1 research outputs found
Soils and sediments of the Thua Thien-Hue Province (central Vietnam): recognizing trace element sources and the likely influence of natural events.
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 210Pb 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