Basic Reseach for Using as a New Environmental Indicator

地衣被认为会在环境中积累某种污染物。为了证实这一点，我们调查了在日本各地采集的地衣的元素浓度和放射性水平。我们用仪器中子活化分析测定了日本地衣的元素浓度。用高纯锗探测器用γ-射线光谱仪测定了样品中~(137)Cs和~(137)Cs的含量。我们在日本的40个地方收集了样本。本研究测定了藻体中Na、Mg、Cl、K、Ca、Ti、V、Cr、Mn、Fe、Co、Cu、As、Br1、I等元素的含量，结果表明，各元素的浓度一般分布在相对较窄的范围内，与生境无关，有些元素分布较广，影响了其生境。例如，Parmelia中Al和V的浓度强烈依赖于它们的基质、树皮或岩石。除锦鸡儿亚种外，几乎所有样品中均未检出砷。寄生在福美乐尔周围的日本稻和海鞘枝藻。生活在铜顶神社边缘的克拉夫利费罗丝虫表现出比其他地方更高的铜浓度。在本研究中，我们获得了日本地衣中典型的化学元素浓度和一些影响其栖息地的异常水平。我们预计地衣是化学元素的指示物。我们观察到在日本最北部的北海道采集的样本中，最高值为87Bq/kg。这一结果与日本随着海拔升高，~(137)Cs和~(137)Cs尘埃水平升高的假说是一致的。

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.