title: Spatial Evaluation of Heavy Metals Concentrations in the Surface Sediment of Taihu Lake.
abstract: With regard to the size of China's freshwater lakes, Taihu Lake ranks third and it plays an important role in the supply of drinking water, flood prevention, farming and navigation, as well as in the travelling industry. The problem of environmental pollution has attracted widespread attention in recent years. In order to understand the levels, distribution and sources of heavy metals in sediments of Taihu Lake, random selection was carried out to obtain 59 samples of surface sediment from the entire lake and study the concentrations of Pb, Cd, Cu, Zn, Cr and Ni. Toxic units were also calculated to normalize the toxicities caused by various heavy metals. As a result, Cd and Cu in sediment were considered lower than the effect range low (ERL) at all regions where samples were gathered, while Pb and Ni were categorized into ERL-effect range median (ERM) at over 22% of the regions where samples were obtained. Nevertheless, all average concentrations of the samples were below the level of potential effect. According to the findings of this research, significant spatial heterogeneity existed in the above heavy metals. In conclusion, the distribution areas of heavy metals with higher concentrations were mainly the north bays, namely Zhushan Bay, Meiliang Bay as well as Gonghu Bay. The distribution areas of Cu, Zn, Cr and Ni with higher concentration also included the lake's central region, whereas the uniform distribution areas of those with lower concentrations were the lake's southeast region. In addition, it was most probable that the spatial distribution of heavy metals was determined by river inputs, whereas atmospheric precipitation caused by urban and traffic contamination also exerted considerable effects on the higher concentrations of Pb and Cd. Through evaluating the total amount of toxic units (ΣTU), it was found that higher toxicity existed primarily in the north bays and central region of the lake. If the heavy metals were sorted by the reduction of mean heavy metal toxic units in Taihu Lake in descending order, it would be Pb, Cr, Ni, Cd, Zn and Cu. Generally speaking, these result of analyses are conducive to alleviating the contamination of heavy metals in Taihu Lake.
authors.affiliation: College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China. ny0626@sina.com.|Research Center of Lake Environment, Chinese Research Academy of Environmental Science, Beijing 100012, China. ny0626@sina.com.
authors.forename: Yong
authors.initials: Y
authors.lastname: Niu
authors.affiliation: School of Environment, Beijing Normal University, Beijing 100875, China. weijiao626@126.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Jiao
authors.affiliation: Research Center of Lake Environment, Chinese Research Academy of Environmental Science, Beijing 100012, China. huiyucraes@126.com.
authors.forename: Hui
authors.initials: H
authors.lastname: Yu
authors.affiliation: Research Center of Lake Environment, Chinese Research Academy of Environmental Science, Beijing 100012, China. niuyuan@craes.org.cn.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Niu
authors.affiliation: College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China. pangyhhu@126.com.
authors.forename: Yong
authors.initials: Y
authors.lastname: Pang
authors.affiliation: College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China. xiangyanghhu@126.com.
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Xu
authors.affiliation: Research Center of Lake Environment, Chinese Research Academy of Environmental Science, Beijing 100012, China. guoxiaochun419@163.com.
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Guo
mesh_terms: D002681:China; D060766:Drinking Water / Q000032:analysis* / Q000737:chemistry; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000032:analysis* / Q000737:chemistry; D060106:Lakes / Q000032:analysis* / Q000737:chemistry; D019216:Metals, Heavy / Q000032:analysis* / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D060766:Drinking Water; D019216:Metals, Heavy; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical
keywords: Taihu Lake; heavy metals; sediment; spatial distribution; toxic unit