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The accumulation of potentially toxic elements in soil poses significant risks to ecosystems and human well-being due to their inherent toxicity, widespread presence, and persistence. The Kangdian metallogenic province, famous for its iron-copper deposits, faces soil pollution challenges due to various potentially toxic elements. This study explored a comprehensive approach that combinescombines the spatial prediction by the two-point machine learning method and ecological-health risk assessment to quantitatively assess the comprehensive potential ecological risk index (PERI), the total hazard index (THI) and the total carcinogenic risk (TCR). The proportions of copper (Cu), cadmium (Cd), manganese (Mn), lead (Pb), zinc (Zn), and arsenic (As) concentrations exceeding the risk screening values (RSVs) were 15.03%, 5.1%, 3.72%, 1.24%, 1.1%, and 0.13%, respectively, across the 725 collected samples. Spatial prediction revealed elevated levels of As, Cd, Cu, Pb, Zn, mercury (Hg), and Mn near the mining sites. Potentially toxic elements exert a slight impact on soil, some regions exhibit moderate to significant ecological risk, particularly in the southwest. Children face higher non-carcinogenic and carcinogenic health risks compared to adults. Mercury poses the highest ecological risk, while chromium (Cr) poses the greatest health hazard for all populations. Oral ingestion represents the highest non-oncogenic and oncogenic risks in all age groups. Adults faced acceptable non-carcinogenic risks. Children in the southwest region confront higher health risks, both non-carcinogenic and carcinogenic, from mining activities. Urgent measures are vital to mitigate Hg and Cr contamination while promoting handwashing practices is essential to minimize health risks. [Display omitted] • Spatial prediction unveils potentially toxic element distinct patterns and hotspots. • Chromium poses the highest health risks for all groups in the metallogenic province. • Oral ingestion has the highest non-oncogenic and oncogenic risks in all age groups. • Kids face higher ecological-health risks than adults due to hand-to-mouth habits. [ABSTRACT FROM AUTHOR]

Advancements in transportation networks have induced a spatial-temporal convergence effect, accelerating socio-economic elements flow and dismantling the conventional "core-periphery" urbanization gradient. Accessibility of transportation networks emerges as a reliable indicator of urbanization. There has been a growing global and Chinese focus on the various forms of metal pollution in urban soil. This study aims to investigate the driving forces and effects of urbanization factors (Gross Domestic Product (GDP), value added of secondary industries (VA), night light (NL), population density (PD), and road density (Distance)), soil property factors (pH, electrical conductivity (EC), and total organic carbon (TOC)), and topographic factors (elevation (DEM), aspect, and slope) on toxic heavy metal elements (Cd, As, and Hg) and trace elements (Mn, Ti, V) in surface soil (0–20 cm) across varying accessibility levels in the Beijing-Tianjin-Hebei urban agglomeration. Results reveal significant influence of accessibility on Cd and Hg levels (p < 0.05), with higher accessibility areas displaying elevated element concentrations. According to the evaluation results of the single-factor pollution index, Cd and V have the highest pollution exceedance rates (93.18% and 75.76%, respectively). Moran's Index results highlight typical spatial clustering of elements, with hotspots in areas of high accessibility. Urbanization has led to distinct spatial agglomeration patterns in element concentrations and environmental factors. Geographic detector analysis reveal that in low accessibility areas, metal element pollution and distribution are influenced by a combination of complex factors, including soil properties (pH), terrain conditions (DEM), and the urbanization process (VA). In high accessibility areas, toxic heavy metal elements are primarily driven by urbanization factors, largely influenced by transportation activities, industrial development, and population density, while elements Mn, Ti, and V are still influenced by both natural processes and urbanization activities. These findings suggest that urbanization intensifies the impact on potential toxic elements in soil, and that trace elements are increasingly affected by urbanization, warranting further attention. [Display omitted] • The content of elements in the topsoil (0–20 cm) is higher than in the subsoil (20–40 cm). • The higher the accessibility level, the higher the average content of elements in the soil. • Cd and V have the highest pollution exceedance rates. • Metal elements exhibit spatial agglomeration characteristics. • In highly accessible areas, urbanization is the main driver of toxic metal elements. [ABSTRACT FROM AUTHOR]

Phosphorus and nitrogen pollution from agricultural nonpoint sources heavily burden the water environment, and a scientific calculating system is needed to calculate the pollutant loads under the water pollution treatment. This study established a system to calculate the coefficients of agricultural nonpoint source pollutants into water bodies in the subregion in Poyang Lake basin in the middle reach of the Yangtze River combining with multiple driving factors. Validation results showed that the errors of the typical unit were 30.58% for total phosphorus (TP), 13.43% for total nitrogen (TN) and 33.93% for ammonia nitrogen (NH 3 -N), respectively. The errors of the subregion were 26.92% for TP, 31.83% for TN and 29.15% for NH 3 -N, respectively. Besides, there were higher TP and TN loads in the east area of subregion in both units and county scales, which indicated the heavy phosphorus and nitrogen burden on water environment. In contrast, higher NH 3 -N loads occurred in the north area of subregion. The establishment of coefficient system for agricultural pollutants into water bodies and the pollutant loads calculation would provide enlightenment for water pollution treatment and agricultural nonpoint source pollution controlling. • Coefficient system of pollutants was established combining with driving factors. • Heavy nitrogen and phosphorus pollution distributed in the east subregion. • High NH 3 -N load was in the north area of the subregion. • Pollutant load calculation provided reliable method for water pollution management. [ABSTRACT FROM AUTHOR]

The presence of trace metals (TMs) in agricultural soil has garnered considerable attention due to their potential migration into crops, posing a significant risk to human health. In this study, we examined the concentrations of eight trace metals (Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn) in the soil and investigated various soil physicochemical characteristics in the Three Rivers Plain region, China. The assessment of the geoaccumulation index (I geo) for the mean concentration of all trace metals indicated that the soils were generally free from significant TM pollution. However, a noteworthy finding emerged in relation to Hg, where the maximum I geo value suggested moderate pollution levels. Kriging prediction results further indicated that approximately 1.55% of the study area might be impacted by Hg pollution. Moreover, it is prudent to direct attention towards Cd, Cr, Cu, Mn, and Ni, as their I geo values revealed that the region with the highest concentrations of these metals ranged from unpolluted to moderately polluted. This study employed a comprehensive approach, utilizing the Self-Organizing Map (SOM), Kriging spatial distribution, and the Positive Matrix Factorization (PMF) model to identify the sources of TMs in agricultural soil. The results unveiled that the primary contributors to TM presence were the natural parental materials, alongside industrial activities such as coal mining and coal plant operations, as well as agricultural practices. These findings provide foundational insights for future management strategies in the Three Rivers Plain, aiming to enhance agricultural productivity and promote sustainability. [Display omitted] • Kriging interpolation reveals possible Hg, Cu, and Ni pollution in the study area. • There were important variations in the spatial distribution of the eight trace metals. • Crop type and flooding frequency may affect the spatial distribution of TMs in soil. • Different trace metal sources were identified and quantified through integrated methods. [ABSTRACT FROM AUTHOR]

Effects of CeO 2 NPs (200 mg.L−1) on rice (Oryza sativa L.) alone or co-exposure with cadmium (Cd) and salt (sodium chloride, NaCl) were investigated in hydroponic systems for two weeks. Physiological results show that rice biomass was significantly inhibited when NaCl or CdCl 2 added alone or in co-exposure treatment. CeO 2 NPs significantly relieve the chlorophyll damage under CdCl 2 environmental stress. The presence of CeO 2 NPs alleviated both stressors induced damages to rice as indicated by the reduced proline level. Additionally, CeO 2 NPs triggered the antioxidant defense systems to counteract the oxidative stress caused by NaCl and CdCl 2. The level of 8-OHdG, one of the most important indicators for genotoxicity, in rice suggest that the presence of CeO 2 NPs reduced the DNA damage in NaCl treated rice. Elemental analysis indicated that co-exposure to NaCl and CdCl 2 slightly decreased the Cd content as compared to the one in the CdCl 2 alone treatment, and this co-exposure also significantly reduced the Na content when comparing with the NaCl alone treatment. Taken together, our findings suggest that CeO 2 NPs could alleviate the CdCl 2 and NaCl stresses, but could not completely change the phenotype of both contaminants treated rice. Image 1 • CeO 2 NPs reduced the proline level of rice seedlings under NaCl and Cd exposures. • CeO 2 NPs counteracted NaCl and Cd induced stresses by antioxidant defense systems. • The content of 8-OHdG in NaCl treated rice seedlings was decreased by CeO 2 NPs. • Both Na and Cd contents in rice seedlings were decreased in the co-stress exposure. CeO 2 NPs alleviated salt stress and cadmium toxicity by lowering the levels of proline and 8-OHdG and triggering the antioxidant defense systems. [ABSTRACT FROM AUTHOR]

Reduced graphene oxide (rGO) is one of the most widely used carbon nanomaterials. When it is released into the environment, rGO can markedly affect the transformation of many pollutants, and change their fate and risk. In this work, the synergetic effects of rGO and Cu(II) on the oxidation of 2-naphthol were examined in water in the dark. It was found that the coexistence of rGO and Cu(II) significantly promoted the oxidation of 2-naphthol. Corresponding products were identified as the coupling oligomers of 2-naphthol (dimer, trimer and tetramer) and hydroxylated compounds (OH-2-naphthol, OH-dimer, di–OH–dimer and naphthoquinone derivatives). In the oxidation reaction, rGO played dual roles, i.e. adsorbent and electron-transfer mediator. rGO firstly adsorbed Cu(II) and 2-naphthol on its surface, and then transferred electrons from 2-naphthol to Cu(II) to yield 2-naphthol radicals and Cu(I). 2-Naphthol radicals coupled to each other to form different oligomers of 2-naphthol. Cu(I) was re-oxidized back to Cu(II) by dissolved oxygen, which sustained the continuous oxidation of 2-naphthol. During the autoxidation of Cu(I), reactive oxygen species were generated, which further reacted with 2-naphthol to form hydroxylated products. These findings provide new insights into the risk assessment of rGO and 2-naphthol in aquatic environments. Image 1 • rGO and Cu(II) synergistically promoted the oxidation of 2-naphthol. • Products were the coupling oligomer and hydroxylated compounds of 2-naphthol. • 2-Naphthol transferred electron to Cu(II) to yield 2-naphthol radical and Cu(I). • Cu(I) was re-oxidized back to Cu(II) by dissolved oxygen. • Reactive oxygen species were formed during the autoxidation of Cu(I). rGO and Cu(II) synergistically promoted the oxidation of 2-naphthol to form the corresponding coupling oligomers and hydroxylated compounds. [ABSTRACT FROM AUTHOR]

A comprehensive analysis of content, pollution characteristics, health hazard, distribution, and source of some broadly concerned potentially toxic elements (PTEs, Pb, V, Mn, Cr, Ba, Zn, Ni, and Cu) in surface fine dust with particle size <63 μm (SFD63) from residence communities in Xi'an, a representative valley industrial city, was conducted in this research to analyze the quality of environment and influencing factors of valley industrial cities in China. The average contents of Ba (794.1 mg kg−1), Cu (61.3 mg kg−1), Pb (99.9 mg kg−1), Zn (408.1 mg kg−1), Cr (110.0 mg kg−1), and Ni (33.4 mg kg−1) in SFD63 of Xi'an residence communities surpassed their background contents of local soil. The high enrichment-value regions of PTEs were chiefly located in the regions with high traffic flow, high population density, and areas around industries. Zn and Pb had moderate enrichment, and the overall pollution level of PTEs was unpolluted-to-moderate and moderate pollution. Three source categories (including natural geogenic source, industrial anthropogenic source, and mixed anthropogenic source of transportation, residential activities, and construction) were identified as the predominant sources for the PTEs pollution in SFD63, with the contribution levels of 29.9%, 32.4%, and 37.7%, respectively. The assessment of health risks according to Monte Carlo simulation revealed that the 95% of the non-cancer risk of PTEs to residents (the elderly, working people, and children) was less than the threshold of 1, while the probability of cancer risk exceeding the acceptable threshold of 1E-6 was 93.76% for children, 68.61% for the elderly, and 67.54% for working people. Industrial source was determined as priority pollution source and Cr was determined as priority pollutant, which should be concerned. [Display omitted] • Source-specific probabilistic health risk assessment was conducted in this study. • Surface fine dust of residential area had elevated toxic elements. • Mixed source was the main anthropogenic source of toxic elements in the fine dusts. • Toxic elements in the fine dusts had a certain cancer risk to the residents. • Industrial source and Cr were the priority control factors for pollution control. [ABSTRACT FROM AUTHOR]

• Prioritizations of the 24 targets of the five LEEW related SDGs were set. • The interactions and performances of targets were assessed to prioritize them. • Key actions for promoting these SDGs were provided (e.g., regional collaboration). • The high trade-offs among water and energy dimensions require attention. The five Sustainable Development Goals (SDGs) related to livelihood, energy, ecosystem, and water (LEEW) are highly interlinked, and their progress is a strong stepping stone to achieve other SDGs. However, research about the effective actions for promoting them in the Asian Water Tower (AWT) region (16 countries) is limited. Here, we measured the interactions (synergies and trade-offs) among and the performances of 24 SDG targets related to LEEW based on calculating correlation coefficients, network analysis, and index-based and benchmarking analysis. By aggregating the results, we eventually prioritized the 24 targets to provide evidence-based support for identifying holistic and synergistic actions across scales. Targets 2.3 (agricultural productivity), 7.1 (modern energy services), 7.2 (renewable energy), 15.2 (sustainable forests), 15.5 (habitat and biodiversity conservation), 15.6 (sharing benefits from genetic resources), and 1.a and 15.a (resources mobilization) were top-prioritized. Mainstreaming them along with numerical target values into strategies across scales can be a useful starting action. Additionally, we highlighted several obstacles for these SDGs' progress (e.g., trade-offs among basin water and energy resource management in the future energy-oriented LEEW actions) and some keys to support their achievements (e.g., interdisciplinary research, sectoral transformation, and transnational and cross-basin collaboration). [ABSTRACT FROM AUTHOR]

A thorough understanding of the labile status and dynamics of phosphorus (P) and iron (Fe) across the sediment-water interface (SWI) is essential for managing internal P release in eutrophic lakes. Fe-coupled inactivation of P in sediments is an important factor which affects internal P release in freshwater lakes. In this study, two in-situ high-resolution diffusive gradients in thin films (DGT) techniques, Zr-Oxide DGT and ZrO-Chelex DGT, were used to investigate the release characteristics of P from sediments in a large freshwater lake (Dongting Lake, China; area of 2691 km 2 ) experiencing a regional summer algal bloom. Two-dimensional distributions of labile P in sediments were imaged with the Zr-Oxide DGT without destruction of the original structure of the sediment layer at four sites of the lake. The concentration of DGT-labile P in the sediments, ranging from 0.007 to 0.206 mg L −1 , was highly heterogeneous across the profiles. The values of apparent diffusion flux (F d ) and release flux (F r ) of P varied between −0.027–0.197 mg m −2 d −1 and 0.037–0.332 mg m −2 d −1 , respectively. Labile P showed a high and positive correlation (p < 0.01) with labile Fe(II) in the profiles, providing high-resolution evidence for the key role of Fe-redox cycling in labile P variation in sediments. [ABSTRACT FROM AUTHOR]

Rare earth elements (REEs) concentrated in soils have attracted increasing attention about their impact on soil health as emerging contaminants. However, the sources of REEs enriched in soils are diverse and need to be further investigated. Here, surface soil samples were collected from southern Jiangxi Province, China. REEs contents and soil physicochemical properties were determined, and cerium (Ce) and europium (Eu) anomalies were calculated. Moreover, we established a model to further identify the main sources of REEs accumulation in the studied soils. Results show that the abundance of soil REEs reveals larger spatial variation, suggesting spatially heterogeneous distribution of REEs. The median content of light REEs in soils (154.5 mg kg−1) of the study area was higher than that of heavy REEs and yttrium (35.8 mg kg−1). In addition, most of the soil samples present negative Ce anomalies and all the soil samples present negative Eu anomalies implying the combined effect of weathering and potential exogenous inputs on soil REEs. Positive matrix factorization modeling reveals that soil REEs content is primarily influenced by soil parent materials. Potential anthropogenic sources include mining-related leachate, traffic exhaust, and industrial dust. These results demonstrate that the identification of sources of soil REEs is an important starting point for targeted REEs sources management and regulation of excessive and potentially harmful REEs levels in the soil. [Display omitted] • Characteristic parameters of soil REEs help to identify the source of REEs. • Parent material dominates the contents of soil REEs. • Multiple anthropogenic sources may affect soil REEs abundance. [ABSTRACT FROM AUTHOR]

Comprehensive efficiency analysis of wastewater treatment plants (WWPTs) in the alpine region with harsh environment and poor techniques as well as managing experience could provide targeted and effective improvement evidences for local wastewater treatment industry and help to improve the water quality of downstream reaches. In this paper, slack–based data envelopment analysis (SBM–DEA) was adopted to assess the operating efficiencies of WWPTs in northeast Qinghai–Tibet Plateau (QTP). Results showed that the average efficiency score for all WWPTs was 0.608, and 32.5% of WWPTs were efficient. Some WWPTs had large improvement potentials in operating costs and pollutant removal rates. Lowering expenditures and promoting facility construction for WWPTs to overcome the climate difficulties and improve management level was necessary according to their improvement potentials. In addition, the relative importance of the quantitative influential factors to efficiencies scores calculated by random forest regression (RFR) indicated that design capacity and temperature were important quantitative factors affecting the performance of WWPTs. Furthermore, geographical location and design capacity also had significant influence on the comprehensive efficiency of WWPTs verified by Kruskal–Wallis test. Our results highlight the importance of facilities upgrading, scientific management for WWPTs. And the relative improvement suggestions on overcoming the high and cold environment should also be considered for the efficient operations of WWTPs as well as the protection the aquatic environment. [Display omitted] • Operating efficiency of WWPTs in the northeast QTP was evaluated by SBM–DEA. • Some WWPTs had improvement potentials on saving cost and pollutant removal rates. • Temperature and designed capacity were important factors in impacting efficiency. • Lower altitude and higher temperature were more benefit for operation of WWPTs. • Insulation, upgrading and reconstructing were necessary for WWPTs in QTP. [ABSTRACT FROM AUTHOR]

Dongting Lake is a typical shallow lake in the lower Yangtze region and is the second largest freshwater lake in China. The distribution, speciation, and sediment release characteristics of phosphorus (P) were investigated by analyzing sediment and water samples collected during high and low flow periods. The average concentration (range) of total phosphorus (TP) in the water was 0.05 mg L − 1 (0.02 ~ 0.09 mg L − 1 ), while the value in sediment was 703 mg kg − 1 (466 ~ 869 mg kg − 1 ). The concentrations of TP and different P forms decreased as depth increased. Inorganic phosphorus was the dominant form of P, accounting for 72% of TP. The bioavailable P was a relatively large portion of TP, indicating a high risk of P release to overlying water. The Langmuir equation can well describe the P isotherm adsorption characteristics in sediment. The amount of P desorption from sediment tended to increase with increasing concentrations of adsorbed P. [ABSTRACT FROM AUTHOR]

The large-scale use of conventional pesticides and fertilizers has put tremendous pressure on agriculture and the environment. In recent years, nanoparticles (NPs) have become the focus of many fields due to their cost-effectiveness, environmental friendliness and high performance, especially in sustainable agriculture. Traditional NPs manufacturing methods are energy-intensive and harmful to environment. In contrast, synthesizing metal-based NPs using plants is similar to chemical synthesis, except the biological extracts replace the chemical reducing agent. This not only greatly reduces the used of traditional chemicals, but also produces NPs that are more economical, efficient, less toxic, and less polluting. Therefore, green synthesized metal nanoparticles (GS-MNPs) are widely used in agriculture to improve yields and quality. This review provides a comprehensive and detailed discussion of GS-MNPs for agriculture, highlights the importance of green synthesis, compares the performance of conventional NPs with GS-MNPs, and highlights the advantages of GS-MNPs in agriculture. The wide applications of these GS-MNPs in agriculture, including plant growth promotion, plant disease control, and heavy metal stress mitigation under various exposure pathways, are summarized. Finally, the shortcomings and prospects of GS-MNPs in agricultural applications are highlighted to provide guidance to nanotechnology for sustainable agriculture. [ABSTRACT FROM AUTHOR]

Dismantling and recycling e-waste has been recognized as a potential emission source of rare earth elements (REEs). However, the presence of REEs in typical regional soils has yet to be studied. Given the potential health implications of such soil contamination, it is vital to study the characteristics, spatial distribution, and pollution level of REEs caused by e-waste dismantling as well as determine the influencing mechanism. This study focused on Guiyu Town as an example site, which is a typical e-waste dismantling base. From the site, 39 topsoil samples of different types were collected according to grid distribution points. Soil profiles were also collected in the dismantling and non-dismantling areas. The REE characteristic parameters showed that the REE distribution was abnormal and was affected by multiple factors. The results of the integrated pollution index showed that approximately 61.5% of soil samples were considered to be lightly polluted. Spatial distribution and correlation analysis showed that hot spots of REE-polluted soil coincided with known, main pollution sources. Moreover, there was a significant negative correlation (p ≤0.05) between the REE concentration and the distance from the pollution source. E-waste disassembly and recycling greatly affect the physical and chemical properties of the surrounding soil as well as downward migration areas. In the disassembly area, REE accumulated more easily in the surface layer (0–20 cm). Geographical detector results showed that distance factor was the main contribution factor for both light rare earth elements (LREE) and heavy rare earth element (HREE) (q = 34.59% and 53.33%, respectively). REE distribution in soil was nonlinear enhanced by different factors. Taken together, these results showed that e-waste disassembling and recycling not only directly affected the spatial distribution of REEs, but that their distribution was also affected by land use type and soil properties. [Display omitted] • Anthropogenic REEs were reported in soil from e-waste recycling site. • Approximately 61.5% of soil samples were considered to be lightly polluted. • Contribution of different factors to the accumulation of REEs is nonlinear enhanced. • Distance was the main contributing factor for both LREE and HREE accumulation. • E-waste disposal indirectly affects REE fractionation by changing soil properties. [ABSTRACT FROM AUTHOR]

The potential toxicity and ecological risks of rare-earth nanoparticles in the environment have become a concern due to their widespread application and inevitable releases. The integration of hydroponics experiments, partial least squares structural equation modeling (PLS-SEM), and Transmission Electron Microscopy (TEM) were utilized to investigate the physiological toxicity, uptake and translocation of yttrium oxide nanoparticles (Y 2 O 3 NPs) under different hydroponic treatments (1, 5, 10, 20, 50 and 100 mg·L−1 of Y 2 O 3 NPs, 19.2 mg·L−1 Y(NO 3) 3 and control) in tomato (Lycopersicon esculentum) seedlings. The results indicated that Y 2 O 3 NPs had a phytotoxic effect on tomato seedlings' germination, morphology, physiology, and oxidative stress. The Y 2 O 3 NPs and soluble YIII reduced the root elongation, bud elongation, root activity, chlorophyll, soluble protein content and superoxide dismutase and accelerated the proline and malondialdehyde in the plant with increasing concentrations. The phytotoxic effects of Y 2 O 3 NPs on tomato seedlings had a higher phytotoxic effect than soluble YIII under the all treatments. The inhibition rates of different levels of Y 2 O 3 NPs in shoot and root biomass ranged from 0.2% to 6.3% and 1.0–11.3%, respectively. The bioaccumulation and translocation factors were less than 1, which suggested that Y 2 O 3 NPs significantly suppressed shoot and root biomass of tomato seedlings and easily bioaccumulated in the root. The observations were consistent with the process of concentration-dependent uptake and translocation factor and confirmed by TEM. Y 2 O 3 NPs penetrate the epidermis, enter the cell wall, and exist in the intercellular space and cytoplasm of mesophyll cells of tomato seedlings by endocytic pathway. Moreover, PLS-SEM revealed that the concentration of NPs significantly negatively affects the morphology and physiology, leading to the change in biomass of plants. This study demonstrated the possible pathway of Y 2 O 3 NPs in uptake, phytotoxicity and translocation of Y 2 O 3 NPs in tomato seedlings. • Y 2 O 3 NPs notably inhibited the morphology, physiology and growth of plants. • Y 2 O 3 NPs translocated from the root to shoot and accumulated aptly in the root. • Y 2 O 3 NPs entered and existed in intercellular space and cytoplasm by endocytosis. [ABSTRACT FROM AUTHOR]

The impact of land use type on the content of potentially toxic elements (PTEs) in the soils of the Qinghai-Tibet Plateau (QTP) and the associated ecological and human health risks has drawn great attention. Consequently, in this study, top- and subsurface soil samples were collected from areas with four different land uses (i.e., cropland, forest, grassland, and developed area) and the total contents of Cr, Cd, Cu, Pb and Zn were determined. Geostatistical analysis, self-organizing map (SOM), and positive matrix factorization (PMF), ecological risk assessment (ERA) and human health risk assessment (HRA) were applied and used to classify and identify the contamination sources and assess the potential risk. Partial least squares path modeling (PLS-PM) was applied to clarify the relationship of land use with PTE contents and risk. The PTE contents in all topsoil samples surpassed the respective background concentrations of China and corresponding subsurface concentrations. However, the ecological risk of all soil samples remained at a moderate or considerable level across the four land use types. Developed area and cropland showed a higher ecological risk than the other two land use types. Industrial discharges (32.8%), agricultural inputs (22.6%), natural sources (23.7%), and traffic emissions (20.9%) were the primary PTE sources in the tested soils, which indicate that anthropogenic activities have significantly affected soil PTE contents to a greater extent than other sources. Industrial discharge was the most prominent source of non-carcinogenic health risk, contributing 37.7% for adults and 35.2% for children of the total risk. The results of PLS-PM revealed that land use change associated with intensive human activities such as industrial activities and agricultural practices distinctly affected the PTE contents in soils of the Qinghai-Tibet Plateau. [Display omitted] • Most samples from developed area and cropland posed a moderate ecological risk. •Industrial discharge was the prominent source of non-carcinogenic health risk. •Intensive human activities affected PTE contents in soils of Qinghai-Tibet Plateau. Capsule : The land use change associated with intensive human disturbance affected the soil PTEs accumulation, ecological risk and human health risk in the Qinghai-Tibet Plateau. [ABSTRACT FROM AUTHOR]

Groundwater is essential for regional ecological-economic system and is an important resource of drinking water, especially in the Chinese Loess Plateau (CLP), where is a typical water-limited ecosystem. Groundwater quality deterioration will affect water security and exacerbate the water shortages. Groundwater hydrochemistry, pollution source apportionment, quality and health risks were evaluated based on analysis of major ions and selected trace elements in seasonal samples of the Fen River Basin (FRB) in the eastern CLP. Groundwaters in the FRB were mainly HCO 3 −-Ca2+-Na+ water type with low dissolved solutes in upstream samples, high values in midstream samples and medium values in downstream samples. Solutes in upstream samples were mainly derived from carbonate weathering, while those in midstream and downstream samples came from silicate weathering, evaporites dissolution and anthropogenic sources. Self-organizing map (SOM) showed the hydrochemistry remained unchanged from dry to wet season for most sampling points. The seasonal variations of Ag, Cd, Ni, Pb, and Tl were significant due to anthropogenic input. High NO 3 − in upstream and downstream samples resulted primarily from sewage discharge, and high SO 4 2− in midstream and downstream samples was from gypsum- and coal-related industries. In addition, anthropogenic input related to coal industries significantly aggravates pollution of As, Ni, Ag, Fe, and Mn. Influenced by evaporites and anthropogenic input, midstream samples had high salinity, total hardness and water quality indices (WQIs) and were unsuitable for irrigation or drinking purposes. Seasonal variation of WQI in the FRB was unsignificant except Jiaokou River sub-basin, where groundwater quality was worse in the wet season than the dry season due to coal mining. Great attention should be paid to the high non-carcinogenic risks of exposure to F, V, Mn, and Cr via dermal absorption, particularly for children. Overall, groundwater quality in the FRB was best in upstream, medium in midstream and worst in midstream based on different index. Groundwater quality is deteriorated by anthropogenic input and the sewage discharge in the FRB should be strictly controlled. Our report provides a reference for groundwater pollution evaluation and source identification in similar areas. [Display omitted] • Seasonal groundwater chemistry and quality was analyzed in Fen River Basin. • Evaporite and anthropogenic input significantly influence groundwater chemistry. • Poor water quality in midstream and wet season are related with human pollution. • Mn, NO 3 and SO 4 were the main pollutants for drinking purpose. • High non-carcinogenic risks of F, V and Mn were found, especially for children. Loess weathering and anthropogenic input significantly influence seasonal groundwater hydrochemistry and groundwater quality in the Fen River Basin. [ABSTRACT FROM AUTHOR]

Terrestrial mosses are promising tracers for research concerning metal atmospheric deposition and pollution. Concentrations of Cr, Co, Ni, Zn, Sr, Cd, Ba, and Pb in different moss species from Mountain Gongga, China were analyzed to investigate the effects of growth substrates, geographic elevation, and type of moss species on the accumulation characteristics of heavy metals, as well as to identify heavy metal sources. The ability of heavy metals to accumulate in moss varied significantly, with low concentrations of Cd and Co; medium concentrations of Cr, Ni, and Pb; and high concentrations of Zn, Sr, and Ba. Elevation significantly influenced the accumulation characteristics of heavy metals, with high concentrations found at lower elevations due to proximal pollution. Growth substrate and moss species were found to have certain influence on the bioconcentration capacities of heavy metals in moss in this study. Correlation analysis showed similar sources for Sr, Zn, and Ba, as well as for Ni, Co, and Cr. The positive matrix factorization (PMF) model was consistent with atmospheric deposition of Pb and Cd; substrate sources of Cr, Co, and Ni; and anthropogenic sources of Ba, Sr, and Zn. This research characterized the accumulation characteristics of heavy metals and their influence factors in different mosses found in alpine ecosystems and provides a reference for future studies in similar areas. Image 1 • Selected heavy metals were analyzed in different mosses species from Mountain Gongga. • High concentrations of heavy metals in mosses were found at lower elevations. • Substrate and moss species have certain effects on heavy metals in mosses. • Anthropogenic inputs, atmospheric deposition and substrates are the sources of heavy metals in mosses. Elevation significantly influence the accumulation characteristics of heavy metals in mosses of Mountain Gongga, China. [ABSTRACT FROM AUTHOR]

A comprehensive study on concentration, spatial distribution, pollution, ecological–health risk and source of potentially toxic elements (PTEs) in dust of residential area in Xi'an, China were conducted to explore the environmental quality of residential area in urban district. The results show that the concentrations of V, Ni, and Mn in the dust were less than, while the contents of Cr, Zn, Pb, Cu, and Ba in the dust were obviously larger than, the soil background values of Shaanxi. The high–value area of PTEs primarily concentrated in densely populated areas, heavily trafficked areas and the surroundings of plants. Cr, Pb and Zn posed moderate enrichment and Pb possessed moderate ecological risk in the dust. The comprehensive pollution levels of PTEs in the dust were uncontaminated to moderately contaminated and their comprehensive ecological risk were moderate. The non–carcinogenic risks of the PTEs for adults and children were in the safe level and the carcinogenic risks of Ni and Cr were under the current acceptable value. Four major sources were discriminated on basis of the multivariate statistical analysis results and the content characteristics, enrichment degrees, and the spatial distribution features of the PTEs, viz. Mn, V, and Ni primarily came from natural source; Pb, Zn, and Cu mainly originated from traffic source; and Ba and Cr were respectively from construction source and coal–fired power plant source, which respectively contributed 22.8%, 28.3%, 47.3%, and 1.6% to the total content of PTEs determined in the dust. ga1 • Dust from residential areas had elevated Pb, Cr, Cu, Zn and Ba levels. • Dense population, traffic and industrial area were PTEs hot spots. • PTEs in the study area posed minimal to moderately polluted ecological risk. • PTEs in dust from residential area posed insignificant health risk. [ABSTRACT FROM AUTHOR]

Phenolic Endocrine Disrupting Chemicals (EDCs) have drawn more and more interest due to their prevalence and persistence in aquatic environment. To study the adsorption of various phenolic EDCs on river sediments under natural conditions, we first sought to analyze the distribution characteristics of phenol and bisphenol A (BPA) in sediment from the Bahe River. The static adsorption experiments contained either single- or dual-contaminant of phenol and/or BPA in the system; they were conducted to characterize the adsorption of these two pollutants in the surface sediments and the main factors affecting the adsorption processes of the dual-contaminant system, including particle size, humic acid (HA) concentration, pH, and temperature. Results showed that in certain seasons, there was a significant correlation between the levels of phenol and BPA in Bahe sediments. When comparing the adsorption behaviors of phenol and BPA on sediments in single- and dual-contaminant systems, we found that the phenol adsorption behavior varied, while that of BPA remained consistent across the different systems. Moreover, different effects were observed with regards to a single factor and the interaction of multiple factors on the adsorption of pollutants. Of the four single factors, only HA concentration had a significant effect on the phenol adsorption in sediment. When considering the interaction of multiple factors, the interaction between HA concentration and temperature significantly promoted the adsorption of phenol. The influence of factors on the adsorption of BPA was in the following order: particle size > HA concentration > pH > temperature. Particle size significantly inhibited BPA adsorption in the sediment, while the interaction between particle size and pH increased BPA adsorption. • Adsorption behavior of phenol varied in single- and dual-contaminant systems. • Factors affecting the phenol and BPA in dual-contaminant system were studied. • Adsorption of phenol increased with increasing HA concentration and temperature. [ABSTRACT FROM AUTHOR]

Intensive anthropogenic activity has triggered serious heavy metal contamination of soil. Land use and land cover (LULC) changes bear significant impacts, either directly or indirectly, on the distribution of heavy metal in soils. A total of 180 samples were acquired from various land covers at different depths, namely surface soils (020 cm) and subsurface soils (20–40 cm). Spatial interpolation, geographically weighted regression (GWR) and self-organizing map (SOM) were used to discern how variations in the spatial distributions of soil heavy metals were caused by human activities for different land uses, and how these pollutants contributed to environmental risks. The medium concentrations of Cd, Cr, Cu, Pb and Zn in surface soil all exceeded the corresponding local background values in flat cropland and developed area soil. The overall ecological risk level of the study varied from low to medium. The GWR model indicated that the land use intensity had a certain influence on the accumulation of heavy metals in the surface soil. K-means clustering of the SOM revealed that the type of LULC also contributed to the redistribution of heavy metals in the surface soil. Image 1 • Heavy metal differentiation in soil was described by spatial interpolation. • The correlation between heavy metals and land use intensity was analyzed. • Most of samples from cropland and developed areas were polluted by heavy metals. • SOM was used to identify the impact of LULC on heavy metal accumulation in soil. Changes in land use and land cover caused by human activities affect the enrichment and redistribution of heavy metals in soil. [ABSTRACT FROM AUTHOR]