The changes in the blood of humans chronically exposed to low level gamma radiation

Ten individuals received an average of 0.211 roentgens of gamma radiation per week for a 77 period week (December 1946-June 1948) for a total average dose of 16.21 roentgens. During this period these 10 men carried out an experiment involving materials which emit gamma radiation and were monitored by daily film badges. The radiation delivered during a week was received in a five day work week and usually they received approximately one-half of their weekly dosage during one of the five days. A significant fall in total white blood count and absolute neutrophil and lymphocytes count was observed during the 77 week period. The degree of fall in counts would not have been predicted from experimental irradiation in animals and so other unknown factors may have been causal agents. It is suggested that hematological and exposure data from other laboratories be analyzed statistically to confirm or disprove the effect of such low- dosages of ionizing radiation on humans