title: Soils and sediments of the Thua Thien-Hue Province (central Vietnam): recognizing trace element sources and the likely influence of natural events.
abstract: Trace element concentrations have been measured in soil and sediment samples taken from the Thua Thien Hue (TT-H) Province and the Tam Giang-Cau Hai (TG-CH) Lagoon in 2002 and 2004. Results show that the lagoon is only slightly contaminated by elements such as Ag, Cd, Cr, Cu, Ni, Pb and Zn, whereas As, probably naturally enriched in this Asian region, reaches values above the lowest internationally accepted sediment quality guidelines. Concentrations in soils are ascribable to natural sources and distributions in the TG-CH Lagoon are mainly influenced by river inputs, with Ag and Cd undergoing estuarine desorption processes. However, concentration-depth profiles of most trace elements in sediments show a recent increasing trend that might be linked to the economic development of the area. The comparison of porosity and (210)Pb depth profiles (confirmed also by Cd and As) from repeated samplings of the same core locations in the TG-CH Lagoon seems to account for a loss of 5-10 cm of surficial sediment that took place during the time interval between the two samplings. It is hypothesized that extreme meteorological events (e.g. a major typhoon that hit the area in November 2003) could be responsible for such sediment displacement.
authors.affiliation: CNR-ISMAR, Consiglio Nazionale delle Ricerche, Istituto di Scienze Marine, Sede di Bologna, Via Gobetti 101, 40129 Bologna, Italy. silvia.giuliani@bo.ismar.cnr.it
authors.forename: Silvia
authors.initials: S
authors.lastname: Giuliani
authors.forename: Stefania
authors.initials: S
authors.lastname: Romano
authors.forename: Clara
authors.initials: C
authors.lastname: Turetta
authors.forename: Nguyen Huu
authors.initials: NH
authors.lastname: Cu
authors.forename: Luca Giorgio
authors.initials: LG
authors.lastname: Bellucci
authors.forename: Gabriele
authors.initials: G
authors.lastname: Capodaglio
authors.forename: Cristian
authors.initials: C
authors.lastname: Mugnai
authors.forename: Dang Hoai
authors.initials: DH
authors.lastname: Nhon
authors.forename: Mauro
authors.initials: M
authors.lastname: Frignani
mesh_terms: D055867:Cyclonic Storms; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D014131:Trace Elements / Q000032:analysis*; D014744:Vietnam; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D014131:Trace Elements; D014874:Water Pollutants, Chemical