Chronological analysis of Omura Bay bottom sediment by measurement of environmental radioactivity

通过环境放射性测量对大村湾海底沉积物进行年代学分析

• 批准号: 14580552
• 负责人: TAKATSUJI Toshihiro
• 金额: $ 2.24万
• 依托单位: Nagasaki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14580552/
• 关键词: Environmental Radioactivity; marine sediment; chronological estimation; elemental analysis; 放射化分析; PIXE

Sediments at the bottom of the Omura bay was analyzed. The radioactivity was analyzed by a Germanium semiconductor detector. The principal elements were analyzed by the inductively coupled, plasma atomic emission spectrometry (ICP-AES). The trace elements were mainly analyzed by the inductively coupled plasma mass spectrometry (ICP-MS).From the radioactivity of Pb-210, horizontally separated core samples of the sediments were dated. The sedimentation rate along the coast tends to be faster than the middle of the bay. The tendency is same as Zbkyo bay and Osaka bay. The vertical distribution of Cs-137 did not show clear peak of the Global fallout of the nuclear tests and the dating with Cs-137 distribution was difficult.The distributions of the principal elements, P, Ti, K, Mg, Na, Al, and Ca were almost uniform vertically and horizontally. The concentration of K, Ti, Y, Rb, Sr, Zr, Nb, Cs, Hf, Th, Na, Zn, W, Pb and Cd was higher than the average concentration of the earth's crust. In the elements, concentration of Na, Zn, W, Pb and Cd were increasing upward. The concentration of Cu was also clearly increasing upward. It is not appropriate to conclude easily that these trace elements pouring into the bay increase with the years because these elements may liquate out up to the surface. But concentration of Fe and Mn, which is known to liquate in anoxic condition, was decreasing upword oppositely. In the elements increasing upward, Cd is an important environmental factor, and if it is increasingly pouring into the bay, it may be the sake of human activity, and very noteworthy result.

对大村湾底的沉积物进行了分析。通过锗半导体检测器分析放射性。采用电感耦合等离子体原子发射光谱法（ICP-AES）对样品中的主要元素进行了分析。微量元素主要采用电感耦合等离子体质谱（ICP-MS）进行分析，并通过Pb-210的放射性对沉积物水平分离的芯样进行测年。沿着的沉积速率往往比海湾中部快。与Zbkyo湾和大坂湾的趋势相同。Cs-137的垂直分布没有显示出明显的核试验全球沉降峰值，用Cs-137分布进行测年比较困难，P、Ti、K、Mg、Na、Al、Ca等主要元素的垂直和水平分布基本一致。K、Ti、Y、Rb、Sr、Zr、Nb、Cs、Hf、Th、Na、Zn、W、Pb、Cd等元素含量高于地壳平均含量。元素中Na、Zn、W、Pb、Cd的含量呈上升趋势。Cu的浓度也明显上升。因此，不能简单地认为注入海湾的微量元素会随着时间的推移而增加，因为这些元素可能会液化到表面。而缺氧条件下易溶出的Fe、Mn浓度则相反地呈上升趋势。在向上递增的元素中，Cd是一个重要的环境因子，如果它越来越多地涌入海湾，这可能是人类活动的缘故，并且非常值得注意的结果。

项目成果

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Yamamoto, M.、Hoshi, M.、Takada, J.、Oikawa, S.、Yoshikawa, L.、Takatsuji, T.等人：“前苏联塞米帕拉金斯克核试验场周围环境放射性的一些方面：

Nakamura, T., Hoel, D.G.: "Comparing cancer risks between radiation and dioxin exposure based on two-stage model"Environmetrics(Europe). 14. 203-211 (2003)

Nakamura, T.、Hoel, D.G.：“基于两阶段模型比较辐射和二恶英暴露之间的癌症风险”Environmetrics（欧洲）。

高辻俊宏, 吉川勲, 藤安得博, 中村成孝, 松瀬美智子, 石井保裕 他: "西彼杵半島及び大村湾周辺の岩石中の放射性物質について、他"第4回環境放射能・放射線-夏の学校 プロシーディング. 64-77 (2003)

Toshihiro Takatsuji、Isao Yoshikawa、Tokuhiro Fujiyasu、Shigetaka Nakamura、Michiko Matsuse、Yasuhiro Ishii 等：“西园半岛和大村湾等岩石中的放射性物质 - 第 4 届环境放射性/辐射 - 暑期学校论文集”。 (2003)

鬼塚昌彦, 遠藤暁, 石川正純, 星正治, 櫻井良憲, 高辻俊宏 他: "硼素含有壁を持つ組織等価比例計数管を用いた重水場の線質評価"京都大学原子炉実験所学術講演会報文集. 37. Web (2003)

Masahiko Onizuka、Akira Endo、Masazumi Ishikawa、Masaharu Hoshi、Yoshinori Sakurai、Toshihiro Takatsuji 等人：“使用含硼壁的组织等效正比计数管评估重水场中的辐射质量”京都大学反应堆研究所学术会议 37. Web (2003)

高辻俊弘: "ポアソン照射の問題点と、単一粒子照射への期待"放射線科学. 45・9. 278-288 (2002)

高辻俊弘：“泊松照射的问题和单粒子照射的期望”《放射科学》278-288（2002）。