Analysis of Blood Lymphocyte Subsets in Children Living around Chernobyl Exposed Long-Term to Low Doses of Cesium-137 and Various Doses of Iodine-131
Title: Analysis of Blood Lymphocyte Subsets in Children Living around Chernobyl Exposed Long-Term to Low Doses of Cesium-137 and Various Doses of Iodine-131
Author: Eugene V. Vykhovanets, Victor P. Chernyshov, Igor I. Slukvin, Yury G. Antipkin, Alexander Vasyuk, and Valerey Colos
Reference: Radiation Research June 2000 : Vol. 153, Issue 6 (Jun 2000), pg(s) 760-772
DOI: http://dx.doi.org/10.1667/0033-7587(2000)153[0760:AOBLSI]2.0.CO;2
Keywords : blood lymphocyte, children, low doses, cesium-137, iodine-131
Abstract: Epidemiological studies have found that children living around Chernobyl have rates of respiratory tract illness that are higher than those seen in the area before the Chernobyl accident. The present study investigates the possible effects of radiation exposure on the composition of peripheral blood lymphocyte subsets in children living around Chernobyl. Two hundred nineteen healthy children and children suffering from recurrent respiratory diseases aged 6–14 years who received both low doses of radiation to the whole body from 137Cs and various doses of radiation to the thyroid from 131I as fallout from the accident were assessed 5 (1991) and 8–10 years (1994–1996) after the accident. A total of 148 healthy children and children suffering from recurrent respiratory diseases living in noncontaminated areas were also evaluated as controls. Children with recurrent respiratory diseases who lived around Chernobyl had a significantly lower percentage of T cells and a higher percentage of NK cells compared to control children with recurrent respiratory diseases during the study period. In contrast to the findings in 1991, a significant decrease in the percentage of helper-inducer cells was observed in children with recurrent respiratory diseases in 1994–1996. In contrast to 1991, there is a positive correlation between the percentage of helper-inducer cells, the helper-inducer/cytotoxic-suppressor cell ratio, and the dose of radiation to the thyroid of healthy children from 131I in 1994–1996. There was a positive correlation between the dose of radiation to the thyroid from 131I and the percentage of helper-inducer cells in children with recurrent respiratory diseases 5 years (1991) after the accident. Further, the dose of radiation to the thyroid from 131I correlated negatively with the percentage of T and B cells and positively with the percentage of NK cells in children with recurrent respiratory diseases 8–10 years (1994–1996) after the accident. These results raise the possibility that long-term exposure to low doses of 137Cs may have altered the composition of the T-cell subsets and NK cells in children with recurrent respiratory diseases. The differences in the composition of the peripheral blood lymphocyte subsets between healthy children and those with recurrent respiratory diseases may be attributed to long-term low-dose exposure of the whole body to radiation from 137Cs and exposure of the thyroid to radiation from 131I subsequent to the Chernobyl accident.