Application of a risk assessment method to Europe-wide geochemical baseline data

Abstract

The environmental risk, defined as the possibility of impairment of biotic or abiotic components of the environment, derived from geological sources was estimated for the whole of Europe. The assessment was based on data obtained from the Geochemical Atlas of Europe and included measured total concentrations of: Al, As, B, Cd, Cr, Cu, Ni, Pb, Se, Zn, Fe, Mn, Cl, NO 3 and SO 4 in stream water; As, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, V and Zn in topsoil; and As, Cd, Cr, Cu, Hg, Ni, Pb and Zn in stream and floodplain sediments. The number of sampling sites varied from 741 (stream water) to 847 (subsoil). The assessment method was based on the calculation of two-step environmental risk index values (I ER ) for individually analysed water, soil and sediment samples. Environmental risk quotients are first calculated for each analysed chemical element or compound that exceeds the limit for risk values, and their sum is then calculated. The risk at each site was defined and classified as negligible, low, medium, high, very high or extremely high. The results are presented as risk maps covering the 26 countries of Europe. Stream waters show a high to extremely high risk value in large areas of southern Finland and Sweden, and sporadically in Spain, southern Italy, the Netherlands, northern Germany and Denmark. Stream sediments show high risk values in Greece, Albania, Sardinia and northern Italy. The risk areas for floodplain sediment differ from those for stream sediment, with no high risk values in Sardinia, but instead in Belgium. The highest risk levels in topsoils were detected in Greece, Albania and northern Italy. The combination of all materials shows a medium-level risk throughout Europe and a high to extremely high risk in Greece, Albania, Sicily and Sardinia, and sporadically in Spain, Belgium and the Netherlands. The calculated maps delineate regions where high elevated concentrations pose a risk to the environment, or where the action limits for soil, sediment or water contamination should be revised using the high local baseline.