Anthropogenic Atmospheric Emissions Research Articles

Quantifying Ice‐Sheet Derived Lead (Pb) Fluxes to the Ocean; A Case Study at Nioghalvfjerdsbræ

AbstractConcentrations of the toxic element lead (Pb) are elevated in seawater due to historical emissions. While anthropogenic atmospheric emissions are the dominant source of dissolved Pb (dPb) to the Atlantic Ocean, evidence is emerging of a natural source associated with subglacial discharge into the ocean but this has yet to be constrained around Greenland. Here, we show subglacial discharge from the cavity underneath Nioghalvfjerdsbræ floating ice tongue, is a previously unrecognized source of dPb to the NE Greenland Shelf. Contrasting cavity‐inflowing and cavity‐outflowing waters, we constrain the associated net‐dPb flux as 2.2 ± 1.4 Mg·yr−1, of which ∼90% originates from dissolution of glacial bedrock and cavity sediments. We propose that the retreat of the floating ice tongue, the ongoing retreat of many glaciers on Greenland, associated shifts in sediment dynamics, and enhanced meltwater discharges into shelf waters may result in pronounced changes, possibly increases, in net‐dPb fluxes to coastal waters.

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.

Field Application of Automated Spectrophotometric Analyzer for High-Resolution In Situ Monitoring of pH in Dynamic Estuarine and Coastal Waters

High quality pH measurements are required in estuarine and coastal waters to assess the impacts of anthropogenic atmospheric CO2 emissions on the marine carbonate system, including the resulting decrease in pH. In addition, pH measurements are needed to determine impacts on carbonate chemistry of phytoplankton blooms and their breakdown, following enhanced anthropogenic nutrient inputs. The spectrophotometric pH technique provides high quality pH data in seawater, and is advantageous for long-term deployments as it is not prone to drift and does not require in situ calibration. In this study, a field application of a fully automated submersible spectrophotometric analyzer for high-resolution in situ pH measurements in dynamic estuarine and coastal waters is presented. A Lab-on-Chip (LOC) pH sensor was deployed from a pontoon in the inner Kiel Fjord, southwestern Baltic Sea, for a total period of 6 weeks. We present a time-series of in situ pHT (total pH scale) and ancillary data, with sensor validation using discretely collected samples for pHT and laboratory analysis. The difference between the sensor and laboratory analyses of discrete samples was within ±0.015 pHT unit, with a mean difference of 0.001 (n=65), demonstrating that the LOC sensor can provide stable and accurate pHT measurements over several weeks.

Major Regional-Scale Production of O3 and Secondary Organic Aerosol in Remote Amazon Regions from the Dynamics and Photochemistry of Urban and Forest Emissions.

The Amazon rainforest suffers increasing pressure from anthropogenic activities. A key aspect not fully understood is how anthropogenic atmospheric emissions within the basin interact with biogenic emissions and impact the forest's atmosphere and biosphere. We combine a high-resolution atmospheric chemical transport model with an improved emissions inventory and in-situ measurements to investigate a surprisingly high concentration of ozone (O3) and secondary organic aerosol (SOA) 150-200 km downwind of Manaus city in an otherwise pristine forested region. We show that atmospheric dynamics and photochemistry determine a gross production of secondary pollutants seen in the simulation. After sunrise, the erosion of the nocturnal boundary layer mixes natural forest emissions, rich in biogenic volatile organic compounds, with a lofted pollution layer transported overnight, rich in nitrogen oxides and formaldehyde. As a result, O3 and SOA concentrations greater than ∼47 ppbv and 1.8 μg m-3, respectively, were found, with maximum concentrations occurring at 2 pm LT, 150-200 km downwind of Manaus city. These high concentrations affect a large primary forested area of about 11,250 km2. These oxidative areas are under a NOx-limited regime so that changes in NOx emissions from Manaus have a significant impact on O3 and SOA production.

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.

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.

Impacts of industrial atmospheric emissions on watershed export of dissolved ions in coastal streams: a Bayesian modeling approach.

Anthropogenic atmospheric emission and subsequent deposition of sulfur (S) has been linked to disrupted watershed biogeochemical processes through soil and surface water acidification. We investigated watershed-scale impacts of acidic deposition on tributary concentrations and watershed exports of major nutrients and ions for the Kitimat River Watershed, British Columbia. Since the 1950s,the Kitimat watershed hadan aluminum smelting facility with substantial emissions at the river estuary. Emissions loadthe airshed overlying the watershed and potentially impact western tributaries leaving eastern tributaries available as reference. We assessed concentrations and export of key compounds in three reference and six potentially impacted tributaries and watersheds in 2015 and 2016. Sulfate (SO4), fluoride (F), nitrate (NO3), and chloride (Cl) were significantly higher in impacted tributaries. F concentrations exceeded the Canadian Council of Ministers of the Environment guideline for aquatic life in 83% of samples collected from impacted streams. Watershed export and associated uncertainty were determined by bootstrapped flow-stratified Beale's unbiased estimator. Impact of emissions on watershed export was modeled in a Bayesian approach to include variance in the export estimate to inform the uncertainty of model parameters. Export of SO4 and Ca increased significantly within 16 km and 8 km, respectively, toward the smelter emissions. The corresponding impacted area for SO4 and Ca was approximately 100 km2 and 45 km2, respectively. SO4 export is likely due to direct impacts of S deposition, with excess S being flushed from the watersheds. Ca export patterns likely result from indirect impacts of S deposition on soil chemistry and flushing of Ca. These impacts may contribute to effects within tributaries on benthic stream communities and regionally important juvenile Pacific salmon.

Global anthropogenic atmospheric emission inventory of twelve typical hazardous trace elements, 1995–2012

Hazardous trace elements (HTEs) cannot be eliminated through microbial degradation in the environment, and moreover, high concentrations of HTEs do not only impose a long term and non-reversible burden on biogeochemical cycling in the ecosystem, but also threaten the health and life of animals and human beings. Taking account of the obvious differences on economic development and technology diffusion among countries, we construct the best available representation of time-varying emission factors of HTEs for primary anthropogenic activities in five regions of the world. Anthropogenic atmospheric emission inventory of twelve typical HTEs (Hg, As, Se, Pb, Cd, Cr, Ni, Sb, Mn, Co, Cu and Zn) characterized by global region, long-term spans and high spatiotemporal resolutions are elaborately established by synthetically using emission factor methods and ArcGIS tools. Our results show that the global total emissions of twelve HTEs from primary anthropogenic sources have decreased from about 268262 tons in 1995–216893 tons in 2012, with an annual decline rate of 1%. For HTE emissions in 2012, coal combustion sources (CC, accounting for about 35–97% of Hg, Se, Cr, Mn, Co and Zn emissions), liquid fuel combustion (LFC, accounting for about 31% of Pb emission), nonferrous metal smelting (NFMS, being responsible for about 51–77% of As, Cd and Ni emissions) and brake wear (BW, contributing about 42–67% of Sb and Cu emissions) are identified as primary contribution sources for the corresponding HTEs. Asia is the highest HTEs emitting continent in 2012, accounting for approximately 59% of the global total emissions. Generally, China, Chile, India, Russia, the United States and South Africa represent the top countries with high HTE emissions from anthropogenic sources. Therein, China ranks as the world's largest country with HTE (except for Sb) emissions. In contrast, the U.S. is found as the country producing the largest Sb emission throughout the world. The top emission intensities of HTEs are found in Eastern and Southern Asia and Eastern Europe.

Melt‐Induced Fractionation of Major Ions and Trace Elements in an Alpine Snowpack

AbstractUnderstanding the impact of melting on the preservation of atmospheric compounds in high‐Alpine snow and glacier ice is crucial for future reconstruction of past atmospheric conditions. However, detailed studies investigating melt‐related changes of such proxy information are rare. Here we present a series of five snow pit profiles of 6 major ions and 34 trace elements at Weissfluhjoch, Switzerland, collected between January and June 2017. Atmospheric composition was preserved during the cold season, while melting toward the summer resulted in preferential loss of certain species from the snowpack or enrichment at the base of the snowpack. Increasing mobilization of major ions with meltwater (NH4+ < Cl− ~ Na+ < NO3− ~ Ca2+ ~ SO42−) can be related to their stronger enrichment at ice crystal surfaces during snow metamorphism. Results for trace elements show that less abundant elements such as Ce, Eu, La, Mo, Nd, Pb, Pr, Sb, Sc, Sm, U, and W were best preserved and may still serve as tracers to reconstruct past natural and anthropogenic atmospheric emissions from melt‐affected snow pit and ice core records. The obtained elution behavior matches the findings from another high‐Alpine site (upper Grenzgletscher) for major ions and the large majority of investigated trace elements. Both studies indicate that water solubility and location at the microscopic scale are likely to determine the relocation behavior with meltwater and also suggest that the observed species‐dependent preservation from melting snow and ice is representative for the Alpine region, reflecting Central European atmospheric aerosol composition.

Investigate the impact of local iron-steel industrial emission on atmospheric mercury concentration in Yangtze River Delta, China.

Mercury is a global neurotoxic pollutant, which can be globally transported and bioaccumulated in the food chain. Iron-steel production is one of the most significant sources of anthropogenic atmospheric mercury emission, while information on this source is scarce. Hourly gaseous elemental mercury (GEM) and particle bound mercury (PBM) were studied inside (IP) and at the boundary (BP) of a typical iron-steel plant in the Yangtze River Delta (YRD), China from September 2016 to August 2017. The GEM concentrations were 0.97-503.1 and 0.05-112.6ng/m3 at the IP and BP sites, respectively, while PBM concentrations were one to four orders of magnitude higher than urban and suburban ambient levels. Several lines of evidences indicated that PBM was mainly originated from the iron-steel manufacturing process, especially from sintering and coke-making processes in this iron-steel plant. However, a combined emission effect contributed to GEM variation. The receptor model of positive matrix factorization (PMF) showed that local direct emissions (coal combustion, industrial activity, vehicle exhaust, and secondary evaporation from polluted soil) contributed 51.3% of the total GEM concentration variation. Potential source contribution function (PSCF) and concentration weighted trajectory (CWT) models clearly showed that air masses moving from areas surrounding YRD had the highest concentrations of atmospheric mercury. These results provided evidence that iron-steel manufacturing emissions have a considerable effect on regional atmospheric mercury concentrations, especially PBM.

Climate change and its relationship with non-melanoma skin cancers.

Climate change is affecting both the environment and human behaviour. One significant impact is related to health, as detailed in the IPCC 2014 report. In the present work, and as a contribution to this commemorative special issue to Prof. Dr Jan van der Leun, we present the results of the squamous (SCC) and basal-cell carcinoma (BCC) incidence change in relation to the ambient temperature increase. This increase is produced by global warming, mainly induced by anthropogenic atmospheric emissions of greenhouse gases. We have broadened a previous study conducted by van der Leun et al. (Photochem. Photobiol. Sci., 2008, 7, 730-733), by analysing the effective carcinogenicity of UV dose, for the period 2000-2200 and four climate change scenarios (called RCP2.6, RCP4.5, RCP6.0 and RCP8.5). The corresponding percentage increases of the incidence of SCC for 2100 are 5.8, 10.4, 13.8 and 21.4%, and for 2200 they are 4.3, 12.1, 19.0 and 40.5%. In a similar way, the percentage increases of the incidence of BCC for 2100 are 2.8, 4.9, 6.5 and 9.9% and for 2200 they are 2.0, 5.8, 8.9 and 18.2%. We report the SCC and BCC percentage effective incidence results as a function of time, for the whole 21st century and we extended the analysis to the 22nd century, since people possibly affected (like the Z and T generations, born at the beginning of this century) will have a life expectancy extending up to the final decades of the present century and even to the first ones of the next century.

Sedimentary mercury (Hg) in the marginal seas adjacent to Chinese high-Hg emissions: Source-to-sink, mass inventory, and accumulation history

We comprehensively investigated sedimentary Hg in Yellow and East China Seas (YECSs), which constitute potentially important depocenters for large anthropogenic Hg emissions from mainland China. A large dataset of Al-TOC-Hg concentrations led to an in-depth understanding of sedimentary Hg in the entire YECSs, including distribution and its determinants, source-to-sink, background levels, inventory in flux and budget, and accumulation history. Especially, the net atmospheric Hg flux to the sediments was estimated to be 1.3 × 10−5 g/m2/yr, which corresponded reasonably well to that calculated using a box model. About 21.2 tons of atmospheric Hg (approximately 4% of the total anthropogenic atmospheric Hg emissions from China) were buried annually in the YECS basin. This result implies that most of atmospheric Hg from China is transferred to the surface of the Pacific (including the East/Japan Sea and South China Sea) by the westerlies and, consequently, can play a critical role in open-sea aquatic ecosystems.

The effect of organic matter and thermal maturity on the wettability of supercritical CO2 on organic shales

The geologic sequestration of CO2 is a potential solution for decreasing anthropogenic atmospheric CO2 emissions by trapping it underground. A primary mechanism for storage is structural trapping where low permeability and high capillary entry pressure caprock materials hold back the buoyant CO2 from rising to the surface. The wettability (or contact angle) of reservoir and caprock materials in relation to CO2 and formation brine partly determines the efficiency of structural trapping. Current practice applies the results of individual reservoir-comprising minerals recorded under laboratory conditions, to rocks under in-situ reservoir conditions. However, the wide variety of measured contact angles reported in the literature calls this practice into question. Moreover, organic shales have not been the focus of systematic studies. Here we analyzed the wettability of CO2 on organic shales at various organic matter concentrations and thermal maturities. We found that bulk organic shale remains highly water wet with respect to CO2 despite changes to the maturity or concentration of organics. This finding is in contrast to recent molecular dynamic simulations and our initial expectations from previous pore-scale analyses in which organic matter was shown to be hydrophobic. The results are likely due to the remaining mineralogy of the rock dominating the wetting behavior despite concentrations of organics up to 7.9%. This means that reservoirs and aquifers capped by organic rich caprocks may be suitable locations for CO2 storage and that organic matter at concentrations below percolation threshold may not have a detrimental effect on structural trapping efficiency.

Chronology and sources of trace elements accumulation in the Rhône pro-delta sediments (Northwestern Mediterranean) during the last 400 years

The Rhône pro-delta sediments receive the particulate inputs from the Rhône River, the largest freshwater discharge of the Western Mediterranean Sea. Trace element (TEs: Ag, Cd, Co, Cr, Cu, Ni, Pb, and Zn) concentrations and stable Pb isotope ratios were determined along a 7.7-m-long sediment core collected from the Rhône prodeltaic lobe, archiving the deposits of the last 400years. Trace element mean concentrations during the pre-industrialized era (before 1850 CE) were no different from the average composition of Earth’s upper crust, except for Cr. Principal component analysis, performed on TEs and tracers, suggests three origins for TEs that we identified as (i) marine biogenic material (Ag, Cd), (ii) ultramafic rocks (Li, Cr, Ni), and (iii) other clay minerals (Co, Cu, Pb and Zn). During the pre-industrial period, several changes in the TE/Al ratios coincided with flood events or/and modifications in the channelization of the Rhône River mouth. Some frequencies in the TEs temporal variations allow us to hypothesize some influence of climate variation. Sediments deposited after 1850 CE exhibited concentrations of certain TEs exceeding 1.3–3.5 times the concentrations of the pre-industrial era (Ag>Cd-Pb>Cu-Zn). Principal component analysis, performed on post-1850 CE data, allows to distinguish pristine and “anthropogenically impacted” TEs. Pristine TEs, such as Co, Cr, and Ni, are linked with clay markers (Al, Li and Fe), Co and Ni are associated with Mn-enrichment, whereas Cr is correlated with Fe. “Anthropogenically impacted” elements consist of Ag, Cd, Cu, Pb, and Zn. Vertical profiles show that TE contamination has increased dramatically after the IInd World War and reached a maximum between 1970 and 1980, consistently with anthropogenic atmospheric emissions changes. Sediment deposited on the Rhône prodelta at the beginning of XVIIth Century have 206/207Pb ratios close to values of natural Pb (1.200), whereas sediments deposited after 1850 CE are clearly contaminated by European gasoline and industrial Pb pools (<1.180). In addition, peak-events can be related to flooding periods, natural and man-induced channelization of the Rhône River mouth, or diagenetic processes.

Meiospore development of the kelps Macrocystis pyrifera and Undaria pinnatifida under ocean acidification and ocean warming: independent effects are more important than their interaction

Anthropogenic atmospheric emissions of CO2 are responsible for simultaneous ocean warming (OW) and ocean acidification (OA). These global events can have important impacts on marine fleshy macroalgae and coastal ecosystems. To understand the effects of OW and OA on the early life history stages of native (Macrocystis pyrifera) and invasive (Undaria pinnatifida) macroalgae, a multi-factorial experiment was performed to determine the independent and interactive effects of the drivers and the corresponding species-specific responses. Meiospores of M. pyrifera and U. pinnatifida were separately exposed to a 4 × 2 factorial design of seawater pH (pHT 7.20, extreme OA predicted for 2300; pHT 7.65, OA predicted for 2100; pHT 8.03, ambient pH; and pHT 8.40, pre-industrial pH) and temperature (12 °C, seasonal average temperature; and 16 °C, OW predicted for 2100). Over 15 days, different physiological parameters (i.e. meiospore germination, germling growth rate, gametophyte development and sex ratio) were measured. Reduced seawater pH and elevated temperature had independent and significant effects on developmental processes (germling growth rate, and male and female gametophyte sizes were independently greater under OA and OW conditions), but the interaction of the abiotic factors had no effect on any stage of meiospore development of either species. Despite some small differences between species (e.g. sex ratio), results of this experiment suggest that microscopic stages of the native M. pyrifera and the invasive U. pinnatifida will respond similarly to OA and OW.

Numerical experiments of density driven CO2 saturated brine migration in heterogeneous two-dimensional geologic fabric materials

CO2 geological sequestration has been recognized as potential solution for reducing anthropogenic atmospheric emissions. To better estimate the storage efficiency (capacity) of subsurface geologic formations and to understand the plume migration mechanism through porous geologic formations, this study performs numerical simulations of density driven CO2-saturated brine flow in highly resolved heterogeneous 2D fabrics. While large-scale convective currents driven by gravity have been cited as important for dissolution of CO2 into brine, the impact of small-scale heterogeneity on the time scale of dissolution and final dissolved concentration is not well understood. Two aspects of small-scale geologic heterogeneity are examined here: 1) the correlation length of the sedimentary structures, or depositional fabric, of the material; and 2) grain size distribution (range of porosity and permeability). Twenty-seven clastic facies with three different fabrics were evaluated. These materials have variable horizontal correlation lengths (1:1 to 50:1) and range from extremely well sorted upper-coarse sand to very poorly sorted upper-coarse silt. We consider density contrast between CO2-saturated brine and initial brine as the main driving force of plume migration due to natural convection. Migration behaviors from both vertical and horizontal line sources are explored. The analysis is done using conservation of mass and momentum, governed by Darcy's law. Results show that effective convective migration is possible only in a limited range of facies at the scales investigated (100's sq. cm.).Only the extremely well and well-sorted coarse sands have mean permeability and porosity that exceed the critical Rayleigh number (≈4π2). Results indicate that convective and dissolution processes are influenced primarily by the range in grain size (permeability), while the correlation length of the sedimentary fabric has minor effect.

Distant evaluation of the influence of air pollution on remote areas

This paper presents a back-trajectory approach to evaluating and forecasting the influence of different atmospheric emissions on the environment of Russia’s remote and hard-to-reach regions. Air-mass trajectories are derived from the HYSPLIT4 model, which is presented on the NOAA Atmospheric Research Laboratory website. Mean concentrations of anthropogenic heavy metals (HMs) in the air, snow, and rainfall and their total fluxes onto the surface for the 2000s are calculated for the Nenetskii, Gydanskii, and Ust’Lenskii State Nature reserves on the coast of the Russian Arctic Ocean. Data on anthropogenic atmospheric emissions of heavy metals (Ni, Cu, Pb, Cd, Zn, Cr, and As) and their annual fluxes for Russian cities and regions are provided by the State Roshydromet Service. The mean deposition velocities of anthropogenic HMs transported on submicron aerosol particles are calculated from the literature data and weather information taking into account climatic distinctions. Spatial distributions of potential anthropogenic HM source functions are presented on maps. These maps are used to estimate the impact of existing and designed pollution sources, including extended ones (forest and grass fires), and to determine the most important sources for the Russian Arctic. Seasonal and spatial variations in the anthropogenic impact through the atmosphere on the Russian Arctic coast are analyzed.

Quantitative assessment of atmospheric emissions of toxic heavy metals from anthropogenic sources in China: historical trend, spatial distribution, uncertainties, and control policies

Abstract. Anthropogenic atmospheric emissions of typical toxic heavy metals have caused worldwide concern due to their adverse effects on human health and the ecosystem. By determining the best available representation of time-varying emission factors with S-shape curves, we establish the multiyear comprehensive atmospheric emission inventories of 12 typical toxic heavy metals (Hg, As, Se, Pb, Cd, Cr, Ni, Sb, Mn, Co, Cu, and Zn) from primary anthropogenic activities in China for the period of 1949–2012 for the first time. Further, we allocate the annual emissions of these heavy metals in 2010 at a high spatial resolution of 0.5° × 0.5° grid with ArcGIS methodology and surrogate indexes, such as regional population and gross domestic product (GDP). Our results show that the historical emissions of Hg, As, Se, Cd, Cr, Ni, Sb, Mn, Co, Cu, and Zn, during the period of 1949–2012, increased by about 22–128 times at an annual average growth rate of 5.1–8.0 %, reaching about 526.9–22 319.6 t in 2012. Nonferrous metal smelting, coal combustion of industrial boilers, brake and tyre wear, and ferrous metal smelting represent the dominant sources of heavy metal emissions. In terms of spatial variation, the majority of emissions are concentrated in relatively developed regions, especially for the northern, eastern, and southern coastal regions. In addition, because of the flourishing nonferrous metal smelting industry, several southwestern and central-southern provinces play a prominent role in some specific toxic heavy metals emissions, like Hg in Guizhou and As in Yunnan. Finally, integrated countermeasures are proposed to minimize the final toxic heavy metals discharge on account of the current and future demand of energy-saving and pollution reduction in China.

Historical Mercury releases from commercial products: global environmental implications.

The intentional use of mercury (Hg) in products and processes ("commercial Hg") has contributed a large and previously unquantified anthropogenic source of Hg to the global environment over the industrial era, with major implications for Hg accumulation in environmental reservoirs. We present a global inventory of commercial Hg uses and releases to the atmosphere, water, soil, and landfills from 1850 to 2010. Previous inventories of anthropogenic Hg releases have focused almost exclusively on atmospheric emissions from "byproduct" sectors (e.g., fossil fuel combustion). Cumulative anthropogenic atmospheric Hg emissions since 1850 have recently been estimated at 215 Gg (only including commercial Hg releases from chlor-alkali production, waste incineration, and mining). We find that other commercial Hg uses and nonatmospheric releases from chlor-alkali and mining result in an additional 540 Gg of Hg released to the global environment since 1850 (air: 20%; water: 30%; soil: 30%; landfills: 20%). Some of this release has been sequestered in landfills and benthic sediments, but 310 Gg actively cycles among geochemical reservoirs and contributes to elevated present-day environmental Hg concentrations. Commercial Hg use peaked in 1970 and has declined sharply since. We use our inventory of historical environmental releases to force a global biogeochemical model that includes new estimates of the global burial in ocean margin sediments. Accounting for commercial Hg releases improves model consistency with observed atmospheric concentrations and associated historical trends.

System-level benefits of extracting and treating saline water from geologic formations during national-scale carbon capture and storage

Despite economic, political, legal, and technical challenges, carbon dioxide (CO2) capture and storage (CCS) holds promise as a means to substantially reduce anthropogenic atmospheric emissions of carbon dioxide. One of the technical challenges to CCS is an accurate quantification of the potential geologic storage resource. This analysis uses the publically available national-scale, systems-level Water Energy and Carbon Sequestration simulation model (WECSsim©), to show that, depending on assumed boundary conditions, the majority of storage associated with large-scale CCS in the U.S. (on the order of 90–100GT of total reduced emissions) would occur at a small number of well-located sites with favorable geologic properties. WECSsim, through the use of marginal abatement cost curves, shows that under such a scenario, added costs associated with resident saline water extraction, transport, and treatment (SWETT) are justified by resulting increases in carbon dioxide storage efficiency in the geologic formation. This argument is strengthened when geologic uncertainty is taken into consideration. Like an insurance policy, the enhanced carbon dioxide storage efficiency that comes from SWETT adds well-defined costs to reduce potential economic risks associated with overestimates of the available geologic storage resource.