Graduate School of Environmental Studies, Tohoku University, 6-6-20 Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan; General Secretariat of National Energy Council, Ministry of Energy and Mineral Resources, Republic of Indonesia, Jl. Jend. Gatot Subroto Kav. 49 Jakarta Selatan, 12950, Indonesia.
Graduate School of Environmental Studies, Tohoku University, 6-6-20 Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan.
Chemosphere. 2021 Jan;263:128268. doi: 10.1016/j.chemosphere.2020.128268. Epub 2020 Sep 6.
The Tohoku region of Japan is geologically diverse, with a long agriculture and mining history; however, little information about the origins and distribution mechanisms of elements in this region has been reported. This study aims to provide fundamental insights into the effects of geological features and anthropogenic activities on various elements, including toxic elements and rare-earth elements (REEs), in the Tohoku region. A geochemical database (2007, AIST) consisting of data for 53 elements in 485 river sediment samples from the region was used, and a data-driven method combining principal component analysis (PCA) was applied for analysis. GBs for numerous types of areas, including general areas (GGB), natural environments (NGB), high anthropogenic-influenced areas (AGB) and mineralised areas (MGB) were established; especially, MGB was newly proposed in this study to illuminate the role of ore deposits. Both PCA and GBs comparison results show that geological features (especially igneous rock distribution) were the most important factor affecting elemental distribution, rather than anthropogenic activities. In the PCA, the first principal component showed that REE resources were commonly associated with the distribution of granitic rocks and REE-bearing minerals. Anthropogenic contaminations from mining, urban, and anthropogenic areas played important roles as the origin of some toxic elements (e.g. Ni, Pb, Sb). Comparisons between these GBs effectively elucidated the enrichment of certain toxic elements (e.g., Hg, Sb) in ore deposit areas. This data-driven study not only clarified the origins of toxic elements, but also revealed the location of potential REE mineral resources in the Tohoku region.
日本东北地区地质多样，拥有悠久的农业和采矿业历史；然而，关于该地区元素的来源和分布机制的信息却很少。本研究旨在深入了解地质特征和人为活动对东北地区各种元素（包括有毒元素和稀土元素）的影响。使用了一个由 485 个河流沉积物样本中的 53 种元素数据组成的地球化学数据库（2007 年，AIST），并应用了一种结合主成分分析（PCA）的数据驱动方法进行分析。建立了针对多种类型区域的地球化学基准（GBs），包括一般区域（GGB）、自然环境（NGB）、高人为影响区域（AGB）和矿化区域（MGB）；特别是在本研究中提出了 MGB，以阐明矿床的作用。PCA 和 GBs 比较结果均表明，地质特征（特别是火成岩分布）是影响元素分布的最重要因素，而非人为活动。在 PCA 中，第一主成分表明，REE 资源通常与花岗岩和含 REE 矿物的分布有关。采矿、城市和人为活动等人为污染是一些有毒元素（如 Ni、Pb、Sb）的来源。这些 GBs 的比较有效地阐明了矿床地区某些有毒元素（如 Hg、Sb）的富集。这项数据驱动研究不仅阐明了有毒元素的来源，还揭示了东北地区潜在 REE 矿产资源的位置。
