Department of Ocean Environmental Sciences, Chungnam National University, Daejeon 34134, Republic of Korea.
School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
Environ Pollut. 2018 Jun;237:842-850. doi: 10.1016/j.envpol.2017.11.020. Epub 2017 Nov 13.
Differences in the distribution, partitioning, and bioaccumulation characteristics of arsenicals between freshwater and saltwater systems remain poorly understood. To determine the characteristics of distribution and behavior of arsenicals, multimedia environmental samples including water, suspended particles, zooplankton, sediments, and porewater were collected from inner (five sites, freshwater) and outer (five sites, saltwater) regions of the estuary dike of the Youngsan River Estuary in South Korea (Nov., 2012). Six organic and inorganic forms of As were separated and measured using HPLC-ICP/MS equipped with an anion exchange column. Concentrations of arsenicals in water samples of the inner region (mean = 1.5 μg As L) were significantly lower than in those of the outer region (mean = 5.2 μg As L). Conversely, concentrations of As in suspended particles in the inner region (mean = 14 μg As g) were much greater than in the outer region (mean = 5.7 μg As g). The field-based distribution coefficient (K) for As depended strongly on salinity; relatively greater K values were found in freshwater compared with saltwater. The As was found to be the major form of As in all water and particle samples in both inner and outer regions. The zooplankton species were significantly distinguishable between the inner and outer regions; cladocerans were the most dominant species in freshwater and cyclopoida were predominantly found in saltwater. The As concentrations in zooplankton were shown to be particle-concentration dependent, suggesting that dietary exposure plays a substantial role in the bioaccumulation of As. Inorganic arsenicals, such as As and As were the most dominant forms found in zooplankton. Partitioning behavior of As between porewater and sediments was similar to that in water-particle distributions. The results of the present study enhance the understanding of As biogeochemistry in river and estuarine environments.
淡水和盐水系统中砷化物的分布、分配和生物积累特征差异仍未得到很好的理解。为了确定砷化物的分布和行为特征，从韩国延寿河口堤坝的内部（五个地点，淡水）和外部（五个地点，盐水）区域采集了包括水、悬浮颗粒、浮游动物、沉积物和孔隙水在内的多介质环境样本。使用配备阴离子交换柱的高效液相色谱-电感耦合等离子体质谱法（HPLC-ICP/MS）分离和测量了六种有机和无机形式的砷。内部区域水样中砷化物的浓度（平均值为 1.5μg As L）明显低于外部区域（平均值为 5.2μg As L）。相反，内部区域悬浮颗粒中砷的浓度（平均值为 14μg As g）远高于外部区域（平均值为 5.7μg As g）。基于现场的砷分配系数（K）强烈依赖于盐度；在淡水中发现相对较大的 K 值，而在海水中则发现相对较小的 K 值。在内外区域的所有水和颗粒样品中，砷被发现是砷的主要形态。内外区域的浮游动物物种差异显著；淡水以桡足类为主，盐水以轮虫类为主。浮游动物中的砷浓度与颗粒浓度有关，表明饮食暴露在砷的生物积累中起着重要作用。在浮游动物中，无机砷化物（如 As 和 As ）是最主要的形式。砷在孔隙水和沉积物之间的分配行为与水-颗粒分布相似。本研究的结果增强了对河流和河口环境中砷生物地球化学的理解。
