The Minamata Convention on Mercury (MC) includes provisions for a global monitoring program (GMP) and effectiveness evaluation (EE) to provide information on changes in mercury sources in various ...environmental media. While conventional measurement and modeling techniques have limitations in explaining the changes in mercury concentrations, the measurements of natural abundances of mercury stable isotopes have become powerful tracers for distinguishing between mercury sources and for understanding biogeochemical processes in the environment. Unfortunately, it is uncertain whether mercury isotope ratios can provide globally comparable results on specific mercury sources for the GMP and trend analyses for the EE. We have compiled a dataset from the literature to evaluate large-scale patterns of mercury isotope ratios in various environmental samples and to summarize sample types that can be used for the GMP. Total gaseous mercury, precipitation, foliage, and litter can provide comparable source information regarding atmospheric mercury across a large spatial scale. Interpretation of spatially relevant information using sediment and fish mercury isotope ratios are challenging because they represent multiple mercury sources and contain mercury that has been subject to biogeochemical transformation leading to isotope fractionation. In regards to the EE, data that provides evidence of changes due to source regulation needs to be gathered from local point source regions to assess health impacts. We recommend that the measurements of particulate-bound mercury in the atmosphere and sediment mercury isotope ratios near mercury hotspots and in fish, are needed to identify ecosystems sensitive to atmospheric deposition and to evaluate the effectiveness of the MC.
Mercury and its compounds are classified into three main groups: metallic mercury (Hg0), inorganic mercury (Hg2+), and organic mercury (methyl mercury: CH3Hg+, etc.). Metallic mercury is the only ...metal that is liquid at ambient temperature and normal pressure, which readily forms an amalgam with other metals. Therefore, mercury has long been used for refining various metals, and mercury amalgam has been used for dental treatment. Mercury has also been used in measuring instruments such as thermometers, barometers and blood pressure monitors, as well as electric appliances such as lighting equipment and dry batteries. Large amounts of metallic mercury are still used in other countries as a catalyst in the production of caustic soda by electrolysis. In addition, mercury compounds have been used in various chemicals such as mercurochrome, agricultural chemicals, and mildew-proofing agents. However, the use of mercury has also caused health problems for people. Minamata disease in Japan is a typical example. Also, since mercury is highly volatile, it is discharged as a product of industrial activities or derived from volcanoes, and it has been concluded on the basis of the findings of the United Nations Environment Program (UNEP) that it is circulating globally. Therefore, with the aim of establishing an internationally legally binding treaty for the regulation of mercury use to reduce risk, an intergovernmental negotiating committee was established in 2009. Japan actively contributed to this negotiation owing to its experience with Minamata disease, which led to the Convention on the regulation of mercury use being discharged as the “Minamata Convention on Mercury” and the treaty came into force on August 16, 2017. In this review, we introduce 1) the Global Mercury Assessment by UNEP; 2) mercury kinetics, exposure assessment and toxicity of different chemical forms; 3) large-scale epidemics of methylmercury poisoning; 4) methylmercury exposure assessment and health survey in whale-eating populations; 5) elemental mercury exposure assessment and health survey of mercury mine workers in China.
Mercury (Hg) pollution is an important environmental and public health issue that has garnered significant interest from policy makers and the global regulatory community. Consumption of seafood is ...the primary mechanism of methyl Hg (MeHg) exposure in humans, globally, and marine fish represent an important linkage between atmospheric dynamics, aquatic biogeochemistry and trophic transfer of this highly neurotoxic and easily assimilated form of Hg. Hg policies and management are highly interdisciplinary and at their foundation are relatively well established scientific principles related to Hg methylation, MeHg cycling and bioaccumulation, and subsequent trophic transfer to humans; however, certain fine-scale aspects of these processes remain poorly understood. After several years of intergovernmental negotiations the Minamata Convention on Mercury (MCM) entered into force in August 2017. Anthropogenic releases (water) and emissions (air) of Hg, human exposure, and environmental health are of considerable importance within the framework and policies outlined in the MCM. Additionally, the overall risk of Hg from artisanal and small-scale gold mining (ASGM) is considered a significant source of human exposure and commonly occurs in low and middle income countries, where miners use elemental Hg to extract gold from ore. Here I outline the history, evolution and progress of the MCM as it relates to the science-policy interface and offer a brief synthesis of the state of Hg science in the context of modeling, temporal assessments of Hg trends and global environmental change and ecosystem sensitivity.
Display omitted
•The Minamata Convention on Mercury (MCM) entered into force in August 2017.•Hg post depositional processes and ecosystem sensitivity are important themes.•Hg models have important limitations and increased transparency is needed.•Valid temporal assessments of Hg in biota need to evaluate concomitant changes in food webs.•The MCM will benefit from treating Hg pollution as a food security issue.
Mercury (Hg) is a naturally occurring element in the Earth's crust. It can be harmful to human health when released in large quantities and/or converted to the neurotoxicant methyl mercury in aquatic ...ecosystems. This study analyzes global and regional trends in anthropogenic Hg releases to the atmosphere between 2010 and 2015, as well as the associated trends in modeled and measured Hg concentrations at sites around the world. In general, we find that global Hg emissions and concentrations have grown slightly in this period, as declines from the phase-out of commercial Hg use in the developed world have been more than matched by increases in Hg-related activities in the industrializing countries of the world. We estimate that global Hg emissions between 2010 and 2015 have grown at a rate of 1.8%/yr, from 2188 Mg (+44%/-20%, 80% C.I.) in 2010 to 2390 Mg (+42%/-19%, 80% C.I.) in 2015. Regionally, emissions declined over this period in the U.S. (−10%), OECD Europe (−5.8%), and Canada (−3.2%), while they increased in Central America (+5.4%), South Asia (+4.6%), and Eastern Africa (+4.0%). East Asia remained the largest emitting region at 1012 Mg in 2015, though growth there has slowed significantly in recent years. The production of Hg (+7.9%), caustic soda (+6.3%), and cement (+6.3%) showed the highest increases by source type, though artisanal and small-scale gold mining (ASGM) was the single largest source of emissions in 2015 (775 Mg). The commercial use of Hg in dental applications (−5.6%) and electrical equipment (−5.2%) continued to decline. These emission trends show a continuation of the regional and sectoral shifts that began in the 1970s, but with a resulting reversal in global trends, because the benefits from Hg phase-out in North America and Europe have been largely realized and industrial growth in developing countries has begun to dominate. The emission trends are in agreement with trends in modeled and measured concentrations, which show small declines in surface air total gaseous Hg concentrations in eastern North America and Western Europe between 2010 and 2015, but slight increases for much of the rest of the world, driven by the continued increases in emissions from Asia and from ASGM. Our results suggest that reductions of Hg in the North Atlantic region have been largely successful, and focus now needs to shift to Asia and to the continued practice of ASGM worldwide.
Display omitted
•Global trends in mercury emissions and concentrations are estimated for 2010–2015.•Declines since the 1970s in North America and Europe are now leveling out.•Emissions continue to grow in Asia, Africa, and other industrializing regions.•As a result, global emissions have grown slightly (1.8%/yr) during this period.•Mercury use, coal combustion, and small-scale gold mining need further controls.
The Minamata Convention on Mercury is a multilateral environmental agreement that obligates Parties to reduce or control sources of mercury pollution in order to protect human health and the ...environment. The Convention includes provisions on providing technical assistance and capacity building, particularly for developing countries and countries with economies in transition, to promote its effective implementation. Evaluating the effectiveness of the Convention (as required by Article 22) is a crucial component to ensure that it meets this objective. We describe an approach to measure effectiveness, which includes a suite of short-, medium-, and long-term metrics related to five major mercury control Articles in the Convention, as well as metrics derived from monitoring of mercury in the environment using select bioindicators, including people. The use of existing biotic Hg data will define spatial gradients (e.g., biological mercury hotspots), baselines to develop relevant temporal trends, and an ability to assess risk to taxa and human communities of greatest concern. We also recommend the development of a technical document that describes monitoring options for the Conference of Parties, to provide science-based standardized guidelines for collecting relevant monitoring information, as guided by Article 19.
Display omitted
India is undergoing rapid industrialisation and globalisation, with a vast and growing population. Rising atmospheric mercury (Hg) emissions are one of the severe environmental crises the country ...faces as a result of this fast-paced development. India is the second largest emitter of Hg in the world. Here, we study the domestic and foreign socioeconomic drivers of India's Hg emission increases over time. We find that the growing domestic per capita final demand level is the most important driver of India's Hg emissions increase, having been responsible for 88% of the total increase of 125 tons (t) during 2004–2017. In contrast, India's changing Hg emission intensity and economic structure contributed to a cumulative decrease in emissions, albeit to a much lower extent (about 22 t). Given the importance of socioeconomic drivers, there is an urgent need to account for them in India's Hg emission mitigation efforts. The Minamata Convention on Mercury currently targets reduced manufacture, trade and use of Hg, and its reduced environmental releases among others. It must also begin to incorporate considerations of evolving socioeconomic drivers such as increasing consumerism and changing economic structures. Thereby it can inspire multi-faceted solutions to the global mercury pollution crisis.
•Only controlling direct emissions is insufficient to solve India's mercury crisis.•Socioeconomic changes influencing India's mercury emissions are assessed.•Growing per capita final demand level (particularly domestic) is most concerning.•Mitigation policies must target changing consumption habits and economic structure.•The Minamata Convention must consider socioeconomic drivers of mercury emissions.
We present data on a rapid assessment of fish Hg concentrations from 40 different waterbodies in 26 countries that includes data on 451 fish of 92 species. Significant differences in fish Hg ...concentrations were observed across fish foraging guilds and in general, higher trophic level fish (i.e., piscivores and carnivores) showed the highest mean total Hg (THg) concentrations. However, elevated THg concentrations observed in a lower trophic level, detrivorous species highlights the importance of understanding Hg concentrations across a wide range of trophic levels, and also characterizing site-specific processes that influence methylmercury (MeHg) bioavailability. A linear mixed effects model was used to evaluate the effects of length, trophic level, sampling location, and taxonomy on THg concentrations. A positive, significant relationship between THg in fish and fish size, trophic level, and latitude of the sampling site was observed. A comparison of Hg concentrations across all sites identifies biological mercury hotspots, as well as sites with reduced Hg concentrations relative to our overall sampling population mean Hg concentration. Results from this study highlight the value of rapid assessments on the availability of methylmercury in the environment using fish as bioindicators and the need for expanded biomonitoring efforts in understudied regions of the world. This study also provides insights for the future design and implementation of large-scale Hg biomonitoring efforts intended to evaluate the effectiveness of future Hg reduction strategies instituted by the Minamata Convention on Mercury.
Display omitted
•Fish mercury (Hg) concentrations are determined from 40 waterbodies in 26 countries•Fish Hg, body size, trophic level and latitude are positively correlated•Biological Hg hotspots are identified in regions where Hg data are limited•Methods provide model for Hg monitoring in support of Minamata Convention on Mercury
The focus of this paper is to briefly discuss the major advances in scientific thinking regarding: a) processes governing the fate and transport of mercury in the environment; b) advances in ...measurement methods; and c) how these advances in knowledge fit in within the context of the Minamata Convention on Mercury. Details regarding the information summarized here can be found in the papers associated with this Virtual Special Issue of STOTEN.
Display omitted
•This paper provides a brief summary of recent advances in Hg science.•Details are presented in 10 papers in a Virtual Special Issue of STOTEN.•Presented are updates in scientific knowledge regarding the fate and transport of Hg.•Advances in measurement methods are synthesized.•Discussion is provided as to how these fit within the Minamata Convention.
The Minamata Convention to reduce anthropogenic mercury (Hg) emissions entered into force in 2017, and attention is now focused on how to best monitor its effectiveness at reducing Hg exposure to ...humans. A key question is how closely Hg concentrations in the human food chain, especially in fish and other aquatic wildlife, will track the changes in atmospheric Hg that are expected to occur following anthropogenic emission reductions. We investigated this question by evaluating several regional groups of case studies where Hg concentrations in aquatic biota have been monitored continuously or intermittently for several decades. Our analysis shows that in most cases Hg time trends in biota did not agree with concurrent Hg trends in atmospheric deposition or concentrations, and the divergence between the two trends has become more apparent over the past two decades. An over-arching general explanation for these results is that the impact of changing atmospheric inputs on biotic Hg is masked by two factors: 1) The aquatic environment contains a large inventory of legacy emitted Hg that remains available for bio-uptake leading to a substantial lag in biotic response time to a change in external inputs; and 2) Biotic Hg trends reflect the dominant effects of changes in multi-causal, local and regional processes (e.g., aquatic or terrestrial biogeochemical processes, feeding ecology, climate) that control the speciation, bioavailability, and bio-uptake of both present-day and legacy emitted Hg. Globally, climate change has become the most prevalent contributor to the divergence. A wide range of biotic Hg outcomes can thus be expected as anthropogenic atmospheric Hg emissions decline, depending on how these processes operate on specific regions and specific organisms. Therefore, evaluating the effectiveness of the Minamata Convention will require biomonitoring of multiple species that represent different trophic and ecological niches in multiple regions of the world.
Display omitted
•Mercury time-trends in aquatic biota often do not agree with atmospheric trends.•Divergence between the two trends has become more apparent in the past two decades.•The divergence is due to legacy mercury and changing biogeochemical processes.•Globally climate change has become the most prevalent contributor to the divergence.•Thus, the efforts of the Minamata Convention may be countered by climate change.
PDF
