Carcinogenic and genetic hazard from background radiation

Various models and predictions of the carcinogenic and genetic hazards of low-level, low-rate ionizing radiation were examined and compared with actual experience in population in the United States of America and elsewhere. All the models predicted a significant increment in malignant mortality, and mortality from genetic disorders, with increasing background. Populations were first examined for malignant mortality, for various age and geographic groups, for all malignancies (ICD 140-205). They were then re-examined for groups of malignancies (e.g. 140-159, 160-164, etc.), and for each of 56 separate malignancy types. These groups and their malignancy rates were compared with the radiation background characteristic of each geographic group. Simultaneous regressions were also performed against over 40 other geographical, social, medical, meteorological, economic, educational, ethnic and pollution parameters. Observation of the populations at risk showed not only no increment in malignant mortality with increasing background, but a consistent and continuous decrement. Similar results were obtained for mortality from congenital malformations. The question of whether low-level radiation, at rates of the order of 0.5 rem/a and below, constitutes a significant environmental hazard is discussed. (author)