Mercury leaching from forest soils to aquatic systems is expected to increase in the south of Sweden following the storm event 'Gudrun', which occurred in January 2005. Methylmercury (MeHg) is the most toxic form of mercury (Hg) in the environment. In most cases, methylmercury constitutes only a small proportion of the total mercury concentration in soil and water. However, methylmercury bioaccumulates in aquatic food chains and therefore nearly 100 percent of the mercury in fish can be in this toxic form. Methylmercury can damage the central nervous system and is particularly harmful to unborn foetuses. The Swedish National Food Administration (Livsmedelsverket) recommends pregnant and breastfeeding women not to consume freshwater fish like perch, pike and eel. Many lakes in Sweden have fish with elevated concentrations of mercury; therefore, preventing mercury from entering the aquatic system is of great importance.
Nyckelord: storm, increased mercury loads, aquatic systems
Författare: Sofie Hellsten, John Munthe, Therese Zetterberg
Publicerad i: Kungl. skogs- och lantbruksakademiens tidskrift, 2009. Nr 1, 2009, årgång 148, pp. 24-26