Trace metal concentrations in the water of small lakes, Finland

Concentrations of metals (Cd, Pb, Ni, Cu, Zn, Mn, Al and Fe) were measured in 256 lakes in 1987 as part of a nationwide acidification survey. Concentrations generally followed the pattern of atmospheric deposition observed in snowpack and moss chemistry. The lakes were separated into groups according to the same level of metal deposition using maps of metal concentration in forest moss. Metal concentrations in lakes were most significantly correlated to lakewater acidity and to the concentration of organic C. In a stepwise regression analysis, these two variables, together with a few catchment characteristics, accounted for ~70% of the variation of Fe and Al, and from 20 to 50% of the variation of the other metals. Copper concentration in lakes was significantly explained by the regional Cu concentration in the fine fraction of till.