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The Fuyang River system (FRS) in north China, for a long time, is seriously polluted with organic compounds and heavy metals due to industrialization. However, the information on heavy metal pollution in this area is still limited, and health risks raised by trace elements are neglected up to now. To characterize the heavy metal pollutants and assess their potential ecological risks scientifically in FRS, surface sediments were collected from 66 sampling sites selected according to the hydrological and anthropogenic conditions along the river. A total of twelve metal pollutants (e.g., Cr, As, and Hg) in the sediments were detected among the distributaries. A combining application of geoaccumulation index (I geo ), ratio of secondary phase and primary phase (RSP), and the ecological risk factor (Er i ) in this study gave systematic assessment results of single or combined pollution status raised by heavy metals in this area. The results show that Cr, Ni, Cu, As, Cd, Co, and Sn are mainly dispersed in the river reaches of Xingtai City and pose potential health risks in midstream, as per the geoaccumulation index and Pearson's correlation analyses. In particular, Cd accumulates strongly in sediments of Ming River and Aixinzhuang dam from Xingtai City. In upstream and downstream of FRS, the potential ecological risk is low, except in Yongnian County where high ecological risk was caused by Cd and Hg. These findings provide new insights into the pollution characteristics and assessment of the potential ecological risks induced by heavy metals along FRS, which suggest new directions should strategically tend to typical pollutants control by policy formulation and taking effective measures to prevent and manage heavy metal pollution in North China., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Concentrations, sources and risk of 16 priority polycyclic aromatic hydrocarbons (PAHs) were investigated in surface sediments from 19 representative tributaries in a regional scale of Chongqing City. The total concentration of 16 PAHs (ΣPAHs) ranged from 221 to 3205 ng g -1 with a mean of 1055 ng g -1 . Most tributaries of the Jialing River exhibited significantly higher ΣPAHs concentrations (mean 1864 ng g -1 ) compared to those flowing into the Yangtze River (mean 787 ng g -1 ). Isomeric ratio and hierarchical clustering analysis showed combustion may impact sedimentary PAHs at most center sites of the City, while PAHs at most sites were mixed of petrogenic and pyrogenic sources. Toxicity equivalency concentration for carcinogenic PAH were 2-4 times more than the Dutch limit. More comprehensive assessment of safety is suggested to reduce environmental risk of PAHs in sediments.