Ecological consideration of trace element contamination in sediment cores from Sundarban wetland, India

• Published in: Environmental earth sciences 2011-07, Vol.63 (6), p.1213-1225
• Main Authors: Silva Filho, E. V., Jonathan, M. P., Chatterjee, M., Sarkar, S. K., Sella, S. M., Bhattacharya, A., Satpathy, K. K.
• Format: Article
• Language: English
• Subjects: Benchmarks; Biogeosciences; Cores; Earth and Environmental Science; Earth science; Earth Sciences; Earth, ocean, space; Ecology; Engineering and environment geology. Geothermics; Environmental conditions; Environmental Science and Engineering; Exact sciences and technology; Geochemistry; Geology; Hydrology/Water Resources; Hydroxides; Industrial areas; Marine and continental quaternary; Original Article; Pollution index; Pollution load; Pollution, environment geology; Sediment load; Sediment pollution; Sediments; Soil and rock geochemistry; Surficial geology; Terrestrial Pollution; Trace elements; Wetlands
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-010-0795-9

This article reports on the concentration of selected trace elements (Mn, Zn, Cr, Cu, Ba, As, B, V, and Hg) and major elements (Fe and Al) from the intertidal sediment cores from Sundarban wetland, India. This is a typical meso-macrotidal estuarine area affected by domestic and industrial activities located upstream. The overall concentrations range is low to moderate, indicating the environmental conditions in the outfall zone (grain size, hydrodynamic regime, and confinement), which favors the in situ accumulation of pollutants. The extent of contamination from trace elements in Sundarban core sediments is evaluated through a two-pronged approach: (i) by determining the metal enrichment in the sediments through the calculation of Pollution Load Index (PLI), Enrichment Factor (EF) and Index of Geoaccumulation ( I geo ), and (ii) by defining a potential level of biological risk by the use of quality criteria such as Threshold Effect Level (TEL) and Effects Range-Low (ERL) benchmarks. On the basis of the calculated indices, sediments are particularly enriched with Cr, Cu, B, V, and As. Those enrichments seem to be due to the fine granulometry of the regions with Fe and Mn oxi-hydroxides being the main metal carriers. Trace Elements input to the Sundarban wetland need to be kept under strict control in future specially with reference to As since, according to TEL and ERL benchmarks, it already appears to be associated with a potential biological risk.