Local analysis of trace elements and lead isotope ratios in bark and bark pockets by laser ablation/ICP-MS

Recently, environmental pollution has become one of the most serious proble ms for human life. It has become very important to consider and evaluate en vironmental pollution from longterm perspectives. The bark and bark pockets of trees were used in this study, because these samples are influenced by air pollutants and can be used as an indicator of environmental pollution. Because the bark pocket samples were very small, the conventional sample di gestion procedures could not be applied. Therefore, laser ablation/inslucti vely coupled plasma mass spectrometry (LA/ICP-MS) was used for the determin ation from major to trace elements in bark and bark pocket samples in this study. From the result, it was found that the concentrations of hazardous e lements, such as Sb, Pb, and Se, in bark were from a few to 100-fold higher compared to those in bark pocket produced 140 years ago. Moreover, Pb isot ope ratio measurements were conducted in this study. It was also found that the Pb isotope ratios were different between bark and bark pockets that pr oduced 70 years ago. The long-term trends of air pollution from Pb were con sidered based on these results.