Category Archives: Leah Stokes

Reflections on the Minamata Convention process (from Leah)

By: Leah Stokes

The negotiations ended a little less than a month ago. Life is back to normal. No more early morning wake ups and late night sessions with delegates from around the globe. The treaty text is finalized, with just the diplomatic convention pending. When I reflect on the final round of negotiations in Geneva, a few thoughts have come to mind.

1) How little the media covered the negotiations. Compared to any round of the climate talks, the mercury treaty largely went ignored. This despite the 15 million people who rely on mercury for small-scale mining, and the 100 million people in turn who rely on these miners. Mining gold with mercury contributes 25% of total global gold production. And using mercury for this purpose is probably the biggest source of acute exposure. To me, this is a compelling story for any news organization. We’re talking about the fate of a group of people that amounts to several large cities. Yet, the world stayed largely silent. The lack of media coverage, in my opinion, probably helped to water down the strength of the agreement.

2) How much the text’s ambition declined over time. At the beginning of the week, there was the possibility that the treaty would meaningfully address emissions, whether from coal plants or ASGM. But by week’s end, the text was allowing countries to take five years just to inventory their emissions, let alone begin to control them. I understand that building an inventory takes considerable time; but we need to view this agreement from a longer time frame. These countries started talks in the early 2000s. Countries have already had a decade to get a handle on their emissions. It’s time to start decreasing emissions now. Unfortunately, this agenda item got dropped along with thresholds, ambitious timetables for reductions and clear targets. These issues, instead, were punted to the first round of the Conference of the Parties (COP) after the treaty is official signed this fall.

3) How much the treaty is a process, not a destination. It was tempting to view these negotiations as the final period on a run-on sentence that needed to end. Instead, they were just a mid-point in a long term project to reduce emissions. Getting countries to focus on the mercury problem is like peering through a prism to see the way the particular angle focuses the problem. I was surprised, for example, when ASGM emissions were deemed larger than coal emissions at UNEP’s scientific briefing at the beginning of the week. In my mind, this changed the priorities for countries, and made mercury emissions even harder to reduce. Future meetings will no doubt update the picture we have on the nature of the mercury problem and how well countries are addressing it. While finalizing a treaty is a noteworthy moment, international environmental negotiations are truly a multi-year decision-making process, with scientific uncertainty and shifting goals. It’s not over yet. And it’s possible the Minamata Convention will grow sea legs over time, allowing countries to steadily reduce mercury emissions on a more ambitious timeline once the treaty is implemented.

Emissions and Releases in the Final Agreement

By: Rebecca Saari and Leah Stokes

Before the negotiations began, we wrote this post summarizing the key issues negotiators were considering for mercury emissions to air and releases to land and water. It was clear that the delegates had much to resolve. What did countries finally decide, and what does it mean? We’ll cover these questions in this post.

Countries addressed how mercury enters the environment by identifying “relevant sources” for emissions in Annex F. The text specifically identifies coal-fired plants and boilers, non-ferrous metal mining activities, waste incineration, and cement production, as sources for mercury emissions that need to be controlled. Oil and gas, facilities where mercury added products are manufactured, and manganese production, which were all included in the draft Annex F at the beginning of the week, were excluded from the final agreement.

Conversely, sources to land and water are not specified in the treaty text. Instead, it is left to Parties to identify these sources within 3 years of the Convention’s entry into force, with the help of the Conference of the Parties. In other words, this decision was left for future rounds of negotiation.

Parties must also create an inventory of their emissions and releases within 5 years the Convention’s entry into force. This is quite a long time. On the one hand, inventories can take a while. Consider that the US Environmental Protection Agency takes three years to issue updates of its National Emissions Inventory of common air contaminants. Still, many countries have been working on inventorying their mercury emissions and releases for many years, in parallel to the negotiations, so, for many countries, a five year period is quite lenient. Many countries have already completed or begun their inventories, and those who haven’t can use the UNEP Toolkit. This inventory is a critical tool for identifying sources and tracking progress. In fact, measuring emissions may be a key way that the treaty changes state behavior over time, by making emissions and releases more visible.

There’s a difference between how the treaty addresses new and existing emission sources. For new sources, parties must apply Best Available Techniques (BAT) and/or Best Environmental Practices (BEP) within five years. To manage existing sources, parties can choose between applying goals, emissions limits, BAT/BEP, multi-pollutant control options, and other measures that reduce emissions. For existing sources, measures must be applied within 10 years for existing sources of air emissions. There isn’t a corresponding deadline for action on releases, though an optional plan of action may be submitted within 4 years.

As discussed above, there are differences in the treatment of emissions to air versus releases to land and water. However, mercury mobilization, whether to the air or water, will have an equivalent fate in the long run, as explained by Helen Amos. Also, our earlier post pointed out that stricter control of air emissions might create perverse incentives to transfer mercury to the water, where it bioaccumulates in seafood and gets into our diets. The relative importance of releases vs. emissions is also an area of ongoing scientific research.

With the adoption of these articles, Parties have made some meaningful progress in policing how mercury enters our environment. The true test of the treaty’s significance and strength will come in the years to follow, as guidance is crafted and implemented. Ultimately, the treaty will need to not only control emissions and releases, but reduce them. In other words, this treaty is just the end of step one.

Daily Roundup for INC5 Day 2 – Monday January 14

By: Leah Stokes

The second day of negotiations at INC5 was a busy day, without any Swiss breaks. Delegates spent significant time discussing key articles on Products & Processes, and Emissions & Releases. Here are some updates from our team’s observations on the proceedings so far. 

Products & Processes

The technical working group focused on products and processes started early and has powered through the entire day. There was a lot of back and forth between the US, Canada, EU, Japan, and the African Group on the one hand and China, India and Brazil on the other about phase-out dates. China was particularly persistent that they could not phase out mercury batteries by 2020, because there are no mercury-free alternatives currently available to China. Compact flourescents and lamps were also hot topics; negotiators broke off into a smaller group around 11:15 PM to try to reach agreement on mercury concentrations and phase-out dates.

The working group has a new co-chair, Donald Hannah from New Zealand. He delivered an inspiring speech at the beginning of the session and set some ambitious goals. “Finding problems with text is unacceptable at this stage of the process,” he told the delegates. “We are not going to let perfection get in the way of a good text.” His expectations for a cooperative and productive group have spurred the discussions forward. By 11 PM, it looked like negotiations on this issue would continue until the middle of the night.

Emissions & Releases

This morning’s plenary session kicked off INC5’s discussion of mercury emissions to air and releases to land and water. Countries noted that emissions and releases were “crucial” and “at the heart” of the treaty. In the plenary, countries sorted into supporting a more stringent approach, binding targets and techniques–option 1–or a more flexible approach with national plans–option 2. With the notable exception of the African Group, developing countries generally favored a flexible approach, while developed countries favored a more stringent approach.

After discussing key issues, the Chair arranged a contact group chaired by John Roberts (UK) and a negotiator from Indonesia. Meeting in the afternoon, the group was tasked with resolving issues around: the use and nature of thresholds to exclude small sources; striking an agreement on the strength of the articles by specifying the precise requirements and controls; and deciding what distinctions should be made between emissions to air versus releases to land and water.

At the end of this meeting, the co-Chairs formed a team to craft the first draft of a new, compromise article (between option 1 and 2) that will specify precise requirements and controls while allowing sufficient flexibility. They are working busily as we craft this blog post. The results of their efforts will be discussed again in the contact group tomorrow. In addition, plans were made for a technical group to provide guidance on the options and implications for various threshold levels and sources in the coming days.

Institutions & Implementation:

Today’s discussions on institutions and implementation in the plenary focused on links with the Basel Convention. Negotiators emphasized there is a need to clarify linkages with Basel, which focuses on chemical waste broadly, and the section in the draft mercury treaty focused on waste. The Chair mentioned that many delegates here worked on drafting the Basel Convention, so he hoped that they would draw their attention to this task. The US notably brought attention to the fact that they had signed the Basel convention; although they have not ratified it.

Definitions was another key issue. There are some proposals for redefining use allowed to ease some of the disagreements in ASGM. More broadly, there is increasing concern that the draft treaty text be consistent across sections, to ensure a smooth implementation.

Financial & Technical Assistance

Discussion in the Financial & Technical Assistance contact group began with restating country positions and then moved to defining technology transfer. It is still undetermined whether the treaty will include both “soft” technology transfer – including best practices and know-how – and/or “hard” technology transfer – namely, the actual technology. As a result, delegates have yet to negotiate a streamlined version of Article 16bis regarding technology transfer.

Discussion of Article 16, regarding technical assistance, centered around whether technological assistance will only flow from developed to developing countries, or will be exchanged among all parties. This discussion was facilitated by a colorful and popular metaphor of countries ‘dancing the tango and deciding who will lead’—doubltless, some stepping on partners’ toes will occur. As of 10 PM, it appeared that all parties would cooperate to provide [something], to developing countries in particular. What that ‘something’ is remains unknown. Although the chairwoman from Jamaica is providing firm and insightful guidance, there is still much to be decided in this area.

Supply & Trade, ASGM and Waste

Supply & Trade, ASGM and Waste were all introduced in the afternoon plenary session today.

On Supply & Trade, countries debated whether to ban existing and future primary mercury mining, with Chile arguing a ban would set a precedent for other treaties. In addition, the specificity of import/export procedures and their similarity to the Stockholm and Rotterdam conventions was a critical issue, as was the question of whether Prior Informed Consent was needed before mercury was traded.

On AGSM, parties discussed whether text should be included for the phase-out of mercury use in ASGM and whether paragraph 6, concerning financial and technical assistance, should be included or deleted. It was unclear whether banning mercury use in ASGM would just push demand for mercury into a black market.

Finally, on waste, the definition of “mercury waste”, and the use of “shall” rather than “may” were discussed in plenary.

The “technical matters” contact group was subsequently tasked with developing clearer text on all these issues. It is unlikely that the contact group will address these issues until late tomorrow.

Measuring Our Mercury Exposure Through Hair Samples

By: Leah Stokes & Noelle Selin

Mercury is a toxin that harms human health. People become exposed to mercury primarily by eating fish. In some communities, where artisanal and small-scale gold mining (ASGM) occurs, exposure can be quite high. This is because people may breathe in mercury fumes from the process.

It is possible to tell how much mercury a person has been exposed to by testing their hair, blood and urine. Estimating mercury exposure through hair samples is primarily a measure of methylmercury — the most toxic form of mercury. But, it may also be influenced by the hair surface’s exposure to emissions. For example, if a person using mercury to capture gold stands over the amalgam (the mixture of mercury and gold) while they are burning off the mercury, it is likely that some of this mercury could end up on their hair.

At INC2, the second round of the mercury treaty negotiations in Chiba, Japan in early 2011, delegates and observers were able to measure the mercury concentration in their hair. We both sent in samples, and found out that Noelle had a concentration of 1.39 ppm while Leah had a concentration of 0.75 ppm. These values are close to, or below the WHO and the US EPA guidance values for mercury in hair: 1.8 ppm and 1.2 ppm respectively.* Many other delegates at the negotiations had mercury concentrations around 4.00 ppm, which is above these guidance values. For most people, mercury concentrations in hair reflect fish consumption, and Leah is mostly a vegetarian, while Noelle is from New England and loves fish.

Chart complied from Arnika data by Amanda Giang and Julie van der Hoop.

Chart complied by Amanda Giang and Julie van der Hoop using self-reported data on Arnika’s website.

Arnika, a Czech non-governmental organization (NGO), and a member of both International POPs Elimination Network (IPEN) and Zero Mercury Working Group (ZMWG), has posted a website where people around the world are reporting the mercury concentrations in their hair. These individuals then reflect on this information in light of the current negotiations, sending a message to delegates.

Amanda Giang and Julie van der Hoop compiled the self-reported data from Arnika’s website, to give you a sense of how mercury concentrations in hair can vary across countries.

* Note: The WHO and EPA actually give their recommendations in terms of daily oral intake of methylmercury. Amanda Giang converted these values to hair mercury concentrations using conversion factors developed by Rice et al. (2010), Stern (2005), and Allen et al. (2007).

Existing Domestic Mercury Regulations


by Leah Stokes and Amanda Giang

Many countries have existing regulations on mercury, whether on emissions from coal plants or on the use of mercury in products and processes. Here is a short summary of key mercury regulations in some of the world’s largest emitters: the US, the European Union (EU), China, India, and Canada.

United States (US)

Emissions and Releases: In the US, mercury is considered a Hazardous Air Pollutant under the Clean Air Act. During the 1990s, the Act was used to motivate limits on mercury emissions from medical and waste incinerators, leading to a 90% reduction in emissions from these sources.

In addition, the 1990 Clean Air Act Amendments aimed to include mercury emissions from coal plants, but these regulations took two decades to finalize. In December of 2011, the EPA began to regulate coal plants, the largest source of US air emissions, through intensity standards. Under this regulation, mercury emissions were limited for each unit of energy generated. This rule, the Mercury and Air Toxics Standards (MATS), is projected to reduce coal plant emissions by 90% by 2016.

In the US, direct and indirect releases of mercury into surface water are estimated to be 1.56 tonnes per year.

Products and Processes: In the past, the US used mercury in products and processes primarily for batteries, chlor-alkali production, and paint. According to the EPA, mercury use has been eliminated in most batteries and paint, but it is still used in electrical and measuring devices (e.g., thermometers). The US has also reduced its reliance on mercury in chlor-alkali production, but there are still some plants that use mercury in this process.

Most action on products and processes in the US has occurred at the state and local level. Many states have passed laws that restrict or ban mercury and require labeling of mercury-containing products. Ensuring that mercury containing products are recycled and do not end up in the waste-stream remains a key challenge.

Trade: The US banned mercury exports as of January 1, 2013.

Europe Union (EU)

Emissions and Releases: In the EU, the Integrated Pollution Prevention and Control Directive (2008/1/EC) regulates emissions from the metals, cement, and chemical industries and coal plants larger than 50MW. This regulation requires the use of best available techniques, but does not set specific emissions limits for mercury. Specific target values for ambient mercury concentrations may be established under Directive 2004/107/EC, which addresses other heavy metals as well.

In the EU, mercury releases from a single source of more than 1 kg per year to water and/or land must be reported.

Products and Processes: The EU prohibits or strictly controls mercury in the following products: batteries; electrical and electronic equipment; pesticides and biocides; cosmetics; wood preservatives; textile treatment agents; anti-fouling agents for boat hulls; and switches in vehicles. Mercury is being phased out of the chlor-alkali production process as well. For more information, see the EU’s Mercury Strategy FAQs.


Emissions and Releases: In 2011, China put out a national emission standard for mercury from coal plants and lead, zinc, and other metal production. The standard, which came into force in 2012, with full implementation to be achieved by 2015, limits mercury concentrations from coal plants to 0.03 mg/m3. The standard for the lead and zinc industries is 0.03 mg/L, and the standard for the copper, nickel, and cobalt industries is 0.05 mg/L.

China is also moving on mercury releases to water. Mercury discharge limits for urban sewage treatment plants are 0.001 mg/L.

Artisanal and Small-Scale Gold Mining (ASGM:) China has banned the use of mercury in ASGM [doc]. However, given that ASGM in China occurs in the informal sector, as is the case globally, this ban may be difficult to enforce.


Products and processes: India has used a voluntary public-private partnership to successfully reduce mercury use in chlor-alkali production. Between 2001 and 2009, mercury used in chlor-alkali production declined by two-thirds with emissions to the environment reduced by 95%.


Emissions and Releases: Canada has a comprehensive risk management strategy for mercury. Canada sets provincial caps on mercury emissions from electrical power generation, metal smelters, cement producers, and waste incinerators. Canada also has a comprehensive inventory of emissions and releases, which indicates that in 2010 total releases to water and land were 259 kg and 99 kg respectively; these releases were much lower than emissions to air, which were 5,222 kg or 5.2 tonnes.

Products and processes: In 2011, Canada began to regulate the domestic manufacture, import, and sale of mercury-containing products including toys, food and health products, pesticides, lamps, and dental amalgam. This regulation is estimated to reduce the amount of mercury in products by 4.5 tonnes each year.

Other countries have emissions regulations as well. For example, Chile has introduced mercury-specific emissions limits of 0.1 mg/m3. In addition, given the stringent regulations for particulate matter (30 mg/m3), further mercury co-benefits are expected.

If you know of another country with emission regulations for mercury, please add a comment to the page or let us know by emailing us at

MIT Mercury group presents poster at INC5


We will be presenting a poster at the MIT Joint Program on the Science and Policy of Global Change display booth at INC5, starting tomorrow and running until the end of the negotiating session. Our poster summarizes recent scientific findings of relevance to the mercury negotiations. If you’re at the INC, please stop by to see us!

Download a copy here: MIT Mercury poster at INC5


Issue Overview: Mercury Emissions and Releases

by Leah Stokes and Rebecca Saari

Each year, humans mobilize around 2000 tonnes of mercury, with about 90% emitted to the air and 10% released to land and water. Since releasing mercury leads to environmental and human health impacts, addressing emissions and releases needs to be a central part of the global mercury treaty.

The draft text of the treaty, developed during the INC4 in Uruguay, distinguishes between emissions to the atmosphere and releases to land and water. However, the extent of controls on anthropogenic emissions remains to be seen, and it is possible that releases will be excluded altogether.


UNEP’s 2013 estimation of  2010 emissions from each global region. These estimations significantly changed since the 2008 reports, where East and Southeast Asia was estimated to contribute two-thirds of global emissions. These changes likely reflect a reduction in the estimation of mercury from coal power plants in Asia and an increase in the estimation of mercury from ASGM in Sub-Saharan Africa and South America.

Currently, almost 40% of mercury emissions come from East and Southeast Asia. Many developed countries have significant regulations on emissions, and the treaty is in part an effort to have all countries adopt standards. Yet most historic emissions came from the developed world. As is the case with climate change negotiations, this dynamic raises equity issues – mainly, who should pay: past emitters or current emitters?

Unlike carbon dioxide, however, mercury is toxic with acute health and environmental impacts, and its release is not tightly coupled with countries’ GDP. For this reason, all countries should be interested in reducing their mercury emissions and releases.

UNEP's 2013 report, "Time to Act" recently updated the proportion of emissions from each source. ASGM is now the largest estimated source of emissions, with coal plants in second place.

UNEP’s 2013 report, “Time to Act” recently updated the proportion of emissions from each source in 2010. ASGM is now the largest estimated source of emissions, with coal plants in second place.

About one-quarter of all global mercury emissions to air come from coal-fired combustion, including power plants and industrial boilers. This suggests an important aim for the treaty is reducing mercury emissions from coal-fired power and heating. There are many ways to achieve this, including pre-treatment of coal and various post-combustion technologies. These options also reduce co-emissions of other harmful air pollutants, and conventional post-combustion treatment can be enhanced to remove 80-90% of mercury emissions. Mercury-specific post-combustion control, which can achieve 90% mercury removal, is also available.

With a variety of emissions control options available, and significant variation in the mercury content of coal, the Chair and delegates are challenged to set appropriate goals and measures. When asked, most countries that currently regulate mercury responded that they employ emissions limits, or limits to the amount of mercury exiting a stack (flue gas concentrations).

Thus far, proposed flue gas limits range from 0.01 to 0.2 mg/m3. For reference, 0.05 mg/mg3 is one of the highest values measured at a series of US plants with limited pollution control through a fabric filter and a low-NOx boiler. In other words, a standard set as high as 0.2 mg/m3 could imply almost no control technology at all (See document: UNEP(DTIE)/Hg/INC.5/4 for more details). Ultimately, the level of control technology required will dramatically affect the treaty’s effectiveness.

While coal-related emissions present a clear priority, other mercury emissions are challenging to address, since they comes from a wide variety of sources, including: gold, cement and metal production, the chlor-alkali industry, waste incineration and dental amalgams. The Chair’s most recent updates also highlighted mining tailings, and sewage and wastewater treatment plants as potential sources. Over one-third of all emissions are from artisanal and small-scale gold mining (ASGM), which is addressed in a separate part of the treaty. Decisions on ASGM will dramatically affect global emissions, given that the UNEP 2013 report recently named it the largest source of emissions.

This week, countries have many decisions to make on mercury emissions and releases. Which sources should be controlled—existing or new plants, and from which industries? For examples, it is currently unclear whether the oil and gas sector will be included as a source.

Should small sources be exempted from requirements to inventory and reduce their emissions, and if so, what would the threshold be for a “small” source? Potential thresholds for required controls are listed in the Chair’s documents. For example, coal-fired power plants smaller than 50 MW could be exempted from mercury control technology. For context, 20% of all US coal units are 50 MW or smaller, meaning that this threshold could exempt a significant proportion of plants.

What should the goal be – should the treaty set reduction goals, emission limits, or require best available techniques? As the discussion about flue gas concentrations implies, these standards will have significant consequences. And finally, how flexible should the requirements be—should countries have to commit to specific standards, or can they develop flexible national plans and report at a later date?

The draft text reflects many of these debates. Article 10, which addresses atmospheric emissions, has two options: one, which would require goals, best available techniques or emissions limits; the other, which would require national plans. These issues and many more will need to be decided in the coming week. Decisions on atmospheric emissions and releases to land and water are essential to shaping the treaty’s ultimate environmental and health impacts.

Want to learn more about Mercury? Play the game!

Are you interested in mercury science and policy? Do you teach an introductory science or environmental issues class and want to include a science-policy element? Do you want to explore science-policy interactions with your colleagues or lab group? We’ve created the Mercury Game to teach people about the role of science in international environmental policy making in an interactive and fun environment — and it’s free to download!

The mercury game is a role-play simulation for ten players aimed at scientists, students and decision makers. Playing the game will help participants explore the consequences of representing scientific uncertainty in various ways in a policy context. The game focuses on the credibility of various sources of technical information, strategies for representing risk and uncertainty, and the balance between scientific and political considerations. The game also requires players to grapple with politics – it explores the dynamic between the global “North” (the developed world) and the global “South” (the developing world) at the heart of most treaty-making difficulties.

For more information on the game, see this video, featuring our own Leah Stokes. Leah wrote the game along with Noelle Selin and Lawrence Susskind at MIT.