A modelistic approach to evaluate the factors affecting the 137Cs transfer from mother to fetus in cattle

The authors have analysed the relationship between 137Cs radioactivity and pregnancy in cattle with radiometric analysis of muscle, kidney and liver of 24 cattle at various stages of pregnancy, fed with fodder exposed to radioactive fall-out. Also the relative fetal muscle, kidney, liver and myocardium have been analysed. The automatic spectra analysis and the statistical one have given the following results: there is no correlation between 137Cs retention and the pregnancy stage in the cattle sampled; the absolute 137Cs concentration is always larger in the kidney than in the muscle (Km/Mm = 1.7), while it is just minor in minor in the liver (Lm/Mm = 0.8). The fetal concentration in muscle, kidney and liver is generally homogeneous, whereas the myocardium tends to retain more 137Cs in the first stages of the pregnancy as against the other tissues. In the last stage of pregnancy it presents a lower concentration. The authors have included the fetal body weight growth to get a more realistic description of the 137Cs transfer in the mother-fetus system; this approach enables to evaluate the kinetic constants so introduced.