Hg Pollution Research Articles

Multigenerational impact of global change: Increased mercury toxicity in a marine copepod.

A multi-generational experiment (F1-F4) was conducted for a marine copepod Tigriopus japonicus to investigate its physiological and molecular responses to mercury (Hg) pollution and/or its combination with ocean acidification (OA) plus ocean warming (OW). The projected future scenario, i.e., OA plus OW (AW) significantly increased methylmercury accumulation in copepods by 1.14 times, despite insignificant change for total Hg bioaccumulation. Transcriptomic analysis indicated that copepods initiated several detoxification defense processes, including reactive oxygen species metabolic process, glutathione metabolism, and protein refolding, in response to increased Hg toxicity under combined exposure of AW and Hg; meanwhile, inhibited energy metabolism was observed in this case, linking to reduced number of nauplii/clutch but accelerated development in copepods probably due to an energetic trade-off. Increased Hg toxicity due to AW could also be ascribed to the impairment in immune defense (e.g., lysosome and vitamin metabolism) and reproduction-related processes (e.g., growth factor activity). Collectively, this study reveals the multi-generational response mechanism of copepods to Hg pollution under global change, emphasizing an exacerbated adverse effect of Hg, and it provides a scientific basis for an accurate understanding of the potential impact of Hg pollution on marine ecosystems.

Transport of Exogenous Anthropogenic Atmospheric Mercury to the Tibetan Plateau Identified Using Mercury Stable Isotopes

AbstractTransport of exogenous anthropogenic mercury (Hg) is an important source of Hg pollution in the Tibetan Plateau (TP) and its downstream water ecosystems, but the origins and contributions of Hg sources remain uncertain. Here, we investigate the concentrations and isotopic compositions of gaseous elemental mercury (GEM) at four rural sites in the TP and three urban sites surrounding the TP to quantify the sources of GEM in the TP. GEM concentrations in the surrounding cities (site‐specific means: 2.36–9.12 ng m−3) were highly elevated mainly due to strong local anthropogenic emissions as indicated by their negative δ202Hg and near zero Δ199Hg and Δ200Hg signatures. GEM isotopes indicate that GEM pollution in the TP, typically observed during the summer monsoon and the pre‐monsoon, were mainly caused by trans‐boundary transport of anthropogenic Hg from surroundings. Using an Hg isotope mixing model, we estimate that exogenous anthropogenic emissions on average contributed 26 ± 5% (1sd) to the GEM in the TP. Further analysis of the transport of anthropogenic Hg emissions based on the backward trajectory and gridded anthropogenic Hg emissions suggests that 16 ± 9% and 6 ± 13% of the GEM in the TP were derived from anthropogenic sources in South Asia and China, respectively. Our study suggests that anthropogenic Hg emissions in South Asia could be effectively transported to the TP across the Himalayan range. Future studies are needed to better assess the role of rapidly increasing anthropogenic Hg emissions in South Asia on the regional to global scale atmospheric Hg cycling.

Spatiotemporal Distribution of Mercury in Tree Rings and Soils Within Forests Surrounding Coal-Fired Power Plants

The release of mercury (Hg) from coal-fired power plants (CPPs) into local ecosystems poses substantial environmental and health hazards. This study was conducted in Chungcheong-nam-do, South Korea, a region featuring over half of the country’s coal power facilities, to estimate the impacts of CPPs on Hg distribution in forest ecosystems. By analyzing Hg concentrations in pine tree rings and soil at 21 locations around CPPs and comparing them to control sites and industrial zones, we present a nuanced understanding of the effects of CPPs on Hg concentration. The analysis of Hg concentrations in tree rings showed a significant decrease in Hg levels as the distance from the power plants increased, suggesting that CPPs primarily influence Hg distribution in trees within a 25 km radius. In contrast, soil Hg concentrations did not exhibit a clear trend. This may reflect the limitations of this study in accounting for the physicochemical properties of the soil at each sampling site. Nevertheless, the Potential Ecological Risk Index for soil Hg contamination indicated a higher risk rating within a 1 km radius of the CPPs compared to other locations. Hg concentrations in tree rings have shown a steady decline since the 1970s, suggesting the positive effects of air pollution regulations. This also highlights the value of tree core samples as effective tools for monitoring historical Hg pollution. Furthermore, the higher historical concentrations of Hg in tree rings imply that trees may have acted as sinks for atmospheric Hg in the past.

Pollution of Heavy Metals in Topsoil of Remote Mountainous Areas in Western Yunnan-Guizhou Plateau

Heavy metals from anthropogenic emissions have had a negative impact on the ecological environment in remote regions. A total of 69 topsoil samples were collected from 13 remote mountainous areas in the western Yunnan-Guizhou Plateau at altitudes of 2 563-4 037 m, and the concentrations of ten heavy metals in the samples were determined. Enrichment characteristics and pollution sources of heavy metals in topsoil were discussed by referencing the enrichment factor （EF）, positive matrix factorization （PMF）, and Pb isotopes. The results showed that the average concentrations of Al, Fe, Cu, V, and Zn in the topsoil were lower than the soil background values in Yunnan Province； the average concentrations of Ni and Pb were similar to the background values； and the average concentrations of Cd, Cr, and Hg were 1.8-3.6 times higher than the background values. The average EF values of Pb, Cr, and Ni were 3.8, 3.4, and 2.3, respectively, showing moderate enrichment according to the EF classification criteria； the average EF values of Cd and Hg were 15.2 and 10.0, reflecting significant enrichment； and the average EF values of the other metals ranged from 1.1 to 1.9, displaying none-weak enrichment. Combining the comparisons of heavy metal concentrations and ratios in topsoil and bedrock and the EF and PMF results, Al, Fe, V, Cr, Cu, Ni, and Zn in topsoil were considered primarily from detrital sources, and the spatial concentration variations of the metals should have been mainly regulated by the parent material. Cadmium, Hg, and Pb were obviously polluted by anthropogenic emissions, and the main sources were non-ferrous metal smelting and coal combustion. The areas with relatively high Cd, Hg, and Pb pollution were mainly distributed in the Jiaozi snow mountain, Bitahai watershed, Luoji Mountain, and Laojun Mountain areas. Anthropogenic emissions contributed 23.8% of the accumulation of heavy metals in the topsoil.

Soil urease functional stability to Hg pollution: An ecotoxicological perspective.

Mercury (Hg) is a persistent soil pollutant, and its toxicity can be evaluated using soil enzyme indicators. However, a thorough understanding of how the enzyme resists and remains resilient to Hg stress is essential, as it significantly impacts the accuracy of toxicity assessments. Therefore, it is worthwhile to understand the functional stability of urease in soil under Hg pollution. This study compares the effects of Hg at different concentrations and exposure times on soil urease. Results indicate that soil urease activity was enhanced in the first two hours under low levels of Hg pollution, decreased after six hours of acute Hg pollution, and reached its maximum reduction in 24 hours. The urease in fluvo-aquic soil, with higher soil organic matter showed higher resistance to Hg acute pollution than that in red soil. Over a longer aging process, soil urease activity gradually recovered with time. Hormesis effects were observed in red soil under high Hg stress after 30 days, showing the strong resilience of urease enzyme function to Hg pollution. The ecological dose, ED10, (the Hg concentration causing a 10% reduction in soil urease activity) ranged from 0.09 to 0.59 mg kg-1 under short-term exposure, and was lower than that under a longer aging process (0.28 to 2.71 mg kg-1). Further, aging reduced the Hg ecotoxicity due to decreased Hg availability and the resilience of soil urease activity. This indicates that the risk of Hg pollution estimated by soil urease as an indicator depends on exposure time and enzyme stability. These factors need consideration in heavy metal pollution assessments using soil enzymes.

Spatial distribution and risk assessment of mercury in soils over the Tibetan Plateau

The Tibetan Plateau is one of the highest and most pristine plateaus in the world, and its ecological environment has a significant impact on global climate and the distribution of water resources. Mercury (Hg), as a toxic metal pollutant, can have a severe impact on the health of living organisms and the ecosystem due to its presence in the environment. This study collected 336 soil samples from 28 sites across four typical surface vegetation landscapes (meadow, grassland, desert, and forest) on the Tibetan Plateau to measure soil THg (Total Hg) concentrations. The research aimed to explore the factors influencing soil THg levels, analyze pollution and environmental risks of THg in the surface soil, and evaluate the associated health risks to the local population. The results indicate that the mean soil THg concentration (31.84 ± 32.58 ng·g−1) of this study is compared to the background value of THg in Tibetan Plateau soils (37.0 ng·g−1), but there are significant differences in THg concentration among soils with different surface vegetation landscapes. The mean THg concentration in soils of forest vegetation types (74.42 ± 41.19 ng·g−1) is approximately twice the background value of Tibetan Plateau soils. In the forested regions of the southeastern, eastern, and southern Tibetan Plateau, soil concentrations of total mercury are relatively high, whereas in the desert areas of the northern, northwestern, and northeastern Tibetan Plateau, the concentrations are lower. Organic matter (soil organic carbon) being an important factor influencing the soil THg. Based on existing surface soil THg data from this and previous research in Tibetan Plateau (n = 477), 34.2 % of the samples show Hg pollution and potential ecological risks. However, the health risks of soil Hg to both adults and children are not significant.

Characteristics and risk assessments of mercury pollution in a county region undergoing industrialization in northeastern China: a case study in Gongzhuling

Mercury pollution in emerging industrial zones and surrounding areas, especially in industrial concentration areas, has attracted much attention. So as to clarify the characteristics of Hg in the environment in China’s small and medium-sized industrial emerging and surrounding areas, central urban area of Gongzhuling, a traditional agricultural town with a high degree of industrialization in northeast Changchun industrial base, is taken as the scope. Geological accumulation trin (Igeo) was used to study the degree of soil mercury contamination in Gongzhuling area, latent Er (ecological risk) trin was used to appraise the Er of soil Hg in the study area, and non-carcinogenic risk assessment of mercury in soil using human exposure risk assessment model. The results showed that 34% of soil samples had higher Hg content than the background value of the province’s soil (0.04 mg kg−1). The Igeo results showed that Hg pollution rate of soil in study area was 9% (index >0). In conclusion, the level of soil Hg pollution in Gongzhuling area was low, and the pollution area is mainly concentrated in the northwestern part of the study range. The highest and lowest Er values of soil Hg from the study sample were 2.23 and 214.83, and 24% of the samples had Er > 40, that means they pose a moderate or higher potential ecological risk, and most of these points are located in the northeast of the study range. The main route of human exposure to Hg is oral ingestion. The HQ (non-carcinogenic risk index) and HI (total non-carcinogenic risk value) of soil mercury were both much less than 1, it indicates that the present level of soil Hg in the study range does not pose a threat to local adult health for the time being. This study provides reference for other urban pollution risk assessment, and further defines the direction of future work.

Quinolone antibiotics stimulate bacterial mercury methylation by Geobacter metallireducens GS-15

Bacterial mercury (Hg) methylation is critical for bioremediating Hg pollution, but the impact of emerging antibiotics on this process has rarely been reported. This study innovatively investigated the interactions between Hg-methylating bacteria of Geobacter metallireducens GS-15 and two quinolone antibiotics: lomefloxacin (LOM) and ciprofloxacin (CIP) at 5 μg/L. Short-term LOM exposure increased methylmercury (MeHg) yield by 36 % compared to antibiotic-free conditions, caused by hormesis to alter bioactivities of single GS-15 cells. Long-term CIP exposure led to more antibiotic resistance and mercury tolerance in GS-15 cells, doubling MeHg productivity and significantly increasing expression of Hg methylation (hgcA by 95 folds) and antibiotic resistance (gyrA by 54 folds) genes, while mercury resistance gene merA only increased by 2.5 folds than without selective pressure. These results suggest quinolone antibiotics at environmentally contaminated concentrations stimulate bacterial Hg methylation to form highly toxic MeHg, raising considerable concern for the Hg-antibiotic complex in contaminated environments.

Unexpectedly high wet mercury deposition observed in the Yarlung Tsangpo Grand canyon

Situated in the south edge of the Tibetan Plateau, the Himalayas is expected to receive direct anthropogenic Hg perturbations from South Asia, yet the measurements of atmospheric Hg deposition in the Himalayan region remain scarce. Here we report wet Hg deposition measured in the Yarlung Tsangpo Grand Canyon of the Eastern Himalayas, which is the deepest and longest canyon on earth. The precipitation Hg concentration (56.3 ng L−1) and wet Hg deposition flux (84.7 μg m−2 yr−1) from the Motuo station were observed among the highest ever reported for the Tibetan Plateau. Together with analysis of principal component suggesting Hg was mainly clustered with anthropogenic ions and backward trajectories indicating 88.8% of air masses came from South Asia, our results show that transboudary pollution influences from South Asia could be largely responsible for the unexpectedly high levels of wet Hg deposition. Moreover, the wet Hg flux measurements (84.7 μg m−2 yr−1) are found an order of magnitude (∼13 times) higher than the GEOS-Chem estimates (6.8 μg m−2 yr−1), most likely due to the underestimation of transboundary Hg pollution influence by this model. Our study has important implications for better understanding Hg dynamics and verifying atmospheric Hg models in the Tibetan Plateau and Himalayas region.

Distribution characteristics, sources and risk assessment of heavy metals in the surface sediments from the largest tributary of the Lancang River in the Tibet Plateau, China.

Angqu, positioned in the eastern expanse of the Tibet Plateau, claims the title of the largest tributary to the Lancang River. In October and December of 2018, in the sediment of Angqu, a comprehensive investigation was conducted on nine heavy metals-arsenic (As), manganese (Mn), chromium (Cr), cadmium (Cd), lead (Pb), mercury (Hg), copper (Cu), zinc (Zn), and nickel (Ni). This investigation aimed to scrutinize the spatial and temporal distribution patterns of these metals, assess the pollution status and ecological risks associated with the sediments, and delve into the sources contributing to their presence. The research results indicate that the average concentrations of As, Hg, and Cd in Angqu sediments exceed the soil background values of Tibet, while the concentrations of other heavy metals are below the soil background values of Tibet. Notably, arsenic poses potential ecological risks. In Angqu sediments, the concentrations of Mn, Cu, Ni, and Pb are generally higher in the wet season, but the seasonal variations of heavy metals in Angqu sediments are not significant. The sediments in the Angqu Basin are predominantly affected by mercury Hg, Cd, and As, with varying degrees of pollution at different sampling points. In the main stream of Angqu (City section), Hg pollution has reached above a moderate level, whereas As pollution near the tributary is only slightly polluted. The analysis of heavy metal sources reveals that there are five primary contributors to heavy metals in surface sediments of Angqu: parent material, agricultural activities, groundwater, atmospheric deposition, and other unidentified sources. Mn, Cr, Pb, and Ni are mainly derived from soil parent material, accounting for more than 50%. About 60.82% of As comes primarily from groundwater. Zn and Cd are mainly sourced from agricultural activities, accounting for 41.25% and 34.33%, respectively. Additionally, 20.6% of Hg originates from atmospheric deposition.

Heavy metal levels of outdoor dust from the Eastern Mediterranean Sea region and assessment of the ecological and health risk.

As a result of some chemical element (heavy metals) pollution of dust, environmental pollution of dust has become an increasing concern, necessitating an assessment of risks to both ecology and human health, particularly in urban areas. Most of these pollutants settle on the outdoors and eventually become part of the outdoor dust. These will have negative long-term repercussions on ecosystems and human health. In this research, energy dispersive X-ray fluorescence (EDXRF) spectrometry analytical method was used to assess the pollution characteristics of the eight heavy metals (HMs): Mn, Cu, As, Hg, Ni, Cr, Zn, and Pb in the East Mediterranean Sea area. The concentration of As, Mn, Cr, Cu, Hg, Ni, Pb, and Zn analyzed in outdoor dust samples varied from 0.94 to 19.52 mg kg-1, 190.08 to 1019.7 mg kg-1, 20.46 to 45.9 mg kg-1, 19.5 to 62.56 mg kg-1, 0.01 to 0.93 mg kg-1, 10.48 to 40.64 mg kg-1, 12. 6 to 36.1 mg kg-1, and 48.96 to 112.41mg kg-1, respectively. HMs have been detected in the outdoor dust samples analyzed in the study, and, as a result, mean concentrations followed the order Mn > Zn > Cu > Cr > Ni > Pb > As > Hg, respectively. The ecological risk was observed at various contamination levels, with As and Hg pollution being the most severe. The highest hazard quotient (HQ) for adults and children was determined as a result of As and Cr, respectively. According to the US-EPA health risk threshold, the cancer risk in the study area is negligible.

Effect of Hg pollution in ex-gold mining soil ameliorated with bamboo biochar on vegetative growth of corn (Zea mays L.)

Effect of Hg pollution in ex-gold mining soil ameliorated with bamboo biochar on vegetative growth of corn (Zea mays L.)

Feather mercury content of grey-faced petrels (Pterodroma gouldi): Relationships with age, breeding success, and foraging behaviour, in known age individuals

Seabirds have been touted as excellent bioindicators of mercury pollution. We utilised grey-faced petrel (Pterodroma gouldi) feathers to assess interannual differences in total mercury (THg) concentrations in adults (2020−2021) and chicks (2019–2021) breeding in the Auckland region of New Zealand. For adults, we also correlated feather THg with bird age (3–37+ years) and breeding outcome (i.e., Non breeder, Egg failed, Chick reared) recorded for that season i.e., 2020 and 2021. Interannual differences in chick feather THg were matched with bulk stable isotopes (δ13C, δ15N) to map the influence of adult foraging behaviour on chick feather THg values.Adult feather THg levels were similar across the years investigated i.e., mean ± S.D. 38.2 ± 12.8 (2020), and 39.5 ± 14.7 (2021) ug g−1 (some of the highest THg values recorded for seabirds). A slight, but significant decrease in THg accumulation was evident as age increased but feather THg had no significant influence on breeding outcome.Interannual differences in chick feather THg concentrations were 7.78 ± 1.6 (2019), 4.23 ± 1.45 (2020) and 6.97 ± 4.41 (2021) μg g−1, (p < 0.01); and correlated with a significantly lower δ13C value i.e., −17.2 ± 0.4 ‰ (2019), −17.8 ± 0.3 ‰ (2020) and -17.6 ± 0.2 ‰ (2021). This suggests that the lower feather THg values in 2020 chicks resulted from more oceanic, rather than shelf-edge, prey being consumed by chicks that year. Values of δ15N in chick feathers remained consistent among years i.e., 15.2 ± 1.2 ‰ (2019), 15.2 ± 0.2 ‰ (2020) and 15.3 ‰ (± 0.4). Due to these interannual differences, we recommend using grey-faced petrel chicks to monitor Hg pollution over adults. Chicks are also subject to cultural harvests by Māori communities, offering partnership opportunities to generate mutually beneficial information streams for Māori communities and scientists alike.

Evaluation of nutrients and heavy metals of surface soil in the upper watershed of Xiashan Reservoir in Shandong Province, China.

Reservoir is easy to be polluted by nutrients and heavy metals in the surrounding soil. There is a close relationship between heavy metals and nutrients in soil. Nutrient salts will affect the activity of heavy metals, and heavy metal pollution will affect plant growth and nutrient salt absorption, thus affecting ecosystem health. This study was performed to evaluate nutrients (TN, TP) and heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, Zn) in the upper watershed of Xiashan Reservoir by the enrichment factor, the geoaccumulation index, the enrichment factor and leaching experiments. The results showed that the average enrichment of TN and TP reached the level of moderate pollution. The nutrient enrichment of different sampling sites increased gradually from south to north, which may be affected by the topography of the study area. The comprehensive trophic level exceeds the criteria for a state of severe eutrophication of water bodies, which may lead to the enrichment of nitrogen and phosphorus in the water body through processes such as runoff. Evaluation of the geoaccumulation index and potential ecological risk index revealed that the soil was primarily contaminated by Cd and Hg, which are in the level of considerable potential ecological risk and high potential ecological risk. So most attention should be paid to Cd and Hg pollution. Pollution control of heavy metals in soil is a priority because they are more difficult to leach than nutrients. This study provided an insight into the nitrogen and phosphorus control and heavy metal pollution management in the upper watershed of Xiashan Reservoir.

Assessing the impact of heavy metals on bacterial diversity in coastal regions of Southeastern India.

Globally, there is growing concern over the environmental contamination of coastal ecosystems caused by anthropogenic activities. Here,we performed a study to evaluate the degree of heavy metal contamination in 5 different sediment samples collected from five sites along the Southeastern coast of India. Additionally, the research aims to explore the potential ecological implications of heavy metal contamination on the bacterial diversity, a crucial factor in upholding a sustainable ecosystem. A total of seven heavy metals, i.e., chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), mercury (Hg), cadmium (Cd) and arsenic (As), were assessed and quantifiedusing inductively coupled plasma mass spectrometry. Targeted amplicon sequencing revealed that phylum Proteobacteria (36.9%) was the most dominating followed by Halobacterota (25.5%), Actinobacteriota (15%), Firmicutes (6.7%), Bacteroidota (4.0%), Thermoplasmatota (2.3%), Acidobacteriota (2.0%), Chloroflexi (1.6%), Planctomycetota (1.2%) and Crenarchaeota (1.1%). According to the alpha diversity estimate, lesser bacterial diversity was observed in areas with high pollution levels. Moreover, the physicochemical parameters of the sediments were analyzed. The contamination levels of the sediments were evaluated using the geo-accumulation index (Igeo), contamination factor (CF) and pollution loading index (PLI) to ascertain the comprehensive toxicity status of the sediments. TheIgeo values revealed sediment pollution with metals such as Hg and Cd. The sediments obtained from the sampling site PU-01 showed the highest concentration of Hg pollution. Considering the ecotoxicological aspect, theestimated risk index (RI) values indicated a range from low to significant ecological risk.

Microplastics at an environmentally relevant dose enhance mercury toxicity in a marine copepod under multigenerational exposure: Multi-omics perspective

Here, we subjected the marine copepod Tigriopus japonicus to environmentally-relevant concentrations of microplastics (MPs) and mercury (Hg) for three generations (F0–F2) to investigate their physiological and molecular responses. Hg accumulation and phenotypic traits were measured in each generation, with multi-omics analysis conducted in F2. The results showed that MPs insignificantly impacted the copepod’s development and reproduction, however, which were significantly compromised by Hg exposure. Interestingly, MPs significantly increased Hg accumulation and consequently aggravated this metal toxicity in T. japonicus, demonstrating their carrier role. Multi-omics analysis indicated that Hg pollution produced numerous toxic events, e.g., induction of apoptosis, damage to cell/organ morphogenesis, and disordered energy metabolism, ultimately resulting in retarded development and decreased fecundity. Importantly, MPs enhanced Hg toxicity mainly via increased oxidative apoptosis, compromised cell/organ morphogenesis, and energy depletion. Additionally, phosphoproteomic analysis revealed extensive regulation of the above processes, and also impaired neuron activity under combined MPs and Hg exposure. These alterations adversely affected development and reproduction of T. japonicus. Overall, our findings should offer novel molecular insights into the response of T. japonicus to long-term exposure to MPs and Hg, with a particular emphasis on the carrier role of MPs on Hg toxicity.

Iodide- and electrochemical assisted removal of mercury by Cirsium arvense from gold tailings in the Amansie West District, Ghana

Mercury (Hg) pollution in Ghana through mining has become a serious environmental challenge. This study investigates the potential of Cirsium arvense to photostabilize Hg using electrokinetic current with or without an iodide solution in gold mine tailings heavily contaminated through mining activities in southern Ghana. An initial Hg concentration of 9.60 mg/kg using cold vapor atomic absorption spectrometry (CVAAS) was determined. The biological absorption coefficient, bioconcentration factor, and translocation factor of Hg have been presented. Cirsium arvense therefore had a higher bioconcentration factor (BCF) of 2.6–5.15 mg/kg, and a transfer factor (TF) of 0.24–0.36 indicating a higher efficiency for phytostabilization. Both the rate and time of extractions of Hg from the tailings by Cirsium arvense are efficiently improved in the combined electric current and iodide treatment. Plant and electric current combined treatment and plant and iodide combined treatment had only 60 and 50% phytostabilization rates, respectively. The combined plant, iodide, and electric current treatment has proven to be superior with about >90% Hg removal rate. Therefore, the combined plant, iodide, and electric current treatment resulted in a higher Hg removal efficiency by Cirsium arvense in a shorter period due to higher solubilization rate and electromigration effects on Hg species.

Geochemical characteristics and provenance of metals in surface sediments of hydrate area, northern south China sea

Geochemical characteristics and provenance of metals in surface sediments of hydrate area, northern South China Sea has not been reported yet, therefore this paper aimed to reveal metals' distribution, assess the pollution of potentially hazradous metals (Cu, Pb, Zn, Cd, Cr, As, Hg), and inferred provenance of metals using principal component analysis. Twenty-five surface sediments were collected by box sampler from 2014 to 2015 in the national special project on gas hydrate. The concentration of MnO and Hg varied greatly. Most of metals were higher in the north of study area. The sediment was mainly polluted by Hg either pollution status or ecological risk, while it's also moderately polluted by Cr and moderately ecological polluted by Cd. The metals were mainly related to terrigenous detrital, biological source, some volcanic activities, and also little atmospheric deposition. Our findings would further improve the understanding of metals and their related biogeochemical process.

Modelling the anthropogenic Hg pollution fingerprint on the marine fishery production worldwide: A preliminary exposure assessment for people living in countries having different income levels

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.

Health and environmental risk assessment of mercury in outdoor and indoor dust in artisanal and small-scale gold mining area in Amansie-west district in the Ashanti Region of Ghana.

Mercury (Hg) pollution around artisanal and small-scale gold mining (ASGM) areas has been of much concern. Many studies have reported elevated Hg concentrations in environmental media, but studies on dust relating to inhalation exposure of Hg around ASGM area are limited. In this study, we investigated Hg in indoor and outdoor dust to reveal environmental and human health risk around ASGM in Amansie West district, Ghana. Indoor and outdoor dust samples were collected from Manso Abore and Manso Nkwanta in Ashanti Region. Concentration of Hg in the samples were analyzed using a direct Hg analyzer. The mean and median value of Hg concentration in the indoor dust (n = 31) were 2.2 ± 3.6mg/kg and 0.72mg/kg respectively while that of the outdoor dust (n = 60) were 0.19 ± 0.48mg/kg and 0.042mg/kg, respectively. The mean and median Hg concentration in indoor dust were about 11 and 17 times higher respectively than that in the outdoor dust. The Hg concentration in the indoor dust was statistically significantly higher than that of the non-miner in Manso Abore (p < 0.05) but was not significant in Manso Nkwanta, probably due to higher mining activity. The geo-accumulation index of the outdoor dust ranged from unpolluted to extremely polluted while that of the indoor dust ranged from moderately polluted to extremely polluted. Health risk assessments suggested that there was no potential non-carcinogenic health effect for Hg exposure relating to the dust to residents living in rooms of miners and non-miners.