Mercury measurements at Cape Point, South Africa - an update on recent findings : highlighted local research

Mercury (Hg) is regarded as a highly toxic, heavy metal and is also considered as a global pollutant due to its long range transport and bio-accumulation in the aquatic nutrition chain, which is not fully understood yet. For this reason and also to initiate international legislation aimed at controlling the use of mercury, a European Union-funded Global Mercury Observing System (GMOS), in which the Cape Point Global Atmospheric Watch (GAW) station participated, was initiated in 2010. The South African Weather Service (SAWS) as well as the Council for Scientific and Industrial Research (CSIR) have been conducting mercury measurements at the Cape Point GAW station since 1995 and 2007, respectively. While SAWS focussed on the measurement of Gaseous Elemental Mercury (GEM) in air, the CSIR has carried out analyses of Total mercury (TotHg) in precipitation samples. The GEM measuring programme, which is ongoing, has led to several publications dealing with long-term trends, seasonal cycles, depletion events and continental emission estimates for Hg.