Covelli V, Di Paola M, Bassani B, Metalli P
Int J Radiat Biol Relat Stud Phys Chem Med. 1976 May;29(5):439-53. doi: 10.1080/09553007614550541.
Life-long observations on mortality and pathology at death were carried out on groups of mice irradiated with 250 kV X-rays or exposed to a 400 MeV neutron beam, both directly and after attenuation corresponding to the maximum dose build-up region, at comparable dose-rates. Doses up to 84 rad of 400 MeV neutrons and up to 200 rad of X-rays showed no effect on the longevity of the animals, which suggest an upper limit to the r.b.e. for life-shortening of approximately 2-5. Similar conclusions were drawn from the data on all types of leukemias. For all other neoplasms, the age-specific death-rate showed a similar shortening of the latency times for groups of mice irradiated with 0-84 rad of 400 MeV direct neutrons and 0-400 rad of X-rays, also suggesting an upper limit to the r.b.e. slightly higher than that previously indicated for life-shortening. No definite effect was observed after exposure to the attenuated neutron beam at the doses used in these experiments.
对几组分别接受250 kV X射线照射或暴露于400 MeV中子束的小鼠进行了终生死亡率和死亡病理学观察，照射方式既有直接照射，也有在对应最大剂量积累区域进行衰减后照射，且剂量率相当。高达84拉德的400 MeV中子剂量和高达200拉德的X射线剂量对动物寿命没有影响，这表明缩短寿命的相对生物效应上限约为2至5。从所有类型白血病的数据中也得出了类似结论。对于所有其他肿瘤，年龄特异性死亡率显示，接受0至84拉德400 MeV直接中子照射和0至400拉德X射线照射的小鼠组的潜伏期有类似程度的缩短，这也表明相对生物效应上限略高于先前指出的缩短寿命的上限。在这些实验所使用的剂量下，暴露于衰减中子束后未观察到明确影响。
