ANALYSIS OF BLOOD LYMPHOCYTE SUBSETS IN CHILDREN LIVING ON TERRITORY THAT RECEIVED HIGH AMOUNTS OF FALLOUT FROM CHERNOBYL ACCIDENT

The major lymphocyte subsets in the peripheral blood were assessed in 120 children 6-13 years old living on areas that received high levels of radioactivity as fallout after the Chernobyl nuclear power plant ac cident. Seventy-one of the children were suffering from recurrent resp iratory disease (RRDC) and 49 were not (non-RRDC). As controls, a tota l of 87 RRDC and non-RRDC living on noncontaminated areas were evaluat ed. We did not find significant differences in major lymphocyte subset s between the values in non-RRDC living on radionuclide-contaminated a reas and noncontaminated areas. However, RRDC living on radionuclide-c ontaminated areas had a significantly lower percentage of CD3(+) T and CD3(+)CD4(+) T-helper/ inducer cells compared to control RRDC. Furthe rmore, the decrease in percentage of CD3(+)CD4(+) cells was more profo und in RRDC living in radiation-contaminated settlements with an avera ge summary dose (ASD) Cs-137(134) and Sr-90 for the population >1.0 mS v than in RRDC living in contaminated settlements with an ASD Cs-137(1 34) and Sr-90 <1.0 mSv. These data indicated that long-time exposure t o small doses of radiation could affect the immune system in children living around Chernobyl. (C) 1997 Academic Press.