Distribution and Accumulation of Mercury in Sediments of Kaohsiung River Mouth, Taiwan

This study was conducted using the data collected in May 2009 to investigate and analyze mercury (Hg) contained in the surface sediments, and to evaluate the accumulation of Hg and the degree of its potential risk. The results show that samples collected at all monitoring stations near the mouth of Kaohsiung River contain 0.15–1.15 mg kg-1of Hg with average of 0.68±0.30 mg kg-1. The spatial distribution of Hg reveals that the Hg concentration is relatively high in the river mouth region, and gradually diminishes toward the harbor region. This indicates that upstream industrial and municipal wastewater discharges along the river bank are major sources of pollution. The accumulation factor and potential ecological risk index indicate that the sedimentation at Kaohsiung River mouth has the most serious degree of Hg accumulation and the highest ecological potential risk. Therefore, a strategy for effective controlling and managing Kaohsiung River upstream pollution needs to be immediately implemented in order to improve the sediment quality and alleviate the ecological risk.