Toxic Trace Element Assessment for Soils/sediments Deposited During Hurricanes Katrina and Rita from Southern Louisiana, USA
A sequential extraction analysis
Analysis of soil/sediment samples collected in the southern Louisiana, USA, region three weeks after Hurricanes Katrina and Rita passed was performed using sequential extraction procedures to determine the origin, mode of occurrence, biological availability ,mobilization, and transport of trace elements in the environment. Five fractions: exchangeable, bound to carbonates, bound to iron (Fe)-manganese (M n) oxides, bound to organic matter, and residual, were subsequently extracted. The toxic trace elements P b, As, V, Cr, Cu, and C d were analyzed in each fraction, together with Fe in 51 soil/sediment samples. Results indicated that P b and As were at relatively high concentrations in many of the soil/sediment samples. Because the forms in which P b and As are present tend to be highly mobile under naturally occurring environmental conditions, these two compounds pose an increased health concern. Vanadium and Cr were mostly associated with the crystal line non mobile residual fraction. A large portion of the Cu was associated with organic matter and residual fraction. Cadmium concentrations were low in all soil/sediment samples analyzed and most of this element tended to be associated with the mobile fractions. An average of 21% of the Fe was found in the Fe-M n oxide fraction, indicating that a substantial part of the Fe was in an oxidized form. The significance of the overall finding of the present study indicated that the high concentrations and high availabilities of the potentially toxic trace elements As and P b may impact the environment and human health in southern Louisiana and, in particular, the New Orleans area. © 2010 SETAC.
H. Shi et al., "Toxic Trace Element Assessment for Soils/sediments Deposited During Hurricanes Katrina and Rita from Southern Louisiana, USA," Environmental Toxicology and Chemistry, Society of Environmental Toxicology and Chemistry Press, Jan 2010.
The definitive version is available at http://dx.doi.org/10.1002/etc.218
Civil, Architectural and Environmental Engineering
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