title: Distribution and risk assessment of metals and arsenic contamination in man-made ditch sediments with different land use types.
abstract: Ditches are subjected to a large input of nutrients, trace metals, and arsenic and the enhancement of sedimentation due to human activities. However, the influence of different types of land uses on the distribution and associated environmental risk of metals and arsenic in the Red purple Sichuan Basin remains largely unclear, which is needed for water management. This study was carried out to characterize metal/metalloid status in ditch sediments from different land uses. A total of 68 surface sediment samples (0-5 cm) were collected from open ditches distributed in different land use types, i.e., cultivated ditches (CD), barren land ditches (BLD), roadside ditches (RSD), and residential ditches (RD), within the Sichuan Basin. Mean concentrations of Cr, Ni, Cu, Zn, Cd, Pb, and Mn in both RD and RSD were above the soil background values of Sichuan Basin, but Cd in ditch sediments of the basin posed considerable ecological risk to the environment. Overall, metals/metalloid (except Pb) decreased in the following order of RD > RSD > BLD > CD. Of the different land use types in the hilly region, residential and roadside land uses were likely to adverse effects on aquatic life. Multivariate statistical analysis showed that Mn, As, Cu, Ni, Zn, Fe, and Al were mainly influenced by natural weathering (erosion), while Pb might come from heavy vehicular traffic. The degree of contamination (Md), enrichment factor (EF), and the geo-accumulation index (Igeo) showed that Cd causes strong sediment pollution in the basin. Sediment quality guidelines SQG-Q values displayed that metals and arsenic created medium-low potential of adverse biological effects. These results provide baseline information on the metals and arsenic pollution in the Sichuan Basin. Awareness of land use type contributions to metals and arsenic requires that these man-made ditches be considered for their mitigation of pollutants in this region.
authors.affiliation: Key Laboratory of Mountain Surface Processes and Ecological Regulation, Chinese Academy of Sciences, Chengdu, 610041, China.|Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.|Faculty of Agronomy, Department of Natural Resources and Environmental Management, University of Lubumbashi, PO Box 1825, Lubumbashi, Democratic Republic of Congo.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Nsenga Kumwimba
authors.affiliation: Key Laboratory of Mountain Surface Processes and Ecological Regulation, Chinese Academy of Sciences, Chengdu, 610041, China. bzhu@imde.ac.cn.|Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China. bzhu@imde.ac.cn.|University of Chinese Academy of Sciences, Beijing, 100049, China. bzhu@imde.ac.cn.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Mountain Surface Processes and Ecological Regulation, Chinese Academy of Sciences, Chengdu, 610041, China. wangt@imde.ac.cn.|Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China. wangt@imde.ac.cn.
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.affiliation: School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, People's Republic of China.
authors.forename: Diana Kavidia
authors.initials: DK
authors.lastname: Muyembe
mesh_terms: D001151:Arsenic / Q000032:analysis*; D004463:Ecology; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000032:analysis*; D006802:Human Activities; D006801:Humans; D019216:Metals, Heavy / Q000032:analysis; D015999:Multivariate Analysis; D018570:Risk Assessment; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014877:Water Pollution, Chemical / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D001151:Arsenic
keywords: Land use; Man-made ditch sediment; Management; Metal/metalloid; Potential ecological risk indices; Purple Sichuan Basin