An analysis of the leukemia incidence in A-bomb survivors at Hiroshima and Nagasaki, which utilizes recently published depth dose calculations, discloses a substantial risk of leukemia induction by the maximum permissible annual dose equivalent for occupational exposure. The possibility that occupational exposure to neutrons may also pose a significant risk of induction of other neoplasms is considered. A reduction in the maximum permissible dose equivalent for neutrons seems indicated.