Epsilon Open Archive

Abstract

Input/output budgets for cadmium (Cd), lead (Pb) and mercury (Hg) in the years 1997 monitored and determined for 14 small forest-covered catchments across Europe as part of the Integrated Monitoring program on the effects of long-range pollutants on ecosystems. Metal inputs were considered to derive from bulk deposition, throughfall and litterfall. Outputs were estimated from run-off values. Litterfall plus throughfall was taken as a measure of the total deposition of Pb and Hg (wet+dry) on the basis of evidence suggesting that, for these metals, internal circulation is negligible. The same is not true for Cd. Excluding a few sites with high discharge, between 74 and 94 % of the input Pb was retained within the catchments; significant Cd retention was also observed. High losses of Pb (>1.4 mgm (>0.15 mgm Central European sites with high water discharge. All other sites had outputs below or equal to 0.36 and 0.06 mgm Almost complete retention of Hg, 86 was reported in the Swedish sites. These high levels of metal retention were maintained even in the face of recent dramatic reductions in pollutant loads.–2011 were−2year−1) and Cd−2year−1) were observed in two mountainous−2year−1, respectively, for the two metals.–99 % of input,