Natural and man–made radionuclide concentrations in lichens at several locations in Austria

Abstract

Regions of elevated natural radioactivity (Gastein–valley, Waldviertel) were compared to regions of low natural radioactivity (surroundings of Salzburg City). The natural radionuclides 238U, 40K and 7Be and the man–made nuclides 137Cs, 144Ce, 95Ze95Nb were measured by gamma ray spectrometry. No statistically significant difference was found between samples of the Gastein–valley, Waldviertel, Salzburg, Grossarl and Dachstein concerning the content of natural radionuclides. The amount of the short–lived fission products 144Ce, 95Zr–95Nb as well as of the natural 7Be increased with altitude. The specific nuclide concentration varies with species but was almost independent of growth form and substrate.

Ecological half-life of 137Cs in lichens in an alpine region

“…As lichens do not have special strategies for excretion, incorporated radionuclides will accumulate over time. The capacity of lichens to incorporate and store a variety of radioactive elements has been known since the period of atmospheric nuclear weapon tests (Larsson, 1970;Mattson, 1975;Holm and Persson, 1975;Eckl et al, 1984Eckl et al, , 1986. More pertinently, lichens were used as biomonitors of the radioactive fallout in the wake of the Chernobyl accident (Gaare, 1987;Seaward et al, 1988;Niemann et al, 1989;Feige et al, 1990;Sloof and Wolterbeek, 1992;Hofmann et al, 1993;Heinrich et al, 1999).…”

Contribution to the knowledge of the chemical composition, biological activities and activity concentration of 40K, 137Cs, 226Ra and 232Th of the lichen Evernia prunastri

“…2,8,9 Lichens and mosses have been reported to accumulate a great variety of radionuclides, such as 7 Be, a light element of cosmogenic origin, 40 K, a natural radionuclide, anthropogenic fallout nuclides such as 55 Fe, 90 Sr, 137 Cs, 106 Ru, 144 Ce, 125 Sb and 239 Pu from nuclear power plants and nuclear tests and, finally, naturally occurring heavy metal nuclides such as 238 U and its decay products. [10][11][12] Lichens depend on nutrients from the atmosphere, since they have no root system or cuticle as vascular plants and are therefore unlikely to accumulate significant levels of radioactive nuclide and other contaminants from the substrate. The lichen E. prunastri was used as bioindicator of radioactive isotope pollution in several biomonitoring studies 12,13 in order to determine the radioactive fallout after the accident due to their ability to intercept and retain long-lived radionuclides such as 137 Cs.…”

Bioconcentration of Fallout 137Cs by Fungi and Red-backed Voles (Clethrionomys gapperi)

“…Cesium-134 was detected in many samples of vegetation, and it should have decayed below its detection limit since the time of nuclear weapons testing (Persson 1968). Similarly, unusual radionuclides such as IMRu and 12%b were detected in epiphytic lichens, known accumulators of atmospheric contaminants (Eckl et al 1984;Hutchison-Benson et al 1985;Eckl et al 1986;Looney et al 1986). These results agree with the trace levels of Chernobyl radionuclides found by others in southern Ontario in the spring of 1986 (Joshi 1987).…”