment or occupational radioactive agents. The subjects were required to rinse their mouths with water before sampling. Buccal cells sampling and their preparation according to Meyer et al. (Мейер и др., 2010). Microscopic analysis was performed using light microscope AXIOSTAR PLUS (Karl Zeiss, 15x40). One slide was prepared for each subject and 1000 cells were evaluated per slide to determine micronucleus frequencies and nuclear changes. Micronucleus and other nuclear abnormalities were classified according to Tolbert et al. (1992). Cells with micronucleus were identified by the presence of both a main nucleus and one or more smaller nuclear structures. A micronucleus should be less than one-third the diameter of the main nucleus; on the same plane of focus; have a same colors, texture and refraction as the main nucleus; have a smooth, oval or round shape and be clearly separated from the main nucleus (Tolbert et al., 1992). Besides micronucleus, other nuclear abnormalies such as karyolysis, pyknosis, karyorrehxis, vacuolizated nucleus, fragmented nucleus, apoptosis, binucleus, nuclear bud and nuclear cut were recorded separately. Registration of the mixed types of ionizing radiation (alpha, beta, gamma and neutron radiation) was performed in the mines using certified procedures on certified hardware by the employees of the regional laboratory of radiating control (RLRC), Institute of Chemistry Technology of Rare Elements and Mineral Raw Materials, Kola Science Centre the Russian Academy of Sciences. “P h y sics o f Auroral P h en om en a", Proc. XXXV A n n u al Sem inar, A p a tity, p p . 1 8 3 - 1 8 5 , 2 0 1 2 © Kola Science Centre, Russian Academy of Science, 2012 и*/ Polar Geophysical Institute 183