ABSTRACT
Knowledge of the speciation of mercury (Hg) is important, particularly in gaining an understanding of its environmental impacts. The main organic mercury species are alkylmercury compounds, particularly monomethylmercury and dimethylmercury. The atmosphere is a more important reservoir of mercury than of other metals because of its volatility. In mineralised areas, pedogenesis on mercury-containing rocks introduces mercury-bearing mineral particles into soils. Concentrations of mercury in lake sediments and peat cores provide evidence of the increased deposition of mercury from the atmosphere since the Industrial Revolution and monitoring in the Arctic indicates that mercury continues to be transported widely in the global atmosphere. Fossil fuel combustion remains a significant source of mercury emissions, despite a gradual decrease over recent decades that has resulted from better pollution control technologies and tighter regulations. Mercury has toxicological effects on various types of organisms, mainly because of its bioaccumulation and biomagnification in the food chain.
