Baeza Antonio, Guillén Fco Javier, Salas Alejandro, Manjón José Luis
Department of Physics, Veterinary Faculty, University of Extremadura, Avda de la Universidad s/n, 10071 Cáceres, Spain.
Sci Total Environ. 2006 Apr 15;359(1-3):255-66. doi: 10.1016/j.scitotenv.2005.05.015. Epub 2005 Sep 8.
Mushrooms are known to be bioaccumulators of radionuclides, but little is known about their distribution within the fruiting bodies or the influence of the degree of maturity on uptake. We carried out a series of cultures of the species Pleurotus eryngii under controlled laboratory conditions to analyze these variables. The maximal uptake of 134Cs and 85Sr was found to occur in mature fruiting bodies, and with the growth of the mushroom the distribution of radionuclides within the fruiting bodies became inhomogeneous. In particular, there was an exponential increase in the percentage of the total activity of 134Cs, 85Sr, and 60Co in the cap+gills as the fruiting bodies matured, accompanied by a complementary decrease in the stem. Radiocaesium, potassium, calcium, (239+240)Pu, (234,238)U, (228,230,232)Th, and 226Ra were assayed in the cap, gills, and stem of fruiting bodies of Tricholoma equestre collected in a natural ecosystem and cultured P. eryngii. Potassium and radiocaesium were mainly located in the cap+gills, and 226Ra in the gills. There was a disequilibrium between (230,232)Th and 228Th in the different parts of the fungi, probably due to uptake of 228Ra and subsequent decay to 228Th. Finally, the distribution pattern of (239+240)Pu, (234,238)U, and (230,232)Th seemed to be species dependent.
众所周知，蘑菇是放射性核素的生物蓄积体，但对于它们在子实体内的分布情况，或者成熟度对其摄取的影响却知之甚少。我们在可控的实验室条件下对杏鲍菇进行了一系列培养，以分析这些变量。结果发现，134Cs和85Sr的最大摄取量出现在成熟子实体中，并且随着蘑菇的生长，放射性核素在子实体内的分布变得不均匀。特别是，随着子实体成熟，菌盖+菌褶中134Cs、85Sr和60Co的总活度百分比呈指数增长，同时菌柄中的活度相应下降。对采自自然生态系统的欧洲口蘑以及培养的杏鲍菇子实体的菌盖、菌褶和菌柄进行了放射性铯、钾、钙、（239+240）钚、（234,238）铀、（228,230,232）钍和226镭的测定。钾和放射性铯主要位于菌盖+菌褶中，而226镭位于菌褶中。真菌不同部位的（230,232）钍和228钍之间存在不平衡，这可能是由于摄取了228镭并随后衰变为228钍所致。最后，（239+240）钚、（234,238）铀和（230,232）钍的分布模式似乎因物种而异。
