Ecological Risk Level Research Articles

Microplastics in China's surface water systems: Distribution, driving forces and ecological risk.

Comprehensively understanding the distribution, driving forces and ecological risk of microplastics (MPs) in China's surface water systems is crucial for future prevention and control of MPs pollution, particularly in the context of regional differences. Nevertheless, traditionally localized investigation and the limited MPs data availability hinder more comprehensive estimation of MPs pollution in surface water systems of China. This study presents a robust dataset, which consists of 14285 samples from 32 provincial districts, describing the MPs pollution characteristics using a data mining method combined with a machine learning model. The results show that the developed model has high accuracy in predicting the abundance, colors, shapes, and polymer types of MPs, with the coefficient of determination (R2) ranging from 0.825 to 0.978. MPs abundance varied greatly in China's surface water systems, ranging over 1-5 orders of magnitude due to the complex influence of anthropogenic activities and natural conditions. Human activities and natural conditions mutually impact the dynamics of MPs in China's surface water systems. Watersheds in almost all provinces of China are contaminated by high and extremely high ecological risk levels, highlighting the urgency for sustainable MPs management.

Temporal and Spatial Variations in Landscape Pattern–Function Risk Coupling over 20 Years in the Dry–Hot Valley of the Jinsha River in China

Extensive and profound landscape alterations significantly contribute to ecological vulnerability in environmentally delicate regions. Existing research primarily emphasizes ecological risks caused by landscape alterations, while overlooking vulnerable characteristics of landscape functions; particularly lacking are studies on the driving mechanism of landscape ecological risk through the reciprocal relationship between landscape pattern risk and function risk. Based on these issues, this paper constructed a landscape pattern risk index (LPRI), a landscape function risk index (LFRI), and a landscape ecological risk index (LERI) in the counties of the dry–hot valley of the Jinsha River in southwest China. By employing a coupling degree and a coordination model, we analyzed temporal and spatial variations in the interaction between two types of ecological risk, thereby revealing the driving mechanisms of landscape ecological risk. The results indicated that the average LPRI values of the study area were 0.373, 0.327, and 0.427, respectively, while the average LFRI values were 0.451, 0.356, and 0.442 in 2000, 2010, and 2020, respectively. More than 90% of the study area exhibited a medium coupling relationship between the two types of ecological risks. The area proportion of the coupling coordination regions has increased from 25.58% to 31.07% from 2010 to 2020. The two types of risk exhibited a low level of constraint inhibition. Extremely evident expansion of high pattern–function risk areas and the area increase of coupling coordination region resulted in the acceleration of regional landscape ecological risk level. Increasing competition between market-driven land-use activities and ecological regulations from the government has rendered the diversification of landscape ecological risk sources and its underlying mechanisms intricate. This study serves as a model reference for assessing landscape ecological risk and a theoretical basis for sustainable landscape management and ecological regulation in the Yangtze River basin.

Preparation of eco-friendly and high-strength ceramsite by granite scraps, granite fine mud, and phosphogypsum: Response surface methodology optimization, environmental safety assessment

Granite scraps (GS), Granite fine mud (GFM), and phosphogypsum (PG) are solid wastes containing harmful substances produced during the processing of granite and the production of phosphate fertilizer. Their resourceful and harmless utilization holds great significance in reducing environmental pollution. This study explores the preparation of eco-friendly and high-strength ceramsite using GS as the primary material, GFM as the binder, and PG as the regulator. The performance of ceramsite was studied by conducting single-factor experiments to examine the impact of the GS, GFM, and PG mass ratios. The Box-Behnken response surface methodology was utilized to optimize the effect of sintering conditions on the strength of ceramsite. The results suggested that the properties of the ceramsite are affected by the material ratios. The sintering temperature and keeping time notably influence the strength of ceramsite. Under optimal preparation conditions, the ceramsite achieved a bulk density of 1085.40kg/m3, apparent density of 2253.63kg/m3, 1-h water absorption of 0.13%, hydrochloric acid soluble rate of 0.016%, and compressive strength of 34.52MPa. Importantly, high-temperature sintering plays an essential role in fixing heavy metals and reducing the ecological risk level of heavy metals in ceramsite, which ensures excellent environmental performance and application prospects for ceramsite.

Revealing Microplastic Risks in Stratified Water Columns of the East China Sea Offshore

Microplastics have been proven to impact a broad range of marine species significantly. This study investigated the vertical distribution characteristics of microplastics (MPs) to verify their potential toxicity, distribution patterns, and affecting probability on organisms offshore of the East China Sea (ECS), China. Significant variations in MP characteristics across stratified water layers were identified and corroborated through artificial neural network (ANN) analysis. By a combination of species sensitivity distribution (SSD), risk quotient (RQ) and joint pourability curves (JPC) method, this study gave the regional risk thresholds and current risk distributions. Based on SSD, the derived predicted no-effect concentration for the ecosystem was 52.0 items/L (95% confidence interval: 13.7-262.8 items/L), with the 5% species hazardous concentration at 103.6 items/L. The RQ assessment results indicated varying ecological risk levels across different water layers, with the highest risks transitioning from north to south and from surface to bottom layers. Most sites exhibited a moderate risk level, with the highest risks identified in surface water near the Yangtze River Estuary, China. Conversely, the JPC analysis suggested a minimal ecological risk across the study area, emphasizing variable ecological risk contingent on species presence. This study underscores the importance of examining surface and intermediate water layers for marine habitats and organisms, highlighting the necessity of prioritizing investigations into the distribution of MPs across different water layers in the ECS, particularly focusing on buoyant polyester fibers present in the upper water column and the layers beneath the offshore surface.

Occurrence, migration, and assessment of human health and ecological risks of PFASs and EDCs in groundwater of Northeast China

Northeast China as an important base of grain production in China, has been suffering from potential groundwater pollution due to the excessive and prolonged application of fertilizers and pesticides. However, exploration of emerging contaminants pollution in groundwater and assessment of human health and ecological risks caused by large-scale agricultural activities have been relatively scarce. This study collected groundwater samples from typical agricultural areas in Northeast China to investigate the extent of contamination by nitrate, per- and polyfluoroalkyl substances (PFASs) and endocrine-disrupting compounds (EDCs), and then compared the levels of these pollutants with those in other regions of China. Groundwater nitrate pollution caused by strong agricultural activity is widespread in Northeast China, with nitrate-nitrogen (NO3N) concentrations exceeding 10 mg/L in as many as 40.3 % of 429 samples. 8 types of PFASs (3.7–7.1 ng/L) and 11 types of EDCs (18,114.0–62,029.8 ng/L) were detected in the collected groundwater samples. Using the Risk Quotient (RQ) method, this study assessed ecological risk and found that the risk level of perfluorooctane sulfonate (PFOS) was higher than that of other PFASs. The groundwater EDCs risks in Northeast China was higher compared to other regions in China, with dibutyl phthalate (DBP), Di-(2-ethylhexyl) phthalate (DEHP), Bisphenol A (BPA) having high ecological risk levels. Nitrate, PFASs and EDCs have been detected in deep groundwater (70–100 m depth), indicating that the deeper aquifers could be significantly threatened by pollutants due to human activities. Fertilizers, pesticides, domestic wastewater, and industrial discharges are major sources of groundwater pollutants in the agricultural regions. Industrial-sourced EDCs were widely detected in groundwater of agricultural area, suggesting that the transport of these pollutants is very active in groundwater system. Groundwater monitoring and pollution prevention are extremely urgent, especially for emerging contaminants. This study can provide important warnings and water resource management references for other agricultural areas affected by intensively agricultural activities in the world.

Multimethod Analysis of Heavy Metal Pollution and Source Apportionment in a Southeastern Chinese Region

Excessive levels of heavy metals in soil can significantly impact human health and ecological safety. Evaluating heavy metal pollution and identifying its sources are crucial for environmental management. This study investigates the status of heavy metal pollution in a southeastern region of China and aims to identify its sources using data from the first national soil pollution survey, which includes 282 sampling points. Indicators such as the geoaccumulation index (Igeo), the potential ecological risk index (RI), the hazard index (HI), and the total lifetime cancer risk (TLCR) were utilized to assess contamination levels. Geographic information systems (GIS), positive matrix factorization (PMF) receptor modeling, cluster analysis (ClusA) and human health risk assessments were integrated to analyze the sources of heavy metals. The results indicate that agricultural pollution sources have a minor impact on overall heavy metal contamination, with low ecological risk levels in the eastern and western regions. In contrast, the central region exhibited moderate risk, with areas of extremely high risk distributed across the central-west and central-south regions. PMF analysis identified pollution sources including natural origins, coal combustion, industrial emissions, and traffic, with contributions of 17.62%, 18.50%, 28.35%, and 35.56%, respectively. Overall, the carcinogenic risk in the study area is not high. Targeted recommendations were made in response to the pollution situation in the study area. This research enhances our understanding of heavy metal pollution in the soil of the study area and provides a reference for pollution source delineation in other regions.

A targeted review on occurrence, remediation, and risk assessments of bisphenol A in Africa.

Bisphenol A (BPA) is a vital raw material used to manufacture various household and commercial goods. However, BPA is a contaminant of emerging concern (CEC) and an endocrine-disrupting chemical (EDC) capable of migrating and bio-accumulating in environmental and biological compartments. At threshold levels, they become toxic causing adverse health and environmental issues. BPA's occurrence in food, food contact materials (FCMs), beverages, water, cosmetics, consumer goods, soil, sediments, and human/biological fluids across Africa was outlined. Unlike most reviews, it further collated data on BPA remediation techniques, including the human and ecological risk assessment studies conducted across Africa. A systematic scrutiny of the major indexing databases was employed extracting relevant data for this study. Results reveal that only 10 out of 54 countries have researched BPA in Africa. BPA levels in water were the most investigated, whereas levels in cosmetics and consumer goods were the least studied. Maximum BPA concentrations found in Africa were 3,590,000ng/g (cosmetic and consumer goods), 154,820,000ng/g (soils), 189ng/mL (water), 1139ng/g (food), and 208.55ng/mL (biological fluids). The optimum percentage removal/degradation of BPA was within 70-100%. The potential health and ecological risk levels were assessed by comparing them with recommended limits and were found to fall within safe/low risks to unsafe/high risks. In conclusion, this study revealed that there is still little research on BPA in Africa. Levels detected in some matrices call for increased research, stricter health and environmental regulations, and surveillance.

Non-targeted Screening and Ecological Risk Assessment of Emerging Contaminants in Beijiang Drinking Water Source of the Pearl River Delta

To investigate the spatial and temporal distribution characteristics and assess the ecological risks associated with emerging contaminants （ECs） in the Beijiang drinking water source, non-targeted screening was conducted using the ultra-high performance liquid chromatography-mass spectrometry technique （UPLC-MS） for one year （June 2022 to May 2023）. This study also involved the quantitative detection of eight typical ECs. The results showed that through the non-targeted screening, a total of 346 pollutants were identified, with industrial materials, pharmaceuticals, and pesticides being the predominant pollutants, collectively accounting for 88.2%. Concentrations of eight representative ECs ranged from n.d （undetected） to 180 ng·L-1, with detection rates exceeding 80% for six of them. Notably, higher concentrations were found in endocrine disruptors such as bisphenol A （BPA） and 4-nonylphenol （4-NP）, along with the pesticides atrazine （ATZ） and propisochlor （PPS）, with median concentrations ranging from 8.12 to 35.58 ng·L-1. The concentrations of ATZ, PPS, roxithromycin （ROX）, and ibuprofen （IBU） were significantly higher in the spring season compared to those in other seasons （P<0.05）. Elevated ecological risk levels （RQ>1） were observed at sampling point 1 （S1） and sampling point 3 （S3） for ATZ and Lomefloxacin （LOM）, while for 4-NP, it was determined to be high only at sampling site 2 （S2）. Given their high detection rates and ecotoxicity, particular attention should be paid to ATZ and 4-NP. The concentration level of ATZ exhibited significant seasonal variation due to its agricultural origin, so it is recommended to strengthen control during spring. Overall, this research provides critical insights into a comprehensive understanding of the presence and impact of ECs in this specific region.

Assessment of the water quality pollution index and ecological risk of microplastic pollution along the Tambakoso River in Surabaya, Indonesia

Increasing human activities and improper waste disposal will cause microplastic pollution in surface water. This study analyzed the abundance and characteristics of microplastics, pollution index based on water quality and its relationship with microplastic pollution, and the potential ecological risk of microplastics along the Tambakoso River which is influenced by various land uses of housing, industry, agriculture, and ponds from 16 sampling points. The average abundance of microplastics in the river was 91.80 particles/L. The Kruskal Wallis test showed that there were significant differences between microplastic pollution at each sampling location (Pvalue <0.05). In general, microplastics were mostly found in the form of fragments (48.36 %), transparent color (73.81 %), SMP size (<1 mm) (81.6 %), and dominated by PVC and nylon polymers. However, the characteristics of microplastics at each sampling location varied. The water quality pollution index value showed a slightly polluted category at most points. Redundancy analysis (RDA) showed that the characteristics of the shape and color of microplastics correlated with water quality parameters. The potential ecological risk based on microplastic pollution showed minor, moderate, and high categories at points with industrial land use. This indicates that the distribution of microplastics is closely related to human activities in the area. The level of ecological risk from microplastics depends on the percentage of each plastic polymer, along with its abundance in the environment. This study offers an important basis for designing efficient countermeasures to reduce microplastic pollution and improve water quality in surface waters.

Effects of straw and roots removal on soil Cd availability and Cd accumulation in rice at different growth stages

It is argument on whether straw removal present a safer alternative compared to straw return or not where in paddy fields contaminated with cadmium (Cd). The objective of this study was to evaluate the impacts of varying levels of straw and roots removal on Cd uptake and accumulation, as well as on the growth of rice, Cd availability of soil at different growth stages, and the safety and nutritional value of brown rice were subject to assessment as well. A field experiment was conducted wherein rice stubble and roots were returned into the paddy field, serving as the control group (CK). The findings revealed that the removal of straw resulted in a decline in the availability of Cd in soil and the accumulation and uptake of Cd by rice plant. At the maturation stage of rice, the soil available Cd content and brown rice Cd content was significantly reduced by 40.39% and 24.79% under the treatment where 100% of rice straw and roots were removed. Moreover, there was a significant decline of 66.54% and 76.35% in dissolved organic carbon (DOC) and Cd concentrations respectively within soil pore water. This suggests that one crucial factor contributing to decreased Cd accumulation is the diminished complexation between DOC and Cd resulting from straw removal treatments. The removal of straw and roots had minimal impact on the nutritional components of brown rice, including essential amino acids. After the removal of straw and roots from the field, there was a reduction in hazard quotient (HQ) for rice consumers of varying genders and ages in the region by 17.71% to 24.95%, leading to a decrease in local ecological risk level from medium to slight. Therefore, the implementation of strategies such as removing straw could potentially lead to successful outcomes in reducing rice Cd uptake in paddy fields contaminated with this metallic element.

A comprehensive approach for quantifying source-specific ecological and health risks of potentially toxic elements in agricultural soil

Given the pollution prevalence of potentially hazardous elements (PTEs) in agricultural soils worldwide, it is crucial to establish a comprehensive approach to accurately assess soil contamination, and quantitatively allocate sources and source-specific risks. In the study, soil contamination was assessed through environmental capacity based on the local geochemical baseline established using PTE contents of the subsoil. The sources of PTEs were quantified through positive matrix factorization (PMF) and GIS mapping. Ecological risk (ER) and human health risk (HHR) models based on PMF were used to evaluate source-specific ER and HHR. Taking Jieyang City as an example, obvious contamination of As, Pb, Cd, Zn and Hg was observed in agricultural soils, and 94.40% of sites had high-to-medium capacity for local PTE contamination. Four sources were apportioned including agricultural activities (17.36%), industrial activities (20.49%), natural sources (34.60%) and traffic emissions (27.55%). The study area was at moderate ER level (121.21) with industrial activities contributing the most (41.26%). The carcinogenic risks (3.21E-05 for children and 1.42E-05 for adults) were within the tolerable range, and non-carcinogenic risks (7.08E-01 for children and 7.70E-02 for adults) were not significant. Agricultural activities were the largest source to the carcinogenic (47.17% for children and 46.31% for adults) and non carcinogenic risks (53.55% for children and 53.03% for adults). Therefore, industrial activities and agricultural activities were the priority control sources to reduce ecological risk and protect human health, respectively.

Pollution Characteristics, Risk Assessment, and Source Analysis of Heavy Metals in Soil from a Typical Abandoned Antimony Smelting Factory

Considering the surface soil （0-20 cm） from a typical abandoned antimony smelting factory area in Dachang Town, Qinglong County, Guizhou Province, as a case study, a total of 14 soil samples were systematically collected from both within and outside the smelting factory area. The analysis focused on the pollution status, distribution characteristics, and potential ecological risks of heavy metals such as Sb, As, Cd, Cr, Pb, Cu, Zn, Ni, and V in the soil. Additionally, an evaluation and analysis of pollution sources were conducted. The results showed that the mean concentrations of heavy metals including ω（Sb）, ω（As）, ω（Cd）, ω（Cr）, ω（Pb）, ω（Cu）, ω（Zn）, ω（Ni）, and ω（V） in the surface soil of the abandoned antimony smelting factory ranged from 4.58 to 15 049.33 mg·kg-1. With the exception of Cr and Ni, all values exceeded the background values of soils in Guizhou province. The single factor pollution indices of Sb and As were 83.61 and 7.01, respectively, indicating severe contamination. In contrast, Pb fell within the non-polluted to slightly polluted range. The comprehensive potential ecological risk of soil heavy metals was characterized by severe potential ecological risk levels for Sb, As, and Cd, while the remaining heavy metals fell within a range of moderate to substantial potential ecological risk levels. The assessment of the geoaccumulation index revealed that the soil in the study area was primarily contaminated by Sb and As, predominantly exhibiting contamination levels ranging from moderate to severe. The results from the RAC method suggested that Sb was the dominant focus for remediation in this abandoned smelting factory. The two primary pollutants, Sb and As, exhibited elevated levels in leachate toxicity, acid-soluble fraction, available fraction, gastric phase, and intestinal phase in terms of bioavailable content, indicating a certain potential hazard. Further, correlation analysis indicated a certain correlation between the total amount of heavy metals and leachate toxicity, available fraction, acid-soluble fraction, reducible fraction, oxidizable fraction, gastric phase extractable fraction, and intestinal phase extractable fraction. The APCS-MLR model indicated that the sources of Sb, As, Zn, Cu, and Cd were primarily industrial, while the sources of Cr and V were mainly natural, and Pb originated mainly from mixed sources.

Assessment of soil pollution in coastal landscapes of the Republic of Djibouti and ecological risks

Tropical ecosystems play an important role in the environment. Coastal areas are subjected to a wide range of impacts and pollution, which have drawn worldwide attention over the past few decades. Comprehensive studies of heavy metal content in soils worldwide are extremely important for assessing and predicting ecological risks. Very few studies have been devoted to a complete study of the physicochemical characteristics of soils, assessment of heavy metal accumulation in coastal zones along the Djibouti coast, and potential ecological risks. The study investigated the physico-chemical characteristics of soil, assessed the accumulation of heavy metals in coastal zones along the Djibouti coast, and analyzed the potential environmental risks associated with the presence of heavy metals in the studied soils. Analysis of heavy metals and trace elements in the soils of the coastal areas of Djibouti revealed that the levels of these elements are lower than in soils of the Red Sea coast and are in line with WHO and other international standards. All heavy metals in the soil of the studied area demonstrate low levels of potential ecological risk. The soils of the studied areas, overall, have not undergone significant heavy metal pollution and can be considered suitable for various types of use.

Compositional-geochemical characterization and multi-element pollution and risk assessment of potentially toxic elements in the urban landfill soil

Urban areas are characterized by the presence of various pollution sources including landfills. During the recent decade, urban landfills were investigated as a source of pollution by potentially toxic elements and potential deposits for landfill mining. The contents of Cr, V, Ti, Ca, K, Mo, Zr, Sr, Rb, As, Zn, Cu, Co, Fe, Mn, Pb, Ba in soils of Vanadzor city landfill site (VL) were determined using the X-ray fluorescence spectrometer to assess multi-element pollution and ecological risk and to identify potentially toxic elements geochemical associations through the application of compositional data analysis. The results showed that Cr, Mo, Zn, Cu, and Pb displayed significant values (>100%) of coefficient of variation suggesting their anthropogenic origin. Moreover, these elements, except Cr, displayed outliers and extreme values in the same sampling sites located directly on the reclaimed part of the landfill. The median contents of Zn, Pb, Cu, Cr, Cd, and As exceeded the global median values by 8.2, 9.8, 19.0, 4.6, 6.1, and 4.5 times, respectively. The multi-element pollution assessment showed that an extremely hazardous level of pollution was observed on the reclaimed part of the VL. From this site, a trend of decrease in the pollution level was observed in the eastern and western directions. In contrast, an allowable level of pollution was observed in the northern part - toward the direction of the above-located hill. The VL was found to be in an inferior ecological condition (a very high level of potential ecological risk was observed), which might also have a negative impact on the ecosystems located in its vicinity. The hierarchical clustering has revealed that the studied elements are grouped in two geochemical associations: a naturally formed - Co, Fe, V, Ti, Mn, Sr, Zr, Rb, K, Ba, As; and an anthropogenic one - Zn, Pb, Cu, Ca.

Pollution Characteristics and Source Apportionment of Heavy Metals in Topsoil of Counties Along the Shandong Section of the Yellow River

The 25 counties along the Shandong section of the Yellow River are the core areas for promoting the ecological protection and high-quality development of the Yellow River in Shandong Province. Moreover, it is of great significance to study the current situation, sources, and potential risks of heavy metal pollution in the topsoil in this region. In this study, 103 soil samples were collected from the 25 counties along the Shandong section of the Yellow River, and the contents of eight heavy metals （As, Cu, Pb, Cr, Zn, Ni, Cd, and Hg） were determined. The pollution characteristics of heavy metals were analyzed and evaluated using the geological accumulation index and potential ecological risk index. Correlation analysis and the positive matrix factorization （PMF） model were used to analyze the sources of heavy metals. The results showed that the average contents of Cu and Cr were lower than that of the background values of soils, whereas the average contents of As, Pb, Zn, Ni, Cd, and Hg were 1.16, 1.42, 1.05, 1.14, 2.29, and 1.85 times higher than that of the background values, respectively, and the average contents of all eight elements were lower than the screening value of soil pollution risk in agricultural land. In terms of different heavy metal variations, the coefficient of variation （CV） of Cu and Cd was higher than 0.500, indicating high variations, whereas As, Pb, Cr, Zn, Ni, and Hg showed moderate variation. Cd and Hg were slightly polluted, whereas the other six elements were not polluted. Cd and Hg had a moderate potential ecological risk level, whereas the other six elements were at a low level. Correlation analysis and PMF model showed that the sources of heavy metals in the study area were influenced by four factors, i.e., agricultural activities, natural sources, industrial emissions, and atmospheric dust from coal combustion and vehicle exhaust emissions, and the relative contribution rates were 32.4%, 34.9%, 16.5%, and 16.2%, respectively.

Occurrence Characteristics and Ecological Risk Assessment of Antibiotics in Reclaimed Water-receiving Rivers in Beijing

Taking Liangshui River, the reclaimed water-receiving river in Beijing, as the research area, the types, detection frequencies, and concentrations of 16 antibiotics in water and sediment were analyzed, and their temporal-spatial variation and occurrence characteristics were discussed. The results showed that nine and 13 target antibiotics were detected in the water and sediment of Liangshui River, with the antibiotic concentration ranges of ND-116.68 ng·L-1 and ND-235.42 ng·g-1, respectively. The main antibiotics in water were ofloxacin and clarithromycin, and the main antibiotic in sediment was ofloxacin. The total concentration of antibiotics in water and sediment showed a gradual decrease from the upstream to the downstream in the Liangshui River mainstream, and the concentration of antibiotics in tributaries was higher than that in the mainstream. The inflow of tributaries had an obvious impact on the antibiotic concentration in water for the Liangshui River but had little impact on its sediment. The total concentration of antibiotics in water and sediment during the dry season was generally higher than that during the wet season. The detected antibiotics with the highest concentration were quinolones in water during the wet season and macrolides in the dry season. Quinolones had the highest concentration in sediment in both seasons. The ecological risk assessment results showed that clarithromycin had a low risk in water in the dry season and sediment in both seasons, whereas the other antibiotics had no risk. The combined ecological risk and the most sensitive trophic level ecological risk assessment showed that all sampling sites had low risk or no risk, and the risk of the dry season was generally greater than that of the wet season. The risk values of some sampling points were close to the medium risk threshold during the dry season, which requires further attention.

Soil pollution identification and human health risk assessment of soil heavy metals in an abandoned mine area in the Republic of Korea

ABSTRACT In this study, the Geo-accumulation index (Igeo), Human Health Risk Assessment (HRA), and Ecological Risk Index (ERI) were utilized to examine the risks associated with the soils at the DaeyangYeongseong mine. Brassica juncea and Raphanus sativus were employed in the ecological toxicity test. In all soil samples, the mean Igeo value of arsenic measured 3.15, and cadmium measured 6.63, indicating a very high level of heavy metal contamination. The carcinogenic risk of cadmium and arsenic for adults was 4.30×10−3 and 1.43×10−5, respectively. For children, these values were 3.92 × 10−2 and 1.33 ×10−4, exceeding the acceptable level (1×10−6). In all soils, cadmium showed extremely high ecological risk levels, and arsenic had extremely high risk levels in 34.8% of the total area. This was also confirmed in toxicity assessments using plants. Therefore, arsenic and cadmium were found to be the main causes of soil contamination and ecological risk.

Determination of contamination, source, and risk of potentially toxic metals in fine road dust in a karst region of Southwest China.

Understanding the pollution situation of potentially toxic metals (PTMs) in fine road dust (FRD) in emerging industrialized cities and identifying priority control factors is crucial for urban environmental management, resident health protection, and pollution control. This study conducted a comprehensive investigation on PTMs pollution in FRD in Zunyi, a representative emerging industrialized city in the karst region of southwestern China. The average contents of Ni, Cr, Mn, Cu, Zn, Ba, Pb, V, and Co in the FRD were 43.2, 127.0, 1232.1, 134.4, 506.6, 597.8, 76.1, 86.8, and 16.2mgkg-1, respectively, which were obviously higher than the corresponding background levels of the local soil except for V and Co. The comprehensive pollution level of the determined PTMs in the FRD was very high, primarily caused by Zn and Cu. The sources of PTMs in Zunyi FRD were traffic, industrial, construction, and natural sources, accounting for 38.0, 23.7, 21.9, and 16.4% of the total PTMs content, respectively. The PTMs in Zunyi FRD exhibited a low to moderate overall ecological risk level, mainly contributed by Cu and traffic source. The cancer risks of PTMs in Zunyi FRD were high for all populations. The non-carcinogenic risk of PTMs in Zunyi FRD was acceptable for adults, but cannot be ignored for children. According to the source-specific probabilistic health risk estimation results, the priority control source is industrial source and the priority control PTM is Cr. Local governments need to give more attention to the carcinogenic risks and health hazards posed by PTMs in the FRD.

Occurrence, Source Apportionment, and Risk Assessment of Antibiotics in Mangrove Sediments from the Lianzhou Bay, China.

In recent years, the widespread application of antibiotics has raised global concerns, posing a severe threat to ecological health. In this study, the occurrence, source, and ecological risks of 39 antibiotics belonging to 5 classes in mangrove sediments from Lianzhou Bay, China, were assessed. The total concentrations of the antibiotics (∑39 antibiotics) ranged from 65.45 to 202.24 ng/g dry weight (dw), with an average of 142.73 ± 36.76 ng/g dw. The concentrations of these five classes of antibiotics were as follows: Sulfonamides (SAs) > Tetracyclines (TCs) > Fluoroquinolones (QUs) > Penicillin (PCs) > Macrolides (MLs). The spatial distribution of antibiotics varied as high tidal zone > middle tidal zone > low tidal zone. The total organic carbon (TOC), pH, nitrate (NO3--N), and nitrite (NO2--N) of the sediment significantly influenced the distribution of antibiotics (p < 0.05). A source analysis identified untreated sewage from aquaculture as the primary source of antibiotics in the local mangrove. A risk assessment revealed that ciprofloxacin, norfloxacin, ofloxacin of QUs, and tetracycline of TCs exhibited medium risks to algae in certain sampling sites, while other antibiotics exhibited low or no risks to all organisms. Nevertheless, the total risk of all the detected antibiotics to algae was medium in 95% of the sites. The overall ecological risk level of antibiotics in the middle tidal zone was slightly lower than in the high tidal zone and the lowest in the low tidal zone. In summary, the experimental results provided insights into the fate and transport behaviors of antibiotics in mangrove sediments from Lianzhou Bay.

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.