title: Geochemical source, deposition, and environmental risk assessment of cadmium in surface and core sediments from the Bohai Sea, China.
abstract: Geochemical sources, spatio-temporal distribution, and associated environmental risk of Cd in the Bohai Sea were investigated using data from 405 surface sediment samples and two sediment cores. Local point Cd sources, TOC content, and currents are the main controlling factors of Cd distribution. The contribution of Cd from river discharge surpasses that from atmospheric deposition. Sediment-quality guidelines, enrichment factors, and chemical fraction analysis were used to assess metal toxicity in the collected sediments. Results show that Bohai Sea sediments have a moderate Cd enrichment level. This enrichment poses a high risk due to the relatively high mobility and bioavailability of Cd despite measured levels below sediment-quality guidelines at most stations. Vertical profiles of Cd concentrations, Al-normalized enrichment factors, and excess burial fluxes combined with210Pb dating reveal the history of Cd pollution in the Bohai Sea over the last century. Data show Cd unvaried before the 1800s, a slight increase from the 1800s to the late 1950s, a decrease from the late 1960s to the 1970s, and an increase from the 1980s to 2001, including a relatively high value in 1998. Historic variation in Cd is closely associated with both natural and anthropogenic activities.
authors.affiliation: First Institute of Oceanography, State Oceanic Administration, Qingdao, 266061, China. huningjing@fio.org.cn.
authors.forename: Hu
authors.initials: H
authors.lastname: Ningjing
authors.affiliation: Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
authors.forename: Huang
authors.initials: H
authors.lastname: Peng
authors.affiliation: First Institute of Oceanography, State Oceanic Administration, Qingdao, 266061, China.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Hui
authors.affiliation: First Institute of Oceanography, State Oceanic Administration, Qingdao, 266061, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Xiaojing
authors.affiliation: First Institute of Oceanography, State Oceanic Administration, Qingdao, 266061, China.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Aimei
authors.affiliation: First Institute of Oceanography, State Oceanic Administration, Qingdao, 266061, China.
authors.forename: Liu
authors.initials: L
authors.lastname: Jihua
authors.affiliation: First Institute of Oceanography, State Oceanic Administration, Qingdao, 266061, China.
authors.forename: Shi
authors.initials: S
authors.lastname: Xuefa
mesh_terms: D002104:Cadmium / Q000032:analysis*; D002681:China; D004784:Environmental Monitoring / Q000379:methods*; D019015:Geologic Sediments / Q000737:chemistry*; D018570:Risk Assessment; D012623:Seawater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D002104:Cadmium
keywords: Bohai Sea; Cadmium; Risk assessment; Sediment; Sedimentary flux; Source