MICRONUCLEATED ERYTHROCYTES FREQUENCY AND RADIOCESIUM BIOCONCENTRATION IN PIKES (ESOX-LUCIUS) CAUGHT IN THE TOM-RIVER NEAR THE NUCLEAR-FACILITIES OF THE SIBERIAN CHEMICAL-COMPLEX (TOMSK-7)

Between 1957 and 1993, the Siberian Chemical Complex (Tomsk-7) located in the Tomsk region (Russia) regularly discharged radioactive liquid wastes into the Tom River which resulted in an extensive contamination of large territories with long lived radionuclides such as cesium-137 and strontium-90. In the summers of 1996 and 1997, Research Team of S iberian Medical University conducted biodosimetry and cytogenetic moni toring of pikes (Esox lucius) caught in the Tom River at various dista nces downstream from the Siberian Chemical Complex (SCC) using the mic ronucleus test and the gamma spectroscopy. Our findings demonstrated t hat the difference in frequency of micronucleated erythrocytes between the radiation-exposed fish caught downstream from the SCC and the con trols was statistically significant (P < 0.01). Moreover, we found a g ood correlation between radiocesium concentration and micronucleated e rythrocyte frequency in pikes. It was found that both the micronucleat ed erythrocyte frequency in pike blood and the level of the pike radio cesium concentration depended on the age of pikes. The micronucleated erythrocyte frequency gradually increased from the 1-year-old pikes to the over 20-year-old pikes. On the other hand, the average level of r adiocesium concentration gradually increased from the 1-year-old pikes only up to the l0-year-old pikes. There is no correlation between rad iocesium concentration and micronucleated erythrocyte frequency in the over 10-year-old pikes. (C) 1998 Elsevier Science B.V. All rights res erved.