Alpha-particle-induced cancer in humans.
Alpha-particle-induced cancer in humans.
复制标题
阿尔法粒子诱发人类癌症。
作者：
Charles W. Mays
关于在体内暴露于222Rn子代、Thorotrast、长寿的226Ra和228Ra以及短寿的224Ra的人中，阿尔法粒子诱发癌症的最新信息被提供。在办公室、学校和家庭的室内空气中呼吸222Rn子代的人患肺癌的风险越来越令人担忧。在德国Thorotrast患者中，最近死亡的患者中约有一半死于肝癌。动物研究表明，Thorotrast的肝癌风险主要来自其放射性，Thorotrast患者的风险系数可以暂时用于人体肝脏中的其他阿尔法发射体。在226Ra和228Ra的平均骨骼剂量在0.85到11.8Gy之间的人中，已经发生了6例骨癌。在低剂量的德国224Ra患者中，大约有两个骨骼肉瘤发生在0.7Gy射线，而高剂量224Ra患者的结果预测了大约六个病例。人体辐射诱发骨肉瘤的最短出现时间约为4年。在短暂的照射后，绝大多数诱发骨肉瘤的出现时间约为30年。随着原子弹幸存者的中子剂量向下修正，对暴露于阿尔法粒子的人的随访可能是直接评估高LET辐射对人类影响的最佳机会。
Updated information is given on alpha-particle-induced cancer in persons internally exposed to 222Rn progeny, Thorotrast, long-lived 226Ra and 228Ra, and short-lived 224Ra. The lung cancer risk to persons breathing 222Rn progeny in the indoor air of offices, schools, and homes is of increasing concern. About half of the recent deaths among the German Thorotrast patients have been from liver cancer. Animal studies indicate that the liver cancer risk from Thorotrast is mainly from its radioactivity and that the risk coefficient for the Thorotrast patients can be used provisionally for other alpha emitters in the human liver. Six skeletal cancers have occurred in persons with average skeletal doses between 0.85 and 11.8 Gy from 226Ra and 228Ra. In the low-dose German 224Ra patients, two skeletal sarcomas have occurred at about 0.7 Gy compared to about six cases predicted by results from 224Ra patients at higher doses. The minimal appearance time for radiation-induced bone sarcomas in humans is about 4 y. Following brief irradiation, the vast majority of induced bone sarcomas are expressed by about 30 y. Recent evidence against the "practical threshold" hypothesis is given. With the downward revision of neutron doses to the atomic-bomb survivors, the follow-up of persons exposed to alpha particles may be the best opportunity to evaluate directly the effects of high LET radiation on humans.