Pöllänen R, Toivonen H
Finnish Centre for Radiation and Nuclear Safety, Helsinki.
Health Phys. 1995 Mar;68(3):401-5. doi: 10.1097/00004032-199503000-00014.
Two different methods for skin dose calculations, VARSKIN Mod 2 and PSS are compared for a spherical uranium fuel particle (diameter 1-500 microns) deposited on the skin. Nuclide-specific beta dose rate at different skin depths for a particle of unit activity is determined as a function of particle size. Both methods show that the effects of self-shielding must be included in the dose calculations for low and medium energy beta emitters. Skin dose rate is drastically overestimated when point source approximation is used. For high energy beta emitters (e.g., 90Y, 106Rh, and 144Pr) the volume source can be approximated as a point source. The difference in doses is then below 20% for particles up to 100 microns in diameter. The models give equal results deep in the skin (in terms of range of the beta particles). The reason is that the correction due to the diminished backscattering in air-tissue interface is insignificant at large distances. For three-dimensional sources the backscattering correction should be introduced in the VARSKIN Mod 2.
针对沉积在皮肤上的球形铀燃料颗粒（直径1 - 500微米），比较了两种不同的皮肤剂量计算方法，即VARSKIN Mod 2和PSS。确定了单位活度颗粒在不同皮肤深度处的核素特异性β剂量率作为颗粒大小的函数。两种方法均表明，对于低能和中能β发射体，剂量计算中必须考虑自屏蔽效应。当使用点源近似时，皮肤剂量率会被大幅高估。对于高能β发射体（如90Y、106Rh和144Pr），体积源可近似为点源。对于直径达100微米的颗粒，剂量差异则低于20%。在皮肤深层（就β粒子的射程而言），这些模型给出相同的结果。原因是在大距离时，空气 - 组织界面处反向散射减弱所引起的校正并不显著。对于三维源，应在VARSKIN Mod 2中引入反向散射校正。
