都内公園土壌中重金属濃度の相関関係

抄録

The concentrations of heavy metals (V, Mn, Co, Cu, Zn, Cd, Ba, in addition to Pb which was reported elsewhere) in surface soil samples collected from 31 public playgrounds in a ward in Tokyo were determined by ICP mass spectrometry after HNO₃/HF/HClO₄ digestion. Mean concentrations of all metals but Ba exceeded the levels of uncontaminated soils in Japan reported in the previous literature indicating the presence of soil pollution. The exposure to V via direct soil ingestion was estimated to contribute more than that via dietary intake; however, it was not serious enough to warrant immediate attention. For other metals, dietary exposure accounted much more than soil ingestion. There were strong positive correlations between metal concentrations in the soil samples, particularly between V and Mn (r=0.97), V and Co (r=0.95), Pb and Cu (r=0.75), or Pb and Zn (r=0.84). These correlations suggested that the metals, to a certain extent, shared common pollution source.