| Research Abstract |
Lichens have been considered to accumulate some kind of pollutants in the environment. To confirm this, we investigate the elemental concentration and radioactivity level of lichens collected in various places in Japan. We determined elemental concentrations of Japanese lichens using instrumental neutron activation analysis. The ^<137>Cs concentration of samples were measured by γ-ray spectromoetry using HPGe detector.
Species of Cladonia rangiferina, Parmotrema tinctrum, Rimelia clavulifera and Flavoparmelia caperata are selected, which were relatively easily available in Japan. We collected samples in 40 places in Japan. Na, Mg, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Cu, As, Br and I were detected in Thalli in the present study.
Generally, the concentration of each element distributes within relatively narrow range irrespect of their habitat, which some elements spread over a relatively wide inflecting their habitat. For example, concentration of Al and V in Parmelia strongly depends on their substrate, bark or rock. Arsenic was not detected in almost of all samples except Cladonia carassensis subsp. Japonica and Cladonia vulcani living around fumerole. Rimelia clavulifera living under the edge of copper roof shrine showed particularly higher concentration of Cu than that living in the other places.
In this study we obtained typical concentrations of chemical element in Japanese lichen and some exceptional levels inflecting their habitat. We expect that lichen is an indicator of chemical elements.
We observed the highest value of 87Bq/kg in the sample collected in Hokkaido, the most northern part of Japan. The result is consisitent with the hipothesis that the ^<137>Cs fallout level increased as higher the altitude in Japan.
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