In compliance with the European Air Quality Directive, an Italian monitoring network was established under the framework of the “Reti Speciali” agreement. A key component of this framework is the monitoring of atmospheric mercury (Hg) across the Italian territory.To this end, a dedicated Hg network was designed including three ground-based monitoring stations, strategically located from Northern to Southern Italy, to identify potential geographical variations.Atmospheric Hg was measured using automated instrumentation, providing high-resolution time series for Total Gaseous Mercury (TGM) or Gaseous Elemental Mercury (GEM). While all three stations monitored these primary Hg species, one master station provided advanced speciation data, including Gaseous Oxidized Mercury (GOM) and Particulate-bound Mercury (PBM).The measurements carried out within this network produced a comprehensive four-year dataset (2020–2023), establishing the first preliminary baseline for atmospheric Hg concentrations in Italy. These Hg data are supplemented by concurrent meteorological measurements at each station, enabling multi-parameter analysis.The provided integrated dataset supports a extensive characterization of atmospheric Hg behaviour across the Italian peninsula, enabling the assessment of emission reduction policies mandated by the Minamata Convention on Mercury.
This study provides a review of 13 oceanographic campaigns between 2000 and 2017 to measure Hg in the Mediterranean, highlighting major findings from measurement and modelling activities during the Med-Oceanor program. The initial campaigns showed that high concentrations of RGM could be found far from industrial source regions and the observed daily variation in concentration, with peaks at midday and lower concentrations during darkness gave the first indications that photochemically mediated oxidation reactions were producing RGM in the MBL. Later atmospheric chemistry modelling studies showed the feasibility of Hg oxidation by bromine containing oxidants, which are released as a result of the acidification of sea salt aerosols in the Marine Boundary Layer (MBL). Spatial and seasonal variations of DGM were observed at different depths in the water column, with average DGM concentrations higher in the West and East Mediterranean deep and intermediate waters, than in overlaying Atlantic waters. DGM in water profiles typically increased with depth, together with nutrients and decreasing oxygen, indicating a possible bacterial and/or geogenic origin. Using measured DGM and meteorological variable values Hg fluxes can be calculated. When these are included in regional and global models they suggest that the net Hg evasion from the Mediterranean is around 30 Mg yr-1. Repetition of these campaigns should be an extremely high priority, both to continue to monitor changes in atmospheric and aquatic Hg species concentrations, but also to perform RGM detection methodology intercomparisons so that the historical data is adequately contextualised and may be used to evaluate temporal trends.
In compliance with European air quality regulations and the Italian "Reti Speciali" agreement, a dedicated network of three strategically positioned monitoring stations was established in 2012. Designed to account for geographical variability, this network enabled the first coordinated sampling campaigns for atmospheric mercury (Hg) data in ambient air and deposition. The resulting representative nationwide data, collected from 2020 to 2023, enabled the detection of seasonal, temporal, and spatial variations, which are analyzed in this study. Throughout the observational period, atmospheric Hg levels varied among the stations, exhibiting annual mean values between 1.22 +/- 0.25 and 2.01 +/- 0.42 ng/m3. A notable decrease in concentrations was evident in the northern and central regions. Conversely, the southern station maintained relatively stable levels, likely attributable to the predominant influence of natural sources. Ambient air Hg concentrations were examined for the impact of potential sources, with analysis conducted at both synoptic and local scales. Long-range transport pathways were identified using Potential Source Contributing Function (PSCF) analysis, while local investigations incorporated meteorological parameters, ozone measurements, and nearby fire hot-spot data. Analysis of samples from Hg deposition monitoring campaigns (2021-2023) revealed total mercury deposition values below 20 ng/m2d. These efforts, which involved four sampling sessions per year at each station, showed that seasonal variations were primarily influenced by rainfall patterns.
The Global Mercury Observation System (GMOS) network, initially a five-year project (2010-2015) funded by the European Commission, continued as a GEO Flagship program to support the Global Observation System for Mercury (GOS4M). GMOS was envisioned as a coordinated global observing system to monitor atmospheric mercury (Hg) on a global scale, to support and evaluate the effective implementation of the Minamata Convention on Mercury (MCM). Twenty-eight ground-based stations have participated in monitoring activities, following GMOS sampling protocols and related data quality control management. The GMOS network provides representative coverage of all latitudes, from the Northern Hemisphere to the Southern Hemisphere including the Arctic Circle, Antarctica, and the Tropical Zone. This work presents atmospheric Hg data, available as Total Gaseous Mercury (TGM) or Gaseous Elemental Mercury (GEM) concentrations, recorded within the GMOS network from 2011 to 2020. TGM/GEM concentrations were analysed in terms of their variability along latitudinal areas, considering their comparability, temporal trends and patterns. The main results confirmed a clear gradient of TGM/GEM concentrations between the northern (1.58 +/- 0.31 ng/m(3)) and southern (0.97 +/- 0.14 ng/m(3)) hemispheres. Decreasing trends in TGM/GEM levels were found to be strongly significant only for selected remote stations with at least 5 years of data coverage. Seasonality in atmospheric TGM/GEM concentrations was observed to increase with latitude and is greater at inland sites than at coastal sites.
The number of atmospheric mercury (Hg) monitoring stations is growing globally. However, there are still many regions and locations where Hg monitoring is limited or non-existent. Expansion of the atmospheric Hg monitoring network could be facilitated by the use of cost-effective monitoring methods. As such, biomonitoring and passive monitoring offer a unique alternative to well-established monitoring by active measurements, since they do not require a power supply and require minimal workload to operate. The use of biomonitoring (lichens and mosses) and passive air samplers (PASs) (various designs with synthetic materials) has been reported in the literature, and comparisons with active measurement methods have also been made. However, these studies compared either biomonitoring or PASs (not both) to only one type of active measurement. In our work, we used transplanted (7 sampling sites) and in situ lichens (8 sampling sites) for biomonitoring, two PASs from different producers (3 sampling sites), and two different active measurement types (continuous and discontinuous active measurements, 1 and 8 sampling sites, respectively) to evaluate their effectiveness as monitoring methods. In the 9-month sampling campaign, 3 sampling locations with different characteristics (unpolluted, vicinity of a cement plant, and vicinity of a former Hg mine) were used. The results obtained with lichens and PASs clearly distinguished between sampling locations with different Hg concentrations; using both PASs and lichens together increased the confidence of our observations. The present work shows that biomonitoring and passive sampling can be effectively used to identify areas with elevated atmospheric Hg concentrations. The same can be said for discontinuous active measurements; however, the discrepancy between atmospheric Hg concentrations derived from PASs and discontinuous active measurements should be further investigated in the future.
Mercury is a toxic pollutant that poses risks for the human population, mainly by eating contaminated fish. Mercury is released into the atmosphere from a variety of anthropogenic activities, with levels of emissions and under policy controls that largely vary across the world, leading thus to different relative contributions to the environmental matrices. Establishing the exact sources of this contaminant in the environment is crucial to optimising the policies aimed at mitigating the exposure risks for specific populations or ecosystems. In this study, we modelled, for the first time, the fingerprint of mercury anthropogenic emissions, jointly released by source-sectors (11) and source-regions (13), on the deposition over (19) FAO fishery zones, and on the FAO official fishery productions worldwide over the 2012-2021 decade. Using mercury anthropogenic emissions for 2012 from EDGAR, East Asia and ”Artisanal and Small scale Gold Mining” result the source-region and the source-sector, respectively, that contribute the most to the mercury deposition over all the FAO fishery zones. The only exception applies for the FAO fishery zone 37, the Mediterranean Sea, where the ”Industrial Combustion” from the closest Europe is the pair region-sector whose joint contribution is the greatest. When normalised to the overall fishery production worldwide, representing the global fish consumption, the anthropogenic mercury fingerprint showed a similar general pattern, however with notable differences, amplifying the relative contributions of all source-sectors from East Asia and attenuating the relative contributions of the regions in the Southern Hemisphere. This fingerprint further changes when the fish consumption in countries, classified by the World Bank as having different incomes, is considered. These results demonstrate that the same anthropogenic mercury deposited on any fishery zone actually affects in a different way the different population segments worldwide. This study aims to urge the science community as well as the policy makers to use a measure that better represents the mercury hazard for human health. Further, we hope that this study, using nomenclatures that are largely used on final shelf-product, could increase the people’s awareness regarding the products they consume.
Mercury (Hg) fate and transport research requires more effort to obtain a deep knowledge of its biogeochemical cycle, particularly in the Southern Hemisphere and Tropics that are still missing of distributed monitoring sites.Continuous monitoring of atmospheric Hg concentrations and trend worldwide is relevant for the effectiveness evaluation of the Minamata Convention on Mercury (MCM) actions. In this context, Gaseous Elemental Mercury (GEM) and total mercury (THg) in precipitations were monitored from 2013 to 2019 at the Amsterdam Island Observatory (AMS - 37°48′S, 77°34′E) to provide insights into the Hg pathway in the remote southern Indian Ocean, also considering ancillary dataset of Rn-222, CO2, CO, and CH4. GEM average concentration was 1.06 ± 0.07 ng m−3, with a slight increase during the austral winter due to both higher wind speed over the surface ocean and contributions from southern Africa. In wet depositions, THg average concentration was 2.39 ± 1.17 ng L−1, whereas the annual flux averaged 2.04 ± 0.80 μg m−2 year−1. In general, both GEM and Volume-Weighted Mean Concentration (VWMC) of THg did not show an increasing/decreasing trend over the seven-year period, suggesting a substantial lack of evolution about emission of Hg reaching AMS.Air masses Cluster Analysis and Potential Source Contribution Function showed that oceanic evasion was the main Hg contributor at AMS, while further contributions were attributable to long-range transport events from southern Africa, particularly when the occurrence of El Niño increased the frequency of wildfires.
The increasing use of agrochemicals, including fertilizers and herbicides, has led to worrying metal contamination of soils and waters and raises serious questions about the effects of their transfer to different levels of the trophic web. Accumulation and biomagnification of essential (K, Na, Mg, Zn, Ca), nonessential (Sr, Hg, Rb, Ba, Se, Cd, Cr, Pb, As), and rare earth elements (REEs) were investigated in newly emerged adults of Tenebrio molitor exposed to field-admitted concentrations of a metribuzin-based herbicide and an NPK blend fertilizer. Chemical analyses were performed using inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) supported by unsupervised pattern recognition techniques. Physiological parameters such as cuticle melanization, cellular (circulating hemocytes), and humoral (phenoloxidase enzyme activity) immune responses and mass loss were tested as exposure markers in both sexes. The results showed that NPK fertilizer application is the main cause of REE accumulation in beetles over time, besides toxic elements (Sr, Hg, Cr, Rb, Ba, Ni, Al, V, U) also present in the herbicide-treated beetles. The biomagnification of Cu and Zn suggested a high potential for food web transfer in agroecosystems. Gender differences in element concentrations suggested that males and females differ in element uptake and excretion. Differences in phenotypic traits show that exposure affects metabolic pathways involving sequestration and detoxification during the transition phase from immature-to-mature beetles, triggering a redistribution of resources between sexual maturation and immune responses. Our findings highlight the importance of setting limits for metals and REEs in herbicides and fertilizers to avoid adverse effects on species that provide ecosystem services and contribute to soil health in agroecosystems.
This chapter gives an overview of the GEO Flagship Global Observation System for Mercury (GOS4M) activity aimed to bridge the gap between Earth observation (EO) and policy decisions. Prominence was assigned to user-access systems that can provide knowledge based on the huge amount of scientific information. The GOS 4 M Knowledge Hub is provided to support decisions on mercury deposition scenarios and enhance integration and sharing of data related to mercury pollution. The Knowledge Hub is timely in light of the recent adoption of the Minamata Convention on Mercury, which welcomed the scientific communities’ efforts to support policy implementation. Long-term and high-precision observations and analysis of the mercury cycle (from emission to deposition) in the different domains of the Earth system (atmosphere, ocean, land) are furthermore required to better quantify sources and sinks, understand the impact on environment and human health, and address their reduction/removal.
The growing need to monitor Hg levels in the environment to control its emissions and evaluate the effectiveness of reduction policies is driving the scientific community to focus efforts on creating analytical methods that are simpler, lower cost, more performing, and environmentally sustainable. In this context, an important contribution is provided by microextraction techniques, which have long proven to be simple, reliable, and to ensure an environmentally responsible sample preparation. This manuscript reviews the recent progress in the determination of environmental Hg using microextraction techniques. The considered studies involve all environmental compartments (i.e., air, water, soil, and biota) and have been discussed by grouping them according to the employed technique while pointing out the main advances achieved and the most important limitations. The ultimate goal is to provide an up-to-date overview of the analytical potential of microextraction techniques that can be exploited in various investigation fields and to highlight the most important knowledge gaps that should be addressed in the coming years, such as in-situ sampling, the use of natural materials, and the value of metrological support to obtain data SI-traceable and comparable.
In the framework of the Italian Special Network for Mercury (ISNM) "Reti Speciali", a sampling campaign to monitor atmospheric mercury (Hg) was carried out at Monte Sant'Angelo (MSA). This is a coastal monitoring station in the Apulia region, representative of the Southern Adriatic area, within the Mediterranean basin. This work presents continuous Gaseous Elemental Mercury (GEM) measurements over about three years at MSA, using the Lumex RA-915AM mercury analyzer. The aim was to obtain a dataset suitable for the analysis of Hg concentrations in terms of source and transport variation. Diurnal cycles of GEM were evaluated to observe the influence of local atmospheric temperature and wind speed on potential re-emissions from surrounding sea and soil surfaces. Data were also analyzed in terms of long-range transport, using backward trajectory cluster analysis. The spatial distribution of potential sources, contributing to higher measured GEM values, was obtained employing Potential Source Contribution Function (PSCF) statistics. The influence of major Hg anthropogenic point sources, such as mining activities and coal-fuel power plants, both regionally and continentally, from mainland Europe, was observed. The role of the vegetation GEM uptake in modulating the seasonal GEM variability was also investigated. The potential of wildfire influence over the highest detected GEM levels was further examined using active fire data and the evaluation of the vegetation dryness index during the selected episodes.
The Minamata Convention on Mercury is an international treaty with the objective of protecting human health by controlling and restricting mercury use and its release to the environment. Numerical modeling tools currently used to study the fate of mercury released to the atmosphere tend to answer questions such as 'what would be the result of a 50% decrease in mercury emissions from this region, or that emission sector?'. They are not generally designed to answer the questions of the type, 'How can a, say 25% reduction, in deposition be achieved for a particular terrestrial ecosystem/region or oceanic basin?'. This paper presents an optimization framework which exploits the numerical tractability and the real-time features of an emulator for Global Chemical Transport Mercury Models. The HERMES emulator uses the results of a large number of scenario simulations to provide the user in real-time the impact on mercury deposition resulting from changes in anthropogenic mercury emissions. The changes in emissions can be by emission sector, emission region or changes in the speciation of the emissions. The optimization framework extends the capabilities of the emulator to give the user the possibility to define a deposition reduction target in one or more regions, and the framework calculates the optimal set of emissions reductions from industrial macro-sectors considering all the geographical source regions. The user may set a maximum feasible emission reduction in each of the sectors or regions, and within these constraints the optimization framework calculates the minimum number of regions in which the emission abatement would need to be applied to achieve the target, or informs the user that the desired target is unattainable with the supplied constraints. The results from the case-study presented here not only demonstrate the need for action to implement the Convention to be concerted and coordinated internationally, but also the usefulness of an optimization framework to tailor policies for specific environmental targets.
We present an overview of the concentrations and distributions of water-soluble ion species and elemental components in ambient particulate matter for five measurement sites in southern Italy with the aim of investigating the influence of the different site characteristics on PM levels. The sites encompass different characteristics, ranging from urban to coastal and high-altitude remote areas. PM10 and PM2.5 fractions were collected simultaneously using dual channel samplers during the winter period from November 2015 to January 2016 and analyzed for water-soluble ion species, using ion chromatography, and elemental composition, using inductively coupled plasma mass spectrometry (ICP-MS). In all sites, PM2.5 represented the higher contribution to particulate mass, usually more than two times that of the coarse fraction (PM2.5−10). At the coastal site in Capo Granitola (Western Sicily), sea salts constituted about 30% of total PM10 mass. On average, ion species accounted for 30% to 60% of total PM10 mass and 15% to 50% of PM2.5 mass. We found that secondary ion species, i.e., SO42−, NO3− and NH4+ dominated the identifiable components within both PM2.5 and PM10 fractions. The chlorine–sodium ratio was usually lower than that expected from the natural level in sea salt, evidencing aged air masses. At the monitoring site in Naples, a highly urbanized area affected by high levels of anthropogenic source emissions, an increased contribution of ammonium was found, which was imputed to the increased ammonia emissions from industrial combustion sources and road traffic. The concentrations of the investigated elements showed noteworthy differences from one site to another. The PM10 fraction was highly enriched by sources of anthropogenic origin in the samples from the most urbanized areas. In general, the enrichment factors of the elements were similar between the PM10 and PM2.5 fractions, confirming common sources for all elements.
Benzothiazoles (BTHs), benzotriazoles (BTRs), and benzenesulfonamides (BSAs) are chemicals used in several industrial and household applications. Despite these compounds are emerging pollutants, there is still a lack of information about their presence in outdoor air samples. In this paper, we developed a new method for the quantification of BTHs, BTRs, and BSAs in airborne particulate matter (PM10). The extraction of fourteen analytes from PM10 was accomplished by microwave-assisted extraction (MAE) using an environmentally friendly mixture of water and ethanol. SPME was used to analyze the target compounds from the MAE extract by gas chromatography-tandem mass spectrometry (SPME-GC-MS/MS), eliminating additional sample clean-up steps. The best working conditions for MAE and SPME were examined multivariately by experimental design techniques. The target compounds were quantified in selected reaction monitoring acquisition mode. The proposed method was carefully validated, and the achieved results were satisfactory in terms of linearity, lower limit of quantification (picograms per cubic meter), intra- and inter-day accuracy (81-118% and 82-114%, respectively), and precision (repeatability and reproducibility in the range 2.3-17% and 7.4-19%, respectively). The application in a real monitoring campaign showed that the developed protocol is a valuable and eco-friendly alternative to the methods proposed so far.
The summer of 2017 in the Calabria Region (South Italy) was an exceptional wildfire season with the largest area burned by wildfires in the last 11 years (2008-2019). The equivalent black carbon (EBC) and carbon monoxide (CO) measurements, recorded at the high-altitude Global Atmosphere Watch (GAW) Monte Curcio (MCU) regional station, were analyzed to establish the wildfires' impact on air quality, human health, and the ecosystem. A method was applied to identify the possible wildfires that influenced the air quality based on the integration of fire data (both satellite and ground-based) and the high-resolution WRF-HYSPLIT trajectories. The satellite-based fires applied to WRF-HYSPLIT with 10 km of spatial resolution allowed us to establish that for 52.5% of total cases, wildfires were located outside the Calabria Region, and they were influenced by long-range transport. Nonetheless, the impact on human health, qualitatively evaluated in terms of passively smoked cigarettes (PSC) corresponding to the EBC, was greater when wildfires were local. Indeed, for wildfires located mainly in Calabria, the equivalent PSC ranged from 2.75 to 11.08. This maximum PSC value was close to the daily number of smoked cigarettes in Calabria (approximately 12.4). Even if this analogy does not imply a proportional effect between the estimated number of cigarettes smoked and the effective wildfire EBC exposure, this result suggests that wildfire emissions may have negative effects on people's health. Moreover, a focus on the Calabria Region was conducted using high-resolution ground-based GPS and higher resolution WRF-HYSPLIT back-trajectories (2 km) to measure wildfires. The validity of the methodology was confirmed by the EBC and CO positive correlation with the ratio between the identified ground-based burned areas and the distance from the sampling station. Moreover, the impact on the ecosystem was studied by analyzing the land vegetation loss due to the wildfires that contributed to air quality reduction at the MCU station. A total of more than 1679 ha of vegetation burned, the main losses comprising forests and shrubland. (C) 2020 Elsevier B.V. All rights reserved.
Passive air samplers (PASs), which provide time-averaged concentrations of gaseous mercury over the timescale of weeks to months, are promising for filling a gap in the monitoring of atmospheric mercury worldwide. Their usefulness will depend on their ease of use and robustness under field conditions, their availability and affordability, and most notably, their ability to provide results of acceptable precision and accuracy. Here we describe a comparative evaluation of three PASs with respect to their ability to precisely and accurately record atmospheric background mercury concentrations at sites in both southern Italy and southern Ontario, Canada. The study includes the CNR-PAS with gold nanoparticles as a sorbent, developed by the Italian National Research Council, the IVL-PAS using an activated carbon-coated disk, developed by the Swedish Environmental Research Institute, and the MerPAS® using a sulfur-impregnated activated carbon sorbent, developed at the University of Toronto and commercialized by Tekran. Detection limits are deduced from the variability in the amount of mercury quantified in more than 20 field blank samples for each PAS. Analytical and sampling precision is quantified through 22 triplicate deployments for each PAS, ranging in duration from 2 to 12 weeks. Accuracy and bias are assessed through comparison with gaseous elemental mercury concentrations recorded by Tekran 2537 automated mercury analyzers operating alongside the PASs at both locations. The performance of the PASs was significantly better in Italy, with all of them providing concentrations that are not significantly different from the average concentrations of the Tekran 2537 instruments. In Canada, where weather conditions were much harsher and more variable during the February through April deployment period, there are differences amongst the PASs. At both sites, the MerPAS® is currently the most sensitive, precise, and accurate among the three PASs. A key reason for this is the larger size and the radial configuration of the MerPAS®, which results in lower blank levels relative to the sequestered amounts of mercury when compared to the other two PASs, which rely on axial diffusion geometries. Since blank correction becomes relatively smaller with longer deployments, performance tends to be closer amongst the PASs during deployments of 8 and 12 weeks.
This study provides a thorough investigation of the trends of organic carbon (OC) and elemental carbon (EC) in particulate matter (PM)10 and PM2.5 samples collected at the Monte Curcio Observatory (1780 m a.s.l.), a station of the Global Atmosphere Watch (GAW) program and Global Mercury Observation System (GMOS) network. Although the drawn attention toward these pollutants, there is still a lack of data for southern Italy, and this work is a contribution toward the filling of this gap. PM was sampled daily in 2016 and analyzed by thermo-optical transmittance method, while equivalent black carbon (eBC) concentrations in PM10 were simultaneously measured using a multiangle absorption photometer. The results showed that in PM10, the average values of OC and EC were 1.43 μgC/m3 and 0.12 μgC/m3, whereas in PM2.5, these concentrations were 1.09 μgC/m3 and 0.12 μgC/m3, respectively. We detected a clear seasonal variability in OC and EC with higher concentrations during the warm period. Moreover, the analysis of the OC/EC ratio revealed that most of the carbonaceous aerosol was transported by long-range air masses, as further confirmed by the use of the concentration-weighed trajectory (CWT) model. The mass absorption cross-section at 632 nm of EC (MACEC) over the entire period was 9.67 ± 4.86 m2/g and 8.70 ± 3.18 m2/g in PM2.5 and PM10, respectively, and did not exhibit a clear seasonal variation. The concentrations for OC and EC were also used for the computation of the secondary organic carbon (SOC) content, whose outcomes resulted in a seasonal trend similar to those obtained for OC and EC. As regards the eBC, its weekly pattern showed a slight increase during the weekend in the warm period, consistent with the anthropic activities in the touristic area surrounding the observatory.
The role of deposition fluxes on the mercury cycle at Concordia station, on the high Antarctic plateau have been investigated over the Austral summer between December 2017 to January 2018. Wet/frozen deposition was collected daily from specially sited tables, simultaneously with the collection of surface (0-3 cm) and subsurface (3-6 cm) snow and the analysis of Hg-0 in the ambient air. Over the course of the experiment the atmospheric Hg-0 concentrations ranged from 0.58 +/- 0.19 to 1.00 +/- 0.33 ng m(-3), surface snow Hg concentrations varied between (0-3 cm) 0.006 +/- 0.003 to 0.001 +/- 0.001 ng cm(-3) and subsurface snow (3-6 cm) concentrations varied between 0.001 +/- 0.001 to 0.003 +/- 0.002 ng cm(-3). The maximum daily wet deposition flux was found to be 23 ng m(-2) d(-)(1). Despite the low temporal resolution of our measurements combined with their potential errors, the linear regression of the Hg deposition fluxes against the snow accumulation rates allowed us to estimate the mean dry deposition rate from the intercept of the graph as -0.005 +- 0.008 ng m(-2) d(-1). From this analysis, we conclude that wet deposition accounts for the vast majority of the Hg deposition fluxes at Concordia Station. The number of snow events, together with the continuous GEM measurements have allowed us to make a first estimation of the mean snow scavenging factor at Dome C. Using the slope of the regression of mercury flux on snow accumulation we obtained a snow scavenging factor that ranges from 0.21 to 0.22 +/- 0.02 (ng(Hg)/g (snow))/(ng(Hg)/m(3) (air)). Our data indicate that the boundary layer height and local meteorological effects influence Hg-0 reemission from the top of (0-3 cm) the snowpack into the atmosphere and into the deeper snowpack layer (3-6 cm). These data will help constrain numerical models on the behaviour of mercury in Antarctica.
The Minamata Convention on Mercury was established to reduce the pressure on the environment caused by mercury by significantly reducing its emissions from anthropogenic activities. However, knowledge gaps still exist concerning emission inventories, emission factors and their integration in modelling frameworks. In addition, tools to facilitate communication between decision-makers and research groups providing measurement and modelling data are still scarce. This work presents the GOS(4)M Knowledge Hub, a public web application that provides an interactive and user friendly experience to access state-of-the-art modelling tools and data available in the literature. The Knowledge Hub currently integrates a Chemical Transport Model emulator, HERMES, coupled with a biogeochemical model, although it has been designed to house and deploy any number of different modelling components. Using the integrated dashboard, non-experts can perturb mercury releases from different anthmpogenic emission sectors, simulating, for example, the application of Best Available Technologies, and then visualise in real-time the short- and long-term effects of the consequent reductions within a source-receptor framework. The dashboard also furnishes an estimate of the statistical significance of the changes in the model results. The analysis of a set of anthropogenic Hg emission reduction scenarios shows how an internationally coordinated effort would be necessary to achieve significant policy goals. It is important to note that the GOS(4)M Knowledge Hub yields the analysis presented here in a matter of seconds, compared to the days or weeks required by traditional modelling tools.