The use of cedar bark in the study of heavy metal contamination in the Nagatsuta area, Japan

Analysis of cedar bark samples and deposition samples in the Nagatsuta area, Yokohama, Japan, shows that there is contamination by heavy metals, Cr, Zn, Cu and Pb, as indicated by enrichment factor values, particularly in the parts adjacent to the highway. It is suggested that motor traffic is the major source. The soil is enriched with respect to these heavy metals by a factor of 2 to 361. It is suggested that this contamination occurs primarily by aerial deposition. A correlation between heavy metal levels and distance from the road was established and a power regression analysis, ln Y = a + B ln X, gave a fit(p < 0.001) indicating an exponential decay function.