High incidence of meningioma among Hiroshima atomic bomb survivors

Since the atomic bomb explosions in Hiroshima and Nagasaki, high incidences of leukemia, thyroid cancer and other tumors have been reported as atomic bomb-induced tumors. We investigated the incidence of meningioma among Hiro shima atomic bomb survivors. Sixty-eight patients surgically treated for me ningioma who had been within 2.0 km of the hypocenter of the explosion were identified. Six hundred and seven non-exposed patients with meningioma wer e also studied. Treatment dates were from 1975 to 1992. The incidences of m eningioma among 68 subjects within 2.0 km and 607 non-exposed patients were 8.7 and 3.0 cases per 10(5) persons per year, respectively. The incidences of meningioma among the survivors of Hiroshima in 5-year intervals since 1 975 were 5.3, 7.4, 10.1, and 14.9, respectively. The incidences of meningio ma classified by distances from the hypocenter of 1.5-2.0 km, 1.0-1.5 km an d less than 1.0 km were 6.3, 7.6 and 20.0, respectively. The incidences of meningioma classified by doses to the brain of 0-0.099 Sv, 0.1-0.99 Sv and more than 1.0 Sv were 7.7, 9.2 and 18.2, respectively. The incidence of men ingioma among Hiroshima atomic bomb survivors has increased since 1975. The re was a significant correlation between the incidence and the dose of radi ation to the brain. The present findings strongly suggest that meningioma i s one of the tumors induced by atomic bombing in Hiroshima.