Baeza A, Paniagua J M, Rufo M, Sterling A, Barandica J
Departamento Física, Facultad de Veterinaria, E. Politécnica-Uex, Cáceres, Spain.
Appl Radiat Isot. 1999 Mar;50(3):467-74. doi: 10.1016/s0969-8043(98)00078-5.
One of the immediate consequences of massive radioisotope release into the atmosphere is contamination of the biosphere. This contamination can affect plants either by direct deposition onto the leaves, or by contaminating the soil followed by absorption by the roots. Knowledge of the efficacy of the two routes of radionuclide incorporation into the food chain is fundamental to understanding the mechanisms by which radioactive contamination reaches man. The present work analyzes the incorporation of 134Cs and 85Sr via root and leaf uptake into the parts consumed by man, for two very different crops: turnip (Brassica napus) and broad bean (Vicia faba). The root uptake studies consider the available soil fraction for these two radionuclides, and indicate greater availability for 85Sr than for 134Cs which is fixed rapidly in the soil. For the study of leaf uptake, leaves were contaminated at three different stages of plant growth; the results indicate an inverse dependence of the transfer coefficients on the time elapsed from the moment of the contamination to harvesting of the edible parts.
大量放射性同位素释放到大气中的直接后果之一是生物圈受到污染。这种污染会通过直接沉积在叶片上或通过污染土壤然后被根部吸收来影响植物。了解放射性核素进入食物链的这两种途径的效率，对于理解放射性污染影响人类的机制至关重要。本研究分析了两种截然不同的作物——芜菁（甘蓝型油菜）和蚕豆（蚕豆）——通过根部和叶片吸收134Cs和85Sr进入人类食用部分的情况。根部吸收研究考虑了这两种放射性核素在土壤中的有效部分，结果表明85Sr的有效性高于134Cs，134Cs会迅速固定在土壤中。对于叶片吸收的研究，在植物生长的三个不同阶段对叶片进行了污染；结果表明，转移系数与从污染时刻到可食用部分收获所经过的时间呈反比。
