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

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

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，作了配对显著性检验。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，经配对显著性检验，差异无显著性（Ｐ＞０．０５）；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著性差别（Ｐ＜０．０１）。结论水生物对２２６Ｒａ、２２８Ｒａ、２１０Ｐｂ和２１０Ｐｏ有很强浓集能力。虽然骨（壳）中２２６Ｒａ、２２８Ｒａ与２１０Ｐｂ含量较高，但在烹饪过程不会明显的向食物中转移；然而２１０Ｐｏ则不然，会有不同程度地转移，这将给食物中?

Objective\ To find out the transfer regularities of 226 Ra, 228 Ra, 210 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.