Metals in Sediment Cores from Nine Coastal Lagoons in Central Vietnam
Stefania Romano, Cristian Mugnai, Silvia Giuliani, Clara Turetta, Nguyen Huu Cu, Luca Giorgio Bellucci, Dang Hoai Nhon, Gabriele Capodaglio and Mauro Frignani
DOI : 10.3844/ajessp.2012.130.142
American Journal of Environmental Sciences
Volume 8, Issue 2
Problem statement: After being dramatically hit by war events, Vietnam is presently experiencing a huge economical and social development. However, very few data, relative to pollution levels and trends, are available for the correct management of critical areas such as coastal lagoons, where many economical activities are linked to high value environmental features. Approach: A set of sediment cores from nine coastal lagoons of central Vietnam (Lang Co, Truong Giang, An Khe, Nuoc Man, Nuoc Ngot, Thi Nai, O Loan, Thuy Trieu and Dam Nai) were sampled in 2008 and analyzed to assess metal and (Al, Cd, Cr, Cu, Fe, Hg, Li, Mn, Ni, Pb, V, U and Zn) and As levels and historical trends. Results: Concentrations are generally low, with the exception of As, which often exceeds ERL guidelines and Ni that does the same at O Loan. In some cases, concentrations-depth profiles account for recent increasing trends but surficial values are still low when compared to both international guidelines and polluted sediments all around the world. Sediment grain size seems to affect the depth distribution of a number of metals and when normalized to the content of silt and clay, values are particularly high at Dam Nai and Thi Nai, due to the very coarse composition of surficial sediments. Conclusion: Metal concentrations in lagoon sediments derive from the composition of rocks and soils in the watersheds. However, recent increasing trends need for further monitoring.
© 2012 Stefania Romano, Cristian Mugnai, Silvia Giuliani, Clara Turetta, Nguyen Huu Cu, Luca Giorgio Bellucci, Dang Hoai Nhon, Gabriele Capodaglio and Mauro Frignani. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.