Current and future levels of mercury atmospheric pollution on global scale

An assessment of current and future emissions, air concentrations and atmospheric deposition of mercury world-wide are presented on the basis of results obtained during the performance of the EU GMOS (Global Mercury Observation System) project. Emission estimates for mercury were prepared with the main goal of applying them in models to assess current (2013) and future (2035) air concentrations and atmospheric deposition of this contaminant. The artisanal and small- scale gold mining, as well as combustion of fossil fuels (mainly coal) for energy and heat production in power plants and in industrial and residential boilers are the major anthropogenic sources of Hg emissions to the atmosphere at present. These sources account for about 37 % and 25 % of the total anthropogenic Hg emissions globally, estimated to be about 2000 tonnes. The emissions in Asian countries, particularly in China and India dominate the total emissions of Hg. The current estimate of mercury emissions from natural processes (primary mercury emissions and re-emissions), including mercury depletion events, were estimated to be 5207 tonnes per year which represent nearly 70 % of the global mercury emission budget. Oceans are the most important sources (36 %) followed by biomass burning (9 %). A comparison of the 2035 anthropogenic emissions estimated for 3 different scenarios with current anthriopogenic emissions indicates a reduction of these emissions in 2035 up to 85 % for the best case scenario. Two global chemical transport models (GLEMOS and ECHMERIT) have been used for the evaluation of future Hg pollution levels considering future emission scenarios. Projections of future changes in Hg deposition on a global scale simulated by these models for three anthropogenic emissions scenarios of 2035 indicate a decrease of up to 50 % deposition in the Northern Hemisphere and up to 35 % in Southern Hemisphere for the best case scenario. The EU GMOS project has proved to be a very important research instrument for supporting, first the scientific justification for the Minamata Convention, and then monitoring of the implementation of targets of this Convention, as well as, the EU Mercury Strategy. This project provided the state-of-the art with regard to the development of the latest emission inventories for mercury, future emission scenarios, dispersion modelling of atmospheric Hg on global and regional scale, and source – receptor techniques for Hg emission apportionment on a global scale.</p

Mapping 1995 global anthropogenic emissions of mercury

This paper presents maps of anthropogenic Hg emissions worldwide within a 1degrees x 1degrees latitude/longitude grid system in 1995. As such, the paper is designed for modelers simulating the Hg transport within air masses and Hg deposition to aquatic and terrestrial ecosystems. Maps of total Hg emissions and its three main chemical species: elemental gaseous Hg. divalent gaseous Hg, and particle-associated Hg are presented. The main emissions occur in southeast Asia (particularly in China), South Africa, Central and Eastern Europe, and the Eastern United States. These are the regions where coal combustion is the main source of electricity and heat production. Waste incineration adds to these emissions in the Eastern United States. Emissions of total Hg and its three species are quite similar in terms of their (global) spatial distributions. They reflect the worldwide distribution of coal consumption in large power plants, industrial burners, and small combustion units, such as residential and commercial furnaces. (C) 2003 Elsevier Science Ltd. All rights reserved

Global anthropogenic mercury emission inventory for 2000

The paper reviews the current state of knowledge regarding global emissions of mercury and presents a new inventory of global emissions of mercury to the atmosphere from anthropogenic sources for the year 2000. The largest emissions of Hg to the global atmosphere occur from combustion of fossil fuels, mainly coal in utility, industrial, and residential boilers. As much as two-thirds of the total emission of ca. 2190 ton of Hg emitted from all anthropogenic sources worldwide in 2000 came from combustion of fossil fuels. Emissions of Hg from coal combustion are between one and two orders of magnitude higher than emissions from oil combustion, depending on the country. Various industrial processes account for additional 30% of Hg emissions from anthropogenic sources worldwide in 2000. Major contribution to emissions from this source category comes from gold production using Hg technology. The Asian countries contributed about 54% to the global Hg emission from anthropogenic sources in 2000, followed by Africa (18%) and Europe, including the European part of Russia (11%). China heads the list of the 10 countries with highest Hg emissions from anthropogenic activities. With more than 600 ton of Hg, China contributes about 28% to the global emissions of mercury. \ It is expected that future changes of Hg emissions from anthropogenic sources worldwide until the year 2020 should be within +/- 20% of the current estimates, although this assessment should be treated with great caution. Emission estimates for various continents presented in this paper were used to prepare global emission maps. These maps are presented in a companion paper (Wilson et al., 2005. Spatial distribution of global anthropogenic mercury atmospheric emissions. Atmospheric Environment, in this issue). (c) 2006 Elsevier Ltd. All rights reserved

Mapping the spatial distribution of global anthropogenic mercury atmospheric emission inventories

This paper describes the procedures employed to spatially distribute global inventories of anthropogenic emissions of mercury to the atmosphere, prepared by Pacyna, E.G., Pacyna, J.M., Steenhuisen, F., Wilson, S. [2006. Global anthropogenic mercury emission inventory for 2000. Atmospheric Environment, this issue, doi:10.1016/j.atmosenv. 2006.03.041], and briefly discusses the results of this work. A new spatially distributed global emission inventory for the (nominal) year 2000, and a revised version of the 1995 inventory are presented. Emissions estimates for total mercury and major species groups are distributed within latitude/longitude-based grids with a resolution of 1 x 1 and 0.5 x 0.5 degrees. A key component in the spatial distribution procedure is the use of population distribution as a surrogate parameter to distribute emissions from sources that cannot be accurately geographically located. In this connection, new gridded population datasets were prepared, based on the CEISIN GPW3 datasets (CIESIN, 2004. Gridded Population of the World (GPW), Version 3. Center for International Earth Science Information Network (CIESIN), Columbia University and Centro Internacional de Agricultura Tropical (CIAT). GPW3 data are available at http://beta.sedac.ciesin.columbia.edu/gpw/ index.jsp). The spatially distributed emissions inventories and population datasets prepared in the course of this work are available on the Internet at www.amap.no/Resources/HgEmissions/ (c) 2006 Elsevier Ltd. All rights reserved.</p

Global Sources and Pathways of Mercury in the Context of Human Health

This paper reviews information from the existing literature and the EU GMOS (Global Mercury Observation System) project to assess the current scientific knowledge on global mercury releases into the atmosphere, on global atmospheric transport and deposition, and on the linkage between environmental contamination and potential impacts on human health. The review concludes that assessment of global sources and pathways of mercury in the context of human health is important for being able to monitor the effects from implementation of the Minamata Convention targets, although new research is needed on the improvement of emission inventory data, the chemical and physical behaviour of mercury in the atmosphere, the improvement of monitoring network data, predictions of future emissions and speciation, and on the subsequent effects on the environment, human health, as well as the economic costs and benefits of reducing these aspects

Towards a global historical emission inventory for selected PCB congeners – a mass balance approach. I. Global production and consumption.

Information on the historical global production and consumption of polychlorinated biphenyls (PCBs) is urgently needed for estimating PCB fluxes to the environment and for interpreting global contamination patterns by these pollutants. This study presents the methodology, principal uncertainties and selected results from an inventory, aiming to quantify the global production and consumption of total PCBs as well as 22 PCB congeners. The available data on the historical production of PCBs and the chemical composition of various technical mixtures have been compiled from the literature. For some producers with less detailed information, the production of individual PCB constituents has been estimated to derive a global estimate for individual homologues and selected congeners. Information on imports, exports and consumption, as well as restrictions on production and imports, has further been compiled for individual countries. These data, along with assumptions on the trade between countries and regions, have been utilised to derive an estimate of the global historical consumption pattern. Although there are substantial uncertainties involved in these estimates, important aspects governing the large scale temporal and spatial patterns are most likely captured in these estimates. In particular, the information on imports and exports for the principal users of PCBs around the time of peak production is considered to be fairly reliable. The estimates account for a reported historical global production of 1.3 million t PCBs, more than 70% of which are tri-, tetra- and pentachlorinated biphenyls. The results further suggest that almost 97% of the global historical use of PCBs have occurred in the Northern Hemisphere

Towards a global historical emission inventory for selected PCB congeners – a mass balance approach. II. Emissions.

Accurate and complete data on the global atmospheric releases (emissions) of individual PCB congeners are essential to study source–receptor relationships and contamination patterns in remote areas, such as the Arctic. Information on the anthropogenic emissions may also be useful for the interpretation of measured levels and patterns of atmospheric PCBs. This study builds upon an accompanying paper, presenting an estimate of the global historical production and consumption of 22 PCB congeners (Breivik K, Sweetman A, Pacyna JM, Jones KC. Towards a global historical emission inventory for selected PCB congeners — a mass balance approach. 1. Global production and consumption. Sci Total Environ, submitted). Here, a dynamic mass balance model is elaborated, parameterised and applied in an attempt to estimate the historical anthropogenic emissions as a direct result of the widespread usage of PCBs for a period of 70 years. This paper presents details of the mass balance approach, along with a discussion of the major uncertainties. It is shown that the diversity of historical usage, disposal and accidental release pathways makes it an extremely difficult task to bridge the gap between consumption and emissions, resulting in an equally complex and diverse true emission pattern. These results may therefore at best represent order-of-magnitude estimates only and the results in absolute terms should be treated with great caution. In spite of these uncertainties, useful information can still be gained. The results suggest that temperature is an extremely important factor controlling both emission amount as well as the emission pattern of PCBs. In particular, the emissions of the more chlorinated (and persistent) PCB congeners appear to be significantly influenced by (uncontrolled) high-temperature sources. As a consequence, it may prove warranted to undertake further measures to avoid that contaminated materials are subject to elevated temperatures and uncontrolled burning. It is furthermore suggested that efforts should be directed towards a better characterisation and quantification of these potentially important release pathways. In addition, alternative approaches to bridge the gap between consumption and emissions in quantitative terms should be considered in order to improve these estimates