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.