Abstract: Mercury (Hg) is the unique heavy metal transported with gaseous elemental Hg (GEM). Atmospheric Hg can be transported for a long distance, which plays an important role in global Hg cycle. Because of global transportation and deposition, Hg pollution in the polar regions has been concerned. Studies found atmospheric Hg depletion events (AMDEs) in Arctic and Antarctic in 1995 and 2000, respectively. This phenomenon presented a new cycling knowledge of atmospheric Hg in extreme climate and environment. However, current knowledge on atmospheric Hg chemistry and transporting process in polar regions is still unclear. In this paper, the authors presented atmospheric Hg distribution and AMDEs mechanisms, re-emission and impact on organisms in polar regions based on recent years work and proposed an overview on future research in the field.

Key words: Wet deposition, Red tide, Changjiang River estuary, Nutrient element