[Levels of toxic elements--Cd, Pb, Hg, Cr, Cu, Zn--in the blood and placenta of cows during parturition and in newborn calves].

It was demonstrated that mother's blood and the blood of new-born calves were contaminated by toxic elements in exposed and non-exposed area. The average Cd and Zn levels differed at high statistical significance (P less than 0.01) in the mothers blood from non-exposed regions in comparison with the average Cd and Zn levels from exposed region. The average residues of toxic elements in breeding cows placenta from the exposed and non-exposed regions were not statistically different. The average Zn content in new-born calves from non-exposed regions differ highly statistically significantly in comparison with the average Zn content in the blood of new-born calves from heifers of the exposed region. The transplacental ratio (TPx) of a toxic element in cow placenta during parturition was expressed from the average ratio of toxic element content in mother's blood: toxic element content in placenta: the toxic element content in blood of newborn calf, while the content of toxic element in mother's blood during parturition was expressed by a value equal to one. TPx in parturition period was expressed by mathematical formula TPx = 1 : Xp : Xk, where Xp = toxic element content in placenta, Xk = content of the toxic element in blood of new-born calf. TPPb, Hg, Cr, Cu, Zn values were not statistically different between the groups of breeding cows from exposed and non-exposed regions. TPCd in the group comprising 14 first-calves from the exposed region (TPCd = 1:0.89:2.59 in comparison with TPCd of six cows from non-exposed region, where TPCd = 1:0.29: 0.70;, differed statistically highly significantly (P less than .01). High statistical differences (P, less than 01) TPCd between these groups were explicitly affected highly statistically significantly (P less than .01) by different average Cd content in the blood of fourteen first-calves, compared with the average Cd content in blood of six cows from non-exposed region, in which the Cd value in blood during parturition was higher by 10(-1).