Keane A T, Lucas H F, Markun F, Essling M A, Holtzman R B
Health Phys. 1986 Sep;51(3):313-27. doi: 10.1097/00004032-198609000-00004.
We made radiochemical determinations of 226Ra and the 228Ra-decay product, 228Th, in samples of bone from former Ra dial workers who belonged to a major cohort of Ra-exposed persons under study for health effects at our institution. Most of the former workers were long-term residents of two communities supplied with drinking water containing elevated natural levels of 228Ra and 226Ra, so determinations also were made of radioactivity in samples of bone from long-term residents not occupationally exposed to Ra. The 228Th activity of the bones of the former workers, after correction for the presence of natural radioactivity, showed that some had significant occupational intakes of 228Ra, contrary to published reports that 228Ra was never used by the Illinois company that had employed the cohort of early workers. For 14 workers hired in the years 1920-23, the calculated ratio of the occupational intake of 228Ra to 226Ra activity averaged 0.15 (coefficient of variation 0.65), whereas for three workers hired in 1924, it was not significantly different from zero (mean 0.05, coefficient of variation 1.5). The risk of radiogenic cancer for the typical worker hired before 1924 may have been nearly twice that incurred in the absence of the 228Ra component of the Ra intakes.
我们对来自曾从事镭表盘工作的人员骨骼样本中的镭-226及其衰变产物钍-228进行了放射化学测定。这些人员是我们机构正在研究健康影响的一大群受镭照射人群中的一部分。大多数 former workers 是两个社区的长期居民，这两个社区的饮用水中天然存在的镭-228和镭-226含量升高，因此我们也对未职业接触镭的长期居民的骨骼样本进行了放射性测定。在对天然放射性进行校正后，former workers 骨骼中的钍-228活性表明，一些人有显著的职业性镭-228摄入量，这与已发表的报告相反，该报告称雇佣早期工人 cohort 的伊利诺伊公司从未使用过镭-228。对于1920 - 23年雇佣的14名工人，计算出的镭-228职业摄入量与镭-226活性的比值平均为0.15（变异系数0.65），而对于1924年雇佣的三名工人，该比值与零无显著差异（平均值0.05，变异系数1.5）。1924年之前雇佣的典型工人患放射性癌症的风险可能几乎是在镭摄入量中不存在镭-228成分时所面临风险的两倍。
