Peripheral blood lymphocyte subsets in radiologists exposed to ionizing radiation.

To investigate whether low dose ionizing radiation caused perturbation of peripheral blood lymphocytes in radiology unit staff, the T-helper/suppressor ratio was examined in eight radiologists exposed to low dose radiation over a period of 6 to 27 years (mean 12 years). No significant difference was noted in the T-cell subsets between exposed radiologists and non-exposed control subjects. The effect of low dose ionizing radiation on peripheral blood lymphocyte subsets seems to be virtually negligible. Further, measurement of the T-helper/suppressor ratio is not a reliable way of demonstrating any damage to bone marrow caused by low dose ionizing radiation.