Chapter 10: We'll Keep on Fighting....

Image: H. Selin

In the final chapter of Mercury Stories, we return to the mercury issue with a focus on sustainability champions, guided by the mantra “We’ll Keep on Fighting….” – a line from the song We are the Champions by Freddie Mercury and Queen, which was played when the negotiations of the Minamata Convention were concluded (as we mentioned in chapter 1). Whether you are a mercury researcher, a decision-maker, or an individual concerned about mercury pollution and exposure, we draw specific lessons relevant to you in chapter 10. 

For mercury researchers:

• Consider mercury in a larger context: Much research is carried out in specific disciplines or focuses on particular aspects of mercury’s behavior, but treating mercury as a sustainability issue requires viewing mercury from a holistic perspective. Many of the gaps in understanding of mercury as a sustainability issue involve the influence of interacting factors. For example, understanding the health impacts of mercury requires not only considering exposure and toxicology, but also genetic factors, cultural traditions around food harvesting and consumption, and local and national laws and regulations.  

• Work across disciplines: Researchers who study different aspects of the mercury issue in isolation run the risk of reaching incomplete or even incorrect conclusions. For example, natural scientists interested in the atmospheric transport of mercury may be better able to understand how politics and economics affect point sources in collaboration with social science colleagues. Governance scholars may reach inadequate conclusions about the fit of institutions if they do not work with experts on technological factors and environmental dynamics unique to mercury. 

• Develop and communicate usable knowledge: Our analysis of the mercury systems demonstrates the importance for researchers to generate and diffuse authoritative information in partnership with non-experts. Two examples are the use of mercury amalgam in dentistry and the use of thimerosal in vaccines, where thinking critically about benefits and harms, including unintended effects and perceived risks, is important. This involves engaging with both members of the general public and decision-makers around issues of dental restorative work and the safe (and life-saving) use of vaccines. 

For decision-makers:

• Intervene in different ways and at multiple scales: Mercury use and pollution is a multi-scale issue, and actions are needed to address mercury problems at levels from local to global. Decision-makers need to be aware of global impacts of specific actions (as well as non-action) on different aspects of the mercury issues, including to future generations, but simultaneously understand local situations of populations particularly vulnerable to mercury exposure. There is much potential for identifying interventions that have multiple and simultaneous benefits for the environment and human well-being. 

• Focus on high-impact interventions: Decision-makers are sometimes faced with a choice between different policy options to address mercury-related problems, or whether to act at all. Our analysis shows that the most effective leverage points for advancing sustainability are not always the most ambitious and idealized solutions, such as pushing for an immediate ban on mercury use or pushing for a ban on coal-burning under the Minamata Convention. Sometimes, incremental changes can have substantial benefits for present and future generations – as seen in examples from mercury use in artisanal and small-scale gold mining and point-source mercury pollution controls.

• Consider long-term impacts: Taking into account perspectives of future generations is important in all forms of sustainability policy-making, but especially so for mercury which can cycle through the environment for many generations. Today’s mercury exposure is the result of mercury use going back hundreds of years, and people who are alive hundreds of years from now may be exposed to mercury from contemporary coal burning. Policy-makers should consider establishing processes and using metrics that make the impact of mercury emissions and releases on future generations explicit and visible. 

For individuals:

• Consider consumption choices: Many individual behaviors are relevant to mercury pollution. For people who are concerned about mercury exposure, especially those who are particularly vulnerable such as pregnant women and children, choosing to eat fish low in methylmercury promotes a healthier diet. Choosing to buy a mercury-free product, and disposing of mercury-containing products according to local guidelines, helps to prevent future contamination. Finally, efforts to conserve energy also prevent mercury pollution in areas where energy production is fueled by coal. 

• Organize to push for change: Individual action in support of environmental protection and advancing sustainability is important, but only goes so far. Collective, institutional change is needed to, from local to global levels. Mercury Stories provides many examples of individuals who organized effectively to make institutional changes that helped protect their well-being – such as workers and community members. Advocacy for collective action will continue to be important in promoting effective implementation of all of the different provisions of the Minamata Convention.

•  Share sustainability stories: Finally, Mercury Stories reminds us that every individual has a story to tell about their experiences, what they value, and what they hope for, for themselves and for future generations. Sharing these stories is a vital part of both envisioning and working toward a world where sustainability is given far greater importance. We encourage everyone to share their stories – about mercury and other sustainability issues – as we express our deep gratitude to, and great respect for, the storytellers from Minamata who have shared their personal stories for over half a century.

Chapter 9: Insights for Sustainability Researchers

Image: NASA

We wrote Mercury Stories for an interdisciplinary audience, and in every chapter we address three sets of topics for communities of researchers who are interested in different aspects of sustainability from varying academic perspectives. Here, we summarize some key insights from the mercury systems related to systems analysis for sustainability, sustainability definitions and transitions, and sustainability governance.

For those interested in systems analysis for sustainability: First, we show that new systems-oriented analytical approaches such as the HTE framework and the associated matrix-based approach can help account for dynamics of human, technical, environmental, institutional, and knowledge components in an integrated way. Multidisciplinary perspectives and analyses that account for two-way interactions between environmental processes and society are especially relevant to sustainability-focused studies.  

Second, adaptive capacity stands out as an important dynamic that influences and explains system behavior over time, and it can have both positive and negative effects on human well-being. In an example of beneficial effects, innovation towards mercury-free alternatives to products maintained the ability to continue to provide socially valuable goods such as thermometers, light bulbs, and batteries over time. In contrast, mercury suppliers adapt to find new both legal and illegal ways to sell mercury for use in artisanal and small-scale gold mining, with harms to human health and the environment, despite increased efforts to intervene and stop the flow of mercury into mining communities.

Third, some of the concepts often applied to describe sustainability-relevant systems – such as the Anthropocene and planetary boundaries – face substantial challenges when applied to the mercury case. It is particularly difficult to determine when global-scale human-induced change characteristic of the Anthropocene began in the mercury case; doing so requires integrated consideration of both societal flows and environmental data. Further, applying the concept of a planetary-scale boundary is challenging for a toxic substance like mercury, which pose both local and global risks simultaneously. A singular focus on a planetary boundary obscures the fact that localized mercury use and exposure can be highly problematic from a sustainability perspective.

For those interested in sustainability definitions and transitions: First, we conclude that different values attributed to benefits and risks by people in varying positions of influence complicate analysis of human well-being across populations and over time, challenging efforts to define sustainability. Further, preventing extraction of a non-renewable resource like mercury does not always benefit contemporaneous and future human well-being, and accounting for the value of assets that might become liabilities in the future is a major challenge for efforts to define sustainability. The existence of trade-offs in benefits and costs of mercury uses also reinforces the importance of considering equity and power when defining and analyzing sustainability.

Second, many transitions toward sustainability were characterized by incremental change, but some nevertheless had substantial benefits for human well-being of both present and future generations. The introduction of new technology had multifaceted implications for sustainability transitions in the mercury systems, with both positive and negative elements. Incremental changes can add up to support more fundamental change. The fact that fundamental change can come from cumulative incremental steps makes it difficult to empirically distinguish between different degrees of transitions. The mercury systems also provide further evidence that a substitution for a known hazardous substance can lessen one kind of damage, but may create new problems. For example, the environmental and human health implications of the use of PFAS as substitutes for mercury-based technology in chlor-alkali plants remain unknown.   

Third, different patterns and modes of transitions with interacting dynamics occurred simultaneously. Transitions in the mercury systems towards greater sustainability reflected economic and technical drivers and scientific advances related to the harmful effects of mercury and the availability of mercury substitutes in medicine, commercial products, and manufacturing processes. Distributions of agency and power often played a substantive role in driving transitions. For example, doctors, employers, and corporations had a large influence on transitions away from the use of mercury in medicine and in commercial applications, while the interests of patients and workers were less influential. 

For those interested in sustainability governance: First, ensuring that institutions fit the physical problems that they are designed to address involves paying close attention to material system components and their interactions. It is important that a governance approach to an individual sustainability issue take into consideration its unique biophysical as well as societal characteristics. The Minamata Convention attempts to engage different aspects of the mercury issue by setting out a global-scale legal framework for action on the full lifecycle of mercury, but our analysis of the mercury systems also shows the benefits of designing a polycentric governance approach across global, regional, national, and local scales.

Second, insights from the mercury systems show that a combination of interventions is often necessary to enhance human well-being for both present and future generations. Governance strategies can also be implemented to address multiple sustainability issues simultaneously through careful institutional design, as it is at least sometimes possible to design interventions on one sustainability issue so that they positively affect another one as well. At the same time, it is important to recognize that efforts to enhance governance synergies across sustainability issues can have drawbacks in the form of political disagreements being transferred from one forum to another.

Third, evaluating institutional effectiveness such as the effectiveness of the Minamata Convention or a national law requires simultaneously considering environmental and societal factors that shape outcomes in the context of advancing sustainability. Evaluating whether governance strategies enhance present and future human well-being is analytically challenging, in part because of the difficulty in attributing causality in complex, adaptive systems. Institutionally focused evaluations of treaty effectiveness such as the one mandated for the Minamata Convention can be aided by the simultaneous use of outcome indicators (focusing on changes in environmental concentrations, for example) and process indicators (looking at practical implementation measures taken by parties).

Chapter 8: Seeing the Matrix

Image: @markusspiske via Unsplash/Squarespace.

For scholars interested in analytical frameworks and methods to examine complex systems relevant to sustainability, the third section of Mercury Stories provides a summary of key insights from across the five mercury systems in chapters 3 to 7. In chapter 8, we reflect on the ways in which our new HTE framework provide insights about mercury (and potentially other sustainability issues) that go beyond previous mercury-focused studies using other analytical frameworks and methods. To this end, chapter 8 is about “seeing the matrix.”

In chapter 8, we return to the first three of the four research questions that we posed in chapter 1 and that guided our application of the HTE framework and the matrix-based approach in chapters 3 to 7. The three research questions were: First, what are the main components of systems relevant to sustainability? Second, in what ways do components of these systems interact? Third, how can actors intervene in these systems to effect change? Here, we briefly summarize our main findings relating to the components of the mercury systems, as well as interactions and past interventions in these systems. For a more detailed discussion with lots of empirical examples, you have to read chapter 8! 

What are the main components of systems relevant to sustainability? We draw three main conclusions. First, we needed all five categories of human, technical, environmental, institutional, and knowledge components to analyze the mercury systems, and all the individual components that we needed fit into one of the five categories. As such, we conclude that our five categories of system components are both necessary and sufficient. Second, we were able to sufficiently analyze the mercury systems by identifying a relatively small number of each type of system component at differing levels of specificity. The total number of system components for each of the mercury systems ranges from 20 to 27. We believe that a greater number of system components would not have had a meaningful positive impact on our analysis of system interactions and interventions. Third, while some components are unique to a single mercury system, others are common across several mercury systems, and these may also be important to other sustainability-relevant systems. Components common across systems may be particularly important for advancing sustainability more broadly.

In what ways do components of these systems interact? We highlight three major findings. First, most interaction pathways (linked interactions that form causal chains) involve interactions among all three categories of material components, demonstrating the analytical value of making a distinction between human, technical, and environmental components (rather than collapsing two of them into a larger category). Second, pathways differ with respect to their scope (the number of interactions that they contain), and their complexity (some pathways are linear while others involve multifactor causality, feedbacks, and reciprocal interactions). A large number of non-linear pathways with multiple interactions poses substantial analytical challenges for researchers to document causality. Third, pathways cross spatial scales from local to global, and temporal scales from minutes to millennia. The fact that pathways cross both spatial and temporal scales can separate impacts in space and time from their causes, which makes it difficult to link specific sources of mercury use, exposure, and discharges to particular observed environmental and human health effects.

How can actors intervene in these systems to effect change? We summarize four different conclusions about how actors can change either system components and/or interactions toward greater sustainability. First, some interveners targeted mercury specifically, while other interventions that affected mercury use and discharges were taken with other goals in mind (such as reducing other forms of pollution or improving a particular product or production process). Interventions had both positive and negative spillover effects, suggesting that both synergies and tradeoffs are prevalent among efforts to address sustainability issues. Second, interventions addressed both material and non-material components at different leverage points across pathways and targeted multiple types of interactions both “upstream” and “downstream” – and many of the more successful interventions addressed material and non-material components simultaneously. Third, interventions occurred at different spatial and temporal scales, but they often propagated across such scales. These processes prompted learning over time and across jurisdictions – for example, the diffusion of mercury-free technologies. Fourth, a broad range of actors with varying levels of power and influence was able to prompt system-level changes. This suggests that there is much potential for many different individuals and groups to act to further sustainability goals.

Since the publication of mercury stories, the HTE framework is beginning to be applied to other systems. See our resources page for some examples including single-use plastics, air pollution and agricultural burning in India, and water and irrigation in Pakistan, in the form of case studies usable for teaching. Further, the three questions posed in Mercury Stories were revised and applied in a 2021 article in Science Advances as a method to evaluate whether research on sustainability-relevant topics accounts for their components and interactions in complex, adaptive systems, and the article highlights the HTE framework as a methodological approach and road map for identifying which components and interactions in systems are most important to account for in research.

Box 1: Characteristics of Sustainability-Relevant Systems Research. from Selin, Science Advances, 2021.

Stay tuned for further refinements and applications! 

Chapter 7: All that Glitters Is Not Gold

Gold bars and coins. Image: Infrarate.com via Squarespace.

The saying all that glitters is not gold refers to the fact that just because something sounds or looks valuable, it might not be. Many things that at first glance look enticing may turn out to have serious downsides. Artisanal and small-scale gold mining (ASGM) is one such thing. Millions of people who otherwise would struggle to make ends meet for themselves and their families are attracted to the promise of ASGM to earn a sometimes life-saving income. Yet, much ASGM also involves great risks to human security and well-being, and contributes to environmental contamination and destruction. Mercury use is one of the major reasons for these harms.

In Chapter 7 of Mercury Stories, we look the use of mercury in ASGM. We start the chapter with a story about Madre de Dios, Peru, a place where much ASGM activity occurs today. The global extent of ASGM is uncertain, but two different 2017 reports by the United Nations Environment Programme (UNEP) and the intergovernmental Forum on Mining, Minerals, metals and Sustainable Development (IGF) estimate that between 10 and 20 million people work as ASGM miners in roughly 70 countries across Latin America, Africa, and Asia. Many more people gain direct and indirect economic benefits from ASGM, as at least 100 million people are believed to rely at least partly on this sector for their livelihoods. This makes ASGM a central economic activity in many of the world’s developing countries. In the mid-2010s, ASGM was believed to produce 600 to 650 tonnes of gold per year, which translates into approximately a quarter of all new gold produced.

While ASGM has increased over the past few decades, the use of mercury to extract silver and gold from ore is hardly new. The development of the patio process of silver amalgamation by the Spanish merchant Bartolomé de Medina in the mid-1500s in New Spain (now Mexico) helped Spanish colonialists extract large amounts of silver from mines in Latin America, as we discuss in Chapter 3. This contributed to the destruction of indigenous communities, while European merchants, the Catholic Church, and Spanish nobility made fortunes. Today, large-scale mining operations, often carried out by multinational firms headquartered in industrialized countries the global North, have moved away from using mercury in the extraction process. However, mercury use continues – and has been growing – in the ASGM sector since the 1980s.

ASGM provides economic benefits to miners, their families, other ASGM community members who supply services, and national economies, but ASGM also occurs in the context of much related human suffering and environmental degradation. Most ASGM miners operate without mining permits in the informal sector. This makes ASGM miners and other community members vulnerable to exploitation, as ASGM sites can be highly dangerous places rife with criminal activities, human trafficking, and (sometimes deadly) violence. Many national governments have responded to the recent increase in ASGM with violence, using force to arrest miners and shut down mining sites. Large mining firms have also often clashed with ASGM miners over mining rights, and governments in developing countries have often sided with these firms.

Mercury is key to both the positive and negative aspects of ASGM. The use of mercury allows ASGM miners to relatively cheaply and easily extract gold from ore. This is particularly lucrative as the price of gold has soared over the past two decades. Growing profitability of ASGM has also resulted in increased levels of competition and violence over gold. Many national governments have banned mercury use in ASGM, but this typically does not stop traders from illegally smuggling mercury into ASGM communities. This pushes ASGM miners further into the informal sector, making them more susceptible to exploitation from unscrupulous mercury and gold traders. The Minamata Convention is calling on parties to take steps towards greater formalization of ASGM, but many governments have been slow to move in that direction. In addition, voluntary partnerships and non-state actors are promoting mercury-free gold mining.

Mercury use in ASGM causes much damage to human health and the environment. When the gold amalgamation is heated up to burn off the mercury, especially if this process takes place in indoor areas with poor ventilation, people can be exposed to dangerously high levels of mercury vapor. If not captured, this mercury will be emitted into the atmosphere, and together with elemental mercury spilled into land and water, will start to cycle through the environment. Some of this mercury will end up in lakes, rivers, and oceans near and far from mining sites. There, it can be transformed into methylmercury, building up in fish that can be consumed by people all over the world. Mercury-fueled ASGM can lead to other sorts of environmental damages as well – for example, ASGM often leads to deforestation that also contributes to biodiversity loss.

ASGM is one of few areas where intentional mercury use is increasing. Thus, mercury use in ASGM going forward is a major determinant of both mercury pollution locally and globally and the effectiveness of the Minamata Convention. All Minamata Convention parties with “more than insignificant” ASGM within their territory must develop National Action Plans to address mercury-related and other problems. In the short term, many such efforts will focus on reducing mercury use and human exposure through behavioral changes and the use of mercury-capture technology. In the longer term, ASGM, even if mercury-free, raises important questions about the role of the extraction of non-renewable natural resources in the context of local, national, and global transitions toward sustainability. We return to issues of sustainability transitions and governance in Chapter 9.

Chapter 6: A Lightbulb Moment

A mercury-containing compact fluorescent bulb. Photo: H. Selin.

Our research for chapter 6 of Mercury Stories led us to a “lightbulb moment” – and not just because mercury was used extensively in lighting-related applications beginning in the 20th century. One of the major surprises of chapter 6 is the wide variety of societal benefits that uses of mercury had over time, in addition to the substantial damages it has caused to the environment and human health.

In chapter 6 of Mercury Stories, we look at intentional uses of mercury in a wide range of products and production processes. We begin the chapter with the story of the mercury thermometer – the dominant temperature-measuring technology for nearly 300 years because of its simplicity, precision, and reliability. While electronic thermometers are increasingly replacing it, the mercury thermometer led to substantial advances in science, meteorology, and medicine. The mercury thermometer is just one well-known example of how mercury has been used to produce consumer goods, and mercury has also been a key component in much chemicals production over the past 100 years. 

The story of compact fluorescent bulbs (CFLs), which use small amounts of mercury, illustrated complexities related to weighing costs and benefits of using this toxic substance. CFLs were marketed starting in the 1990s as much more energy-efficient alternatives to the older incandescent bulbs. Similar to other types of fluorescent lamps, CFLs contain a small amount of mercury, whereas incandescent light bulbs do not. However, CFLs uses less energy compared to incandescent light bulbs. Reduced energy use from fossil fuels helps address climate change. And in places where electricity is generated by coal-fired power plants, the related reduction in mercury emissions from the energy sector can result in reduced mercury discharges to the environment. But this is influenced by the degree to which the mercury in discarded CFLs is safely managed. 

Other examples of benefits of mercury uses that may not be readily apparent are found in the chemical production sector. The use of mercury in chlorine production was more energy efficient than alternative techniques, which can also help reduce emissions of mercury and other air pollutants if energy for chemicals production comes from coal and other fossil fuels. Further, chlorine that was made using mercury-based production techniques benefited public health – for example, chlorination of water supplies in the early 20th century protected people against waterborne diseases.

These sometimes beneficial uses of mercury in products and processes have at the same time resulted in large amounts of mercury being discharged into the environment, and have put workers at risk (we discuss human health issues in chapter 4). The benefits and costs of mercury uses were thus not equally shared, and the costs were substantial. Along with the story of the benefits of the thermometer to science and innovation is the story of a thermometer factory in Kodaikanal in the Indian state of Tamil Nadu. Built in 1983 with equipment from a decommissioned US plant, the factory was forced to shut down in 2001 by the Tamil Nadu Pollution board after public protests. Workers at the factory were exposed to mercury, and showed symptoms of mercury poisoning. Soils around the factory are still contaminated with mercury, and the process of cleaning up the site continues to be controversial. Chemicals manufacturing was an important part of the industrialization of Japan, but lead to the outbreak of Minamata Disease among local fishers and their families in Minamata. Unsafe handling of mercury from chemical manufacturing plants have also caused severe local contamination issues elsewhere. Further, excess mercury from especially chlor-alkali plants was exported after their closure – some of this mercury made its way to artisanal and small-scale gold mining activities, which is the topic of chapter 7. 

In chapter 6, we examine how societies have responded over time to complexities surrounding the benefits and harms of mercury use in products and processes. Many early efforts to develop mercury-free products and processes occurred within the private sector. These were typically driven by economic interests, as mercury-free alternatives were cheaper or otherwise more profitable. More recently, government controls have been instituted because of growing environmental and human health concerns about mercury. Most common commercial products and production processes using mercury are currently being phased out under the Minamata Convention, including mercury thermometers. The Minamata Convention still allows the production of CFLs with small amounts of mercury, but the introduction of newer and more energy-efficient light-emitting diode (LED) lightbulbs that do not use mercury at all shifts the market away from CFLs. Large-scale industrial uses of mercury are mostly in the past, but the negative environmental and human health impacts and related economic clean-up costs of these uses will persist long into the future. 

Chapter 5: It’s in the air

Burning fossil fuels emits air pollutants, including mercury. Photo: @mattartz via Unsplash/Squarespace

When we talk about mercury pollution with various audiences, we are often asked about its connection to the challenge of addressing other air pollutants and climate change more broadly: How do mercury emissions relate to other air pollutants and carbon emissions? Do stories about mercury provide any lessons for today’s efforts to phase out the use of fossil fuels? We argue in chapter 5 that analyzing the mercury issue provides several useful insights to those who are grappling with how to mitigate regional air pollution as well as global climate change.

The future of mercury emissions from large industrial sources is intimately tied to other air pollution issues and climate change. We start chapter 5 with a story of Steubenville, Ohio. Almost 50 years ago, Steubenville was identified in a famous six-cities study as one of the cities in the United States with the worst air quality. Since then, the air in that part of Ohio as well as in many other regions of the United States has become much cleaner. This has been due to both increased regulations and a gradual closing of heavy industrial manufacturing. The latter often resulted in a painful reconstruction of the local economy, as many factory workers lost their jobs, affecting them and their family members. And the United States still face the enormous challenge of significantly cutting emissions of carbon dioxide and other greenhouse gases.

Extensive burning of fossil fuels during the industrial era has resulted in the emission of large amounts of hazardous substances into the atmosphere, including carbon dioxide, sulfur as well as mercury. As we discuss in chapter 3, different forms of mercury can travel via air currents over shorter and longer distances, harming populations both nearby and far away. Air pollution controls and reduced reliance on coal, especially in North America and Europe, have resulted in a reduction in emissions of mercury and other harmful substances with many environmental and human health benefits. However, carbon dioxide emission continues at high levels, contributing to climate change.

Some air pollution controls reduce multiple pollutants, including mercury and sulfur, simultaneously. Air pollution control devices – often “end-of-pipe” technologies – on industrial point sources capture these pollutants before they are emitted to the atmosphere. The fact that different air pollution control devices capture varying amounts of different forms of mercury has implications for how far emitted mercury can travel in the atmosphere and where it deposits. Some control technologies preferentially capture more soluble (oxidized) or particulate forms of mercury that tend to travel mainly regionally. More advanced controls such as activated carbon injection can control elemental mercury emissions, which travel globally. This process can capture as much as 98 percent of mercury emissions.

End-of-pipe controls prevent mercury emissions to the atmosphere, but importantly they do not change the total amount of mercury removed from fossil fuel reserves. The fact that mercury is captured by end-of-pipe technology raises new technology and governance issues. Mercury-containing fly ash from a coal-fired power plant, for example, may be later reused. When fly ash is heated to high temperatures as a component in making cement, mercury can be emitted to the atmosphere unless appropriate control technology is present in the cement factory. Thus, if byproducts are not properly disposed of or used in environmentally safe ways, at least some of the previously captured mercury can be emitted from these industrial point sources.

Most national and regional action on mercury emissions from large point sources have relied on an incremental introduction of stricter pollution control technologies rather than seeking to shift underlying activities of coal-burning and industrial production. The Minamata Convention, due to political resistance from many of the world’s countries, would not exist today had the treaty sought to restrict coal use; rather, the Minamata Convention mandates the application of control technologies on large industrial sources to mitigate mercury emissions. This approach is less ambitious than an alternative that would have looked to phase out coal burning. Yet, the existence of technology-based mandates under the Minamata Convention may push countries to adopt them at a faster pace than they otherwise would have done and strengthen standards over time. This helps reduce mercury deposition both in the present and future with clear human health benefits.

The Minamata Convention was agreed in 2013, two years before the Paris Agreement, and would not exist today had the treaty sought to restrict coal use. Photo: N. Selin.

The mercury case shows that technology-based approaches can, under some conditions, lead to more fundamental change. Mercury standards in the United States and Canada accelerated the closing of some coal-fired power plants that were too old or unprofitable to warrant the addition of new end-of-pipe technology. This illustrates how dynamics that lead to gradual progress toward sustainability and more disruptive change can be simultaneously present and reinforcing. At the same time, the application of control technology that mitigate mercury emissions and other local pollution problems may extend the operability of modern coal-fired power plants in China and other mainly Asian countries, slowing down efforts to cut carbon dioxide emissions and address climate change. We further discuss issues around these types of trade-offs and broader lessons for sustainability transitions in chapter 8.

Chapter 4: Just what the doctor ordered?

Calomel, a mercury-containing medical treatment (Photo: H. Selin)

It probably comes as no surprise to many who are reading this that exposure to mercury is dangerous to human health. We begin our book in chapter 1 with the story of how fishers and their families in Minamata were seriously harmed (and hundreds died) as a result of eating fish high in methylmercury. People today living all over the world continue to be exposed to methylmercury through their consumption of seafood. This is of particular concern for pregnant women and small children that can suffer developmental effects. Over thousands of years, mercury miners were exposed to high concentrations of mercury vapor in narrow mining shafts and during extraction from cinnabar, and experienced serious and often lethal health impacts. Through centuries, people engaged in gold and silver mining also suffered from being exposed to mercury vapor. Today’s artisanal and small-scale gold mining communities are sites of continuing mercury exposure (we address this further in chapter 7). At the same time, and despite of all the known harms that mercury has caused, mercury in different forms has been used for millennia in medicine. In some cases, this had beneficial and sometimes even lifesaving effects (such as in vaccines), but in others, uses continued despite no evidence of benefits and ample evidence of harm.

In the process of researching linkages between mercury use and human health for Mercury Stories, we uncovered a rather curious fact about medicinal uses of mercury (spoiler alert!): People have, over time, intentionally inserted mercury or mercury compounds into every possible bodily orifice. The use of mercury in medicine dates back many thousands of years. It was used in ancient China, India, Greece, Rome, and the Arab world, and in medieval Europe. Uses continued into the 21st century. Mercury-containing medicines were used extensively against syphilis starting in the 15th century; high-dose applications led to mercury poisoning, but its symptoms were often mistaken for those of syphilis itself. Patients were often treated while sitting in a tub, and the children’s rhyme “rub-a-dub-dub, three men in a tub” is thought to be a reference to syphilis treatment. The use of mercury in dentistry goes back at least to the first century CE in China, and has grown sharply over the past two hundred years. Doctors used cinnabar to tattoo the surrounding area as a treatment against pruritus ani (intense anal itching). Soldiers starting during World War I were administered mercury-containing solutions as a preventative measure against the spread of syphilis and gonorrhea. In the mid-20th century, mercury was also an active ingredient in contraceptive suppositories used by women. Some more recent examples include the use of mercury compounds as a preservative in eye and ear drops and nasal sprays. 

One of our favorite stories about mercury use in medicine involves its subsequent fate: Members of the Lewis and Clark Expedition in the U.S. in the 1800s used mercury-containing laxatives, nicknamed “Thunderbolts” or “Thunderclappers” for their effectiveness, as their diet during the arduous journey took its toll on their digestion. Years later, traces of mercury in latrine pits helped researchers track some of the expedition’s route from St. Louis to the Pacific coast.

Vintage WWII sign featuring mercury-containing prophylactics for syphilis and gonorrhea (Photo: N. Selin)

It is important to note that some mercury use in medicine, both historical and present, has had decidedly positive impacts. For example, ground-breaking mercury-containing medical devices such as thermometers and sphygmomanometers greatly advanced diagnostic and treatment capacity starting in the 1700s (we cover the history of the thermometer more extensively in chapter 6). Mercury’s use in dental amalgam provided effective oral health care to hundreds of millions of people. While dental use of mercury is being substituted for other alternatives in a growing number of countries and regions, mercury-containing amalgams still facilitate necessary and affordable oral health care in many places in the world. The antimicrobial properties of mercury made mercury compounds effective preservatives in a variety of medical products. This includes the eye and ear drops discussed above, as well as vaccines. Ethylmercury, the type of mercury in thimerosal used in vaccines, is different from other mercury forms. This use has had tremendous health benefits in preventing the spread of dangerous diseases worldwide. The presence of very small amounts of ethylmercury reduces the need for cold storage and allows vaccines to be transported to and used in remote areas. While there is no scientific evidence to support this claim, some, including anti-vaccine groups, have falsely linked its use to autism in children. During the negotiations of the Minamata Convention, the World Health Organization, GAVI (The Vaccine Alliance) and the United Nations Children’s Fund (UNICEF) successfully argued that the use of mercury in vaccines be exempted from requirements on mercury in products, due to its importance in global health protection.

The challenge of balancing benefits and harms in the context of sustainability is a theme that emerges in chapter 4, and which we return to throughout the book. The harms of mercury were often disregarded: doctors continued to prescribe damaging treatments, and governments only recently began to actively mitigate health dangers of mercury use and exposure. But governance strategies need to be designed to ensure they do not have damaging consequences. Efforts to advise vulnerable populations such as pregnant women to avoid eating fish high in methylmercury need to be designed to ensure the targeted populations keep eating healthy fish choices containing important nutrients. Reducing mercury use in dental amalgam and childhood vaccines can be appropriate where there are safe alternatives, but need to be implemented carefully to avoid feeding misinformation about the safety of life-saving vaccines. It also raises important equity issues about access to safe alternatives among poorer and wealthier communities and countries.

We argue in Mercury Stories that the history of mercury, including its use in medicine, provides important lessons for the multifaceted sustainability challenge of how to make informed decisions that enhance human well-being for all in the present and into the future. 

Chapter 3: What Goes Around, Comes Around

Interior of the cathedral in Seville (Photo: N. Selin)

In one of our last trips before the COVID-19 pandemic, we visited southern Spain. We joined a crowded line of tourists walking through the famous cathedral in Seville, marveling at the ornate silver objects on display. As we were admiring the silver, we also could not help thinking about mercury, and that was not just because we were still putting the finishing touches on the Mercury Stories book. Mercury is deeply connected to both silver production and history in that area of southern Spain, which has historically been the world’s largest producer of mercury extracted from cinnabar.

Chapter 3 tells the story of global mercury cycling in both society and the environment, and how those two processes must be examined together. We begin the chapter by introducing the history of silver amalgamation. In 1554, the Spanish merchant Bartolomé de Medina developed the patio process, which uses mercury in the process of extracting silver from the mined ore. This patio process made mines in the Americas, which contained large amounts of low-quality silver ore, much more profitable for Spanish colonialists, and this societal flow and use of mercury powered Spanish colonialization of the Americas and reshaped international trade and commerce between Europe and the Americas in the 1500s and 1600s. 

Cinnabar rock from the area of Almadén (Photo: H. Selin)

The fate of all the mercury used in the silver mining process in the Americas in the 16th and 17th centuries is still unknown – some estimates put that total at more than 100,000 tonnes of mercury. Some scientists have argued that this mercury still cycles globally in the environment in substantial quantities today; others point to evidence from deposits in sediments and argue that this mercury mostly remained where it was used. Mercury is discharged into the environment in many different forms, and can also change form as it cycles between the atmosphere, oceans, and land. Some mercury is transformed into highly toxic methylmercury through bacterial process in aquatic environments, where it accumulates in fish and marine mammals, posing risks to seafood consumers.

In Chapter 3, we discuss how mercury can continue to cycle between the atmosphere, oceans, and land for decades and even centuries. The mercury depositing in ecosystems today comes not only from modern-day sources, but also from the historical legacy of past mercury use and emissions. It is possible that some of the methylmercury in your last portion of tuna sushi originates from other forms of mercury that was emitted hundreds of years ago! It is important to note, though, that methylmercury concentrations in fish can respond quickly to changes in deposition. Thus, reductions in mercury emissions today can lead to positive impacts both now and long in the future. 

While the exact environmental fate of colonial-era mercury use in the Americas is still scientifically contested, its human impact and societal legacy are undeniable. Large quantities of mercury moved across the world on ships, fueling the accumulation of wealth by some and leading to grave harms to many others. A few days after our visit to the cathedral in Seville, we journeyed to Almadén, the mine where roughly one-third of all the world’s mined mercury –  over a quarter of a million tonnes -- originated over its 2000-year history. Having closed in 2002, this mine is now a UNESCO World Heritage site, together with another former large mercury mine in Idrija, Slovenia (which we have also visited – twice!). 

Sign at the entrance to Almadén, Spain (Photo: H. Selin)

Almadén is only three hours by car from Seville, but the life experiences of the people who for centuries worked down in the mine were worlds away from those with great wealth who accumulated the shiny silver objects now on display in the cathedral in Seville. The impacts of mercury exposure to miners – in Almadén, in Idrija, and in other mercury mines – were well-known five hundred years ago. The toll that extracting mercury took on the mine workers is covered in detail in the museum located in Almadén’s former hospital. Over time, these workers included enslaved people as far back as Roman times, inmates from the prison strategically located next to the mine with direct access to the shafts, and (more recently) salaried employees.

There was also much human suffering in mercury mining in the Americas. In the mercury mine in Huancavelica, Peru, in the 1500s, the Spanish introduced a system called the mita to force Indian laborers into the mercury mine, which devastated indigenous populations through a combination of high mortality rates in mining and flight of potential laborers to avoid conscription. Work in the mine, even for a short time, was often a death sentence. In addition, many forced workers in silver and gold mining in the Americas and elsewhere were exposed to high levels of mercury during extraction processes. Dangerous mercury exposure continues today in the artisanal and small-scale gold mining sector, which we discuss further in chapter 7.

We argue in Chapter 3 that to fully understand the fate of mercury and its impact on human health, researchers and others have to account for its societal movements as well as its environmental behavior. It is important to take a perspective that goes beyond typical scientific analysis focused on biological, geological, and chemical processes in the environment. We call this perspective human-technical-environmental cycling. A systems perspective such as the HTE framework that we set out in chapter 2 helps us do just that – illustrating not only how mercury cycles in the environment, but also its interactions with humans and technologies in the context of institutions and knowledge. 

We end Chapter 3 with a discussion of the Minamata Convention and its provisions. The Minamata Convention takes a life-cycle approach to addressing mercury-related challenges – addressing not only its emissions and releases to the environment, but also its use and trade across borders. A life-cycle approach to mercury is necessary, but challenging – in chapter 10, we evaluate some of the lessons for mercury policy that we draw from the analysis in the book. Stay tuned!

Chapter 2: The Matrix

The “Mercury Cube” in the mercury mining museum in Idrija, Slovenia (Photo: N. E. Selin)

In our book, we structure our analysis using a new framework and analytical approach. Our human-technical-environmental (HTE) framework and matrix-based approach incorporates a four-step approach that we believe is a useful model for analyzing a broad range of systems of relevance to sustainability. Through the development and application of the HTE framework together with the matrix-based approach we aim to contribute both to the literature on sustainability science and practical efforts to advance human well-being in the context of sustainability. We hope the use of this framework in the book inspires you to try it out to analyze other important sustainability issues from a systems perspective. 

Matrices are commonly-used tools in science and engineering, and some of you might be familiar with the design structure matrix approach in engineering systems. This, and the use of matrices in systems modeling, informed our thinking. As we developed the approach, we were also inspired by popular culture. In the film The Matrix, Neo (played by Keanu Reeves) discovers that people are living in a simulation controlled by intelligent machines who harness human biological processes to provide energy. Neo’s activities enable him not only to see connections and underlying processes, but also to work to assist his fellow humans who are harmed by an unjust system – both the ability to see connections and take actions to change interactions are important themes in our work.

Here, we answer some questions about the HTE framework and the matrix-based approach. For more information, see chapter 2 of the book, where we describe our analytical structure in greater detail. From the “Resources” page on this website, you can download a how-to guide to using the framework and matrix approach for your choice of sustainability challenge. There, you can also read a case study that applies the HTE framework and the matrix approach to single-use plastics, view related short video lectures, and download interactive activities designed for classroom teaching.  

Why did we develop a new HTE framework and the matrix-based approach?

We did so for two main reasons. 

First, we found that existing systems-oriented analytical frameworks and approaches did not provide what we needed to fully analyze the complexity of the empirical material on mercury. We needed an analytical framework and approach that acknowledged the physical and material nature of the problem as well as allowed for addressing institutional and knowledge issues that interacted with material flows. To these ends, we found it analytically helpful to include human, technical, and environmental components as three separate material categories, rather than combining two of them into one, such as putting technical and environmental components into a single category. It was also analytically critical to identify and take into consideration major non-material institutional and knowledge components. And while our analysis of the mercury systems in the book was qualitative, we also wanted a framework and approach that could be applied in a quantitative way, if such data were available. 

Second, we wanted to make sure that our work was accessible to the broad range of readers interested in sustainability analysis. We wanted to enable researchers who come from different scholarly backgrounds to use a common language and structure to identify and examine systems of relevance to sustainability, without prioritizing the terminology used by any one particular discipline or field. These researchers include social scientists from political science, sociology, geography, history, or economics, natural scientists who study mercury and other physical processes in the environment, and engineers who study technical or systems processes or develop new techniques for production or environmental remediation. We also wanted the book to be accessible to practitioners who are interested in how systems approaches can inform their efforts to address mercury and other sustainability issues.

How is the HTE framework different?

The HTE framework is named after the material human, technical and environmental components of the systems involved. The HTE framework also explicitly includes institutions and knowledge as non-material components. This framework provides the necessary structure for our matrix-based approach, which can be used for both quantitative and qualitative sustainability analysis.

There are many terms for the types of systems we are interested in relevant for sustainability, which, like our framework, include what we refer to as human, technical, environmental, institutional, and knowledge components. These include coupled human-natural systems, socio-environmental systems, social-environmental systems, social-natural systems, and other variants. There is also a lot of debate in the literature about terminology, but many of these terms and associated analytical frameworks contain similar components as our HTE framework. 

In our framework, we found it useful in particular to explicitly include both material and non-material components, and to treat them in different ways in constructing the matrix. We also wanted to explicitly differentiate the dynamics of technological and human systems. This was for analytical reasons – we wanted a framework that captured a material system in a way it could be analyzed and potentially even modeled, but that simultaneously captured important non-material components in a structured way. 

How do I apply the HTE Framework? 

Our analytical approach involves a four-step process. The first three steps involve constructing matrices that identify system components, their interactions, and potential interventions. We present system components, interaction, and intervention matrices for each of the five mercury systems in chapters 3-7 of the book. The final step draws insights from the analysis.

The first step is to identify the relevant human, technical, environmental, institutional, and knowledge components that are important for sustainability-focused systems analysis. Individual components are the building blocks that determine the state, structure, and function of a system at various points in time. It is important to include all components necessary to capture critical system dynamics, but also not to identify so many components that it hampers effective analysis – we found that no more than 5-7 components of each type were sufficient for analyzing the mercury systems. 

The second step involves creating an “interaction matrix” that identifies major interactions between the material components, in the context of institutions and knowledge. To do this, we place each material component in both a row and column of a matrix. If an interaction occurs, we note this in the cell where the row and column intersect, along with the relevant institutional and/or knowledge components that influence it. We then trace pathways of linked interactions through the matrix, which show causal mechanisms in the system.

The third step is to identify interveners – actors that can modify components and/or interactions in the system – and to create an “intervention matrix” that shows which components and interactions they can influence and how. In the book, we do this by examining how interveners in the past have both intentionally and unintentionally affected all five human, technical, environmental, institutional, and knowledge components as well as interactions among these components for all five mercury systems, with mixed implications for human well-being. 

The fourth step involves drawing insights from the analysis conducted during the first three steps. In the book, we focus on insights of particular relevance to three distinct audiences. First, we address issues relating to systems analysis for sustainability, of interest especially to those who study complex adaptive systems more generally. Second, we address issues of concern to researchers who are interested in how sustainability is defined and dynamics of sustainability transitions. Third, we examine topics of policy-making and management of particular interest to scholars who study governance for sustainability. 

We will provide more details on the insights we draw from across the five mercury systems when we discuss issues related to chapters 8 and 9 in future blog posts!