Smith-Briggs J L, Bradley E J, Potter M D
Sci Total Environ. 1986 Oct;54:127-33. doi: 10.1016/0048-9697(86)90260-3.
The levels of the natural radionuclides, 210Pb and 210Po, in U.K. diet have been measured previously. However, in the earlier measurements, the samples were sufficiently aged for 210Pb and 210Po to have attained secular equilibrium. In order to determine the extent of disequilibrium between these radionuclides in fresh food, measurements have been made on recently collected dietary samples. Disequilibrium has been observed in five food groups. The activity per unit mass of 210Pb was found to be greater than that of 210Po in bread, cereals, sugar and preserves, whereas the opposite was found to be true for eggs and beverages. When account is taken of consumption rates, however, the total intakes of 210Pb and 210Po from these food groups are approximately the same. The annual effective dose equivalents from the ingestion of 210Pb and 210Po have been re-estimated at 41 and 12 mu Sv, respectively.
此前已对英国饮食中天然放射性核素210Pb和210Po的含量进行过测量。然而，在早期测量中，样本存放时间足够长，使得210Pb和210Po达到了长期平衡。为了确定新鲜食物中这些放射性核素的不平衡程度，已对近期采集的饮食样本进行了测量。在五个食物类别中观察到了不平衡现象。发现面包、谷物、糖及蜜饯中每单位质量的210Pb活度大于210Po的活度，而鸡蛋和饮料的情况则相反。然而，考虑到消费率，这些食物类别中210Pb和210Po的总摄入量大致相同。经重新估算，摄入210Pb和210Po所致的年有效剂量当量分别为41 μSv和12 μSv。
