Search Results (965)

Riverbank height plays a potentially important role in hydrological dynamics and pollutant transport, yet its influence on long-term water quality trends remains insufficiently documented. This study explores possible relationships between riverbank height variations and the Global Pollution Index ($I_{GP}^{*}$) in the Timiș River, Romania, over eleven (11) years (2013–2023). A dataset of 17 physicochemical parameters—including BOD₅, COD-Cr, dissolved oxygen, nutrients (N and P species), heavy metals (As, Cr, Cu, and Zn), detergents, and phenols—was used to tentatively assess ecological status. The results suggest that, despite a maximum riverbank elevation change of ~11 cm between 2020 and 2025, $I_{GP}^{*}$ values remained within a relatively narrow range (1.98–2.56, mean 2.19), pointing to persistent but moderate anthropogenic pressure. The highest index value (2.56, in 2016) coincided with a transient pollution event, whereas subsequent years stabilized around 2.0–2.3, which may reflect chronic diffuse pollution. Correlation analysis revealed strong associations between BOD₅ and conductivity (r = 0.76, linked to organic loads), COD-Cr and heavy metals (r = 0.79, suggestive of industrial influence), and total nitrogen and nitrate (r = 0.97, related to agricultural inputs), appear to outline distinct source-related signatures. This study offers preliminary evidence that even modest riverbank fluctuations may influence hydrodynamics and the fate of pollutants, while basin-scale water quality seems to remain largely governed by diffuse pollution sources. By integrating long-term geomorphological monitoring with multi-parameter water quality data into a composite index ($I_{GP}^{*}$), our work sketches a potentially innovative framework for diagnosing pollution drivers. The findings underscore the importance of incorporating riverbank morphology into EU Water Framework Directive monitoring, alongside GIS, IoT, and machine learning tools, could contribute to more adaptive river basin management. Full article

With the acceleration of industrialization, the impact of the toxic metalloid arsenic (As) and metal lead (Pb) on aquatic ecosystems has garnered widespread concern. However, the specific toxic effects of how these two metals jointly impact aquatic organisms are not yet fully understood. This study aims to investigate the toxic effects of As and Pb individually and in combination of the mixture on the growth of Chlamydomonas reinhardtii (C. reinhardtii) in a lab setup using the Concentration Addition (CA) model and the Independent Action (IA) model to predict the toxic effects at different concentrations. The results indicated that As and Pb had significant inhibitory effects on the growth of algae, and the toxicity of As was greater than that of Pb (As EC50 = 374.87 μg/L, Pb EC50 = 19,988.75 μg/L), measured by Spectrophotometer. As the metal concentrations increased, both metals demonstrated classic sigmoidal concentration-effect curves. Furthermore, we discovered that in mixtures of As and Pb at varying concentration ratios, the combined toxic effect shifted from additive to synergistic with increasing As concentration, exhibiting a pronounced concentration ratio dependency. Utilizing nonlinear least squares regression, we successfully constructed concentration-response models for both As and Pb, employing Observation-based Confidence Intervals (OCIs) to reflect the uncertainty of the data. By comparing experimental data with model predictions, the EC50 was used as an index to compare the toxicity magnitude of As/Pb mixtures. The toxicity of As and Pb mixtures gradually increases with the increase in their concentration ratios. Scanning and transmission electron microscopic observations revealed that the combination of 200 μg/L As and 2000 μg/L Pb resulted in the greatest synergistic toxic effect, with severe breakage and indentation to C. reinhardtii cells. This study not only provided new insights into the environmental behavior and ecological risks of As and Pb but also held significant implications for effective water pollution management strategies by offering a validated model-based framework for predicting mixture toxicity across different concentration regimes. Full article

Marine protected areas (MPAs) near the coast are a global concern due to potential impact of anthropogenic activities highly relevant when it comes to trace elements pollution in sediment. This study aims to assess the levels of trace elements in sediment, their potential mobility and the ecological risk in Tremiti Islands, a sensitive and vulnerable MPA. Sediment was analyzed for granulometry, mineralogy, pseudo-metal concentrations and available fractions using BCR method. Statistical analysis and different pollution and ecological risk indices were applied to interpret the results, determine the contamination levels and assess the element availability and their potential impact using Sediment Quality Guidelines. Spatial variability in grain size and mineralogy was found across the sampling sites. The finer quartz-rich sediments exhibiting higher trace element concentrations. Site-specific enrichments were evident for As and Zn at Cala Spido and for Pb at Cala Matano. Cu and Mn showed notable potential bioavailability with residual fractions below 30% at all sites; low Cd concentrations were found, but it was highly available. Cala Spido and Grotta del Sale showed higher contamination-degree, while Pagliai and Cala Matano stood out for their higher ecological risk and availability indexes. These findings demonstrated that even within a Marine Protected Area, site-specific anthropogenic pressures can significantly influence sediment quality and ecological risk. Full article

Soil samples from the urban area of Novi Sad were analyzed to determine the total concentrations of heavy metals including Cr, Pb, Cu, Zn, As, Mn, Ni, Co, Cd and Fe. In addition, leaching tests according to CEN 12457-2—Milli-Q deionized leaching procedure and ISO/TS 21268-2—CaCl₂ solution leaching procedure were conducted to assess the mobility of these metals. Multivariate statistical methods, including Pearson’s correlation, Principal Component Analysis (PCA) and Cluster Analysis, were applied to identify pollution sources and grouping patterns among elements. The results revealed a distinct clustering of Pb and Zn, separate from other metals, indicating their predominant origin from anthropogenic activities. Contamination Factor (CF), Pollution Load Index (PLI), and Geoaccumulation Index (Igeo) were calculated to evaluate the degree of pollution. Combining total concentration, mobility, and multivariate analyses offers a more comprehensive insight into the extent and origin of pollution in the urban area of Novi Sad. The results obtained are valuable for evaluating the soil conditions in the Western Balkans, which have been recognized as a necessity by the EU. Full article

With the increasing emphasis on environmental protection and sustainable development, improving air pollution control technology has become imperative. In this study, Ce-based catalysts are used as research objects to explore the effects of hydrothermal aging on their performance in oxidizing PM. Different Mn, Na, Pt and Zr-doped Ce-based catalysts were prepared based on the impregnation method and the PM oxidation performance of Ce-based catalysts before and after hydrothermal aging was investigated using thermogravimetric experiments, and the catalytic activity change pattern of fresh/hydrothermal aging Ce-based catalysts was analyzed by comparing the comprehensive combustion index S and combustion stability index Rw, revealing the PM oxidation process. The conclusion showed that the cerium-based catalyst significantly enhanced the oxidation efficiency of PM compared with PU. By comparing the performance of different metal-modified catalysts, it was found that the order of activity was: Pt > Na > Mn > Zr. With the metal doping increased, only the comprehensive combustion index S and combustion stability index Rw of Na/CeO₂ catalysts decreased. After hydrothermal aging treatment, the Zr/CeO₂ catalysts showed the best hydrothermal aging resistance, and the comprehensive combustion index S and combustion stability index Rw remained stable (<5%). Ce-based catalysts have the strongest to weakest hydrothermal aging resistance in the following order: Zr > Mn > Pt > Na. This study not only provides an important scientific reference for the application of Ce-based catalysts in the field of environmental purification but also contributes new ideas and methods to promote the green and sustainable development of air pollution control technology. Full article

Human activities have led to severe aquatic pollution and significant concerns about the ecological health of the Lianjiang River Basin (LRB). These concerns resulted in the implementation of comprehensive policies and treatments to improve the sediment and water quality. Herein, we explore the concentrations, sources, and degree of metal contamination in filtered water (FW), suspended solids (SSs), and surficial channel sediments (SCSs) in streams of the LRB. Calculated enrichment factors, an ecological risk index, and a principal component analysis were employed to understand the degree of elemental contamination, ecological risks, and their potential sources. Elements (e.g., Hg, Cd, Sn, Sb, Cu, and Mo) were mainly detected in FW, SSs, and SCSs in the Bergang, Hucheng, Xiashan, and Zhonggang rivers, and the mainstream of the LR. Four potential anthropogenic sources were identified, including electronic waste recycling (e.g., Cu, Sb, Pb, and Ni), mixed pollution (e.g., Se, Zn, Mn, and Mo), metal processing (e.g., Hg, Cr, Sn, and Cd), and battery manufacturing and recycling (e.g., Co, Ni, and Mn). Overall, Sn, Sb, Hg, Cu, and Cd were enriched by 37.5–79.2% and 34.8–91.3% at the SS and SCS sites, respectively. Mercury, Cd, Sn, Sb, Cu, and Mo posed the most risk both in the SSs and SCSs. Overall, the SS and SCS samples from the LRB remain severely contaminated with metals after recent environmental remediation. The implementation of pollution source control, sewage interception, and dredging operations should be further enhanced. Full article

Introduction: Over the last two decades, obesity has evolved into a global pandemic. Environmental pollutants, as endocrine disruptors, may play a key role in the development of obesity. The study aimed to assess the relationship between the concentration of certain trace elements and heavy metals (Cu, Zn, Mn, Co, Cr and Fe) and ferritin in blood serum, with anthropometric and physiological parameters associated with overweight and obesity in individuals following myocardial infarction and without a previous myocardial infarction. Method: The study was conducted in a group of 146 respondents divided into two groups: a study group (SG) of patients that had a history of myocardial infarction (n = 74) and a control group (CG) of patients that had no history (n = 72). The inductively coupled plasma mass spectrometry was employed to assess the concentration of trace elements and heavy metals. Measurements were taken to determine the anthropometric indices associated with overweight and obesity. Results: In the SG, there was a positive correlation between Cr concentration and body adiposity index (BAI) and a negative correlation between Zn, Zn/Cu, and ferritin level and percentage body fat (FM%). In the CG, there was a positive correlation between Zn concentration and WHtR and between ferritin level and BMI, WC, WHR and WHtR. Additionally, a negative correlation was found between Mn concentration and WHR and ferritin level and BAI and FM%. Conclusions: This study found a link between certain blood concentrations of trace elements and heavy metals and anthropometric and physiological indices associated with overweight and obesity. It, therefore, has substantial implications for public health. Full article

Heavy metal pollutants and organic contaminants often co-exist in the environment, posing significant ecological risks due to their combined toxicity. Phytoremediation, a plant-based biotechnology, offers a promising solution for pollutant removal. This study investigated the potential cadmium (Cd) removal capacity of Narrow Crown Black-Cathay poplar (Populus × canadensis Moench × Populus simonii Carr. f. fastigiata Schneid.) under combined Cd-phenol stress. The results showed that the combined stress synergistically inhibited the photosynthetic physiological characteristics, with an inhibition rate up to 54.0%, significantly higher than that under single stress (p < 0.05). Cd accumulation varied markedly among plant organs, following the order: root (ranging from 4000.2 to 9277.0 mg/kg) > stems (ranging from 96.0 to 383.6 mg/kg) > leaf (ranging from 10.3 to 40.1 mg/kg). Phenol enhanced Cd absorption and enrichment in the roots by up to 1.8 times but reduced its translocation to aboveground parts by 37.8–40.0%. Notably, at low Cd concentrations, the Cd removal efficiency under combined stress (26.0%) was substantially higher than under single Cd stress (6.6%). In contrast, biomass, tolerance index, and root–shoot ratio were slightly affected in all treatments (p > 0.05). These findings demonstrate that Narrow Crown Black-Cathay poplar is a suitable candidate for the short-term remediation of Cd in environments co-contaminated with cadmium and phenol. Full article

Agricultural soils near industrial parks in the Yellow River bend region face severe heavy metal pollution, posing a significant to human health. This study integrated field sampling with laboratory analysis and applied geostatistical analysis, positive matrix factorization (PMF) modeling, and health risk assessment models to systematically investigate the pollution levels, spatial distribution, sources, and ecological health risks of heavy metals in the area. The main findings are as follows: (1) The average concentrations of the eight heavy metals (Hg, Cr, Cu, Pb, Zn, As, Cd, and Ni) in the study area were 0.04, 48.3, 54.3, 45.7, 70.0, 22.9, 0.4, and 35.7 mg·kg⁻¹, respectively. The concentrations exceeded local background values by factors ranging from 1.32 to 11.2. Exceedances of soil screening and control values were particularly pronounced for Cd and As. Based on the geoaccumulation index, over 75% of the sampling sites for Cr, Pb, Zn, and Cd were classified as moderately to heavily polluted. Potential ecological risk assessment highlighted Cd as the significant ecological risk factor, indicating considerable heavy metal pollution in the region. (2) Kriging interpolation demonstrated elevated concentrations in the western (mid-upper) and eastern (mid-lower) subregions. Pearson correlation analysis suggested common sources for Cu-Pb-As-Cd and Cr-Zn-Ni. (3) PMF source apportionment identified four primary sources: traffic emissions (38.19%), natural and agricultural mixed sources (34.55%), metal smelting (17.61%), and atmospheric deposition (10.10%). (4) Health risk assessment indicated that the non-carcinogenic risk for both adults and children was within acceptable limits (adults: 0.065; children: 0.12). Carcinogenic risks were also acceptable (adults: 5.67 × 10⁻⁵; children: 6.70 × 10⁻⁵). In conclusion, priority should be given to the control of traffic emissions and agriculturally derived sources in the management of soil heavy metal contamination in this region, while the considerable contribution of smelting activities warrants heightened attention. This study provides a scientific basis for the prevention, control, and targeted remediation of regional soil heavy metal pollution. Full article

The Three Gorges Reservoir, serving as a crucial ecological barrier for the middle-lower Yangtze River basin, faces substantial threats to watershed ecosystems from sediment-associated heavy metal, threatening aquatic ecosystems and human health via bioaccumulation. Leveraging the legislative framework of the Yangtze River Protection Law, this study analyzed sediment cores (0–65 cm) collected from 12 representative sites in the Three Gorges Reservoir using 2020 Air–Space–Ground integrated monitoring data from the Changjiang Water Resources Commission. Concentrations of nine heavy metals (Cd, Cu, Pb, Fe, Mn, Cr, As, Hg, and Zn) were quantified to characterize spatial and vertical distribution patterns. Source apportionment was conducted through correlation analysis and principal component analysis (PCA). Contamination severity and ecological risks were assessed via geo-accumulation index (I_geo), potential ecological risk index (RI), and acute toxicity metrics. The findings indicated substantial spatial heterogeneity in sediment heavy-metal concentrations, with the coefficients of variation (CV) for Hg and Cd reaching 214.46% and 116.76%, respectively. Cu and Pb showed surface enrichment, while Cd exhibited distinct vertical accumulation. Source apportionment indicated geogenic dominance for most metals, with anthropogenic contributions specifically linked to Cd and Hg enrichment. Among the metals assessed, Cd emerged as the primary ecological risk driver, with localized strong risk levels (E_i > 320), particularly at FP and SS sites. These findings establish a scientific foundation for precision pollution control and ecological restoration strategies targeting reservoir sediments. Full article

This study focused on the Wugong coal fire area in the Zhunnan coalfield of Xinjiang, analyzing 41 soil samples extending from the fire center outward. The key parameters included pH, soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), available potassium (AK), various ions (Ca²⁺, Na⁺, Mg²⁺, SO₄²⁻, CO₃²⁻, HCO₃⁻, and Cl⁻), and heavy metal concentrations (As, Cr, Hg, Ni, Cd, Cu, Zn, and Pb). The primary objectives were to evaluate heavy metal pollution levels and potential ecological risks using the single factor pollution index (P_i), the Geo-accumulation index (I_Geo), Nemero’s pollution index (P_n), the pollution load index (PLI), and the ecological risk factor (E_rⁱ) and risk index (RI). Spatial distribution analysis indicated higher heavy metal concentrations in the southwestern and central regions. The heavy metals Cr, Ni, Cd, Cu, and Zn reached mild pollution levels, while Hg exhibited high pollution, with P_i, I_Geo, and P_n values of 3.27, 0.61, and 9.68, respectively. Hg (E_rⁱ = 111.07) and Cd (E_rⁱ = 45.91) emerged as the primary ecological risk factors. The overall ecological risk index (RI) of 184.98 indicated a moderate ecological risk. The results demonstrate that soils surrounding the coal fire zone are significantly impacted by coal fire, characterized by severe heavy metal contamination and nutrient deficiency. Full article

The chemical composition of bottom sediments in the northern part of Lake Umbozero, located in close proximity to a closed rare metal mine in the Murmansk Region, was studied. This study is a continuation of our research into the impact of closed rare metal mines and tailings on the environment. Samples were collected using an open gravity sampler in two sections of the lake in three replicates. The content of rare earth elements was determined using inductively coupled plasma mass spectrometry. The total content of elements was determined both in the surface layers of bottom sediments and in the deep layers that were formed in the preindustrial period and, thus, characterize the geochemical background of the study area. The average ∑REE in the surface layers of bottom sediments of Lake Umbozero in the wastewater reception area (Site 1) reaches 774 mg/kg, while for the area located north of the discharge site (Site 2), ∑REE was 208 mg/kg. The enrichment factor (EF), the geoaccumulation index (I_geo), the coefficient of the index of potential ecological risk (E_ir) and the index of potential ecological hazard (RI) were calculated. Assessing the total pollution of bottom sediments of Lake Umbozero with rare earth elements, the value of potential ecological risk reaches values corresponding to the level of low and moderate ecological risk of pollution (RI_{Site 1} = 164; RI_{Site 2} = 104). The conducted correlation analysis allowed us to establish the main phases containing rare earth elements in the bottom sediments of Lake Umbozero—oxyhydroxide complex compounds with iron and manganese. Full article

Heavy metals, nitrogen, and phosphorus play a significant role in the marine ecosystem and human health. In this work, the concentrations of heavy metals, inorganic nitrogen, and phosphorus were determined to assess the distribution characteristics, risk levels, and possible sources in seawater from Taizhou Bay. The concentration ranges of Cu, Pb, Zn, Cd, Hg, As, ammonia, nitrate, nitrite, and phosphate were 1.87–3.65 μg/L, 0.10–0.95 μg/L, 2.98–16.80 μg/L, 0.07–0.38 μg/L, 0.011–0.043 μg/L, 0.93–2.06 μg/L, 0.011–0.608 mg-N/L, 0.012–0.722 mg-N/L, 0.001–0.022 mg-N/L, and 0.004–0.044 mg-P/L, respectively. The ecological risks were evaluated by the single factor index, Nemerow pollution index, and risk quotient. The results indicated that Taizhou Bay is not currently facing ecological risk related to heavy metals, nitrogen, and phosphorus, but the RQ values emphasized the urgency of strengthening continuous monitoring of As, Cu, and Zn. The results of Pearson’s correlation indicated that salinity and chemical oxygen demand had a significant impact on nitrogen and phosphorus but little impact on heavy metals. Principal component analysis was then applied to analyze the probable origins of heavy metals and inorganic pollutants, suggesting that these pollutants were mainly derived from human activities along the bay. Full article

The Sanqi–pine agroforestry (SPA) system is considered a sustainable agroforestry model. However, empirical studies that clearly elucidate the impact of Sanqi cultivation on soil fertility and the heavy metal content within the SPA system are still lacking. This study established monoculture Pinus armandii (MPA) and SPA systems to conduct a comparative analysis of dynamic changes in soil physicochemical properties and the heavy metal content of Sanqi and pine over one year (with semi-monthly sampling), followed by a comprehensive evaluation of soil fertility and heavy metal pollution. Following the land use conversion from MPA to SPA, there was a notable increase in soil moisture (SM), total nitrogen (TN), and nitrate nitrogen (NO₃⁻-N) levels within Sanqi soil. Conversely, total potassium (TK), ammonium nitrogen (NH₄⁺-N), plumbum (Pb), and chromium (Cr) levels experienced a significant reduction. In the case of pine soil, soil moisture (SM), pH levels, and ammonium nitrogen (NH₄⁺-N) content exhibited an increase. However, soil organic carbon (SOC), total phosphorus (TP), total potassium (TK), zinc (Zn), manganese (Mn), plumbum (Pb), and chromium (Cr) contents all significantly decreased. The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) demonstrated that Sanqi cultivation not only significantly enhanced soil fertility for Sanqi rather than pine but also reduced the heavy metal content in the soil of both Sanqi and pine within the SPA system. Furthermore, the Nemerow pollution index for both Sanqi and pine soils has decreased, transitioning the pollution status from relatively safe to safe. This suggests that the introduction of Sanqi promotes the sustainable development of the SPA system. Full article

Background: Foods containing nutraceuticals from the mineral element group are being developed to compensate for the problem of deficiency in billions of people around the world. This research focuses on essential elements of patented cereal-based mixtures to complement the deficiencies of these elements and, at the same time, assesses their safety in terms of toxic elements in the human diet. Methods: The mineral and trace element contents in the mixtures were determined using the ICP-MS method with a subsequent evaluation of the contributions of the mixtures to the essential and toxic reference values based on dietary intakes and exposures for adults at 60, 80 and 100 kg of adult body weight and a portion size of 50 g. The potential health risk was evaluated using a metal pollution index. Results: The concentrations of minerals and trace elements in the cereal-based mixtures analyzed were as follows: K (up to 4150 µg/g) ≥ P > Mg > Ca > Na > Fe > Zn > Mn > Cu > Al > Ba (up to 4.40 µg/g) > Sr (up to 480 ng/g) ≥ Ti ≥ Ni > Ce ≥ Co > As ≥ Cs > Ag ≥ Li > Se > Be > Cr > Tl > Pb ≥ Hg > Ho > Cd > Sn (up to 1.12 ng/g). The mixtures contribute significantly to the reference values for Mn, Cu, Zn, Fe, and P for adults. Individual dietary exposure values of toxic elements for adults weighing 60 kg decrease in this order: Al (10.1 µg/kg bw/day) > Ni (362 ng/kg bw/day) > As ≥ Pb > Ag > Hg > Cd > and Sn (0.93 ng/kg bw/day). Conclusions: In terms of Regulation (EU) No 1924/2006 of the European Parliament and of the Council on nutrition and health claims made on foods, the cereal-based mixtures could be labelled “source of” Mn, Cu, Zn, Fe, and P when their contributions to the reference values exceeded 15%; in addition, “low sodium/salt” or “very low sodium/salt” can be applied. The mixtures contribute insignificantly to the toxic reference values of Al, Sn, Hg, Cd, Ni, and Ag, and the exposure values of Pb for developmental neurotoxicity, nephrotoxicity, and cardiovascular effects were considered safe. Regarding the metal pollution index of mixtures, there is no concern for potential health effects. Cereal-based mixtures are suitable for use in the food industry as a potential source of beneficial micronutrients for the human diet, although bioaccessible studies should not be neglected. Full article