Consequences of long-term exposure to ionizing radiation on the hematopoietic system of fish in the water bodies of the Chornobyl Exclusion Zone

The hematological parameters of the common rudd Scardinius erythrophthalmus, roach Rutilus rutilus, perch Perca fluviatilis and Prussian carp Carassius gibelio from the most radionuclide-contaminated water bodies of the Chornobyl Exclusion Zone were analyzed. Data on changes in the absolute number and relative composition of leukocytes, as well as morphological disorders of erythrocytes in the peripheral blood of fish in the absorbed dose rate gradient of 5.1 - 84.5 μGy/h are presented. In control water bodies, radiation doses did not exceed 0.07 μGy/h. At current absorbed dose rates of up to 30 - 40 μGy/h, mostly reactive compensatory changes were registered in the blood of fish with an increase in the content of leukocytes due to the lymphocytic and granulocytic fractions. At higher doses, deterioration of the state of hematopoiesis with a decrease in the content of leukocytes and significant changes in leukograms were noted. It was established that with an increase in the absorbed dose rate, the number of morphological disorders and pathological changes in erythrocytes increases.