Assessment of heavy metals contamination in the western Drama plain soils (Macedonia, N. Greece), using combined geochemistry and GIS mapping techniques

Περίληψη

Heavy metals (HMs) pollution of rural soils in the vicinity of both active and abandoned mines continues to attract attention because of their potential human health risk via food chain. Long-term manganese mining and ore processing activities in the Drama district, Macedonia (Northern Greece) have resulted in a tremendous legacy of abandoned mining wastes at the 25km Mn-mine site, without any safety measures. Current research was focused at the western part Drama plain, lying close to the above mine site. The concentration of 6 health related elements (Mn, Pb, Zn, Cu, Cd, and As) in the surface soils from this area was assessed using the Inductively Coupled Plasma-mass pectrometry (ICPMS) technique. The results indicated that total metal concentration ranges (in mg.kg-1) observed in study soils were: 245-130013 for Mn, 11-1996 for Pb , 23-2140 for Zn, 5-153 for Cu, 0.4-28 for Cd, and 2-1077 for As, with mean values of 4133, 183, 134, 33, 2, and 43, respectively. The overall degree of the total HMs soil pollution and their ecological risks were evaluated using the composite pollution (CPI) and the potential ecological risk (RI) indices espectively. Geostatistical analysis and GIS mapping techniques were employed to the dataset to produce spatial distribution maps for the 6 studied elements, and 3D graphics for the presentation of the above mentioned indices. Similar spatial distribution patterns were found in the geochemical maps of metal concentrations, confirming a strong geochemical association and common source of the 6 HMs. Highest values of total HMs concentrations were observed close and along both sides of the Xiropotamos stream. Soils at these sites display moderate to extremely high degree of contamination and considerable potential ecological risk by multiple HMs. Thus, an immediate action to remediate the contaminated topsoils is recommended to safeguard the health of residents in the studied area.