This study assesses the occurrence of trace elements (TEs) in sediments of the southern Caspian Sea. A total of 16 shoreline sediment samples and 15 seabed sediment samples along five coastal transects were studied. The mean concentration of TEs follows the order of Zn > V > Cr > Ni > Cu > Pb > Co > As > Sb > Mo > Cd. The TEs had an uneven, heterogeneous distribution within the shoreline and seabed sampling sites. This is due to that the study area comprises a large number of different pollution sources, also different sediment physicochemical characteristics. Levels of individual TEs within the seabed sediment transects were higher where their shoreline sites had higher concentrations, reflecting that the coastal sites play an important role in diffusing the contaminants towards the sea. The main anthropogenic source of TEs in this highly populated region, especially in the western part, is likely a large number of discharge points of greywater entering the sea. In addition, dominant fishing industry, tourism, intense agriculture, and textile and paper industry, as well as several other commercial activities, contribute significantly to the overall loading of TEs. Based on the statistical analyses, the organic matter and mud fraction had a strong explanatory value for the spatial variation of Cu, while oxyhydroxides of Fe and Mn had good explanatory factors to govern the spatial variation of other TEs. Pb and Zn had a relatively high partition coefficient (Kd), reflecting the affinity of these elements to be sorbed to the sediment phase. Cd and Sb had lower Kd, tending to remain in the aqueous phase. Geochemical indices indicated high enrichment of Cd, Sb, Zn, and Pb at a number of sampling sites, reflecting potential local sources of contamination. The Sisangan recreational area was identified as the most contaminated site. From a public health perspective, the non-carcinogenic risk of TEs was significant only at this site. The carcinogenic risks of Pb(II) and As(III) in adults, and Pb(II), Cd(II), and As(III) in children, were tolerable.

本研究评估了里海南部沉积物中微量元素 (TE) 的存在情况。共研究了 5 个沿海断面的 16 个海岸线沉积物样品和 15 个海底沉积物样品。TEs 的平均浓度遵循以下顺序：Zn > V > Cr > Ni > Cu > Pb > Co > As > Sb > Mo > Cd。TE 在海岸线和海床采样点内具有不均匀、异质的分布。这是由于研究区包含大量不同的污染源，沉积物的理化特征也不同。海床沉积断面内单个 TE 的水平在其海岸线站点浓度较高的地方较高，这反映了沿海站点在向海洋扩散污染物方面起着重要作用。在这个人口稠密的地区，尤其是西部地区，TE 的主要人为来源很可能是大量的灰水入海排放点。此外，占主导地位的渔业、旅游业、集约化农业、纺织和造纸业以及其他一些商业活动对 TE 的总体负载做出了重大贡献。统计分析表明，有机质和泥浆比例对Cu的空间变化具有较强的解释价值，而Fe和Mn的羟基氧化物对其他TEs的空间变化具有较好的解释作用。Pb 和 Zn 具有相对较高的分配系数 (Kd)，反映了这些元素对沉积物相吸附的亲和力。Cd 和 Sb 的 Kd 较低，倾向于保留在水相中。地球化学指数表明，许多采样点的 Cd、Sb、Zn 和 Pb 富集度很高，反映了当地潜在的污染源。Sisangan 休闲区被确定为污染最严重的地点。从公共卫生的角度来看，TE 的非致癌风险仅在该地点显着。成人 Pb(II) 和 As(III) 以及儿童 Pb(II)、Cd(II) 和 As(III) 的致癌风险是可以容忍的。