Farid I, Conibear S A
Health Phys. 1983;44 Suppl 1:221-30. doi: 10.1097/00004032-198306001-00019.
The effect of thorium exposure on hepatic function was investigated in 275 former workers of a thorium refinery. Body burden of radioactivity from the decay chain of thorium was measured as 212Bi and 220Rn in the exhaled breath. Asparate aminotransferase, globulin and total bilirubin in sera were found to be associated with body burden of radioactivity at high levels of significance. Thorium-exposed workers were also compared with a population of white males from the Health and Nutrition Survey conducted by the National Center for Health Statistics from 1971 to 1975. The results showed the means of aspartate aminotransferase alkaline phosphatase to be significantly higher (P = 0.0001) in the thorium-exposed workers when corrected for age, alcohol use and weight. The changes observed in liver function may be compatible with a toxic effect of thorium or daughter products on hepatocytes. The correlation of some hepatic function tests with body burden of radioactivity suggests a radiation effect of thorium although a chemical toxic effect cannot be ruled out and further investigation of chemical toxicity of rare earths are indicated.
在一家钍精炼厂的275名 former workers 中，研究了钍暴露对肝功能的影响。通过测量呼出气中钍衰变链产生的放射性物质 212Bi 和 220Rn 来确定体内放射性物质的负荷。发现血清中的天冬氨酸转氨酶、球蛋白和总胆红素与高水平的放射性物质负荷存在高度显著的关联。还将接触钍的工人与1971年至1975年由国家卫生统计中心进行的健康与营养调查中的白人男性人群进行了比较。结果显示，在对年龄、饮酒量和体重进行校正后，接触钍的工人中天冬氨酸转氨酶和碱性磷酸酶的均值显著更高（P = 0.0001）。观察到的肝功能变化可能与钍或其衰变产物对肝细胞的毒性作用相符。一些肝功能测试与放射性物质负荷之间的相关性表明钍存在辐射效应，尽管不能排除化学毒性作用，且需要对稀土元素的化学毒性进行进一步研究。
