ABSTRACT
On April 6, 1993, near the town of Tomsk (Russia) there was an accident at the Siberian Chemical Plant (SCP) which resulted in extensive contamination of an area of 250 km(2) to the north of SCP with long-lived radionuclides such as (239)Pu, (137)Cs and (90)Sr. Cytogenetic methods and electron spin resonance (ESR) spectrometry of tooth enamel were used to estimate the radiation doses received by the population. The ESR signal intensity and the chromosomal aberration frequency in lymphocytes of the tooth donors showed a good correlation. The data showed that 15% of the inhabitants of the Samus settlement received a radiation dose >90 cGy. The exceptions were results of an examination of fishermen, where ESR gave high values (80-210 cGy) but both the chromosome assay and the cytokinesis block micronucleus method gave lower ones (8-52 cGy). A large increase in chromosome damage was observed in people born between 1961 and 1969. It was found that during these years several serious accidents at the Siberian Chemical Plant had occurred causing radiation pollution of the area. The number of cells with chromosome aberrations was significantly less among the people arriving in Samus after 1980. We found good correlations between the level of carotene consumption and a decrease in frequency of both micronuclei in binucleated lymphocytes (r = 0.68, P < 0.01) and chromatid aberrations (r = 0.61, P < 0.01) among the inhabitants. We also examined the inhabitants of Samus for opisthorchis infection, which was present in 30% of the population. The Samus inhabitants affected by Opisthorchis felineus showed significantly increased levels of micronuclei in binucleated lymphocytes and chromatid aberrations as compared with the controls.
