Historical trend in heavy metal pollution in core sediments from the Masan Bay, Korea

The spatiotemporal distribution and their mass accumulation rate (MAR) of heavy metals were investigated to evaluate the time-dependent historical trends of heavy metal concentration. The three short cores used for this study were collected from the catchment area (MS-PC5, 60 cm length), the central part (MS-PC4, 40 cm length) and the offshore (MS-PC2, 60 cm length) of the Masan Bay, Korea. The concentration of heavy metals (Co, Ni, Cu, Zn, Cr and Pb) in catchment area is as much as 1.5-2 times higher than central part of the Bay, and about 2 times higher than offshore area approximately. In particular, MAR of metals (Cu, Zn and Pb) show clear spatiotemporal variation, so that MAR's of heavy metal may provide more accurate information in evaluating the degree of pollution. Temporally, the heavy metal concentration had been increased since the late 1970s, but it seems to decrease again since the 2004 yr in catchment area. This may came from concentrated efforts for the government to reduce industrial waste release. (C) 2015 Elsevier Ltd. All rights reserved.