Radioactive background in principal components of the Jihlava River ecosystem

In 1976 through to 1978, the radioactive background was investigated in the various components of the Jihlava River ecosystem. The investigations involved total β-activity, 40K, residual β-activity, sup(nat)U, 226Ra and, in some of the samples, also 210Pb, 90Sr and 137Cs. The analyses included water, bottom sediments, samples of aquatic macrophytes (Batrachium fluitans), samples of aquatic invertebrates (Herpobdella octoculata, Anodonta cygnea, Asellus aquaticus, larval Ephemeroptera, larval Trichoptera, exuviae of pupae of Chironomidae) and samples of the tissues of 8 species of fishes (Salmo trutta m. fario, Cyprinus carpio, Rutilus rutilus, Leuciscus cephalus, Leuciscus leuciscus, Chondrostoma nasus, Gobio gobio, Barbus barbus). The activity of the radionuclides under study corresponded to the values reported for uncontaminated streams. (author)