Distribution of organometals in Seto Inland Sea and their influence on thebio-system

本研究旨在探索一种新的海底环境金属污染评价指标。以甲苯和甲醇（1:1体积）为溶剂，对大阪湾154份泥质沉积物中的金属元素进行了测定。用ICP-MS （hp4500）分析样品中Mg、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Se、Cd、Sn、Hg和Pb的含量。现总结如下：1)浅滩海岸受人类活动影响较少的沉积物中有机金属含量较少。因此，有机金属可以作为环境污染的指标。2)在好氧条件下的沿海地区，有机质来源于陆地、海洋生物，来源于有机质与锰、铁氧化物/氢氧化物形成的层状胶体。总硫富集的浅部为非好氧条件，而受当前体系强烈混合的浅部为好氧条件。大阪湾各地区氧化还原条件的差异使我们推测，层状胶体对近海沉积物的贡献比浅海沉积物的贡献更大，可以解释有机锰的分布。有机质- mn含量高的沉积物有机质- mn与有机质- as呈正相关关系。这种相关性表明Mn和As都被纳入分层胶体中。3)吸收光谱表明，沉积物中的有机mg含量主要来源于浮游植物的叶绿素。浮游植物可能对浅层有机砷的沉积起重要作用，因为有机镁和有机砷之间存在正相关关系。④三江口沉积物中有机金属富集种类的差异可能是由三江沿岸工业种类的差异造成的。另一种可能性是，河口沉积物氧化还原条件的差异可能控制了其中所含有机金属的行为。研究表明，沉积物中的有机金属不仅来源于人工材料，还来源于生物活性和层状胶体等次生过程形成的有机金属，沉积物氧化还原条件的差异可能控制着有机金属的行为。该研究表明，有机金属可以作为环境污染的一个指标。少

This research aims to explore a new indicator for the assessment of marine bottom environment with respect to metal contamination. Metal elements, extracted with toluene and methanol (1:1 volume) solvent, were determined for 154 muddy sediments from Osaka Bay. The samples were analyzed for Mg, Cr Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Sn, Hg and Pb by an ICP-MS (HP 4500).The followings are concluded ; 1) Sediments with scarce influence of human activity from the Awaji coasts contain a smaller amount of organo-metals. Therefore, organo-metals may be used as an indicator of environmental pollution. 2) In coastal area under an aerobic condition, organic matter originates from land, marine organisms, and from stratified colloid formed by organic matter with Mn and Fe oxides/hydroxides. The shallow area enriched in total sulfur is considered to be under an un-aerobic condition, while the offing area mixed strongly by the current system is under an aerobic condition. The difference of redox con … More ditions among Osaka Bay leads to presumption that the distribution of organo-Mn can be explained by the stronger contribution of the stratified colloid to the offing sediments and that to shallow ones. Moreover, sediments with high organo-Mn content show a positive correlation between organo-Mn and organo-As. This correlation suggests that both Mn and As are incorporated into the stratified colloid. 3) The absorption spectrum shows that organo-Mg content in sediments originated mainly from chlorophyll of phytoplankton. Phytoplankton may play an important role on the sedimentation of organo-As in the shallow area because of the positive correlation between organo-Mg and organo-As. 4) The difference of enriched organo-metal species among three mouth sediments may be caused by the difference of kind, of industries along three rivers. As another possibility, the difference of redox conditions of the mouth sediments may control the behavior of organo-metals contained in them.From this study, organo-metals contained in sediments originate not only from artificial materials but from those formed by secondary processes such as biogenic activity and stratified colloid, and the difference of redox conditions of sediments may control the behavior of organo-metals. This study suggests that organo-metals can be used as an indicator of environmental pollution. Less