Elsevier

Atmospheric Environment

Volume 40, Issue 22, July 2006, Pages 4048-4063
Atmospheric Environment

Global anthropogenic mercury emission inventory for 2000

https://doi.org/10.1016/j.atmosenv.2006.03.041Get rights and content

Abstract

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).

Introduction

During the past 5 years considerable progress has been made in better understanding sources, transport routes and behavior of mercury in global environment (e.g. presentation of recent research results at the Seventh International Conference on Mercury as a Global Pollutant in Ljubljana, Slovenia in 2004—http://congress.cd-cc.si/icmgp04). A substantial body of information has been collected on sources and emissions of mercury in Europe through European Union (EU) funded research projects, including the following: MAMCS (Mediterranean Atmospheric Mercury Cycle System: www.eloisegroup.org), MOE (Mercury Over Europe: www.eloisegroup.org), MERCYMS (An Integrated Approach to Assess the Mercury Cycle into the Mediterranean Basin: www.iia-cnr.unical.it/MERCYMS/project.htm), and ESPREME (Estimation of Willingness-to-pay to Reduce Risks of Exposure to Heavy Metals and Cost–benefit Analysis for Reducing Heavy Metals Occurrence in Europe: http://espreme.ier.uni-stuttgart.de).

Improved information on emissions, particularly emissions in Europe and North America has contributed to further progress in assessment of regional impacts of mercury on the terrestrial and aquatic environment. Major international activity to assess source–receptor relationships for mercury in the environment has been carried out within the UN Economic Commission for Europe (UN ECE) Convention on Long-range Transboundary Air Pollution Transmission (LRTAP) (www.unece.org). The aim of this activity is to assess major sources of mercury emissions in Europe, the environmental impact of these emissions, and eventually the emission reductions. There are also at least three other conventions in Europe working on the basis of international agreements which aim to reduce the environmental inputs of various pollutants, including mercury to the marine environment. These include: the Oslo and Paris Commissions (OSPAR) program on reduction of land-based pollutants transported to the North Sea and the North-East Atlantic (www.ospar.org), and the regional programs for the Baltic Sea (Helsinki Commission—HELCOM) (www.helcom.fi) and the Mediterranean Sea (Barcelona Convention). All the above-mentioned Conventions collect information on emissions from their member states. In addition, these conventions also benefit from the European emission inventory activities carried out under the above-mentioned EU funded research projects.

Policy makers in Europe have also taken the advantage of improved information on emissions. Following the preparation of a Position Paper on Ambient Air Pollution by Mercury (http://europa.eu.int/comm/environment/air/background.htm#mercury see also EU 2001), the EU adopted the European Mercury Strategy (http://europa.eu.int/comm/environment/chemicals/mercury), the EU Community Strategy Concerning Mercury.

The US Environmental Protection Agency's (EPA's) Office of Research and Development (ORD) has also developed a Mercury Research Strategy. This strategy guided ORD's mercury research program during the period 2001–2005. The Mercury Research Strategy addresses the human health and ecological risks posed by mercury and methylmercury, and concluded that mercury needs to be considered at local, regional, and global scales. It identified the key scientific questions of greatest importance to the Agency, and a research program to address these (http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=20853).

There has also been improvement in emission inventory activities in other regions of the world. The Arctic Council's Action Plan to Eliminate Pollution of the Arctic (ACAP) Mercury Project has examined emission inventories in the Arctic countries, including Canada, Denmark, Finland, Iceland, Norway, the Russian Federation, Sweden and the United States (ACAP, 2005a). On the basis of this, the ACAP has reviewed possibilities for the reduction of atmospheric mercury emissions in these countries. A detailed assessment of mercury releases from the Russian Federation was also part of the ACAP (ACAP, 2005b). Reports from this project are available on http://www.mst.dk/homepage/default.asp?Sub=http://www.mst.dk/udgiv/publications/2005/87-7614-515-8/html/default_eng.htm.

The International Joint Commission (IJC) in North America, largely through its International Air Quality Advisory Board and the North American Commission for Environmental Cooperation (CEC) have also recognized the importance of Hg in contaminating the environment (e.g. IJC, 2003). Already in the 1990s a number of initiatives were organized in order to improve the understanding of emissions of Hg and other persistent toxic substances. A mercury task force was also established recommending further reductions in anthropogenic mercury emissions, among other activities.

Some industries have established programs aiming at the reduction of mercury releases to the environment, e.g. the chlor-alkali industry (as represented by EuroChlor, www.eurochlor.org), various branches of the non-ferrous metal smelting industry, and the electric power generation industry.

In issuing the Clean Air Mercury Ruling in March 2005, the US administration hoped to ease health concerns about mercury from coal-fired power plants. The White House enacted a “cap and trade” approach to reduce emissions of the element nationwide by about 20% in five years and 70% by 2018.

Finally, in 2002, the Governing Council of UNEP initiated a global assessment of mercury and mercury compounds, by UNEP in cooperation with other members of the Inter-Organization Programme for the Sound Management of Chemicals (IOMC). The report describing the results of the UNEP global mercury assessment is available electronically from the following website: http://www.chem.unep.ch/mercury/Report/Final%20Assessment%20report.htm.

Sources of Hg contamination worldwide have become a subject of increasing interest to the general public. One of the most prominent publication was presented in the Wall Street Journal (WSJ) at the end of 2004 where emissions and migration of mercury on global scale are discussed as a hidden cost of China's growth (Pottinger et al., 2004).

The purpose of this paper is to review the current state of knowledge regarding global emissions of mercury and to present a new inventory of global emissions of mercury to the atmosphere from anthropogenic sources for the year 2000. The authors of this paper have been involved in the emission inventorization work within most of the above-mentioned programs and conventions. The inventory presented in this paper has been prepared on the basis of information obtained during the course of this work in combination with the authors’ independent estimates. The goal was to bring together currently available information on emission of mercury to the atmosphere in 2000 worldwide. In this way, an update of the author's earlier work on the 1995 global anthropogenic mercury emissions inventory (Pacyna et al., 2003) has been made. An attempt is also made to address the important question of future emissions of Hg to the atmosphere.

The information presented in this paper should be useful for policy makers on a regional and global scale, proposing various strategies for Hg emission control. The general public may find in the paper scientifically based information on the importance of various emission sources in polluting the global atmosphere by Hg, together with information about historical and future trends of this pollution. A companion paper in this issue presents the results of an exercise to map the global emission of Hg. This information is urgently needed by modelers studying transport and atmospheric deposition of mercury on a global scale.

Section snippets

Methodology of emission estimates

Two approaches were used for the calculation of global anthropogenic emissions of mercury in the reference year 2000:

  • collection of emission data from countries where such data were estimated by national emission experts or reported to international programs and conventions, and

  • estimates of emissions on the basis of emission factors and statistical data on the production of industrial goods and/or the consumption of raw materials. These estimates were carried out by the authors of this paper for

Estimates of total mercury emissions in 2000

Mercury emissions for the year 2000 were estimated for the following source categories in individual countries of the world:

  • combustion of coal in utility, industrial, commercial, and residential boilers,

  • oil product combustion in utility, industrial, commercial, and residential boilers,

  • cement production in wet and dry rotary kilns,

  • primary and secondary lead production,

  • primary and secondary zinc production,

  • pig iron and steel production,

  • caustic soda production,

  • mercury production,

  • gold production,

Chemical species of mercury emitted to the atmosphere

Information on the chemical speciation of mercury emitted from various sources is important for the assessment of environmental and human health risks and effects, as well as description of mercury transport, fate, and behavior in the environment. Atmospheric and more general environmental chemistry of mercury is also very much dependent on the chemical and physical speciation of the element in during its emission.

The first assessment of chemical speciation in the Hg emissions to the global

Spatial distribution

Emission maps are a topic of a companion paper (Wilson et al., 2005). These maps were prepared on the basis of information on emissions and geographical location of point sources and the emissions and location of area sources worldwide. The following section of this paper presents an overview of countries and regions/continents with largest total Hg emissions in 2000; 1999 emission data were used for the United States as no 2000 national inventory for this country was available to the authors.

Historical trends and future projections of global Hg emissions

The authors have produced global emission inventories for Hg from anthropogenic sources for various reference years in the past (Pacyna and Pacyna, 2002; Pacyna et al., 2003). The same estimation procedures, based on emission factors and statistical data on the production of industrial goods and the consumption of raw materials have been used. It should be noted, however, that the procedure used to estimate emissions from Russia was improved in the case of the 2000 estimates for this country.

Comparison of emission estimates for anthropogenic and natural sources on a global scale

Natural sources can be an important contributor to the total budgets of atmospheric mercury at the local, regional and global scale. Therefore estimates of emissions from these sources are very important for better understating the fate and effects of mercury on the environment, as well as for development of policies to reduce these impacts. Emission estimates for natural sources are, however, very difficult to assess and even to define. It is not intended here to discuss in detail estimates

Final comments

Complete and accurate Hg emissions estimates are needed for both policy-makers making science-based policy decisions and scientists studying the fate and effects of this element in the environment. Global Hg emission data form the basis for these studies and policy making on a global scale. However, these data are still limited in the literature. More estimates are clearly needed to provide solid justification for global Hg emissions estimate and contribution from various sources to this

Acknowledgments

This work presented in this paper has been carried out with the financial support from the EU project ESPREME (Contract No. SSPI-CT2003-502527) and from the Arctic Monitoring and Assessment Programme (AMAP). The authors are grateful to the European Commission and AMAP for this support.

We are also grateful to our colleagues working on the ESPREME project, including Dr. J. Fudala, Prof. S. Hlawiczka, and Mrs. E. Jastrzab Strzelecka of the Institute for Ecology of Industrial Areas in Katowice,

References (23)

  • J.M. Pacyna et al.

    Mapping 1995 global anthropogenic emissions of mercury

    Atmospheric Environment

    (2003)
  • ACAP, 2005a. Arctic mercury releases assessment. Reduction of atmospheric mercury releases from Arctic states. The...
  • ACAP, 2005b. Assessment of mercury releases from the Russian Federation. The Arctic Council Action Plan (ACAP) to...
  • Akers, D., Dospoy, R., Raleigh, C., 1993. The effect of coal cleaning on trace elements. Development of algorithms....
  • EU, 2001. Ambient air pollution by mercury (Hg). Position paper. The European Commission Report,...
  • IJC, 2003. Addressing atmospheric mercury: science and policy. The 2001 Workshop Proceedings. The International Air...
  • P. Maxson

    Mercury flows in Europe and the world: the impact of decommissioned chlor-alkali plants

  • MRI, 1993. Locating and estimating air emissions from sources of mercury and mercury compounds. Midwest Research...
  • Munthe, J., 2005. Private...
  • NAPAP, 1990. Technologies and other measures for controlling emissions: performance, costs, and applicability. National...
  • J.O. Nriagu

    A global assessment of natural sources of atmospheric trace metals

    Nature

    (1989)
  • Cited by (851)

    View all citing articles on Scopus
    View full text