title: Spatial variation and risk assessment of trace metals in water and sediment of the Mekong Delta.
abstract: The Mekong Delta, is home to 17 million inhabitants and faces numerous challenges relating to climate change, environmental degradation and water issues. In this study, we assess trace metals concentrations (Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Mo, Cd, Hg, Pb) in the water, suspended particulate matter and surface sediments of the Tien River, the Northern branch of the Mekong Delta, during both dry and rainy seasons. Metal concentrations in the dissolved and suspended particle phases remain in the low concentration range of the main Asian Tropical River. During transportation in the riverine part, we evidenced that V, Cr, Co, As and Pb are dominant in the particulate phase while Mo, Ni and Cu dominate in the dissolved fraction. In the salinity gradient, dissolved U, V, Mo exhibit conservative behaviour while Ni, Cu, As, Co and Cd showed additive behaviour suggesting desorption processes. In the surface sediment, metal concentrations are controlled by the particle-size, POC contents and Fe, Al and Mn - oxy(hydr)oxides. Calculated Enrichment Factor and Geoaccumulation Index evidenced As enrichment while the calculated mean effect range median quotients evidenced a low to medium ecotoxicological potential effects range in the surface sediments.
authors.affiliation: Univ. Grenoble Alpes, CNRS, IRD, Grenoble INP, IGE, F-38000 Grenoble, France; CARE-HCMUT, Ho Chi Minh City, Viet Nam. Electronic address: emilie.strady@ird.fr.
authors.forename: Emilie
authors.initials: E
authors.lastname: Strady
authors.affiliation: CARE-HCMUT, Ho Chi Minh City, Viet Nam; Faculty of Environment, HCMUT, Ho Chi Minh City, Viet Nam.
authors.forename: Quoc Tuc
authors.initials: QT
authors.lastname: Dinh
authors.affiliation: Univ. Grenoble Alpes, CNRS, IRD, Grenoble INP, IGE, F-38000 Grenoble, France; CARE-HCMUT, Ho Chi Minh City, Viet Nam.
authors.forename: Julien
authors.initials: J
authors.lastname: Némery
authors.affiliation: Faculty of Chemistry, University of Sciences, Ho Chi Minh City, Viet Nam.
authors.forename: Thanh Nho
authors.initials: TN
authors.lastname: Nguyen
authors.affiliation: Univ. Grenoble Alpes, CNRS, IRD, ISTerre, F-38000 Grenoble, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Guédron
authors.affiliation: Faculty of Environment, HCMUT, Ho Chi Minh City, Viet Nam.
authors.forename: Nhu Sang
authors.initials: NS
authors.lastname: Nguyen
authors.affiliation: Univ. Grenoble Alpes, CNRS, IRD, Grenoble INP, IGE, F-38000 Grenoble, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Denis
authors.affiliation: Faculty of Environment, HCMUT, Ho Chi Minh City, Viet Nam.
authors.forename: Phuoc Dan
authors.initials: PD
authors.lastname: Nguyen
mesh_terms: D057231:Climate Change; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D019216:Metals, Heavy / Q000032:analysis*; D010316:Particle Size; D045483:Rivers / Q000737:chemistry; D012621:Seasons; D014131:Trace Elements / Q000032:analysis*; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D019216:Metals, Heavy; D014131:Trace Elements; D014874:Water Pollutants, Chemical; D014867:Water
keywords: Ecotoxicological index; Estuary; Mekong Delta; Trace metals; Tropical river