Contamination and Potential Toxicity of Mercury in the Sediments of Salt River Mouth, Taiwan

This study was conducted using the data collected at the mouth of Salt River 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 Salt River contain 0.23-2.12 mg kg(-1) of Hg with average of 1.01+/-0.52 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 Salt River mouth has the most serious degree of Hg accumulation and the highest ecological potential risk. Therefore, a strategy for effective controlling and managing Salt River upstream pollution needs to be immediately implemented in order to improve the sediment quality and alleviate the ecological risk.