Soil Mercury Concentrations Research Articles

Mercury contamination of soil and Matricaria chamomilla in selected regions of the Slovak Republic

Abstract Background The aim of our study was to determine the amount of mercury in Chamomile. In certain parts of Slovakia, such as Middle Spiš region in Eastern Slovakia, there has been reports of higher concentration of mercury in the soil. Heavy metals, including mercury, can enter human organism by ingestion. In case of using Chamomile infusions orally there is a risk of administration of mercury into the organism through digestive system. Methods We monitored mercury presence in Chamomile (Matricaria chamomilla) (n = 20) and the soil. We determined the mercury concentration by using the flameless atomic absorption spectrometer - Advanced Mercury Analyzer (AMA-254). Results Chamomile: The lowest concentration was in the roots (0.513 mg.kg-1). The second lowest was in the flower stem samples (1.105 mg.kg-1). The concentration of mercury was higher in the leaves (2.205 mg.kg-1). The highest was measured in the flower (2.541 mg.kg-1). Soil: The mercury content in soil in the entire territory of Slovakia is higher compared to the soil in the world. During our measurements, the concentration of mercury in the soil samples in the territory of Middle Spiš ranged from 100 to 500 mg.kg-1. Conclusions We have to take into account that the quality and contents of the soil are important for the crops, as it will entail their contents. With the knowledge of exceeded norms of mercury content in Slovak soils, it is crucial to monitor the mercury concentration in plants that are harvested there. Key messages • In the examined samples of Chamomile we found mercury, with its highest concentration in flowers and lowest in roots. • In the regions with significant mercury contamination it is crucial to monitor mercury content in harvested plants and to be cautious in regards of their consumption.

Retrieval of chromium and mercury concentrations in agricultural soils: Using spectral information, environmental covariates, or a fusion of both?

The universal contamination of arable land with potentially toxic elements (PTEs) poses a severe threat to food security and jeopardizes worldwide efforts to meet the United Nations Sustainable Development Goals (SDGs). How to obtain more reliable concentrations of PTEs in regional agricultural soils is a priority problem to be solved. Multispectral satellite remote sensing, with its advantages of high spatial and temporal resolution, broad coverage, and low cost, offers the potential to acquire spatial distribution of PTEs in agricultural soils over large areas. However, owing to the complexity of soil environments and the insufficiency of spectral information, the mechanism for retrieving concentrations of PTEs in agricultural soils via multispectral satellites is not yet clear, and the accuracy needs to be improved. In this study, we aimed to assess whether employing a fusion of spectral information and environmental covariates, results in more accurate retrievals of PTEs, specifically chromium (Cr) and mercury (Hg), in croplands than does employing spectral information alone. Three machine learning algorithms—kernel-based support vector machine (SVM), neural network-based back propagation neural network (BPNN), and tree-based extreme gradient boosting (XGBoost)—were developed to retrieve Cr and Hg concentrations in agricultural soils. The results showed that the fusion of spectral information and environmental covariates combined with the XGBoost model performed best in retrieving both Cr and Hg concentrations in agricultural soils with coefficient of determination (R2) values of 0.73 and 0.74, respectively. Environmental covariates were important variables for determining Cr and Hg concentrations in agricultural soils, but the ability to retrieve these element concentrations by utilizing spectral information alone was limited. High Cr concentrations occurred in central towns and southern hilly mountains. High Hg concentrations were detected in the northwestern region and southern hilly mountains. The potential of fusing spectral information and environmental covariates to precisely retrieve PTE concentrations in agricultural soils can serve as a reference for agricultural soil health information monitoring worldwide.

Warming-Induced Vegetation Greening May Aggravate Soil Mercury Levels Worldwide.

Mercury, a neurotoxic substance, circulates globally, significantly stored in soils through atmospheric deposition and plant decay. Despite being deposited, mercury can be remobilized and released into the atmosphere and water, enhancing its global cycle. Recent research suggests that climate warming may amplify the remobilization of soil mercury, facilitating its incorporation into food webs that humans exploit. However, the potential geospatial feedback of soil mercury levels in response to warming remains unclear. By leveraging up-to-date soil measurements and observation-driven models, we determined the amount of mercury stored in global 0-100 cm soils to be 4.3 Tg (interquartile range: 2.5-6.3 Tg). Furthermore, our analysis indicates that warming likely aggravates global soil mercury levels, particularly in many temperate areas in East Asia, North Europe, and North America (>20 ng g-1 increase by 2100) due to warming-induced vegetation greening. Critically, observation-driven models raise the possibility that implementing ambitious mercury-emission-control schemes alone may be insufficient to counterbalance the positive feedback of soil mercury concentration, while process-based biogeochemical modeling demonstrates consistent patterns that reinforce this concern. These findings hold broad implications; for example, such feedback may catalyze mercury remobilization in land-ocean continuums and exacerbate human risks, stressing the necessity for continued reductions in greenhouse gas and mercury emissions.

Determination of Low Concentrations of Mercury Based on the Electrodeposition Time.

Soil plays a crucial role in human health through its impact on food and habitation. However, it often contains toxic heavy metals, with mercury being particularly hazardous when methylated. Currently, high-sensitivity, rapid detection of mercury is achievable only through electrochemical measurements. These measurements require pretreatment of the soil sample and the preparation of a calibration curve tailored to the sample's condition. In this study, we developed a method to determine the environmental standard value of mercury content in soil by significantly reducing the pretreatment process. Our approach involves analyzing current peaks from electrodeposition times using specific electrodes and solvent settings. This method demonstrates low error rates under low concentration conditions and can detect mercury levels as low as 0.5 ppb in soil leachate and reagent dilution series. This research facilitates the determination of low mercury concentrations in solutions containing various soil micro-compounds without the need for calibration curves.

Assessment of Mercury Contamination in Water and Soil from Informal Artisanal Gold Mining: Implications for Environmental and Human Health in Darmali Area, Sudan

Mercury contamination stemming from artisanal and small-scale gold mining (ASGM) operations poses significant environmental and health concerns. This study focuses on the Darmali area in River Nile State, Sudan, where the reprocessing of amalgamation tailings has led to mercury contamination. This study assessed the mercury content in soil and tailings samples, as well as in tap and groundwater, to evaluate the human health risks from ASGM activities and assess contamination levels within the study area. Soil and water samples were collected from various locations, including agricultural, residential, and tailings sites, as well as groundwater and tap water from the Nile. Mercury analysis was conducted using MA-3000 (NIC), and geo-accumulation index analysis revealed extreme pollution levels in areas with tailings and moderate pollution levels in agricultural and residential areas. Hazard quotients were applied to assess health risks, with inhalation of mercury vapor identified as the primary exposure route. The results indicated that tailings pose significant health risks, particularly for children, while water samples and soil from agricultural and residential areas did not pose significant risks. These findings underscore the urgent need for authorities and local communities to address mercury contamination by removing and treating tailings from affected areas to mitigate health risks.

Assessment of mobile mercury concentration in soils of an abandoned coalfield waste pile in Douro region: the Fojo waste pile (Portugal) study case

PurposePejão Mining Complex locates in Castelo de Paiva municipality and, until its closure in 1994, was one of the most important coal mines in the Douro Coalfield. This work aims to study the presence, quantify, and evaluate the dissemination of mercury (Hg), a potentially toxic element (PTE) of major public health concern by the World Health Organization (WHO), from a waste pile affected by coal fires.Materials and methodsSamples from areas affected and unaffected by the combustion and from surrounding soil were collected from Fojo waste pile region. First, the Hg pseudo-total concentration was estimated for all collected samples by soil microwave–assisted digestion with aqua regia (USEPA 3051A). Then, a sequential extraction procedure (SEP), the USEPA 3200, was applied for Hg fractionation and speciation aiming to evaluate Hg mobility and bioavailability to surrounding ecosystems.Results and discussionThe results obtained showed a Hg enrichment in soil samples when compared to Portuguese and international reference values for soils. Relatively to the Hg availability and mobility, although it predominates in the semi-mobile fraction, the waste pile materials exposed to combustion showed a concerning increase of Hg levels in the mobile fraction that contains the more labile Hg species, being a major source of environmental contamination by Hg.ConclusionsThis study allowed to conclude that combustion of mining residues increased Hg mobility, toxicity, and bioavailability, increasing the contamination potential of the coal waste pile. The methodology applied in this work can be replicated in other abandoned mines to monitor, control, and/or mitigate the Hg environmental impact in the surrounding soils and waters.

Assessment of mercury accumulation in various tissues of rice plant (Oryza sativa L.) from a Ramsar site in India

Dietary exposure to mercury through rice consumption is an issue of solemn global concern. The favourable bio-geochemical environment of paddy fields often makes them potential mercury cycling hotspots. India is one of the largest producers and consumers of rice globally. To date, studies focusing on mercury bioaccumulation in rice during the different stages of its growth cycle have not been studied in Indian agro-ecosystems.This inturn resulted in a knowledge gap in the global mercury assessment. Being a party to the Minamata Convention, there is an urgent need to unravel the scenario of mercury contamination in rice, one of the staple food crops across the world. In the present study, total mercury (THg) in the rhizosphere soil as well as its accumulation in different tissues of the rice plant were examined by a field investigation in Kuttanad – a unique Ramsar site in Kerala, India. For the purpose of the study five permanent plots were selected and monitored for the entire rice-growing season (from the 30th to the 120th day). Direct Mercury Analyzer (DMA – 80, Milestone, USA) was used for analyzing THg in rhizosphere soil and plant tissues. Mercury concentration in soils varied from 0.037 mg/kg to 0.117 mg/kg with a mean concentration of 0.088 mg/kg. The THg accumulation pattern in plant tissues followed the order: root > leaf > grain > husk > stem. The mean THg concentration in rice grains was 0.22 mg/kg. The low values for bioaccumulation factor (0.616) and translocation factor (0.425) revealed that a major portion of mercury accumulated by the plant is stored in the roots.

Identifikasi Pencemaran Merkuri di Tanah Lokasi Aktivitas dan Pasca Aktivitas Penambangan Emas Tanpa Izin di Desa Roko Kabupaten Halmahera Utara

Research has been carried out with the title identification of mercury pollution in soil at activity locations and post-unlicensed gold mining (PETI) activities in Roko Village, North Halmahera Regency, with the aim of determining the level of pollution and distribution of mercury at PETI and post-PETI activity locations. Sampling used the proportional sampling method in which 5 soil samples were taken at each location. Soil pH measurements were carried out in situ using a Soil Survey Instrument. To analyze mercury concentration in soil, soil samples were taken, preserved, prepared and tested for mercury concentration using a mercury analyzer. The analysis results show that the pH category at the PETI activity location is in the acid category with a pH range of 4.5-5. Meanwhile, the soil pH at the post-PETI location is in the acid to slightly acid category, namely pH 5-6. The results of the analysis of mercury concentrations in the soil at the PETI location ranged from 3.21 mg/kg - 74.99 mg/kg and post-PETI activity locations ranged from 1.76 mg/kg - 167.1 mg/kg at a radius of 0-50 m and has exceeded the normal criteria for mercury in soil and reached the very critical criteria category.

Distribution And Adsorption of Mercury in Abandoned Mines in The Laberinto - Tambopata -Puerto Maldonado Sector

The study was conducted in the Laberinto Sector. It determined the distribution and adsorption capacity of mercury in the soil, how the physical-chemical characteristics of the soil influence the adsorption, and the entry of mercury into the vegetation. An area of 20 km2 was studied, applying the Soil Sampling Guide of the Ministry of the Environment, using the Circular Grid sampling, obtaining 4 Quadrants (A, B, C, and D) with 8 sectors, extracting a total of 33 samples, with 17 samples for physical-chemical study. For the vegetation samples, it was based on the Inventory Guide of Flora and Vegetation of the Ministry of the Environment, obtaining a total of 21 samples. The concentration of mercury in soil and vegetation samples was analyzed in the laboratory by atomic adsorption analysis, and the adsorption capacity was obtained by the Langmuir Isotherm formula. As a result, the distribution of mercury concentration is not homogeneous in the study area, and the concentration of mercury in the soil does not exceed the Environmental Quality Standards of the Peruvian Ministry of the Environment but does exceed the standards of the United Nations Environmental Program (UNEP). The adsorption capacity of mercury decreases as the mercury concentration increases, being fundamental to the physical and chemical characteristics of the soil in the entry of mercury into the plants. The concentration of mercury in vegetation exceeds the maximum standards allowed by the European Union Commission by Regulation.

Characteristics of Mercury Fluxes between Soil and Air in the Farming-Pastoral Ecotone of Songnen Grassland

In order to understand the characteristics and influencing factors of surface release fluxes in the typical agro-pastoral mosaic region of the Songnen grasslands of northern China, this study selected two sample plots to, respectively, represent the L. chinensis covered grassland (L), and the Z. mays covered fields (Z) in the Waizi area of Changling County, with western Jilin Province as the study area. This study investigated the atmospheric mercury (Total Gaseous Mercury (TGM)) concentrations, surface soil mercury concentrations, the gaseous elemental mercury exchange fluxes, and related environmental factors. The results showed that the TGM concentrations in two sample plots in the study area were basically the same during the summer and autumn months, but were higher in summer than in autumn, and there was a clear diurnal pattern. The average mercury concentrations in the surface soil were also higher in summer than in autumn. Furthermore, the surface soil has a clear mercury release process, and the mercury release were higher in the sheep grass field than the maize field during the same season. The mercury release fluxes in each site within the ecotone were related to the solar radiation and soil temperature values, and the effects of them on the soil mercury release were independent from one another.

Risk Assessment of the Wild Edible Leccinum Mushrooms Consumption According to the Total Mercury Content.

Wild-growing edible mushrooms contain many biologically valuable substances. However, they are considered a risk commodity due to their extremely high capacity for bioaccumulation of potential risk elements and pollutants from the environment. Four bolete mushrooms from the genus Leccinum were collected from 16 forested areas of Slovakia from June to October 2019. The total mercury content in soil and fruiting body parts was determined by an AMA-254 Advanced Mercury Analyzer. Soil pollution by total mercury was evaluated by contamination factor (Cfi). Bioaccumulation factor (BCF), translocation factor (Qc/s), percentage of provisional tolerable weekly intake (%PTWI), and target hazard quotient (THQ) were used to describe and compare uptake and transition abilities of mushrooms, and the health risk arising from consumption of the mushrooms. Total mercury content varied between 0.05 to 0.61 mg kg-1 DW in the soil/substrate samples, and between 0.16 and 5.82 (caps), and 0.20 and 3.50 mg kg-1 DW (stems) in fruiting body samples. None of the analyzed locations represented a health risk based on %PTWI values, however, three locations may pose a significant health risk from the perspective of THQ values.

Mercury accumulation potential of aquatic plant species in West Dongting Lake, China

West Dongting Lake is a protected wetland with the potential for high levels of mercury release via wastewater and deposition from industry and agriculture during the last decade. To find out the ability of various plant species to accumulate mercury pollutants from soil and water, nine sites were studied in the downstream direction of the flow of the Yuan and Li Rivers, which are tributaries of the Yellow River flowing into West Dongting Lake, where mercury levels arere high in soil and plant tissues. The total mercury (THg) concentration in wetland soil was 0.078–1.659 mg/kg, which varied along the gradient of water flow along the river. According to canonical correspondence analysis and correlation analysis, there was a positive correlation between the soil THg concentration and the soil moisture in West Dongting Lake. There is high heterogeneity in the spatial distribution of soil THg concentration in West Dongting Lake, which may be related to the spatial heterogeneity of the soil moisture. Some plant species had higher THg concentrations in aboveground tissues (translocation factor >1), but none of these plant species fit the criteria as hyperaccumulators of mercury. And some species of the same ecological type (e.g., emergent, submergent, floating-leaved) exhibited very different strategies for mercury uptake. The concentrations of mercury in these species were lower than in other studies but these had relatively higher translocation factors. To phytoremediate soil mercury in West Dongting Lake, the regular harvest of plants could help remove mercury from soil and plant tissue.

Heavy Metal Content and Resistance Gene Abundance and Related Properties in the Surface Soil around Qinghai Lake

Soil heavy metal pollution and the prevalence of resistance genes have been a global concern, and thus many studies have reported the content of heavy metals and resistance genes in soils; however, the contents of heavy metals and antibiotic resistance genes (ARGs) in the soil in highland areas is still unclear. In this study, the environmental residues and distribution of heavy metals and resistance genes in the soil in Qinghai were analyzed, and the relationship between the concentration of heavy metals and antibiotic resistance genes in the soil was explored. Among the soil samples, the content of heavy metal zinc was the highest ［mean: (50.27±19.88) mg·kg-1］, followed by the content of heavy metal cadmium ［mean: (30.27±9.45) mg·kg-1］, and the content of heavy metal mercury was the lowest ［mean: (0.027±0.019) mg·kg-1］. The subtypes of heavy metal resistance genes in soils were mainly czcA, merA, and merP, whose main function was to be responsible for developing mercury resistance. The relative abundance of β-lactamase resistance genes (0.1505) was the highest in soil, accounting for 47.54% of the total abundance of ARGs; tetracycline resistance genes accounted for 16.93% of the total abundance of ARGs, FCA accounted for approximately 14.56%, and MLSB accounted for approximately 8.77%. The diversity and relative abundance of movable genetic elements (MGEs) were low, and only the [STBX]tnpA01[STBZ] gene was detected; intl[STBX]1[STBZ] and intl[STBX]2[STBZ] were not detected. Correlation studies showed that Cu content (r=-0.533, P=0.006) and Hg (r=0.692, P=0.006) in soil were significantly negatively correlated with altitude, whereas other heavy metals were not significantly correlated with altitude. In addition, heavy metal content was significantly correlated with soil type (P<0.05). There was a significant positive correlation between heavy metal mercury content in soils and czcA (r=0.692, P=0.006), merA (r=0.816, P=0.007), and merP (r=0.594, P=0.02). The results of this study elucidated the occurrence and distribution of heavy metals and ARGs in the Tibetan Plateau region and found that the content of heavy metals in the soil was significantly related to resistance genes.

СОДЕРЖАНИЕ РТУТИ В ПОЧВЕННЫХ БЕСПОЗВОНОЧНЫХ РЕКРЕАЦИОННОЙ ЗОНЫ КРУПНОГО ПРОМЫШЛЕННОГО ГОРОДА (Г. ЧЕРЕПОВЕЦ)

Soil invertebrates are the main food resource for birds and small mammals. The migration of mercury into the food webs of terrestrial ecosystems is still poorly investigated. The mercury content in soil, earthworms, wolf spiders and harvesters of the forest park zone of Cherepovets (Vologda region) was determined. The collection of the material was carried out on 5 sites (birch-aspen forest, wet pine forest, dry pine forest, wet meadow, dry meadow) differing in the composition of vegetation and the position in the cascade of geochemical landscapes. The minimum mercury content was found in the soils of the dry meadow (eluvial landscape) – 25 ng/g, the maximum – in the soils of the wet meadow (accumulative landscape) – 188 ng/g. The maximum concentrations of mercury in all sites were found in earthworms – from 261 ng/g in the dry pine forest to 1095 ng/g in the wet meadow. The concentration of mercury in wolf spiders was lower than in earthworms. The minimum values were found in a dry meadow. In all sites, the mercury content in wolf spiders was significantly higher than in harvesters. There are no significant correlations between the mercury content in soils and the organism of the studied invertebrates.

MERCURY CONTENT IN THE WILD EDIBLE LECCINUM MUSHROOMS GROWING IN SLOVAKIA: ENVIRONMENTAL AND HEALTH RISK ASSESSMENT

The samples of 4 mushroom species from the genus Leccinum ((Leccinum pseudoscabrum (Kallenb.) Šutara, Leccinum scabrum (Bull.) Gray, Leccinum duriusculum (Schulzer ex Kalchbr.) Singer, and Leccinum albostipitatum den Bakker &amp; Noordel) were picked from 6 forested areas of Slovakia in 2020 (Čačín – Jelšovec, Hliník and Hronom, Kurima – Taraš, Mníšek nad Popradom, Snina – Štefekovo, Žákylské pleso). Total mercury content in soil and mushroom parts was determined by cold-vapor AAS analyzer AMA 254. Mercury content in monitored soil samples ranged from 0.07 to 0.18 mg.kg-1 DM. The limit value for Hg in soil ( 0.50 mg.kg-1) was not exceeded. Mercury content in analyzed cap samples ranged from 0.41 to 7.52 mg.kg-1 DM. Mercury content in analyzed stem samples ranged from 0.40 to 2.91 mg.kg-1 DM. The EU limit value in edible mushrooms for Hg (0.75 mg kg-1 FW) was exceeded in caps from Mníšek nad Popradom. Values of the bioconcentration factor indicate that Leccinum mushrooms are accumulators of Hg. The PTWI of Hg was not exceeded. The THQ of all samples was lower than 1. This means that the average consumption of mushrooms from this localities should not cause a serious risk to human health. However, the intake of Hg from other sources must also be taken into account.

Analysis of Mercury Content in Plants of Biogeochemical Territory Aydarken

Mercury is a highly volatile chemical element. It is characterized by high geochemical mobility in various natural processes. It belongs to the class I highly toxic chemical elements. Its toxicity depends on the type of chemical compounds and the concentration. Mineralization of plant samples was carried out using a microwave system Minotaur-2, and the concentration of mercury was determined on an MGA-915 atomic absorption spectrometer. The mercury concentration is above the maximum allowable level in all studied plant samples. The coefficient of biological absorption of mercury for Artemisia tenuisecta Nevski ranged from 0.008 to 0.100. The relationship between mercury content in soils and plants was studied and correlation coefficients were calculated. Plants of the genus Artemisia have the highest resistance to the toxic effects of mercury.

Relationships between concentrations of mercury and organic carbon in soils allow the identification of Antarctic ice-free areas with enhanced deposition of the metal

Antarctica is a sink for mercury (Hg) and plays an important role in the global Hg cycle. Knowledge about the environmental fate of Hg in Antarctic terrestrial ecosystems, however, remains highly restricted. In this study, we investigated soil Hg in samples from three areas located across a wide latitudinal range from about 62°S to over 74°S with very different climatic and environmental conditions and different potential (natural and anthropogenic) sources of Hg. The highest Hg levels were found in soils beneath mosses and ornithogenic soils in the Antarctic Peninsula, whereas extremely low values were found in coastal East Antarctica. Total Hg concentrations in soil samples from the three study areas were always closely related to those of organic carbon (OC). In corroborating the results of previous studies, this large-scale survey strongly suggests that OC is a dominant driver affecting Hg distribution in Antarctic soils. The observed linear relationship between Hg and OC concentrations, also supported by available literature data, probably, has a general relevance for Antarctic soils, and allows to identify samples affected by enhanced Hg deposition from anthropogenic or natural sources. In providing a better understanding of the biogeochemical cycle of Hg in Antarctic terrestrial ecosystems, this study suggests that soil OC content must be considered to assess Hg distribution patterns in Antarctic soils. In samples (including those of lacustrine sediments, planktonic, and benthic algal mats) unaffected by an accentuated deposition of Hg, the value of the ratio [Hg ng/g]/[OC %] appears to be less than ∼ 11.

Mercury in soil, sediment, and lake water in upland headwater catchments in Ireland

Mercury concentrations in the atmosphere, surface waters, and soils have increased beyond natural levels as a result of human activities, which poses a risk to human and environmental health. Ireland is situated on the western periphery of Europe, and it is generally assumed that environmental mercury is low but there is limited information on mercury within natural environments. In this study, the interlinkages in the concentration of mercury in soils, lake sediment, and lake water were investigated in remote upland acid-sensitive catchments influenced by low deposition of atmospheric mercury. Thirty-one upland lake catchments were sampled for topsoil, lake sediment, and lake water during 2017–2018. Total mercury (THg) concentrations in water (median 5.4 ng/L) and sediment (median 30 ng/g) were low, owing to the remote location of the lakes. In contrast, THg in catchment soil was relatively high for a background region (median: 240 ng/g), which was attributed to the high organic matter content of the soil (median 87%). The results suggest catchment soils are the dominant driver of variation in THg in lake water and sediment in upland regions in Ireland. Further, given that highly organic soils can obscure interlinkages within catchments, this study demonstrated the value of exploring mercury independent of the influence of organic matter, i.e., THg normalized by organic carbon. As global action (such as the Minamata Convention) decreases mercury emissions, legacy soil mercury may become a more important input to aquatic systems than atmospheric deposition, which makes the relationships between terrestrial catchments and their water bodies vital for our understanding of mercury cycling.

Mercury Concentrations in Water, Sediments, Soil, and Fish Around Ancestral Afro-Descendant Territories Impacted by Gold Mining in the Cauca Department, Colombia

Mercury Concentrations in Water, Sediments, Soil, and Fish Around Ancestral Afro-Descendant Territories Impacted by Gold Mining in the Cauca Department, Colombia

Evaluation of Mercury Pollution in Soil of Different Land Use Types in Coal-fired Industrial Area

The geo-accumulation index, potential ecological risk index, health risk model, and geographical detector were used to evaluate the soil mercury (Hg) concentrations and assess the health risks for various land use types to reveal the characteristics and spatial variability of soil Hg pollution under different land uses in the coal-fired industrial area of the Loess Plateau. The study area included seven counties in the western part of Xinzhou City, Shanxi province. The results showed that the average ω(Hg) in the agricultural land, grass land, wood land, and residential land were 0.48, 0.34, 0.58, and 0.52 mg·kg-1, respectively, which were 16.00, 11.33, 19.33, and 17.33 times higher than the background value, respectively. The variation coefficients were ranked as residential land>agricultural land>grass land>wood land. The evaluation results of the geo-accumulation index and potential ecological risk index indicated a high ecological risk of Hg pollution in the entire study area with extreme pollution points in certain aeras. The health risk assessment results indicated no non-carcinogenic health risks for children and adults in the study area from Hg. Additionally, the geographical detection results revealed that the spatial variability in Hg was mainly impacted by industrial and agricultural activities in agricultural land, by soil organic matter and pH value in grass land, by soil salinity in wood land, and by soil salinity and organic matter in residential land. The spatial distribution pattern of Hg concentrations peaked in both the northern and southern edges, with a decreasing trend towards the middle and the majorly polluted areas being caused by human activities such as coal mining and industrial production.