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 accident. Seventy-one of the children were suffering from recurrent respiratory disease (RRDC) and 49 were not (non-RRDC). As controls, a total of 87 RRDC and non-RRDC living on noncontaminated areas were evaluated. We did not find significant differences in major lymphocyte subsets between the values in non-RRDC living on radionuclide-contaminated areas and noncontaminated areas. However, RRDC living on radionuclide-contaminated areas had a significantly lower percentage of CD3+ T and CD3+CD4+ T-helper/ inducer cells compared to control RRDC. Furthermore, the decrease in percentage of CD3+CD4+ cells was more profound in RRDC living in radiation-contaminated settlements with an average summary dose (ASD) Cs-137(134) and Sr-90 for the population > 1.0 mSv than in RRDC living in contaminated settlements with an ASD Cs-137(134) and Sr-90 < 1.0 mSv. These data indicated that long-time exposure to small doses of radiation could affect the immune system in children living around Chernobyl.