Category Archives: Noelle Selin



The Minamata Convention will be signed this week in Kumamoto, Japan. Stay tuned to the Mercury Science and Policy at MIT blog for real-time updates from the preparatory meeting and the diplomatic conference.

If you’re interested in some of the background on the convention, check out the issue overview posts that the MIT Mercury team posted during the final negotiating session back in January. Also, you can follow us at our twitter account @MITMercury and #MITMercury.


Will the new global mercury treaty be effective?

After four years of negotiations, delegates from more than 140 countries met last January to finalize the first global treaty to mitigate and prevent mercury pollution, the Minamata Convention. A new paper out from MIT Mercury looks at what the impact of the treaty will be. The bottom line? Globally, the treaty should avoid the future mercury increases that would otherwise occur but more aggressive action would be needed to decrease concentrations. Also, new science and analysis is needed to help policy-makers figure out the reason for environmental mercury changes. Read more at MIT News: Will the new global mercury treaty be effective? – MIT News Office.

The new paper, in Environmental Toxicology and Chemistry, is available here.

Mercury NOMADSS travel to Smyrna, TN!

Greetings from sunny Smyrna, TN, where for the last few weeks we (Noelle Selin, Amanda Giang and Shaojie Song) have been participating in a mission to measure mercury and other pollutants in the atmosphere. NOMADSS is the title of the airplane-based campaign, which stands for “Nitrogen, Oxidants, Mercury and Aerosol Distributions, Sources and Sinks.” It’s part of the larger Southeast Atmosphere study that’s investigating air quality in the southeast U.S. this summer. We are using our models to predict where we’re likely to find pollution, and to interpret data from the last several days to guide planning.

If you’re interested in following all of the science going on this summer, check out the Southeast Atmosphere Study home page, follow @SAS_Operations on twitter. There’s also a great blog on another component of the Southeast Atmosphere Study, the Southern Oxidant and Aerosol Study. Stay tuned for further updates from the field!

For mercury-specific updates, stay tuned to #MITMercury.


Minimata Convention: What happened?

MIT Mercury team, Saturday morning celebrating negotiation conclusion!

MIT Mercury team, Saturday morning, tired but celebrating the negotiation conclusion! L-R: Ellen Czaika, Philip Wolfe, Bethanie Edwards, Amanda Giang, Julie van der Hoop, Mark Staples, Noelle Selin

Early in the morning, at 7 AM on Saturday, January 19 in Geneva, 140 countries agreed to adopt a new, global treaty on mercury. The Convention will be signed in early October in Kumamoto, Japan, and will be called the Minimata Convention, in recognition of the city in which methylmercury poisoning was identified in the 1950s.

Over the past week, we’ve covered many of the outstanding issues in the negotiations. In this post, I’ll give a brief roundup of some of the major areas of agreement. Over the next week, the teams that covered each issue will provide some more detail about the specifics in the final agreement. In addition, we’ll all be posting our individual reflections on the events of the week.

Mercury Supply, Trade and Waste

The major agreement reached in the area of mercury supply is that countries must eliminate existing primary mercury mining fifteen years after becoming a party to the Convention. New primary mining is not allowed. During the fifteen-year transition period, mercury from primary mining can only be used in certain products and processes allowed by the Convention.

A prior informed consent procedure also applies to the export of mercury.Parties must manage mercury waste in an environmentally sound manner, taking into account the guidelines of the Basel Convention.  See our earlier overview of supply and trade and waste issues for more background on these issues.

Products and Processes

The Convention phases out the manufacture, import and export of several mercury-added products by 2020. Examples include thermometers and barometers, cosmetics with mercury content above 1 part per million including skin lightening soaps, pesticides, certain lamps with high mercury content, and most mercury-containing batteries. The use of mercury-containing dental amalgam is to be phased down, with no particular date attached.

For processes, the use of mercury in chlor-alkali production is to be phased out by 2025, and in acetaldehyde production by 2018. Parties to the Convention may request exemptions from these requirements for an additional five years, with exemptions renewable once by the Conference of the Parties. For more background on products and processes, see the guest post by Hannah Horowitz on mercury in unexpected products and our background post.

Artisanal and Small-Scale Gold Mining (ASGM)

Parties with artisanal and small-scale gold mining (ASGM) are required to reduce, and where feasible eliminate, the use of mercury and releases to the environment from this activity. National plans to address this issue are required for parties that have significant ASGM mercury use. For more on the concerns about ASGM, see our issue overview.


The Minimata Convention has a dedicated section devoted to health aspects, which negotiators referred to as precedent-setting for a multilateral environmental agreement. The section encourages the promotion of activities to help populations at risk of adverse mercury health effects, and the cooperation and exchange of information with the World Health Organization, the International Labour Organization and other intergovernmental organizations. For more on the health effects of mercury, see our earlier post.

Emissions and Releases

The agreement has similar but distinct requirements for mercury emissions to air versus releases to land and water. In both cases, Parties may develop national goals, must prepare inventories, and must take some measures of control. For air emissions, the treaty identifies relevant sources as: coal-fired plants and boilers, non-ferrous metal mining activities, waste incineration, and cement production.

The agreement distinguishes between new and existing emissions sources. For new relevant sources, Parties must apply Best Available Techniques (BAT) and Best Environmental Practices (BEP) within five years of the Convention’s entry into force. For existing sources to air, parties have ten years to act, and can choose between applying goals, emissions limits, BAT/BEP, multi-pollutant control options, and other measures that reduce mercury. A similar menu of options is available for releases to land and water. Earlier, we covered the technologies that are available to control mercury emissions and some of their co-benefits and also wrote an issue overview. 

Financial Mechanism

The financial mechanism for the Convention includes two elements: the Global Environment Facility (GEF) trust fund, and a specific international programme to support capacity-building and technical assistance. The GEF is to provide new resources to meet implementation costs, guided by the Conference of the Parties to the Minimata Convention. The programme will be operated by the Conference of Parties, hosted by an existing institution and consisting of voluntary contributions.  For more details and background about the importance of financial and technical assistance, see our issue overview.


Where in the World is Mercury? Part 2: Ocean and Fish

By: Noelle Selin

Our previous posts have addressed mercury in the atmosphere, global reservoirs such as oceans and soils, fish and human hair. Since oceans and fish are so important to global mercury exposure, I thought it would be useful to highlight sources of more information about mercury concentrations there. Two recent major studies have been released looking at the mercury problem in aquatic systems. Both of these are being presented at INC-5.

The Biodiversity Research Institute and IPEN, a non-governmental organization involved in the negotiations, have collected worldwide data on so-called “hotspots” of mercury concentrations in fish and human hair samples. The report, available here, found that mercury contamination is ubiquitous in marine and freshwater systems along the world. The report compares fish mercury concentrations from around the world to U.S. EPA human health advisory guidelines. Depending on the country, between 43 to 100% of fish sampled exceeded guidelines; in Japan and Uruguay, concentrations were so high that no consumption was recommended. These guidelines are for one fish mean per month.

From BRI-IPEN report: % of fish samples above health thresholds

Look for Alice Alpert’s interview with Biodiversity Research Institute’s David Evers, who’s here in Geneva, to be posted soon on our blog.

Another key report came out of the Coastal and Marine Mercury Ecosystem Research Collaborative (C-MERC), brought together by the Toxic Metals Superfund Research Program at Dartmouth College. The report analyzed and synthesized the current science on mercury sources  in seafood, and explored ecosystem responses to potential emissions controls.

The report found that mercury pollution is on the rise. In response to emissions controls, methylmercury in open ocean fish would only begin to decrease within several years to decades, while fish in coastal systems could respond over many decades to centuries. In other words, these effects are very long lasting. An interview with Celia Chen, who co-authored the report, was conducted here at INC-5 by Amanda Giang and is posted below.

Forms of Mercury: Beyond the Silver Liquid

By: Noelle Selin

It seems a bit strange to hear delegates at an intergovernmental negotiation on mercury discussing how to define “mercury.” Doesn’t the periodic table define it? Not only is mercury an element, but it’s also the reason why we’re all here in Geneva to negotiate an agreement. But defining exactly what is being addressed by the treaty is a critical issue – especially since mercury exists in many different forms in the environment.

Mercury in its liquid form is most  familiar.

Mercury in its liquid form is most familiar.

The chair’s draft treaty text defines mercury as “elemental mercury”. Elemental mercury is the liquid substance that many people recall when they think of mercury. In the atmosphere, most mercury is in elemental form, but it is a gas rather than a liquid. Elemental mercury is often abbreviated as Hg(0).

Another definition in the convention is “mercury compounds,” which addresses forms of mercury other than elemental mercury. What other forms of mercury are there?

Methylmercury is of particular concern, because it is the toxic form of mercury found in fish. Mercury is converted to methylmercury in aquatic systems by sulfate- and iron-reducing bacteria. For more on the health effects of methylmercury, see our earlier post.

In addition to elemental mercury, atmospheric mercury also exists as divalent mercury. Divalent mercury, also referred to as Hg(II), is formed when elemental mercury has undergone a chemical reaction of oxidation, losing electrons. In the atmosphere, Hg(II) can bind with other elements, but scientists don’t yet know exactly what these forms are. The chemical form of Hg(II) in the atmosphere could be HgCl2, HgBr2, Hg(OH)2, or HgO. The leading candidate is HgCl2, [give the name for this?], but this is a topic of current research. When Hg(II) is measured in the atmosphere, it is referred to as reactive gaseous mercury. Forms of mercury found in the ocean include both Hg(0) and Hg(II).

Emissions from different sources release different forms of mercury. Emissions from the surface ocean and land are in the form of elemental mercury. Anthropogenic sources, such as coal power plants, can release both Hg(0) and Hg(II). This is important because the two forms of mercury have different environmental behavior.

Hg(0) lasts for a long time in the atmosphere (6 months to a year), meaning that it circulates around the globe and can travel long distances. Hg(II) can easily rain or settle out after only a few days in the atmosphere, which means it is more likely to enter the environment nearby its source. Thus, reducing Hg(II) emissions will have important local benefits, compared with reducing Hg(0), which has important global benefits.

The behavior of mercury in the environment, however, is complex. Thus, we need to use computer models [pdf] to determine how mercury changes form and travels after it is emitted. These models use the chemical and physical properties of mercury in its various forms to estimate where mercury will travel over time. Mercury deposited to the environment as Hg(II) can return to the atmosphere as Hg(0). Additionally, Hg(0) can react (oxidize) to form Hg(II) in the atmosphere, and Hg(II) can then reduce back to Hg(0). In other words, mercury can change its form. This can occur anywhere in the atmosphere, even when it is being released from power plant plumes [pdf]. Ultimately, all mercury released continues to cycle through the environment for centuries, contributing to the global mercury legacy.

Many of these reactions are not well understood by scientists, so the transport and fate of mercury in the environment is a topic of significant ongoing research.

Forty Years of International Mercury Policy: the 2000s and beyond (Part 3 of 3)

By: Noelle Selin

In previous posts, we looked at the evolution of international mercury policy in the 1970s and 1980s-1990s. By the 2000s, countries began to realize that addressing the mercury problem would require global-scale action.

From the UNEP "Time to Act "report
Timeline of global mercury events from the UNEP “Time to Act” report

The process towards a global treaty began with a scientific assessment report, the 2002 Global Mercury Assessment. A main conclusion of that assessment was that there was sufficient evidence of significant global adverse impacts to warrant international action to reduce the risks to human health and/or the environment arising from the release of mercury into the environment. In 2003, in response to this report, the UNEP Governing Council launched a voluntary programme to address mercury. Between 2003 and 2009, this programme organized a series of awareness-raising workshops, developed guidance and training materials, and established a clearinghouse for mercury-related information. Much of this work was conducted under the auspices of mercury partnerships, which began in 2005 (see our blog post on that topic).

The UNEP Governing Council in 2009 established a mandate to begin negotiations for a global, legally-binding mercury treaty [pdf]. An ad-hoc open-ended working group met to prepare for the beginning of negotiations in 2009 in Bangkok. The Intergovernmental Negotiating Committee process began with a first meeting in Stockholm in June 2010. A second meeting was held in Chiba, Japan in January 2011, a third in Nairobi in November 2011, and a fourth in Punta del Este, Uruguay in July 2012. We are now in Geneva for the fifth and (hopefully) final session, before a treaty is expected be signed in Minamata, Japan in October 2013. More information about the negotiating process to date is available from the Earth Negotiations Bulletin.

Forty Years of International Mercury Policy: the 1980s and 1990s (Part 2 of 3)

By: Noelle Selin

My previous post looked at early international efforts to regulate mercury from the 1970s. This post looks at developments in the 1980s and 1990s, as science and policy communities began to realize that mercury was not just a regional, industrial pollutant but a global challenge. Scientific assessments showed that despite action in the 1970s, mercury levels remained high, and by the 1990s, new evidence emerged that mercury has health effects at low-doses (we’ll cover these in an upcoming post on mercury health effects). Revisions of some of the agreements from the 1970s also set new, ambitious goals. Actions in the 1980s and 1990s included:

  • The HELCOM Ministerial Declaration in 1988 [pdf], which stated a goal (never reached) to reduce total discharges of mercury and other hazardous substances by 50% by 1995, and a series of binding recommendations targeting mercury uses and emission sources
  • The Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR Convention, which updates the Oslo and Paris Conventions), 1992, with a goal of achieving natural background levels of hazardous substances by 2020
  • Further cooperation around the Mediterranean Sea included a 1995 update to the Barcelona Convention, and a 1996 Hazardous Wastes Protocol [pdf] that obligates parties to reduce and where possible eliminate the generation of hazardous wastes in the Mediterranean, including mercury waste, and a 1997 Strategic Action Programme under the Mediterranean Action Plan that sets a 2025 goal for complete phase-out of all input of mercury into the Mediterranean [pdf]
  • Mercury in hazardous wastes is covered by the Basel Convention (1989)

A major regional agreement on heavy metals (including mercury, cadmium and lead) completed in the 1990s was the Heavy Metals Protocol to the Convention on Long-Range Transboundary Air Pollution (CLRTAP), an agreement that covers the U.S., Canada, western and eastern Europe, and Russia. The CLRTAP heavy metals protocol, completed at the same time as another protocol on persistent organic pollutants (POPs), set a strong precedent for global action on both POPs (eventually the Stockholm Convention) as well as mercury.

In the third and final post, we’ll look at the road towards the global treaty process beginning in the 2000s.

For more information on the history of mercury policy, see the following article: N. E. Selin and H. Selin, “Global Politics of Mercury Pollution: The Need for Multi-Scale Governance,” RECIEL 15 (3) 2006. [pdf]