Heavy metal pollution of bottom sediments in Ise Bay.

Abstract

The horizontal and vertical distributions of chromium, zinc, copper, lead and nickel in the sediments in Ise Bay were determined. Judging from the results of the sedimentation rates determined by 210 Pb dating technique, the pollution of sediments by these heavy metals seemed to have been occurring since about 1960. The concentration of these heavy metals at each sampling station was constant in the deeper part of the vertical distribution. The constant value was taken as the background concentration at each station considering the sedimentation rate. The amounts of artificial accumulation of these heavy metals were estimated at each station by integrating values which exceeded the background concentrations. These values were 0-510 for chromium, 0-1700 for zinc, 0-760 for copper, 0-1200 for lead, and 0-160 for nickel in units of μg/cm2 respectively. Moreover they were higher at the head of the bay. From the horizontal distribution of these values, total amounts of artificial accumulation of heavy metals in Ise Bay were, respectively, found to be in tons, 1000 for chromium, 4800 for zinc, 1200 for copper, 1300 for lead, and 300 for niekel.