CYTOGENETIC DAMAGE IN LYMPHOCYTES OF HEALTHY AND THYROID TUMOR-AFFECTED CHILDREN FROM THE GOMEL REGION (BYELARUS)

During 1994, 19 thyroid tumor-affected children and 17 healthy childre n from the Gomel region, one of the areas most polluted by the Chernob yl fallout, were analysed for (i) the presence of Cs-137 in their urin e and (ii) chromosome aberrations (CA) in circulating lymphocytes. The y were compared with 35 healthy children from Pisa, Italy. Tumor-affec ted children showed significantly (p < 0.05) higher Cs-137 levels in t heir urine as compared to healthy controls from the Gomel region. No r adioactivity was found in urine from the Pisa controls. CA frequency w as significantly higher in tumor-affected children compared to the Gom el controls, but was not significantly different between Gomel and Pis a controls. However, dicentric chromosomes were found in a significant ly (p < 0.01) greater proportion in both affected and healthy Gomel ch ildren (3.4 and 1.3/1000 cells, respectively) as compared to the Pisa controls (0.4/1000 cells). Multiple regression analysis showed that th e proportion of cells with acentric fragments, dicentric and ring chro mosomes was significantly correlated(p < 0.05) with the amount of Cs-1 37 excreted in their urine. These findings suggest that children from the Gomel region were still being exposed to radionuclides, which make s it possible to study a dose-effect relationship. (C) 1998 Elsevier S cience B.V. All rights reserved.