Groundwater quality in the major industrial area of Thessaloniki, Greece part 2: Heavy metal distribution‐source identification

The distribution of some heavy metals and toxic elements (Pb, Cd, Cu, Cr, Mn, Fe and As) in groundwaters of the major area of Thessaloniki, northern Greece, was investigated. Trace elements were generally found at low concentration levels, although some extreme values were observed, particularly for Mn, Cd and As. Correlation and Principal Component Analysis showed that two major factors affected heavy metals content in groundwaters: salinity and redox conditions. Salinity had a strong influence on Pb, Cd and Cu probably due to adsorption — desorption processes. Redox conditions affected mainly the As content that was higher under reducing conditions. Based on statistical analysis of experimental data, isotopic analysis of groundwaters and local hydrogeologic conditions the origin of As was attributed to geogenic factors.