EFFECT OF SOMEUNFAVORABLE FACTORS OF ENVIRONMENT ON THE SURVIVAL OF CHILDREN WITH ACUTE LEUKEMIA IN A LONG6TERM PERIOD AFTER ACCIDENT ON THE CHORNOBYL NPP. / VPLYV DEIaKYKh NESPRYIaTLYVYKh ChYNNYKIV DOVKILLIa NA VYZhYVANIST' DITEI Z GOSTRYMY LEIKEMIIaMY U VIDDALENYI PERIOD PISLIa AVARIÏ NA ChORNOBYL'S'KII AES.

OBJECTIVE: Determine of the influence of adverse environmental factors, including irradiation, on the survival ofchildren with acute leukemia in the long-term period after the Chornobyl accident (2008-2017). MATERIALS AND METHODS: Examined 74 children with acute leukemia (АL): 64 with acute lymphoblastic leukemia(ALL); 10 - acute myeloblastic leukemia (AML). The influence of negative environmental factors was assessed bythe degree of integrated pollution of the atmospheric air, surface waters and soils with pesticides, heavy metals (Pb,Cu, Ni, Cr, Mn, Zn, Fe) and cesium isotope 137Cs. These regions were ranked on a moderately polluted (1), polluted (2),very (3) and extremely (4) polluted territories. Took into account the age of children, blood test, immunophenotyp-ic of variant the acute leukemia, survival of patients and place of residence (city / village), serum ferritin level (SF). RESULTS: Exposure doses of children were in the range from 0.4 mSv to 35.0 mSv (average values were (4.25 ± 0.63 mSv)and did not affect the prognosis and variants of AL. 52 children lived in moderately and polluted territories (30 wereresidents of cities, 22 - villages). 22 patients were lived in very and extremely polluted territories (4 were residentsof cities, 18 - villages). Of 74 patients with ALL and AML 24 children died (32.4 %). The smallest number ofchildren, who died, were patients with «general type¼ В-ALL (18.7 %), most of all children with pro-В-ALL (8 out of10) and Т-ALL (3 of 4). Of the 52 patients, the inhabitants of moderately and polluted regions, 13 patients died (25%), while out of 22 patients, who lived in very and extremely polluted areas, 11 children died (50 % share)(rs = 0.39; p < 0.05). Of the 10 patients with AML, 4 children died. Most often, children died, who were residents ofvillages. Moreover, the level of SF was significantly higher in children over 6 years, the inhabitants of villages -(406.8 ± 40.6) ng/ml, compared to younger patients - (211.2 ± 32.1) ng/ml) and residents of of cities: up to 6years - (297.4 ± 52.3) ng/ml; over 6 years - (275.6 ± 29.8) ng/ml. CONCLUSIONS: The obtained data testify to the negative influence of environmental factors, including iron, and canbe the basis for understanding the mechanisms of potentiating influence of metals and their compounds on thedevelopment of malignant diseases of the blood system in children.

Effect of radiation and non radiation environmental factors on children hematopoietic system. / VPLYV RADIATsIY̆NYKh TA NERADIATsIY̆NYKh FAKTORIV DOVKILLIa NA STAN SYSTEMY KROVOTVORENNIa DITEY̆.

OBJECTIVE: Identification of impact of radiation and non radiation environmental factors on development of hematopoi etic abnormalities in children and justification of criteria for the increased risk groups of hematologic diseases. MATERIALS AND METHODS: The results of clinical and hematological survey of 1465 children living in Kyiv, Zhytomyr and Chernihiv regions for the period from 2008 to 2014 were presented. There were 777 children with anemia, 466 with changes in hemogram, 191 with acute leukemia. The irradiation doses, correlation of integrated pollution degree of territories with hematopoietic parameters and course hematologic diseases were estimated. Metal con tent in hair, nails, and blood was determined in 121 children. RESULTS: We have found the most common cause of anemia in children and peculiarities of acute leukemia depend ing on the area integrated contamination. Number of children living in contaminated areas with pro B ALL and T ALL having an initial leukocytosis and unfavorable course of the disease was higher compared to the number of patients from moderately polluted regions (r = 0.47). There is a direct correlation between percentage of children with monocytosis and degree of territory contamination: the 20.2 % of such children lived in the intensively polluted areas and 10,3 % in moderately contaminated ones (p < 0.05). Content of Pb, Cu, Cr, Mn, Zn in biological tissues did not exceed the permissible MAC. Level of Zn in all children was at the lower normal threshold. Individual levels of metals in hair, nails and blood did not depend on gender of patients and their radiation doses. Criteria of increased risk of hematologic diseases in children living in ecologically unfavorable regions were grounded. CONCLUSIONS: Radiation and non radiation environmental factors influencing the development of changes in hematopoiesis and characteristics of the blood system diseases in children play a role in leukeima development processes. These findings are the basis for a further research in the field of radiobiology and ecology.