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Following a well established international research trend, adopting widely recognized scientific methodologies and innovative approaches as well, it has been compiled the Geochemical Environmental Atlas of the Soils of Salerno that presents the results of a geochemical survey conducted in the municipal territory of of Salerno (Italy). This atlas represents a further effort to produce geochemical atlases of the main cities of Campania region (Italy) after the publishing of the ones of Napoli (1), Avellino (2) and Caserta (3) (based on soil sampling) and of Campania region (4) (based on stream sediment sampling).
For Salerno, 151 soil samples have been collected, with a sampling grid of 0.5 x 0.5 km, over an area of ∼ 60 sq. Km; samples have been analyzed by mean of ICP-MS, following digestion in a modified aqua regia solution, to obtain concentration values for 42 elements (major, minor and trace).
The main aims of the Atlas are:
1) to show the distribution of concentration values and to determine baseline values for each element in the top soils of the municipal area of Salerno;
2) to provide reliable analytical data to allow a quantitative assessment of the toxic element pollution threat to the ecosystem and to human health;
3) to inform policy makers and provide a sound basis for legislation, addressing in particular public concerns regarding environmental pollution.
Univariate and multivariate statistical analyses were carried out in order to show the single element geochemical distribution and the distribution of factor scores elemental associations from R-mode factor analysis. Geochemical data were reclassified by means of a recently developed multifractal IDW interpolation method and a fractal filtering (S-A) technique implemented in the GeoDAS software (5).
Different kinds of geochemical maps have been produced (dot, multifractal IDW interpolated, baseline and risk maps) for each considered element in addition to factor scores maps of elemental associations resulting from R-mode factor analysis and maps showing radioactivity values distribution.
Results can be summarized as follows:
1. The concentrations of Be, Pb, Sn and Zn in the municipal territory of Salerno exceed the action limits fixed by Italian Law (Dlgs. 152/2006).
2. R-mode factor analysis has been very useful in interpreting the spatial distribution of elemental associations, allowing to discriminate the values reflecting anthropogenic sources (Sb, Sn, Pb, Cd, Zn, Ag, Cr, Cu, Au, Hg) from those controlled by geogenic sources (La, Be, Th, Ti, V, As, Fe, Bi, Mn, Co, W, Sc, K, U).
3. The distribution pattern of 238U, 232Th, 40K and Total gamma-ray radioactivity levels tend to relate to the bedrock lithologies.
(1) De Vivo et al., 2006. Aracne Editrice, Roma, 315 pp.
(2) Albanese et al., 2007. Aracne Editrice, Roma, 192 pp.
(3) Lima et al., 2007. Aracne Editrice, Roma, 208 pp.
(4) De Vivo et al. 2006. Aracne Editrice, Roma, 216 pp.
(5) Lima et al., 2003. Appl. Geochem., 18, 1853-1865
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