Multivariate statistics and spatial interpretation of geochemical data for assessing soil contamination by potentially toxic elements in the mining area of Stratoni, north Greece

摘要

A preliminary soil survey was undertaken in the mining region of Stratoni in Chalkidiki peninsula, north Greece. The objectives of the study were to assess the levels of soil contamination with respect to average concentrations of toxic elements in the region, to determine the associations between the different chemical elements and their spatial distribution, and to identify possible sources of contamination that can explain the spatial patterns of soil pollution in the area. Forty-nine surface soil samples were collected and analysed by inductively coupled plasma-atomic emission spectroscopy after digestion with a mixture of HClO4-HNO3-HCl-HF. The study focused on ten elements (Pb, Zn, Cu, As, Cd, Mn, Fe, Ni, Co, Cr), all of which were present in soil with concentrations well above the global soil means. Lead, As and Ni, with means of 895 mu g g(-1), 364 mu g g(-1) and 161 mu g g(-1) respectively, exceeded the tentative trigger concentration set by the Netherlands and the UK Interdepartmental Committee on the Redevelopment of Contaminated Land (ICRCL) regulations. Factor analysis explained 89% of the total variance of the data through four factors. Combined with spatial interpretation of its output, the method successfully grouped the elements according to their sources and provided evidence about their geogenic or anthropogenic origin.