Information about the influence of A-bomb radiation on non-malignant, or benign, tumors comes mostly from research in the clinical Adult Health Study (AHS). Studies have been conducted with respect to benign thyroid, parathyroid, salivary gland and uterine tumors, and gastric polyps. In each case, a relationship to radiation dose was seen. In contrast, no clear excess of pathologically-confirmed benign ovarian tumors was seen except for sex-cord stromal tumors. Figure 1 shows a distinct radiation dose response relationship for benign uterine tumors. The relative risk value at 1 Gy is 1.5 (95% confidence interval: 1.27-1.70).
Figure 1. Relative risk by radiation dose for uterine myomata, AHS, 1958-1998. The dotted lines indicate 95% confidence bounds.
Figure 2 shows AHS prevalence data for hyperparathyroidism (caused mainly by benign parathyroid tumors) in relation to radiation exposure and age ATB. The prevalence at a 1-Gy tissue dose for all cases combined was four times greater than for controls (95% confidence interval: 1.7-14.0). The prevalence increase was particularly marked for persons who were children ATB.