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A Holistic Perspective Is Needed To Ensure Success of Minamata Convention on Mercury Yan Lin,† Shuxiao Wang,*,‡ Eirik Hovland Steindal,§ Zuguang Wang,∥ Hans Fredrik Veiteberg Braaten,† Qingru Wu,‡ and Thorjørn Larssen† †
Norwegian Institute for Water Research, Oslo, 0349, Norway State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China § Norwegian Environment Agency, Oslo, 0661, Norway ∥ Renmin University of China, Beijing, 100872, China the increase of Hg volume in other overlooked flows. For example, there may be more sulfuric acid generated as byproduct by increasing number of nonferrous metal smelters which install acid plant to remove SO2, the flow of Hg in the sulfuric acid which may be sold to various downstream industries is completely overlooked by the current MC. Without a holistic perspective, the reduced Hg emission/ release from one article may end up in the articles with soft obligations or materials flows that are not covered by the MC. The potential consequences of this may undermine the overall performance of MC. We recently developed a tool to quantify the material flow of Hg for intentional use in products and manufacturing processes (related to Article 3 Hg supply and trade, Article 4 Hg used in products and Article 5 Hg used in manufacturing processes) which used China as a case study.4 We estimated that the total demand of Hg in 2011 in China was about 1272 tons, but we also found that a surprisingly high amount of Hg ended up as untraceable flow (∼200 tons) which may represent the biggest material flow of Hg into the environment in China. The volume of Hg in the untraceable flow is much bigger than Hg emission to air (∼60 tons) and releases into soil (∼35 tons) and water ercury (Hg) and its compounds can be transported (∼35 tons). Most of Hg in the untraceable flow exist as Hg globally in the environment and have adverse health impurities in byproducts or wastes. For example, HCl acid as a effects for both humans1and animals.2 To address this global 3 byproduct in vinyl chloride monomer (VCM) production environmental issue, the Minamata Convention on Mercury contains high amount of Hg, and the acid is sold to untraceable (MC) was agreed by 128 countries at the fifth session of the uses which are not covered by the MC at all. Landfill as the Intergovernmental Negotiating Committee (INC) in Geneva, second largest flow (∼160 tons) represents the single biggest Switzerland, on January 19, 2013. Thirty-five countries have pool of Hg in waste; this shows the importance of more ratified the MC as of December 2016, and the ratification concrete and firm obligations for Hg containing waste process is expected to start in the countries of the European management (Article 11). The tool was further developed to Union, which consists of twenty-eight member states, in 2017. incorporate unintentional Hg emissions (Article 8), releases The MC will then enter into force 90 days after it has been (Article 9) and waste flows (Article 11).5 The Chinese case ratified by 50 countries. study revealed that measures to reduce Hg emission to air may The MC includes different types of articles with individual lead to increasing flows of Hg in desulfurization gypsum and fly functions, among which the operational articles define the ash in coal fired power plants. The gypsum and fly ash, which obligations for parties (Articles 3−12). Figure 1 shows the contain approximately 184 tons of Hg, are used to produce timeline of MC firm obligations. However, articles regarding building materials, which causes 37 tons of Hg re-emitted to air Hg containing waste (Article 11) and contaminated sites in the process of production; this process is also not covered in (Article 12) have in general very soft wording by using, for the MC. example, “parties may” and “parties are encouraged to”. The current structure of MC has a weakness which overlooks the interconnections between different articles of MC. This means Received: December 13, 2016 the measures taken to comply with one MC article may lead to ‡
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© XXXX American Chemical Society
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DOI: 10.1021/acs.est.6b06309 Environ. Sci. Technol. XXXX, XXX, XXX−XXX
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Environmental Science & Technology
Figure 1. Implementation timeline for Minamata Convention firm obligations. The timeline setup is based on the assumption that MC will enter into force in 2017. Article 11 (Hg waste) and Article 12 (contaminated sites) contain soft obligations, and are therefore not shown in the figure. Note: A.3 means Article 3; BAT/BEP means best available techniques/best environmental practices; COP means Conference of the Parties.
In order to comply with MC, many countries are taking stringent measures to curb their Hg atmospheric emissions. For example, the current Hg emission limit (30 μg m−3) in flue gas from coal-fired power plants in both China and Germany is lenient compared to the U.S. standard (∼6 μg m−3 ; an approximation since the United States uses performance metrics (pounds per GWh) rather than concentration limits). Germany is currently developing a more stringent emission standard, and China may follow suit. If China’s coal fired power plants achieve 75% Hg removal efficiency in 2020 based on full implementation of MC obligations, an emission limit of 5 μg m−3 is realistic in 2020 and a further reduction to 3 μg m−3 limit in 2030 is achievable.6 The efforts to reduce Hg from being emitted to air will result in more Hg that is captured and stored in form of solid waste. As solid waste utilization and minimization is a general policy in many countries, much of the Hg in solid waste may potentially be re-emitted in the processes of utilization (see gypsum example above). It is therefore important to take precautionary measure to make sure the Hg that is captured is stabilized and stored in an environmentally sound manner; furthermore, secondary emissions and releases should also be considered by the MC in a holistic perspective when amendments are proposed in the implementation stage. A holistic perspective for Hg management is urgently needed when the MC parties are developing their National Implementation Plans (NIPs). Effective policy decisions for Hg control should consider the life cycle of Hg, including secondary Hg emissions and releases that are uncovered by the current MC. The policy decisions should also consider the interconnections between different MC articles and avoid shifting Hg from one environmental medium to another for which the MC is soft in phrasing the obligations, for example from atmospheric emission (Article 8) to contaminated sites (Article 12). An integrated Hg material flow track system based on the life cycle concept should be put on the agenda of NIP development. The United Nations Environment Programme’s Hg toolkit7 could serve as a starting point; parties with better knowledge of their Hg flows should consider expanding the toolkit to cover currently overlooked Hg flows and consider the overall reduction of Hg pollution.
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Shuxiao Wang: 0000-0003-3381-4767 Notes
The authors declare no competing financial interest.
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ACKNOWLEDGMENTS This study was supported by the Major State Basic Research Development Program of China (973 Program) (2013CB430001).
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REFERENCES
(1) Zahir, F.; Rizwi, S. J.; Haq, S. K.; Khan, R. H. Low dose mercury toxicity and human health. Environ. Toxicol. Pharmacol. 2005, 20 (2), 351−360. (2) Wolfe, M. F.; Schwarzbach, S.; Sulaiman, R. A. Effects of mercury on wildlife: A comprehensive review. Environ. Toxicol. Chem. 1998, 17 (2), 146−160. (3) Minamata Convention on Mercury website; http://www. mercuryconvention.org/. (4) Lin, Y.; Wang, S.; Wu, Q.; Larssen, T. Material Flow for the Intentional Use of Mercury in China. Environ. Sci. Technol. 2016, 50 (5), 2337−2344. (5) Hui, M.; Wu, Q.; Wang, S.; Liang, S.; Zhang, L.; Wang, F.; Lenzen, M.; Wang, Y.; Xu, L.; Lin, Z.; Yang, H.; Lin, Y.; Larssen, T.; Xu, M.; Hao, J. Mercury flows in China and global drivers. Environ. Sci. Technol. 2016, DOI: 10.1021/acs.est.6b04094. (6) Ancora, M. P.; Zhang, L.; Wang, S. X.; Schreifels, J. J.; Hao, J. M. Meeting Minamata: Cost-effective compliance options for atmospheric mercury control in Chinese coal-fired power plants. Energy Policy 2016, 88, 485−494. (7) Toolkit for Identification and Quantification of Mercury Releases; http://www.unep.org/chemicalsandwaste/Mercury/ ReportsandPublications/MercuryToolkit/tabid/4566/Default.aspx.
AUTHOR INFORMATION
Corresponding Author
*Phone: 86-10-62771466; fax: 86-10-62773650; e-mail:
[email protected]. ORCID
Yan Lin: 0000-0002-8746-3387 B
DOI: 10.1021/acs.est.6b06309 Environ. Sci. Technol. XXXX, XXX, XXX−XXX
