Spatial and temporal variations of mercury in sediments from Victoria Harbour, Hong Kong

摘要

Mercury (Hg) is listed as a priority pollutant by many international agencies because of its persistence, bioaccu-mulation, and toxicity (PBT) in the environment. With the development of agriculture and industry, Hg has been extensively used in the manufacture of pesticides, fungicides, electrical goods, paper, batteries and other items, which has caused large amounts of Hg to be emitted to the environment. The ocean is an important sink in the global Hg cycling. In recent years, the biogeochemistry of Hg in coastal and estuarial environments has received particular attention (Mason et al., 1996; Horvat et al., 1999; Hines et al., 2000; Conaway et al., 2003). Mercury enters the marine environment through various pathways, including waste-water discharges and atmospheric deposition. Two important processes are involved in the cycling of Hg in coastal and ocean environments. The first is the methylation of inorganic Hg to organomercury ia water and sediment systems. This will affect the toxicity and bioavailability of Hg. The second is the bioaccumulation of Hg in aquatic organisms through the food chain. This will result in higher methylmercury (MeHg) concentrations in seafood, and may ultimately threaten human health.