Atmospheric Mercury Emissions Research Articles

Variations in methylmercury contamination levels and associated health risks in different fish species across three coastal bays in China

The growing atmospheric mercury (Hg) emissions in China have raised ongoing concerns regarding contamination in marine fish. To better understand the pollution patterns and associated risks, we examined methylmercury (MeHg) content in demersal and pelagic fish from four commonly found families in three geographically distinct bays along the Chinese coast. We identified significant spatial variations in MeHg levels within the same fish family across regions. Specifically, fish collected from the Beibu Gulf in the South China Sea consistently exhibited significantly higher MeHg levels compared to those from the Laizhou Bay in the Northeast and/or Haizhou Bay in the East of China. In contrast, MeHg levels in fish collected from Haizhou Bay consistently remained the lowest. Within each region, we observed significantly higher MeHg concentrations in demersal species compared to pelagic species. This trend was particularly evident in fish species including bartail flathead (Platycephalus indicus), small-scale tongue sole (Cynoglossus microlepis) and greater lizardfish (Saurida tumbil) from the Beibu Gulf (0.50, 0.21, and 0.18 mg/kg dw, respectively), as well as bartail flathead and slender lizardfish (Saurida elongata) from Laizhou Bay (0.09 and 0.12 mg/kg dw, respectively). By comparison, MeHg content in silver pomfret (Pampus argenteus) from all three regions consistently remained relatively lower than in other species. Using target hazardous quotient (THQ) calculations, we estimated potential health risks in local populations associated with the consumption of the studied fish species. Our results showed a lack of apparent health risks to local residents, as all THQ values obtained from the three regions fell within the safe limits (0.02–0.94). However, it remains important to conduct additional assessments and spatiotemporal monitoring that encompass a broader range of species and regions.

Geographic Drivers of Mercury Entry into Aquatic Food Webs Revealed by Mercury Stable Isotopes in Dragonfly Larvae.

Atmospheric mercury (Hg) emissions and subsequent transport and deposition are major concerns within protected lands, including national parks, where Hg can bioaccumulate to levels detrimental to human and wildlife health. Despite this risk to biological resources, there is limited understanding of the relative importance of different Hg sources and delivery pathways within the protected regions. Here, we used Hg stable isotope measurements within a single aquatic bioindicator, dragonfly larvae, to determine if these tracers can resolve spatial patterns in Hg sources, delivery mechanisms, and aquatic cycling at a national scale. Mercury isotope values in dragonfly tissues varied among habitat types (e.g., lentic, lotic, and wetland) and geographic location. Photochemical-derived isotope fractionation was habitat-dependent and influenced by factors that impact light penetration directly or indirectly, including dissolved organic matter, canopy cover, and total phosphorus. Strong patterns for Δ200Hg emerged in the western United States, highlighting the relative importance of wet deposition sources in arid regions in contrast to dry deposition delivery in forested regions. This work demonstrates the efficacy of dragonfly larvae as biosentinels for Hg isotope studies due to their ubiquity across freshwater ecosystems and ability to track variation in Hg sources and processing attributed to small-scale habitat and large-scale regional patterns.

Parsing India's mercury crisis: A socioeconomic take reveals the defining role of domestic consumerism

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.

High-resolution atmospheric mercury emission from open biomass burning in China: Integration of localized emission factors and multi-source finer resolution remote sensing data

Mercury (Hg) emissions from open biomass burning represent one of the largest Hg inputs to the atmosphere, with considerable effects on the atmospheric Hg budget. However, there is currently large uncertainty in the inventory of Hg emissions from open biomass burning in China due to limitations on the coarse resolution of burned area products, rough biomass data, and the unavailability of suitable emission factors (EFs). In this study, we developed high tempo-spatial resolution (30 m) and long time-series (2000–2019) atmospheric Hg emission inventories from open biomass burning using the Global Annual Burned Area Map (GABAM) product, high-resolution biomass map, Landsat-based tree cover datasets as well as local EFs in China. The results showed that the average annual Hg emission from open biomass burning in China amounted to 172.6 kg during 2000–2019, with a range of 63–398.5 kg. The largest Hg emissions were found in cropland (72%), followed by forest (25.9%), and grassland (2.1%). On a regional level, Northeast China (NE) and Southwest China (SW) were the two main contributors, together accounting for more than 60% of total Hg emissions. The temporal distribution of Hg emissions showed that the peaks occurred in 2003 and 2014. This is a comprehensive estimation of Hg emissions from open biomass burning in China by integrating various high-resolution remotely sensed data and nationwide localized EFs, which has important implications for understanding the role of open biomass burning in China in regional and global atmospheric Hg budget.

Scenarios for reducing copper smelting-related atmospheric mercury emissions through copper recycling and mercury removal technologies in major countries

Scenarios for reducing copper smelting-related atmospheric mercury emissions through copper recycling and mercury removal technologies in major countries

Atmospheric Mercury Emission from the Surface of the Ursk Dump (the Kemerovo Region)

Atmospheric Mercury Emission from the Surface of the Ursk Dump (the Kemerovo Region)

Atmospheric Mercury Emission from the Surface of the Ursk Dump (the Kemerovo Region)

Atmospheric Mercury Emission from the Surface of the Ursk Dump (the Kemerovo Region)

Reducing Mercury Emission Uncertainty from Artisanal and Small-Scale Gold Mining Using Bootstrap Confidence Intervals: An Assessment of Emission Reduction Scenarios

Atmospheric mercury emission scenarios from artisanal and small-scale gold mining for 56 tropical and subtropical countries have been elaborated and assessed for their comparative significance. A multi-step quantitative method that yields narrow and robust confidence intervals for mercury emission estimates was employed. Firstly, data on gold production for different years, the ratio of mercury used in the different amalgamation processes, and ancillary input parameters were retrieved from official and unofficial sources, and their potential for emission reduction examined. Then, a Monte Carlo method to combine the data and generate mercury emission samples was used. These samples were processed by a non-parametric re-sampling method (bootstrap) to obtain robust estimates of mercury emissions, and their 95% confidence intervals, both for the current state and for the emission scenarios designed in this study. The artisanal and small-scale gold mining mercury emission (to the atmosphere) estimates agree with those reported in the Global Mercury Assessment 2018; however, the overall uncertainty is reduced from roughly 100% in the Global Mercury Assessment (779.59 tons/y; uncertainty range: 361.07–1197.97) to 27% (1091.93 tons/y; confidence interval at 95% level of confidence: 964.54–1219.77) in this study. This is a substantial outcome since the narrowing of the confidence intervals permits a more meaningful evaluation of the different emission scenarios investigated, which otherwise, given the broad uncertainty of other estimates, would have led only to vague conclusions in a study of this nature.

A high spatial resolution dataset for anthropogenic atmospheric mercury emissions in China during 1998–2014

China is the largest atmospheric mercury (Hg) emitter globally, which has been substantially investigated. However, the estimation of national or regional Hg emissions in China is insufficient in supporting emission control, as the location of the sources may have significant impacts on the effects of Hg emissions. In this concern, high-spatial-resolution datasets of China’s Hg emissions are necessary for in-depth and accurate Hg-related studies and policymaking. Existing gridded datasets are constructed using population distribution as the proxy, which is limited as Hg emissions are closely related to energy consumption and economic processes. This study constructs a dataset of anthropogenic atmospheric Hg emissions in China gridded to a 1 km resolution during 1998–2014. This dataset is produced based on data of land uses, individual enterprises, roadmaps, and population, uncovering Hg emissions in agriculture, industries, services, and residents. This dataset can promote the reliability of Hg-related studies at a high spatial resolution. Moreover, this dataset can support spatially explicit Hg reduction of economic sectors.

Impacts of Material Input and Production Process on the Isotopic Fingerprint of Atmospheric Mercury Emissions from Cement Clinker Production

Impacts of Material Input and Production Process on the Isotopic Fingerprint of Atmospheric Mercury Emissions from Cement Clinker Production

Heterogeneous Variations on Historical and Future Trends of CO2 and Multiple Air Pollutants from the Cement Production Process in China: Emission Inventory, Spatial-Temporal Characteristics, and Scenario Projections.

Cement production is a major contributor to carbon dioxide (CO2) and multiple hazardous air pollutant (HAP) emissions, threatening climate mitigation and urban/regional air quality improvement. In this study, we established a comprehensive emission inventory by coupling the unit-based bottom-up and mass balance methods, revealing that emissions of most HAPs have been remarkably controlled. However, an increasing 6.0% of atmospheric mercury emissions, as well as 14.1 and 23.7% of fuel-related and process-related CO2 emission growth were witnessed unexpectedly. Industrial adjustment policies have imposed a great impact on the spatiotemporal changes in emission characteristics. Monthly emissions of CO2 and multiple HAPs decreased from December to February due to the "staggered peak production," especially in northern China after implementing the intensified action plan for air pollution control in winter. Upgrading environmental technologies and adjusting capacity structures are identified as dominant driving forces for reducing HAP emissions. Besides, energy intensity improvement can help offset some of the impact caused by the increase in clinker/cement production. Furthermore, scenario analysis results show that ultra-low emission and low-carbon technology transformation constitute the keys to achieve the synergic reduction of CO2 and multiple HAP emissions in the future.

Global health impact of atmospheric mercury emissions from artisanal and small-scale gold mining

SummaryArtisanal and small-scale gold mining (ASGM) is the leading source of mercury (Hg), a global neurotoxin. Past research has focused on the health impacts on miners and nearby residents; here, we estimate the risk for global general populations by employing a comprehensive atmosphere-land-ocean-ecosystem and exposure-risk-valuation model framework. Our results suggest that ASGM sources contribute 12%, 10%, and 0.63% to the atmospheric Hg deposition, plankton methylmercury concentrations, and soil total Hg concentrations at present day, respectively, and cause 5.8×105 points of intelligence quotient decrements and 1,430 deaths for global general populations per year. The monetized global health impact of ASGM ($154 billion) is 1.5 times its local impact and accounts for half of the total revenue of ASGM ($319 billion). A major spatial decoupling between the health impact and economic gains is also revealed, suggesting that intervention measures such as awareness-raising, capacity-building, and technology transfer funded by the Global North are cost-effective.

Sediment mercury concentration changes as a response to increased industrial activity in Coronel Bay, Chile

Among the main sources of atmospheric mercury emissions are thermoelectric plants that use coal to generate electricity. This heavy metal is transported by air from its origin to neighboring coastal areas, where it is deposited in the sediment record. This research evaluated the content and temporal distribution of Hg in the coastal sediments of Central Chile, Coronel Bay, industrialized zone with two operative thermoelectric plants, and Coliumo Bay, reference zone free of industry. To this end, sediment cores from the centers of the two bays were obtained. Laboratory results show that the greatest Hg contents were found in the surface strata of the Coronel Bay core, with concentrations up to an order of magnitude greater than those obtained in the same strata in Coliumo Bay. This increase in Hg concentration coincides with the beginning of industrial activity in Coronel, with greater concentrations observed from 2012 on, the year in which the industrial operation of two coal-fired thermoelectric plants on the bay began. Based on 210Pb activity and the relationships between Hg content and organic matter, it was established that the main pathway of Hg to sediment is atmospheric deposition, while Coliumo presented inputs that reflect local non anthropogenic sources.

Mercury emission characteristics and mechanism in the raw mill system of cement clinker production

Mercury pollution has attracted worldwide attention due to its toxicity, bioaccumulation and persistence. Cement clinker production is the top emitter of atmospheric mercury in China and the emissions from raw mill systems account for about 85% of all emissions. However, the mercury emission characteristics and mechanisms as a function of time during an operation cycle are still unclear. This study aims to reveal the mercury emission characteristics and mechanisms in cement plants by comprehensively using offline and online field measurements, control experiments and heat transfer analysis. Research results indicated that an intermediate temperature (300–500 °C) desorption and the heterogeneous oxidation of mercury in the precalciner, the selective adsorption of oxidized gaseous mercury (Hg2+) to raw meal, and Hg2+ re-vaporization in the conditioning tower jointly caused an increase in the Hg2+ ratio (15.3%−83.6%) during the mill-off mode. In addition, mercury concentrations remained at approximately 6.5 μg/Nm3 during the mill-on mode while the values reached a peak of 1835.4 μg/Nm3 during the mill-off mode. Thus, atmospheric mercury emissions during the mill-off mode accounted for 35.0%− 71.7% of the emissions during the entire cycle, although the mill-off period only lasted for 5%− 17% of the whole cycle. Our results therefore suggest that supervisory monitoring of mercury in cement clinker production should specify the operating status of raw mills. Mercury control technologies targeting a relatively short period for the mill-off mode can substantially reduce mercury emissions from cement clinker production, and thus, the related impacts on ecosystems and human health.

Role of Trade in India's Rising Atmospheric Mercury Emissions.

India is among the largest emitters of atmospheric mercury (Hg) in the world. India's production activities have associated Hg emissions which can be attributed to final demands (e.g., purchases by households, governments, and private investments) of nations driving upstream production from the demand perspective, or primary inputs (e.g., labor and capital supply) of nations enabling downstream production from the supply perspective. This study identifies key nations and sectors that directly and indirectly drove India's Hg emissions from both the demand and supply perspectives during 2004-2014. While domestic final demand was the dominant driver from the demand perspective (driving about 80-85% of the total), USA, China, and UAE are important foreign drivers. Similarly, from the supply perspective, domestic primary inputs were the dominant drivers. However, the share of foreign inputs enabling Hg emissions increased from 16 to 23% during the decade. Saudi Arabia, Indonesia, Australia, and China are the top foreign supply-side drivers. The Construction sector is an important demand-side driver, whereas fossil fuel sectors are important supply-side drivers. These findings can guide global and national policies for demand- and supply-side management of Hg emissions in India and assist in the successful implementation of the Minamata Convention on Mercury.

Development of an anthropogenic atmospheric mercury emissions inventory in Thailand in 2018

Mercury (Hg) is a highly toxic pollutant characterized by its long-range transport in the atmosphere. In the present study, the atmospheric Hg emission inventory in Thailand was developed using a bottom-up approach. To reflect the emitting behaviors of various Hg sources in Thailand in 2018, activity data specific to individual sources were collected, and emission factors were obtained from local sources or adapted from the literature with proper adjustments. It was found that about 4,337.8 kg of anthropogenic Hg was emitted: 52 % from biomass open burning and 40 % from combustion sources. Mercury speciation was also investigated. Hg0 was found to be dominant at 73 %, followed by Hg2+ at 18 % and HgP at 9 %. Maps were produced using the Spatial Geographic Information System, which showed that the emissions were relatively dense in the Central region of Thailand where most industrial activities take place and in the Northern and Northwestern regions as a result of biomass open burning. Hg emissions were also observed to mainly take place during the early months of the year, particularly in March and April. These two months were determined to account for 47 % of the total annual emissions of Hg, mostly due to increased combustion activities and biomass open burning. The output of the present work is a Hg emission database that can serve as model to investigate the status of Hg and the risks it poses to human health and ecosystems as well as support policy makers in developing emission control strategies.

Critical transmission sectors in embodied atmospheric mercury emission network in China

AbstractAtmospheric mercury is a crucial pollutant that must be well‐controlled to avoid damaging public health. It is thus necessary to understand from multiple perspectives the roles played by different industrial sectors, as well as their geographical distribution. Existing studies have overlooked the transmission sectors in the economic supply chains of the embodied atmospheric mercury emission network. In this paper, we offer a betweenness‐based account (BBA) for Chinese regions and industrial sectors in transmitting embodied atmospheric mercury emissions and in doing so have identified the transmitting hubs. Our results show that the Henan province acts as the transmission hub of the embodied atmospheric mercury emission network in China. The metallurgy, chemical, and construction industries generally play important roles in the transmission of embodied atmospheric mercury emissions across China. Henan's metallurgy sector, the third highest of all, is more closely linked with inter‐provincial sectors than the top two transmission sectors (the metallurgy industry of Jiangsu and the chemical industry of Shandong). This study can help policy makers improve mercury control measures by focusing on transmission processes for effective and comprehensive atmospheric mercury emission control.

Global Economic Structure Transition Boosts Atmospheric Mercury Emissions in China

AbstractAs the “world factory,” China has the most massive anthropogenic atmospheric mercury (Hg) emissions in the world along with its intense production activities. The development of global society and economy, including technology development, consumption behavior evolution, population growth, and so on, would significantly affect China's production and thus the Hg emissions. Here we uncover critical global socioeconomic drivers of atmospheric Hg emission changes in China during 2005–2015. Results show that the transition of global economic structures (i.e., production and final demand structures) caused 179 tons of increase in China's atmospheric Hg emissions during this period if other factors remained constant, while the transition of foreign economic structures contributed as much as 83% (149 tons). More importantly, for the first time, we reveal the crucial role of production structure transition in foreign nations. The cumulative effect of foreign production structure transition during this period (93 tons) was larger than that of foreign final demand structure transition (56 tons). It is also far more extensive than the cumulative effect of China's production structure transition (9.5 tons). Previous studies on China's atmospheric Hg emissions driven by global final demand focused more on optimizing consumption behaviors. However, this study proves the significance of a greener global production structure for reducing anthropogenic atmospheric Hg emissions in China, thus implementing the Minamata Convention on Mercury.

Global health effects of future atmospheric mercury emissions

Mercury is a potent neurotoxin that poses health risks to the global population. Anthropogenic mercury emissions to the atmosphere are projected to decrease in the future due to enhanced policy efforts such as the Minamata Convention, a legally-binding international treaty entered into force in 2017. Here, we report the development of a comprehensive climate-atmosphere-land-ocean-ecosystem and exposure-risk model framework for mercury and its application to project the health effects of future atmospheric emissions. Our results show that the accumulated health effects associated with mercury exposure during 2010–2050 are $19 (95% confidence interval: 4.7–54) trillion (2020 USD) realized to 2050 (3% discount rate) for the current policy scenario. Our results suggest a substantial increase in global human health cost if emission reduction actions are delayed. This comprehensive modeling approach provides a much-needed tool to help parties to evaluate the effectiveness of Hg emission controls as required by the Minamata Convention.

Rapidly changing coal-related city-level atmospheric mercury emissions and their driving forces

The up-to-date city-level mercury emission inventory is essential for effective mitigation policy designs due to rapid changes in energy consumption and industrial structures in Chinese cities. This study updated the atmospheric mercury emission inventory in 2015 based on the most recent information on plant-specific air pollution control devices (APCDs) and coal consumption for 45 sectors in 215 Chinese cities. Total emissions were estimated at 218 t with an uncertainty range of − 54.0% to 147%, to which coal-fired industrial boilers (CFIBs) contributed 58.1%, followed by coal-fired power plants (CFPPs, 32.7%). Mercury emissions varied significantly among cities, ranging from 0.0218 to 6.89 t. The Logistics Mean Division Index (LMDI) model was then applied to identify key factors driving mercury emission changes in 50 representative cities from 2010 to 2015. Although coal consumption increased by nearly one fifth across the 50 cities, their total emissions declined by 2.36%, largely due to energy structure adjustments and widespread installations of more efficient APCDs. However, key drivers of mercury mitigation differed widely between the cities, being driven by energy intensity improvements in Chongqing and Guangzhou (Guangdong province) and by energy structure adjustments in Wuhan (Hubei province) and Yinchuan (Ningxia province). Mitigation strategies should be tailored to reflect these differences.