Contents lists available at ScienceDirect Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul Baseline Distribution and ecological risks of heavy metals in river sediments and overlying water in typical mining areas of China Ming Chen ⁎ , Fengguo Li ⁎ , Meixia Tao, Lanwen Hu, Yanli Shi, Youcun Liu Jiangxi Key Laboratory of Mining & Metallurgy Environmental Pollution Control, Jiangxi University of Science and Technology, No.156, Hakka Ave, Ganzhou, Jiangxi 341000, PR China ARTICLE INFO Keywords: Metal mines Taojiang river Overlying water Sediments Heavy metals Ecological risk ABSTRACT The distribution and potential ecological risks of eight heavy metal elements including Cr, Cu, Zn, As, Cd, Pb, Hg, and W in the overlying water and sediments of the Taojiang River were investigated. The concentrations of eight heavy metals were measured by inductively coupled plasma mass spectrometer (ICP-MS), and the distribution coefficients were exploited to estimate the partition coefficient between overlying water and sediment phases, which were subsequently used to establish the potential ecological risk of heavy metals in sediments. The results revealed that the contents of Pb (33.47 μg·L -1 ), Cd (153.03 μg·L -1 ) and Hg (1.12 μg·L -1 ) in the water samples exceeded threshold values as proposed by the limits of the class III environmental quality standard. On the other hand, Cr, Cu, Zn, As, and Pb within sediments were below threshold limits. In recent years, most socio-economy, urban and industrial activities generate tons of pollutants (solid, liquid and gas) which then enter into various types of environmental ecosystems. Among these pollutants, heavy metals are the most important components for some of these industrial wastes. However, those industrial wastes which contain high level of heavy metal pollutants were discharged into environments without proper treatments or recovery operations. A large number of heavy metals accompanied with solid or liquid wastes are subsequently discharged into the natural ecosystems, predominantly river bodies, can result in serious negative effects on water toxicity, eutrophication and destruction of aquatic lives. Besides industries, significant concentra- tions of heavy metals were reported to have come from non-point sources, mining activities, agriculture fields, and atmospheric deposi- tion (Yang et al., 2015; Zhang et al., 2017) . What is worth to mention is that livestock manure, poultry manure, pesticides and fertilizers also contain cadmium, mercury, copper, zinc and other heavy metals upon the river (Chai et al., 2012; Chen et al., 2015). Therefore, improper treatment of such wastes to recover or remove heavy metals will sub- sequently enter into river bodies, which then can be subject to migra- tion and transformation processes, including adsorption, desorption, precipitation, and biological absorption, in waterbodies, sediments and organisms. Furthermore, heavy metals can be accumulated in organ- isms through food chain circulation, threatening human health (Zhang et al., 2013). A number of studies have established extensive dynamics and relationship of these heavy metals between waterbodies and sediments. For instance, the distribution, migration and transformation processes of Hg, Cr, Cu, Zn, As. within the Yangtze estuary, Pearl river, Yongming river and Chao-hu lake were widely explored (Liu et al., 2007; Gong et al., 2017; Tang et al., 2017; Li et al., 2019). However, due to the high toxicity, high potential accumulation effect, non-bio- degradability and long-term existence within the food chain (Li et al., 2014Ai et al., 2018), these heavy metals have become important pol- lution issues that require urgent, extensive and drastic measures. In recent years, due to pollution treaties and policies signed on by developed countries, the ecological safety of heavy metals has aroused extensive attention. China is currently one of the major producer, consumer and exporter of a number of heavy metals including tungsten, which may result in high potentials to cause severe pollution problems if left unattended (Varol, 2011; Koutsospyros et al., 2011). Conse- quently, a substantial number of government departments and agencies across the world have funded studies on the ecotoxicity and toxic me- chanism of heavy metals (particularly tungsten) in order to promote the formulation of relevant standards and regulations (Gao and Chen, 2012; Dietrich et al., 2018). As indicated above, China is not exception so far as heavy metal pollution is concerned. For instance, heavy metal mining is very prevalent within the Taojiang River basin located in Gannan County, Jiangxi province of China. In the early periods of a decommissioned mine, heavy metals in- cluding lead, cadmium, arsenic, copper and zinc are often washed off from wastewater and slag into surrounding river by rain runoff leading https://doi.org/10.1016/j.marpolbul.2019.07.029 Received 31 March 2019; Received in revised form 9 July 2019; Accepted 12 July 2019 ⁎ Corresponding authors. E-mail addresses: jxlgdx@qq.com (M. Chen), 792512371@qq.com (F. Li). Marine Pollution Bulletin 146 (2019) 893–899 Available online 26 July 2019 0025-326X/ © 2019 Elsevier Ltd. All rights reserved. T