Accumulation of Heavy Metals in Oak Wood from Polluted Regions

Concentrations of ecotoxic heavy metals Cd and Pb and of essential heavy metals Cu and Zn were determined in annual growth rings from a polluted region of Konigstein (F.R.G.) and an unpolluted region of Valdivia (Rep. of Chile) by ditrerential pulse anodic stripping voltametry (DPASV). The radial distribution of the four metals investigated is similar in oaks from both regions. No significant differences in the average concentrations of the essential metals Cu and Zn in the oak tree rings from the two regions have been observed. For the toxic metals Cd and Pb, however, a significant increase of factor of 2 for Cd and of factor of 12 for Pb, respectively, has been found when the Konigstein region and the Valdivia region are compared. This evidences a sensible pollution of the Konigstein region by Pb, and to a lesser extent by Cd, since 1940 or earlier.