Long-term effects of radium exposure in female dial workers: Differential white blood cell count

Abstract

The long-term effects of bone-seeking radionuclides on bone marrow in humans seem worthy of exploration. Leukocyte counts (total white cells, polymorphonuclears, lymphocytes, eosinophils, and monocytes) were analyzed among 393 female radium dial workers who were first employed between 1913 and 1929 and most recently examined between 1954 and 1975. Mean and median counts were compared by initial intake level (μCi of radium per kg of skeleton) within three age-at-last-examination groups (45–54, 55–64, and 65–74 yr). Median estimated 40-yr average alpha doses to trabecular bone marrow in the highest intake levels compared were 9 rad, 104 rad, and 40 rad, in the three age groups. Spearman rank correlation coefficients between radium intake and white cell counts were also calculated. There was little evidence for long-term or late effects of radium exposure on white cell counts. In the younger age groups, lymphocyte count tended to increase with increasing radium intake. In 65–74 year olds, eosinophil count decreased with increasing intake (Spearman r = −0.14, P < 0.05). Continued follow-up of this population should help clarify the question of possible long-term effects (direct or indirect) of radium exposure.