226Ra 228Ra 210Pb和210Po在水生生物及食物链中转移规律的探讨

目的 为了解天然放射性核素²²⁶Ra、²²⁸Ra、²¹⁰Pb与²¹⁰Po在水生物及食物链中转移和蓄积情况。方法 定点采集养殖水产品及栖息环境中水与底质沉积物, 按不同的实验需要, 每个鲜样分别剥取肉, 骨(壳),鳞片和胃肠。烹饪样品, 洗净、称重、清炖, 熟后分离出骨(壳),余为食物。样品分别测定²²⁶Ra、²²⁸Ra、²¹⁰Pb和²¹⁰Po含量。数据按统计学要求处理, 配对数据, 作了配对显着性检验。结果 ²²⁶Ra、²²⁸Ra和²¹⁰Pb主要沉积于骨(壳)中, 浓集系数为10²～10³,肉中为10⁰～10².²¹⁰Po主要蓄积在水生物胃肠中, 浓集系数在10²～10⁴,鱼类胃肠与贝类肉中可达10⁴.水产食品烹饪加工过程²²⁶Ra、²²⁸Ra和²¹⁰Pb在食物链中转移不明显, 经配对显着性检验, 差异无显着性(P0.05);然而210Po在淡水鱼类和虾类中转移是明显的, 肉配对检验有非常显着性差别(P<0.01).结论水生物对²²⁶Ra、²²⁸Ra、²¹⁰Pb和²¹⁰Po有很强浓集能力。

Transfer of 226 Ra, 228 Ra, 210 Pb and 210 Po in aquatic organisms and food chain

Objective To find out the transfer regularities of ²²⁶ Ra, ²²⁸ Ra, <>sup210 Pb and 210 Po,which are natural radionuclides in the aquatic organisms and food chain.Methods Large amount of breed of representative aquatic products and their living waters and sediments were collected and treated according to routine experimental procedures.The contents of ²²⁶ Ra, 228 Ra, ²¹⁰ Pb and ²¹⁰ Po were detected in each sample.Measured data were analyzed statistically and pairwise comparisons were made to determine the differences between groups.Results ²²⁶ Ra, ²²⁸ Ra and ²¹⁰ Pb were mainly deposited in the bones(or shells),their concentration factors(CF)ranged from 10 ² to 10 ³;the CF ranged only from 10 ⁰ to 10 ² in the flesh.²¹⁰ Po was mainly deposited in the soft tissues,CF ranged from 10 ² to 10 ⁴;especially in the stomaches and intestines of fishes,the value reached 10 ⁴.The cooking process did not impinge significantly on the transfer of ²²⁶ Ra, ²²⁸ Ra and ²¹⁰ Pb in the food chain (P>0.05),but did significantly influence the transfer of ²¹⁰ Po,especially in the freshwater fishes and shrimps.Paired comparison test of the activities between raw flesh and cooked flesh showed very significant difference (P <0.01).Conclusion Aquatic organisms have very strong concentration capabilities for ²²⁶ Ra, ²²⁸ Ra, ²¹⁰ Pb and ²¹⁰ Po.Even though the bones (or shells) of aquatic organisms contained relatively higher levels of 226 Ra, ²²⁸ Ra and ²¹⁰ Pb,the cooking process does not significantly increase the radioactive contents in the foodstuffs.However,the cooking process does significantly influence the transfer of ²¹⁰ Po.It does significantly increase the content of ²¹⁰ Po in foodstuffs.