Occupational Health, Mercury Exposure, and Environmental Justice: Learning From Experiences in Tanzania

Abstract

Mercury is a potent neurotoxin that is used by poverty-driven miners to extract gold in more than 50 countries. This article examines efforts of the United Nations to address occupational health and environmental justice amid these challenges, focusing on a 3-year campaign in one of the fastest-growing mining communities in Tanzania. By providing an integrative analysis of environmental health risks, labor practices, public health policies, and drivers of social inequity and marginalization, this study highlights the need for interdisciplinary public health approaches that support community development by strengthening local capacities. It illustrates why, to ensure that the needs of vulnerable populations are met, environmental justice and public health paradigms have to expand beyond the conventionally narrow attention paid to toxic exposure and emissions issues.

Public health literature has increasingly highlighted the need to recognize the interlinkages between occupational health and environmental justice concerns in low-income settings.¹ Combining analysis about justice (i.e., “what is fair”) with an appreciation of diverse determinants of health, many researchers have suggested that public health analysis can only be truly effective if it integrates methodological approaches across different disciplines^1–5; this integration must be pursued in ways that draw attention to not only the impacts on but also the needs of vulnerable populations.

Previous research in the Journal has stressed the need for interdisciplinary development approaches in poorer settings by outlining synergies between epidemiological, educational, and environmental justice paradigms.⁶ Notably, some in this journal have suggested that mining-community dynamics in Africa require much more attention from public health professionals, because miners have long been socially marginalized and excluded from the skilled workforce. As Braun and Kisting noted in their study on asbestos and mining in South Africa, public health researchers need to understand the “social production of an invisible epidemic”—how toxic exposure is a result of both poor practice and social inequality.⁷ I build on these insights by examining the challenges of reducing mercury exposure from gold mining, focusing on a United Nations (UN) program in Tanzania. The analysis is based on a 3-year community-based study in which I served as a policy advisor in the UN's Global Mercury Project, drawing together insights to enhance global mercury strategies and multifaceted public health programming.

In recent years, the use of mercury in artisanal and small-scale gold mining has been drawing more and more concern at international intergovernmental meetings.⁸ Artisanal and small-scale gold mining is largely a poverty-driven activity that constitutes an important source of livelihood for many rural communities, but it is also the world's fastest-growing source of mercury contamination.⁹ Between 80 and 100 million people are dependent on artisanal and small-scale gold mining activities for their livelihoods, and between 13 and 15 million artisanal gold miners worldwide produce 500 to 800 tons of gold per annum and release 800 to 1000 tons of mercury. Urgent attention is needed in Tanzania, where artisanal and small-scale gold mining has been one of the fastest growing industries,¹⁰ involving as many as 1 million gold miners. Artisanal and small-scale gold mining activities are frequently linked with extensive environmental degradation and conditions of extreme poverty, conditions in which HIV/AIDS is often a pressing problem.

The use of mercury to recover gold, or amalgamation, is a common and simple extraction process, but it is dangerous and contaminates air, soil, rivers, and lakes. Although scientists have known mercury to be a toxic substance for many decades,¹¹ “it was not until the 1980s,” wrote one Tanzanian researcher, “that the widespread use of metallic mercury at the Garimpo gold mining operations in the Amazon region of Brazil attracted world attention,”^12(p23) suggesting that public health movements were all too slow to develop in the mining context, particularly in Africa. Most large-scale mining companies have since phased out mercury use in their operations, often switching to cyanide processing, posing another set of serious human and environmental health risks.¹³ Many other industries in developed countries have retired mercury through education campaigns,¹⁴ often exporting that recycled mercury to developing countries where it is used for mining and skin creams.^15,16 Workers in the artisanal and small-scale gold-mining sector use mercury more than in any other single sector,⁹ and the number of poor miners has grown considerably in many regions across Africa, Asia, and South America.¹⁷

Mercury is now commonly considered an “invisible epidemic” because its impacts are usually not seen immediately but can accumulate; indeed, mercury has been called a “chemical time bomb” because it can bioaccumulate in the food chain and create new dangers once transformed into methyl mercury.¹⁸ The health of people living in mining areas is negatively affected through inhalation of mercury vapor, direct contact with mercury, and the consumption of fish and other food affected by mercury contamination.¹⁹ A robust body of research has exposed the “downstream effects” of mining, often showing how miners are endangering other people's public health, and some governments have banned mercury as a result.²⁰

Critical researchers have suggested, though, that public health funding has largely gone to studies that have focused on “effects” while neglecting the mining-community dynamics themselves. This trend arguably increases social marginalization and even makes mercury problems worse—by not giving sufficient attention to local needs of miners, sometimes increasing the stigmatization of “criminal or dirty livelihoods,” while often promoting faulty solutions.²¹ Some public health literature suggests that workers who are regarded as “illegal” have been specifically excluded from international assistance programs and national public health programs as part of patterns of socioeconomic marginalization.²² Governments often will not educate miners unless they are legal landowners or registered workers, which may be difficult because of bureaucratic constraints or political reasons, as in Ghana,^21–23 China,²⁴ Brazil,^25,26 and Zimbabwe,²⁷ and resources for massive police crackdowns against miners often take precedence over education and assistance.^21–28 This inequity is arguably one of the more pressing public health concerns because miners are often some of the most vulnerable groups in poorer countries and their ability to participate in mercury reduction programs is vital.

Placing a central focus on challenges that workers face, I examined the need for interdisciplinary learning and community-driven development approaches, deriving lessons from the multipronged efforts of the UN to address mercury exposure in Tanzania from 2005 to 2008. Program officers obtained permission from the government to work with both registered and unregistered miners in capacity-building activities. Results from interventions give a key indication of how challenges can be addressed to tackle direct public health hazards and underlying social, economic, and political challenges that impede more healthful behavior. This capacity-building program helped to develop new UN international guidelines on mercury in mining and generated useful insights that could help inform other countries' development strategies as well.

In the first section of the article I discuss challenges and methods of UN intervention, and in the second section I report on my examination of a community case study in Tanzania to highlight the relation between labor practices and the disproportionate exposure burden among vulnerable workers, particularly women and children. In the third section, I report on results from UN training activities with miners, actions taken by the community to improve practices, and local advocacies for reforming institutional policies. I also report on my examination of broader implications for understanding environmental justice and health in the sector.

GLOBAL MERCURY CHALLENGES AND INTERVENTION STRATEGIES

Public health literature has taken an increasing interest in the concept of environmental injustice, often understood as the unequal spatial distribution of pollution and toxicity and the disproportionate environmental burden borne by racial minorities and poorer communities.^29–31 An important body of environmental justice literature on pollution has examined adverse impacts of large-scale mining companies by emphasizing the “polluter pays principle,” based on the idea that companies must be economically and legally responsible for preventing hazards (and compensating communities if prevention fails).³²

However, the international community has faced growing challenges in coming to common terms with the problems of mercury use in artisanal and small-scale gold mining, a sector in which conditions of extreme poverty often render simplistic criticisms of mine workers ineffective and even unethical, particularly if such criticisms mask underlying constraints that workers face.²³ Poorer artisanal and small-scale gold mining workers often have limited (if any) economic means to “pay”; the geographically disbursed nature of artisanal and small-scale gold mining activities often makes monitoring difficult, and safe technologies have been inaccessible to many workers. Various mercury-free technology alternatives for gold extraction have been demonstrated in artisanal and small-scale gold mining communities, and these must be encouraged as a public health priority.^33,34 The UN notes, though, that 100% mercury-free technology alternatives (e.g., cyanide leaching) often require a higher order of economic capital, training, and organization than most poverty-driven workers currently have access to³⁵; mercury is thus regarded as “an agent of poverty” that needs to be mitigated through targeted emissions reduction strategy even if a complete phaseout is not realistic in the short term.³⁶

In 2003, against this background, 3 UN agencies launched the first global effort to mitigate environmental health impacts resulting from mercury released by the artisanal and small-scale gold-mining sector. The project, entitled Removal of Barriers to the Introduction of Cleaner Artisanal Gold Mining and Extraction Technologies, or the Global Mercury Project (GMP) for short, was approved by the Global Environmental Facility. The UN Development Program acts as the Implementing Agency and the UN Industrial Development Organization is responsible for project execution. The 6 main pilot programs, all located in key transboundary river or lake basins, included Brazil, Indonesia, the Lao People's Democratic Republic, Sudan, Tanzania, and Zimbabwe. In these areas artisanal gold mining directly involves at least 2 million people in total, supporting more than 10 million dependents.³⁷

The GMP is the UN's largest initiative to date to work with governments and public health professionals in small-scale mining communities. Its goals are to assist institutions in the assessment of the extent of pollution from current activities, to introduce cleaner gold mining and extraction technologies that minimize or eliminate mercury releases, and to develop institutional capacity mechanisms that will enable the sector to minimize negative environmental impacts. It also supports the development of monitoring programs and policies and legislation to regulate artisanal and small-scale gold mining. The project works to build the capacity of local laboratories through training and material support to enable continuous monitoring beyond the initial project's term and build knowledge and awareness of risks associated with amalgamation among miners, government institutions, and the public at large. The project is guided by the philosophy of promoting cleaner and more-efficient technology that minimizes negative environmental impacts while also improving earnings, health, and safety.³⁸

Methods of Intervention and Equity Concerns

Designed to promote “an ecosystem approach to health,” the program emphasized 3 pillars—interdisciplinarity, participation, and equity.³⁹ The program implementation occurred in various phases, and its organizers collaborated with community leaders in socializing a multifaceted training strategy⁴⁰ to encourage behavior change among miners. The first phase of the GMP involved assessment of environmental and health impacts of artisanal and small-scale gold mining in selected study areas to provide a baseline and ensure that other GMP activities were properly targeted. Environmental and Health Assessment teams conducted studies in each pilot country with the UN Protocols for Environmental and Health Assessment of Mercury Released by Artisanal and Small-Scale Gold Miners⁴¹ developed by the UN Industrial Development Organization as a guiding reference to ensure quality and provide a basis for integrating knowledge about occupational practices and pathways of risk.

The aim of environmental assessment was to identify hotspots in pilot sites, conduct geochemical and toxicological studies, and undertake other investigations to assess the extent of pollution in surrounding water bodies. The health assessment was designed to complement the environmental assessment by providing an indication of the level of mercury poisoning attributable to mercury vapor exposure and to the ingestion of contaminated food. Based on investigation of the pathways and bioavailability of mercury vapor and methyl mercury to the mining communities, the health assessment combines information from biological samples with medical exams to evaluate the level of impact that the pollutant caused or may cause to individuals residing in hotspots.

The integration of the health and environmental assessments, summarized in this article, is vital to identifying the potential overall effects that any one variable might have on the biophysical and social environment. Although these assessments are an important “first step,” many researchers (and miners) stress that assessments must be immediately followed by an introduction of concrete solutions to reduce emissions, stop human exposure, and mitigate critical situations. Weed and McKeown, in a discussion of researcher ethics and responsibilities as an underappreciated element of environmental injustice, critiqued the

lack of attention to the central responsibility of public health researchers to actively participate in interventions consistent with their role as professionals committed to the interconnected social goods of scientific knowledge and improved health.^5(p1808)

Public health programs that address mining in poorer countries often suffer from being “fly-in, fly-out” (some might say “drive-by data collection”) research models in which hazards are studied but solutions remain unidentified and elusive for local workers.^42–44 Some researchers suggest the need to replace hair and blood sample techniques with more speedy (although also less scientifically precise) diagnosis methods such as breath analysis to encourage a faster learning process that is more interactive with miners.^23,45,46

Even if researchers share their findings quickly, narrow approaches emphasizing “awareness” do not necessarily stimulate behavior changes among mining populations who may need to see demonstrations of technologies, learn about alternatives, and build trust to change practice.⁴⁷ Thus, locally managed “mobile training units” were promoted by the UN team to engage miners, and a UN Manual for Training Artisanal and Small-Scale Gold Miners⁴⁸ was designed to provide guidance on low-cost solutions. Brochures were developed in Swahili, and local cartoonists developed pictorials, providing discussion material to address challenges that ranged from mercury to HIV/AIDS prevention and other community-specific concerns. Interactive policy discussions were undertaken to examine broader social, economic, and political determinants of public health and to explore what “environmental justice” means locally to understand how health promotion programs may lead to policy changes. Such policy discussions, which I facilitated through structured and semistructured interviews and group workshops in 2007, are explored in the final section of the article.

The workshops included community members of diverse occupational backgrounds, particularly targeting mercury users, gold and mercury dealers, family members of miners, district politicians, officers from the Ministry of Mines, government health workers, microfinance bank representatives, mining company representatives, and others with different types of influence. Notably, women who might not be miners themselves but who are responsible for cooking (including mercury-polluted fish) were participants, encouraging dialogue on multiple avenues of health risk. Environmental justice activists call for

policy-making procedures that encourage active community participation, institutionalize public participation, recognize community knowledge, and utilize cross-cultural formats and exchanges to enable the participation of as much diversity as exists in a community.^30(p522)

Seeking to promote this synergy, the group discussions were facilitated with the goal of encouraging an inclusive dialogue that would identify both short- and long-term measures for improving institutional policies affecting health. Individual interviews were also facilitated to allow for more-personal views to be shared about employer–employee relationships and other aspects that may affect relevant labor practices.

CASE STUDY OF UNDERSTANDING MERCURY RISKS IN TANZANIA

Rwamagasa, with a population of 27 000, is located in the Geita District, south of Lake Victoria, and is one of the fastest-growing mining areas in Tanzania. Geita District has a population of approximately 712 000 mostly impoverished, unlicensed panners, including an estimated 150 000 artisanal and small-scale miners. Geita is located in the Lake Victoria Goldfields region, which produces more than 95% of Tanzania's gold and has the highest intensity of small-scale mining in the country. Rwamagasa is only 37 km south of Lake Victoria, but the area drains into Lake Tangayika. Intensive small-scale gold mining began there in the 1980s, but mining activities date back more than a century. Most of the population is involved in mining, either as miners, part-time miners, or buyers. Young men tend to work in larger excavation operations, whereas older people, women, and children work in smaller ore-processing sites in which mercury is most heavily used (Image 1).⁴⁹

The occupational environment for ore processing in Geita District, Tanzania. Photograph by author.

There are 2 main small-scale milling operations in Rwamagasa: the small-scale Blue Reef Mine and milling and sluicing by miners near the River Isingile (both involve licensed and unlicensed workers). At Blue Reef Mine, 150 people work at mining and milling primary ore from underground shafts. At the riverside location, the millers, employing approximately 300 people at 10 sites, process tailing material or weathered ore from pits or shafts. Ore is transported in bags to the milling centers, manually crushed, and sun dried. The ore is dry milled in small ball mills, without mercury, then slurried and passed over sluices. The sluice concentrates are amalgamated in metal trays, with bare hands, and the amalgamation tailing is stored in concrete or wood-lined tanks and is frequently reprocessed. Amalgam is burned in a small charcoal fire with no device to contain the emissions (i.e., retort). In prior UN programs elsewhere in Africa, this practice—uncontained amalgamation burning—has been found to cause elemental mercury concentrations in air exceeding 50 μg/m³, 50 times the World Health Organization maximum public exposure guideline.^9,46 In Rwamagasa, similar methods of air analysis surrounding worker bonfires found concentrations to be as high as 25 μg/m³.

Housing, food stalls, and schools are all located close to amalgamation sites, and contaminated tailing material is stored near wells and agricultural land, sometimes directly adjacent. The mines release an estimated 27 kg of mercury per annum. The GMP team collected and analyzed 271 samples taken from soils, drainage sediments, tailing material, and water.⁵⁰ Drainage sediments showed mercury concentrations ranging from 0.04 to 3.02 ppm, and the concentration in background sediment was approximately 0.08 ppm. Tailing material had a mean of 3 to 5 ppm Hg and ranged from 0.2 to 56.5 ppm Hg. Amalgamation tailing had a mean of 86 ppm Hg and ranged from 28.5 to 193 ppm Hg. To put this in perspective, the maximum permissible concentration of mercury in agricultural soil in the United Kingdom is 8 ppm and in Canada, 6.6 ppm.⁵⁰ About 8% of soil sampled exceeded 1 ppm Hg.

Total mercury concentrations were measured in 285 fish samples from 4 main species, collected from ponds around mining sites, nearby rivers, and farther downstream the watershed. Fish sampled from ponds nearest mining activities were the worst affected, with a mean concentration of 0.80 ppm Hg wet weight, reaching up to 2.65 ppm Hg, considerably exceeding the World Health Organization safety guideline value of 0.5 ppm and recommended limit of 0.2 ppm for the protection of vulnerable groups (i.e., frequent fish consumers, pregnant women, and children younger than 15 years).⁵¹ Mercury in fish collected in nearby rivers had lower, although still elevated, mercury concentrations with a mean of 0.13 ppm. These places, however, can be transformed into environmental hotspots in which mercury transported by sediments from mining areas can be methylated.

Fish originating from Lake Victoria and sampled from the Rwamagasa market have shown mercury concentrations of some concern, yet often these concentrations are lower than international guidelines limits.^52–54 Although scientific evidence indicates that occupational exposure risks are much greater than risks from consuming fish from Lake Victoria, it is the latter pathway that has often been associated with considerable public controversy, resulting in a widespread environmental justice concern in which miners are often portrayed as culprits for both environmental health and economic problems. According to the Director General of the Tanzania Food and Drugs Authority, Turkey rejected more than 16 000 kg of fish fillet from Tanzania earlier in 2008, after tests revealed that the product contained mercury, and it is well accepted that the largest pollution source is artisanal and small-scale gold mining. In 1999, the Tanzania Food and Drugs Authority noted that Tanzania “lost US $90m after the European Union banned importation of Tanzanian fish fillets into its markets for similar reasons.”^55(p1)

Notably, concentrations found in the UN's assessments in Tanzania were less severe than were similarly intensive small-scale mining operations in Brazil, Indonesia, and Zimbabwe, the most polluted sites studied by the UN program.⁵⁶ This was primarily because of current milling practices of using mercury to amalgamate only sluice concentrates, rather than amalgamating all the ore (known as whole-ore amalgamation—common in Indonesia, Brazil, and Zimbabwe). Early on, UN reports stressed that “care must be taken to avoid the introduction of technologies which could lead to whole ore amalgamation”^57(p16) but evidence of this practice began to surface in Tanzania for the first time in 2007. Notably, the interaction between mercury released from artisanal and small-scale gold mining and cyanide leakage from the improper disposal of mine wastes by larger mining companies also makes mercury more bioavailable in the ecosystem, thus increasing the sum total of risks.⁴¹ Kitula noted that the combination of these tailings emissions in Geita, from both large-scale mining companies and artisanal and small-scale gold mining operations, “can be deadly to humans and can poison ground water, farming land and the resources in water bodies which the livelihood of the majority of Sukuma Tribe depend on for their survival.”^58(p410)

Local Health Inequities

Health conditions in Rwamagasa are very poor, with low hygiene standards and high rates of infectious diseases such as diarrhea, typhoid, and parasitism. The dominant causes of morbidity and mortality are road accidents, accidents in insecure mining tunnels and amalgamation plants, malaria, tuberculosis, and sexually transmitted diseases including AIDS. No special health service exists for the mining community; the nearest dispensary is about 10 km away (about 6 miles), and all nonminor illnesses must be transferred to Geita Hospital. There is no effective disposal system for sanitary or other domestic waste.

The health status of 211 volunteers in Rwamagasa and 41 from a control area in Katoro (located 30 km from Rwamagasa) was assessed by using the GMP's environmental and health assessment protocols. The GMP team collected 252 blood samples, 249 urine samples, and 212 hair samples.⁵⁹ Medical questionnaires were given to 252 participants. Participants were examined to assess their general health condition as well as the possibility of mercury poisoning. Neurological and toxicological tests were used to identify neurologic disturbances, behavioral disorders, motor neurologic functions, cognitive capabilities, balance, gait, and reflexes.

Miners and millers are directly exposed to mercury during both amalgamation and burning without retorts. Housing, food areas, and schools are all near amalgamation and burning places. Tailings containing mercury are found within the village, adjacent to cultivated land, and near local water wells. Dozens of open pools of stagnant water are located near dwellings, increasing malaria risks (Image 2). Child labor is very common from age 10 years on and children work and play with mercury using their bare hands (Images 3 and 4). Babies nursed by mothers who work as amalgam burners show a high mercury burden because of placental transfer of mercury during pregnancy and then high mercury concentration in breast milk.

Open pools of stagnant water stand on the immediate outskirts of Mgusu village, in Geita District, Tanzania. Such pools are common near most mining villages. Photograph by author.

Workers mix mercury by hand in an amalgamation pool in Geita District, Tanzania. Photograph by author.

Children work in an amalgamation processing center in Geita District, Tanzania. Photograph by author.

Typical symptoms of mercury intoxication were prevalent in the exposed group. In addition to sleep disturbance, excessive salivation, and metallic taste, Rwamagasa workers also demonstrated fine tremor of eyelids, lips, and fingers; ataxia; dysdiadochokinesis; and altered tendon reflexes. Participants who had worked in the area for 5 to 10 years demonstrated more-severe symptoms. The control group in Katoro was healthy and did not show any special problems. Mercury concentrations in Rwamagasa villagers' blood, hair, and urine were statistically significant and higher than those in the control group; however, only amalgam burners showed extremely high levels.

The GMP team's results indicated that 25 of 99 amalgam burners were suffering from chronic mercury intoxication, as were 3 of 15 former amalgam burners. Recent research suggests how mercury can compound other health problems, serving as not only a “distinct” public health risk but also as one that can insidiously affect communities in multiple ways. Silbergeld et al. showed how mercury exposure in gold mining can induce autoimmune disease, drawing a correlation between mercury and malaria⁶⁰ (the problem is compounded by the fact that stagnant water near mining communities provides a mosquito breeding ground), and Trasande et al. discussed economic consequences of mercury exposure as they linked methyl mercury toxicity to the developing brain and diminished economic productivity among workers in the United States⁶¹ (who are far less exposed than are many artisanal miners in Rwamagasa). It should be noted that various respondents in Tanzania were concerned that mercury-related illness may inhibit their day-to-day activities; also, many miners were concerned because sickness and poor health inhibits their ability to earn money for their families.

IMPROVING OCCUPATIONAL HEALTH AND ENVIRONMENTAL JUSTICE

Mercury emissions in low-income countries have given rise to diverse concerns about occupational health and environmental justice and—as demonstrated in the soil, sediment, tailing, and fish-sampling program—mining in Rwamagasa, Tanzania, releases considerable mercury emissions. To immediately reduce emissions, UN workers showed miners how to use retorts, which can contain 95% of mercury vapor and allow mercury to be condensed for reuse, drastically reducing the exposure risk.^35,46 Elsewhere it has been written that retorts introduced at some mining sites have not reduced the emissions of mercury to an acceptable concentration,⁶² illustrating why training on proper retort use and other phase-out strategies are key.

The UN team integrated mercury concerns with other basic health services and used the mobile training vehicles as an opportunity to address HIV/AIDS issues, malaria treatment, and mercury in an integrated approach. Community “town hall” discussions were facilitated to collectively explore technology standards, and local mining community members demonstrated why a clearer set of standards was needed both in a legal sense (creating regulations) and through customs and community codes. Theater events, cartoons, and videos were also used as public health communication tools, with positive messages that show how mercury can be reduced. Through discussion workshops, miners emphasized the need for a stronger role for government assistance and the need for changing worker–landlord relationships that affect decisions about mercury use. Numerous community members also stressed that the large mining companies in Geita have not fulfilled their promises to assist local workers and should do more to provide technical and public health services for the community.

Governments in some countries have taken severe measures recently to ban mercury use completely, with Mongolia and French Guiana being much-debated examples.^22,63 By contrast, most Tanzanian interviewees (including nonminers) emphasized the need for a more gradual phaseout so that miners are not “indiscriminately criminalized,” as one local environmental health educator put it. Discussions in Tanzania were instrumental in designing a set of UN international guidelines on mercury in small-scale mining, which provide guidance on waste management techniques, how to use retorts, how to eliminate whole-ore amalgamation, and other factors that have been published online by the UN Environment Programme for global implementation.⁶⁴ The UN supported the fabrication of 95 retorts locally and estimated that more than 6000 miners participated in the training in the Geita District; 4 local fabrication shops are now producing mercury-reducing technology alternatives. Concurrently, Jønsson et al. used similar approaches in promoting retorts in two other areas in Tanzania and noted how “18 [miner groups] used the retorts over a period of five months, recycling 10 kilos of mercury.”^65(p77)

With more than 20 newspaper articles covering the activities, public awareness is considerably raised, and the community is now putting pressure on polluters (e.g., batch-mills, washing pond owners) to operate away from residential areas and sources of water; village executive offices have received several letters of complaint and have mediated cases against polluters brought by villagers. Gold buyers are taking measures to improve ventilation in their offices and they have started to use protective gear and retorts as a way of sustaining their businesses. Individual miners now prefer to sell their gold to brokers who have retorts. Also, gold brokers who do not use retorts are prohibited from operating in the village centers. Although these indications of behavior change suggest positive short-term impacts, a longer-term monitoring program is clearly needed.

Policy discussions have reinforced recommendations of the International Labor Organization that mine workers, mine owners, and women of child-bearing age near mining areas particularly need education about the dangers of mercury exposure to the fetus and nursing baby.⁶⁶ Child labor must be addressed because children and women are often the primary amalgamation workers. Health facilities and health workers need to be equipped and trained to deal with mercury exposure and intoxication.

It should be emphasized, though, that public health programming must go beyond hazard awareness. Concrete support for the active introduction of cleaner, safer gold extraction technologies is required. Public health institutions have been poorly funded because of various government policies that have effectually resulted in “awareness-only” policies that leave technical assistance wanting; furthermore, poor government policies have decreased miners' ability to access microcredit from banks and other services to which they have historically been excluded.^67,68 From an interdisciplinary public health perspective, the lack of government assistance and the lack of fair prices for gold marketing are both serious public health problems. Notably, mercury dealers provide mercury for free in exchange for exclusive purchasing rights of the gold for below-market value, which traps miners in poverty while paradoxically creating incentives to use mercury in excessive quantities.⁶⁹ Many villagers in discussion workshops have suggested that the government should use tax revenues from the large-scale mining sector to support small-scale mining assistance programs and to create fairer and safer gold marketing arrangements that minimize mercury use.

The President of Tanzania has urged (on many occasions in 2007 and 2008) that large mining companies need to work more with indigenous miners to improve technology—which is particularly important because many critics claim that “systematic harassment of small-scale miners by authorities has become the order of the day.”^70(p1) Large (mainly foreign) mining companies own more than 90% of mineral-rich land in the Geita region, and microcredit is difficult to obtain among the poorer groups who do not have land rights and need assistance to transfer to cleaner technology.

Mining companies can provide jobs for local miners, but often, conflicts arise because miners cannot find jobs and companies use police forces to guard their land. As a World Bank consultant noted,

Recent initiatives to formalize land tenure [i.e., register indigenous miners] will hopefully help reduce conflicts in the future, but they will not be of much help in areas where mining companies have already secured concessions and started mining.^71(p30)

The lack of secure legal status is recognized as a growing public health concern for multiple reasons; in addition to conflict over ancestral land rights, the insecure atmosphere for pursuing livelihoods makes local business planning exceedingly difficult, and financial credit for safer technology cannot be obtained without first showing proof of legality to banks.

Although the failure to offer local workers access to legalization opportunities inhibits healthful behavior, the registration process is designed, in theory, to familiarize workers with key environmental and health hazards. Most miners are excluded from this process but express a deep desire to learn more about safety, risk-mitigation methods, and efficient processing and obtain a legitimate mining license. Although it is increasingly being recognized that socioeconomic and health disparities are interwoven in Tanzania,⁷² the experiences with miners underscores why promoting fair access to resources (secure land rights, equitable markets, and safer technologies) needs to be viewed as a public health priority.

Although environmental justice research has increasingly highlighted the need for more proactively engaging the private sector,³² one of the project's most crucial collaborations linking public health planning and the private sector was with the Federal Bank of the Middle East. With UN guidance and government support, the Federal Bank of the Middle East launched a $1 million gold refinery in the region of the project; the refinery is designed to use mercury-safe technology standards and pay international gold prices to miners.⁷³ Safe refineries such as this can help create mercury-free environments while encouraging a broader phaseout of mercury with inexpensive gravity technology alternatives—products such as the Cleangold Sluice (Cleangold, Lincoln City, OR), which is simple to use and needs no chemicals.⁷⁴

Ultimately, it should be recognized that artisanal mining occurs, whether with or without mercury, predominantly because of poverty and unemployment and safer jobs are needed. Various community members—health workers, mining engineers, and others—have suggested the need for wider structural understandings of environmental injustice to account for why alternative income-earning opportunities besides mining are so scarce in the region. If stable jobs are created, the impetus for artisanal mining will diminish; this is essentially the trajectory traced in countries such as the United States and Canada, where artisanal mining boomed during the gold-rush years but declined for reasons that included sustainable economic growth and job creation. Although mining may be a source of poverty alleviation in Tanzania⁷⁵ and throughout Africa and beyond,⁷⁶ policy measures to encourage safer livelihoods are increasingly needed.

CONCLUSION

Results from this study illustrate how social disparities and health inequalities are closely linked and show that unsafe occupational practices will likely continue to flourish unless policy reforms are initiated to assist workers. The early successes in the UN pilot program offer a sign of promise and illustrate the positive impacts of community training and the role for participatory efforts to address the drivers of worker marginalization. Yet, because funds for local training were limited in this pilot program, some workers feared that not enough momentum was created to ensure sustainable project impacts beyond the short term and may only benefit a relatively small part of the Geita community. It also remains to be seen whether the government agencies, mining companies, and other influential actors will take the recommended steps to redistribute resources locally and amend policies.

The study ultimately illustrates how mercury is a rising public health concern for multiple reasons. Not only is mercury a hazard in mining areas, but it also contributes to downstream problems and negatively impacts the ability of communities to earn income. By taking an interdisciplinary view of health, it is evident the reasons public health workers need to be mindful of and engage with the complex networks of labor relationships and institutional factors that affect health and environmental justice. The most important recommendation of this study is that public health workers must be allowed to work with “illegal” workers, because it can yield positive benefits—for worker health and the wider environment. If government agencies intend to reduce the threat of a mercury disaster, they should move toward reducing the “illegal” stigma associated with mining by providing incentives to integrate into the formal, legalized sector, with assistance for upgrading technologies.

The prospect for a new era of responsible mining with adherence to national laws is plausible, but new opportunities for collaboration are urgently needed that link public health workers, nongovernmental organizations, environmental advocates, the private sector, and governments. There is an emerging concern among public health workers that some governments in poorer countries who ban mercury completely (e.g., Mongolia) might be perilously leaving mercury in an “underground” market that cannot be regulated effectively. From a public health perspective, this should be closely examined, and the phase-out strategy in Tanzania provides an example of how legalization of miners is another route for policymakers to consider closely.

In addition to health and environmental incentives, economic incentives to reduce mercury use may arise from various internationally supported “fair trade” initiatives in which certified dealers are to pay premium prices for mercury-free gold from artisanal and small-scale gold mining.⁷⁷ Restriction of global mercury trade also provides another pressure point to promote environmental justice—one that can be understood as part of a longer-standing environmental justice movement focused on global phaseout of toxic trade.^31,32

The European Union and various countries have agreed to implement a mercury export ban (to be implemented by 2011), and it is widely believed that this may provide incentives to phase out mercury use in Africa by raising mercury prices. In some circumstances, research suggests that this may actually increase illicit trade and increase miners' reliance on mercury dealers who provide mercury for free in exchange for exclusive gold purchasing rights, which can exacerbate pollution in the short term,^36,78,79 and some also suggest that export bans, although necessary, can in the short term lead to an oversupply of cheap mercury in poorer countries.¹⁶ Ultimately, although cutting off mercury trade from rich countries to countries with artisanal and small-scale gold mining may be a requisite overall long-term toxic phase-out strategy, such efforts must be met with increased international and national commitments to support local health promotion and empowerment.

Tanzania's case illustrates why top-down regulations, in short, cannot be a substitute for community assistance. As mercury exposure, poverty, and mining continue to increase together in much of Africa and globally, the world urgently needs public health commitments that tackle the social, economic, and political inequities that are ultimately the greatest threat to health and well-being.