| Summary: | "The Global Mercury Assessment 2013 (GMA 2013) (AMAP/UNEP, 2013) was prepared in accordance with the request of the UNEP’s Governing Council (Decision 25/5 III, paragraph 36) to support negotiations on the development of the Minamata Convention on Mercury, a global treaty to reduce mercury pollution adopted by governments in October 2013. GMA 2013 covered a variety of aspects of the fate and transport of mercury in the environment including emissions to air and releases to the aquatic environment, dispersion and chemical transformations in the atmosphere and aquatic environment, and exchange fluxes between different environmental media. The assessment paid particular attention to the development of an up-to-date global inventory of anthropogenic mercury emissions. Evaluation of mercury pollution on a global scale was based on the analysis of available observational data and modelling results. The current report aims to update the information presented in section 3.6 of the Technical Background Report for the Global Mercury Assessment 2013 (AMAP/UNEP, 2013) with new model simulation results and focusing on an evaluation of mercury intercontinental transport and source attribution of mercury deposition. The character of mercury dispersion in the atmosphere and transport from one region to another is largely affected by the physicochemical properties of the atmospheric mercury species. Poorly soluble and relatively stable gaseous elemental mercury (GEM) can drift in the air for months providing transport of mercury mass between different regions of the planet. In contrast, oxidized mercury species – gaseous oxidized mercury (GOM) and particle bound mercury (PBM) – are easily removed from the air by precipitation scavenging or surface uptake (Selin, 2009; Travnikov, 2011; AMAP/UNEP, 2013). Therefore, levels of mercury deposition and its source apportionment in each region are determined by the magnitude and speciation of domestic emissions, emissions in other regions and by the oxidative capacity of the atmosphere ...
|
|---|