Potentially hazardous elements in sediments and Ceratophyllum demersum: an ecotoxicological risk assessment in Miliç Wetland, Samsun, Türkiye

Community-level risk assessments on organophosphate esters in the sediments from the Bohai Sea of China based on multimodal species sensitivity distributions coupled with the equilibrium partitioning method

Organophosphate esters (OPEs), increasingly used as alternatives to brominated flame retardants, are ubiquitous in the global aquatic environment. Despite their potential toxicological impact on ecosystems, community-level risk assessments for OPEs in sediments remain scarce. This study investigated OPE occurrences and composition characteristics in the Bohai Sea's sediments and appraised both individual and joint ecological risks posed by characteristic OPE homologs using ten commonly used species sensitivity distribution (SSD) models, integrating acute-to-chronic conversion and phase equilibrium partitioning. OPEs were detected across all sediment samples, with total concentrations ranging from 0.213 ng/g dry weight (dw) to 91.1 ng/g dw. The predominant congeners included tri-n-butyl phosphate (TnBP), triisobutyl phosphate (TiBP), tri(2-ethylhexyl) phosphate, tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), tris(1, 3-dichloro-2-propyl) phosphate (TDCIPP), and triphenylphosphine oxide. Best-fit SSD models varied among TnBP, TiBP, TCEP, TCPP, and TDCIPP, demonstrating Sigmoid, Burr III, Sigmoid, Burr III, and Burr III, respectively. The same parametric model demonstrated variability in the fitting process for different OPE congeners, which also happened to the fitting results of ten parametric models for the same specific characteristic congener, underscoring the necessity of employing multiple models for precise community-level risk assessments. Hazard concentrations for a 5% cumulative probability were 0.116 mg/L, 2.88 mg/L, 1.30 mg/L, 1.44 mg/L, and 1.85 mg/L for each respective congener. The resulting risk quotients (RQ) and overall hazard index (HI) were selected as criteria to assess the individual and joint ecological risks of OPEs in sediments from the Bohai Sea, respectively. RQ and HI were both below 0.1, indicating a low risk to the local ecosystems. Multi-model SSD analysis could provide refined data for community-level risk evaluation, offering valuable insights for the development of evidence-based environmental standards and pollution control strategies.

First assessment of trace metals in the intertidal zone of the world's longest continuous beach, Cox's Bazar, Bangladesh

This study aimed to assess the concentrations of eight trace metals - Cr, As, Pb, Mn, Ni, Zn, Hg, and Co - in the intertidal zone of Cox's Bazar of Bangladesh, the world's longest continuous beach. Most metal concentrations were below sediment quality guidelines and other comparative studies. The mean metal concentrations (mg kg-1) were as follows: Mn (471.67) > Zn (256.35) > Cr (89.96) > Pb (39.66) > Ni (36.44) > As (18.79) > Co (11.08) > Hg (0.0036). Statistical analyses revealed that only samples collected from stations 5 and 7 presented any cause for concern. Risk assessment indices, i.e., Geo-accumulation Index (Igeo), Contamination Factor (CF), Pollution Load Index (PLI), Potential Ecological Risk Index (PERI), and Toxic Risk Index (TRI), all indicated a low to moderate risk of pollution for all sites, suggesting that the study area is currently free from any significant negative impacts resulting from human activities. The calculated Hazard Index (HI) was <1, indicating no significant non-carcinogenic impact on adults or children. The Total Carcinogenic Risk was also well below the threshold value.

Human and environmental risk assessment and plausible sources of toxic heavy metals at beach placers in southeast Sri Lanka

Beach placers are typically rich in heavy minerals, which are crucial for a wide range of industrial applications. This study investigates the human and environmental risks posed by toxic heavy metals (As, Pb, Zn, Cu, Cr, Fe, V and Mn) in beach placers of southeastern Sri Lanka using 42 X-ray fluorescence data. Risk indicators (EF, Igeo, CF and PLI) indicate the polluted nature of the placers. Correlation analysis (correlation matrix and HCA) identified pollution sources as heavy mineral-rich rocks, agricultural fertilizers, pesticides and municipal wastes. The environmental impact caused by toxic metals is less in placers. The highest non-carcinogenic risks (HI) resulted by Cr (1.69E+00), V (4.29E+00) and Fe (2.06E+00) to children. The total cancer risk of As and Cr in placers is unacceptable (children: 2.60E-04, 2.48E-03, and adults: 3.14E-05, 2.87E-04, respectively). Different strategies are introduced to mitigate the identified risks in source areas and the coastal environment.

Assessing spatio-temporal heterogeneity and drivers of ecosystem services to support zonal management in mountainous cities

With complex topography and geomorphology, mountainous cities possess abundant natural resources. They are constrained by ecological environment and topographic conditions, leading to a prominent contradiction between urbanization development and ecological protection. As a result, ecosystem services (ESs) are under greater regulatory pressure. The identification of ecosystem services bundles (ESBs) can be the foundation for developing zonal ecological protection planning policies. We took Chongqing as a case study, investigated the impact mechanisms of socio-ecological factors on the level of ES supply in each ESB. The findings reveal that: (1) The quantitative assessment of ESs for 2000, 2010, and 2020 showed that ESs were temporally stable and spatially heterogeneous. Areas with high supplies of food production (FP) and water yield (WY) were predominantly found in the northwestern cropland and urban built-up regions, whereas high supply areas for the other four ESs were primarily located in the northeastern Dabashan Mountains and the southern Wuling Mountains. (2) The quantification of trade-offs and synergies between ESs showed that FP had a trade-off effect with all five other ESs, while most other ES pairs exhibited synergistic effects. It was found that the interrelationships produced changes over time. (3) Then, three types of ESBs were identified. After examining the influence mechanisms of socio-ecological factors across the three ESBs, individual ESs were found to have essentially the same types of main impact factors in three ESBs, but varies in impact. (4) Finally, with reference to changes in ES levels and interrelationships and the driving mechanisms of socio-ecological factors in each zone, this study proposed zonal strategies for managing ecosystem services and optimizing territorial space based on the geographic characteristics and socio-economic development in different ESBs, with the goal of attaining sustainable urban development and improving human welfare.

Risk assessment and soil heavy metal contamination near marble processing plants (MPPs) in district Malakand, Pakistan

Soil heavy metals (HMs) pollution is a growing global concern, mainly in regions with rapid industrial growth. This study assessed the concentrations, potential sources, and health risks of HMs in agricultural soils near marble processing plants in Malakand, Pakistan. A total of 21 soil samples were analyzed for essential and toxic HMs via inductively coupled plasma‒optical emission spectrometry (ICP‒OES), and probabilistic health risks were evaluated via Monte Carlo simulation. The concentrations (mg/kg) of Ca (29,250), P (805.5) and Cd (4.5) exceeded the average shale limits of 22,100, 700, and 3.0 mg/kg, respectively, and indices such as Nemerow's synthetic contamination index (NSCI) and the geoaccumulation index (Igeo) categorized the soil sites as moderately polluted. The potential ecological risk index (PERI) indicated considerable to high ecological risk for As and Cd. The deterministic analysis indicated non-carcinogenic risks for children (HI > 1), whereas the probabilistic analysis suggested no significant risk (HI < 1) for both adults and children. Both methods indicated that the total cancer risk for Cr, Ni, Cd, and As exceeded the USEPA safety limits of 1.0E-06 and 1.0E-04. Sensitivity analysis identified heavy metal concentration, exposure duration, and frequency as key risk factors. The study suggested that HM contamination is mainly anthropogenic, poses a threat to soil and human health, and highlights the need for management strategies and surveillance programs to mitigate these risks.

Global, regional, and national burden of cancers attributable to particulate matter pollution from 1990 to 2019 and projection to 2050: Worsening or improving?

Particulate matter pollution (PMP) has been identified as a substantial contributor to cancer. However, accurately delineating the evolving trends in cancer burden attributable to PMP remains an ongoing challenge. The 1990-2019 disability-adjusted life years (DALYs) were used for cancers attributable to PMP from the Global Burden and Disease Study (GBD) 2019, including ambient particulate matter pollution (APMP) and household air pollution from solid fuels (HAP). The joinpoint regression and the Bayesian age-period-cohort (BAPC) model were employed to assess the corresponding trends over the periods 1990-2019 and 2020-2050, respectively. Additionally, statistical models such as frontier analysis and health inequality analysis were also utilized. During the 30-year period, cancer DALYs attributable to APMP increased globally, while those attributable to HAP and PMP decreased. Cancer DALYs attributable to APMP were positively correlated with socio-demographic index (SDI), while those attributable to PMP and HAP were negatively correlated with SDI. Frontier analysis identified the countries and regions requiring urgent action to mitigate PMP-attributable cancer. Finally, it was anticipated that the cancer burden attributable to APMP would increase during 2020 to 2050, while the burden attributable to HAP and PMP would decrease. This study conducted an epidemiological investigation of the burden of cancer attributable to APMP, HAP and PMP in various regions and populations worldwide, providing epidemiological insights into the global burden of cancer attributable to PMP and guiding policy and research directions.

Heavy metals and metalloid contamination and risk evaluation in the surface sediment of the Bakkhali River estuary in Bangladesh

Current state of contamination and subsequent risk of contaminated sediment of a tidal river of Bangladesh was evaluated in the present study. Sediment samples were collected from five locations in the tributary of Bakkhali River estuary during summer (April) and winter (December) season, 2020. Collected samples were processed using standard protocol and the content of heavy metals (Cd, Cr, Cu, Pb and Zn) and metalloid (As), were analyzed by the Flame Atomic Absorption Spectrometer. Sediment contamination was evaluated by pollution load index (PLI), contamination factor (CF), degree of contamination (Cd), potential ecological risk index (PERI), non-carcinogenic and carcinogenic risk (CR) due to the dermal contact of the sediment. Multivariate statistical analysis such as principal component analysis (PCA) and cluster analysis (CA) were also applied to find out the possible sources of the contaminant in the sediment. Results showed the average concentration of As, Cd, Cr, Pb, Cu and Zn was 9.74 ± 3.57, 2.00 ± 0.85, 48.75 ± 8.92, 29.78 ± 8.39, 5.44 ± 2.03 and 56.94 ± 8.57 mg/kg, respectively. Concentration of Cu, Pb and Zn were within the recommended level whereas the concentration of As, Cd and Cr were suppressed the recommended level of WHO and FAO/WHO standards. PLI, CF and Cd revealed considerably low degree of contamination of the sediment. Geo-accumulation index indicated uncontaminated to moderately contaminated condition of the sediment. Although the values of enrichment factor revealed no potential enrichment for most of the metals, Cd showed a minor enrichment during the winter season. Based on the ecological risk assessment, the sediment from all of the sample locations was found to be of moderate to low risk. PCA and CA analysis revealed the origin of contaminants mainly from anthropogenic sources. Although different metals showed non-carcinogenic risk to the inhabitants, cancer risk values for dermal contact (CRderm) were much lower than 10-6 indicating no cancer risk for adult and child. However, the findings also revealed that children were more susceptible to CRderm compared to adults. The present study concluded that long term dermal contact of the sediment of Bakkhali River estuary will be contagious to the people. Therefore, regular monitoring of the estuarine environment is necessary so that contamination does not get worse.

Distribution and effects of microplastics as carriers of heavy metals in river surface sediments

There are few studies on microplastics (MPs) in urban river sediments compared to oceans, soils, and even rivers. In this study, the seasonal abundance of MPs, as well as their influencing factors on heavy metal adsorption in river sediments of the Ancient Canal of Zhenjiang City, China, were investigated for the first time. Through on-site sampling, microscopic observation, Raman spectroscopy, scanning electron microscopy, and high-temperature digestion, the abundance, shape, color, particle size, type, and surface characteristics of MPs in Ancient Canal sediments in different seasons, as well as the influencing factors of MPs as heavy metal carriers in different seasons, were analyzed. The results showed that the average abundance of MPs is 2049.09 ± 883.78 and 2216.36 ± 826.21 items kg-1 dry sediments in summer and winter, respectively, and different sites change significantly. In addition, particle sizes, types, colors, and shapes of MPs exhibited seasonal variations. Four MPs shapes were mainly observed: fibers, fragments, particles, and films. Among them, MPs in summer sediments are mainly fiber, and MPs in winter sediments are mainly particles. In the sediment in summer and winter, transparent MPs and small-size (<0.5 mm) MPs are the main ones, where the abundance of MPs decreased with increasing MPs size. The main MPs species are polyvinyl chloride (PVC), polystyrene (PS), polypropylene (PP), polyethylene terephthalate (PET), polycarbonate (PC), and polyethylene (PE), with PP being the predominant MPs in the sediments in different seasons. Scanning electron microscopy-energy dispersive spectrometer (SEM-EDS) revealed that the surfaces of the MPs were characterized by rough, porous, cracked, and torn, with the attachment of various heavy metal elements, and all of the heavy metal elements accumulated to different degrees on the MPs. There was a significant positive correlation (p < 0.05) between the Mn content in the MPs and the Mn content in the sediments in winter, suggesting that the Mn in the MPs in winter may be derived from the sediments. In addition, the type, shape, size, and color of MPs affect the adsorption capacity of heavy metals. Most of the adsorption of MPs on Pb showed a significant negative correlation, and the adsorption of MPs on Cr, Zn, Cu, Cd, and Mn showed a significant positive correlation. MPs can be used as carriers of heavy metals, which will further enhance the hazards of living organisms and pose a potential threat to the safety of the urban river environment.

Microplastics emerge as a hotspot for dibutyl phthalate sources in rivers and oceans: Leaching behavior and potential risks

Dibutyl phthalate (DBP) as a plasticizer has been widely used in the processing of plastic products. Nevertheless, these DBP additives have the potential to be released into the environment throughout the entire life cycle of plastic products. Herein, the leaching behavior of DBP from PVC microplastics (MPs) in freshwater and seawater and its potential risks were investigated. The results show that the plasticizer content, UV irradiation, and hydrochemical conditions have a great influence on the leaching of DBP from the MPs. The release of DBP into the environment increases proportionally with higher concentrations of additive DBP in MPs, particularly when it exceeds 15 %. The surface of MPs undergoes accelerated oxidation and increased hydrophilicity under UV radiation, thereby facilitating the leaching of DBP. Through 30 continuous leaching experiments, the leaching of DBP from MPs in freshwater and seawater can reach up to 12.28 and 5.42 mg g-1, respectively, indicating that MPs are a continuous source of DBP pollution in the aquatic environment. Moreover, phthalate pollution index (PPI) indicates that MPs can significantly increase DBP pollution in marine environment through land and sea transport processes. Therefore, we advocate that the management of MPs waste containing DBP be prioritized in coastal sustainable development.

Effects of microplastics on sedimentary greenhouse gas emissions and underlying microbiome-mediated mechanisms: A comparison of sediments from distinct altitudes

Microplastics (MPs) are emerging contaminants in aquatic ecosystems that can profoundly affect carbon and nitrogen cycling. However, the impact mechanisms of MPs on sedimentary greenhouse gas (GHG) emissions at distinct altitudes remain poorly elucidated. Here, we investigated the effects of polyvinyl chloride (PVC) and polylactic acid (PLA) on sedimentary CO2, CH4, and N2O emissions at distinct altitudes of the Yellow River. PVC increased the relative abundance of denitrifiers (e.g., Xanthobacteriaceae, Rhodocyclaceae) to promote N2O emissions, whereas PLA reduced the abundance of AOA gene and denitrifiers (e.g., Pseudomonadaceae, Sphingomonadaceae), impeding N2O emissions. Both PVC and PLA stimulated the growth of microbes (Saprospiraceae, Aquabacterium, and Desulfuromonadia) associated with complex organics degradation, leading to increased CO2 emissions. Notably, the concurrent inhibition of PLA on mcrA and pmoA genes led to its minimal impact on CH4 emissions. High-altitude MQ sediments, characterized by abundant substrate and a higher abundance of functional genes (AOA, AOB, nirK, mcrA), demonstrated higher GHG emissions. Conversely, lower microbial diversity rendered the low-altitude LJ microbial community more susceptible to PVC, leading to a more significant promotion on GHG emissions. This study unequivocally confirms that MPs exacerbate GHG emissions via microbiome-mediated mechanisms, providing a robust theoretical foundation for microplastic control to mitigate global warming.

Mercapto-functionalized palygorskite modified the growth of Ligusticum Chuanxiong and restrained the Cd migration in the soil-plant system

Ligusticum Chuanxiong is an essential medicinal and edible plant, but it is highly susceptible to the enrichment of soil Cadmium (Cd), which seriously affects its medical safety. However, the control of Cd uptake by Ligusticum Chuanxiong is little reported. In this study, we reported that a green Mercapto-functionalized palygorskite (MPAL) effectively promoted Ligusticum Chuanxiong growth, and restrained the Cd uptake by Ligusticum Chuanxiong both in the mildly contaminated soil (M-Soil) and severely contaminated soil (S-Soil). The experimental results demonstrated that the application of MPAL significantly increased the biomass and antioxidant enzyme activity of Ligusticum Chuanxiong. In the M-Soil, the Cd content in the roots, stems, and leaves of Ligusticum Chuanxiong decreased markedly by 82.46-86.66%, 64.17-71.73%, and 64.94-76.66%, respectively, after the MPAL treatment. In the S-Soil, MPAL application decreased the Cd content in roots, stems, and leaves by 89.43-98.92%, 24.19-86.22%, and 67.14-77.90%, respectively. Based on Diethylenetriamine Pentaacetic Acid (DTPA) extraction, the immobilization efficiency of MPAL for Cd in soils ranged from 22.01% to 77.04%. Additionally, the HOAc extractable Cd was transformed into reducible and oxidizable fractions. Furthermore, MPAL enhanced the activities of soil alkaline phosphatase, and urease, but decreased sucrase activity. Environmental toxicological analysis indicated that MPAL reduced the potential ecological risk of Cd in the soil. These findings revealed that MPAL can effectively reduce Cd accumulation in Ligusticum Chuanxiong and promote plant growth, suggesting its potential as a viable amendment for remediating Cd-contaminated soils.

Mapping of metals contamination in coastal sediments around the world in the last decades: A bibliometric analysis and systematic review

The quality of coastal sediments contaminated by metals has been discussed for decades worldwide. However, there is a lack of information on the current situation and trends in this research field. For this reason, this is the first study to present an integrated analysis of bibliometric mapping and systematic review, using the Scopus database. The subject has grown exponentially, with a notable increase in citations and predicted increases for the coming years. The Chinese Academy of Sciences and Chinese authors were highlighted. The main areas of study were the Yellow Sea, Adriatic Sea and Persian Gulf. The main metals related were Cu, Pb, Zn, Cr and Cd, linked to anthropogenic sources such as agriculture, domestic sewage and mining and industry activities. The IGEO proved to be the main index for assessing pollution. This research is useful for pointing out the needs of future research, supporting the development of this topic.

A novel assessment of potentially toxic elements (PTEs) in water and sediment samples from the Indus River, Pakistan: An ecological risk assessment approach

Pakistan, a country with limited water resources and highly vulnerable to the adverse effects of climate change, faces numerous challenges in managing its water supply. In this sense, this study assessed potentially toxic elements (PTEs) in the surface water and sediments of Pakistan's Indus River and its tributaries. Key water quality parameters such as pH, electrical conductivity (EC), and total dissolved solids (TDS) were determined, with respective average values of 7.1, 40 μS/cm, and 208 mg L-1. The concentrations of Cd, Cr, Cu, Ni, and Zn in surface water samples averaged 26 μg L-1, 0.9 μg L-1, 1.4 μg L-1, 22 μg L-1, and 2.1 μg L-1, respectively. The general sediment PTE profile was Ni > Cd > Zn > Cu > Cr. Certain PTE levels exceeded recommended thresholds, indicating the establishment of environmental pollution. Calculated geo-accumulation index values suggested moderate to heavy pollution levels in sediment, with PERI (404) values reinforcing the ecological risk posed by elevated PTE concentrations. Furthermore, significant correlations were observed between specific PTE pairs in both water and sediment samples. This study contributes with novel insights into the distribution and ecological implications of PTE contamination in the Indus River and its tributaries, paving the way for ecological risk management efforts.

Investigation of groundwater quality in the Southern Coast of the Black Sea: application of computational health risk assessment in Giresun, Türkiye

Potentially toxic elements (PTEs), especially arsenic in drinking water, pose significant global health risks, including cancer. This study evaluates the groundwater quality in Giresun province on the Black Sea coast of Türkiye by analyzing twelve groundwater resources. The mean concentrations of macronutrients (mg/L) were: Ca (10.53 ± 6.63), Na (6.81 ± 3.47), Mg (3.39 ± 2.27), and K (2.05 ± 1.10). The mean levels of PTEs (µg/L) were: Al (40.02 ± 15.45), Fe (17.65 ± 14.35), Zn (5.63 ± 2.59), V (4.74 ± 5.85), Cu (1.57 ± 0.81), Mn (1.02 ± 0.76), As (0.93 ± 0.73), Cr (0.75 ± 0.57), Ni (0.41 ± 0.18), Pb (0.36 ± 0.23), and Cd (0.10 ± 0.05). All PTE levels complied with WHO drinking water safety guidelines, and overall water quality was excellent. The heavy metal evaluation index (HEI < 10) and heavy metal pollution index (HPI < 45) indicate low pollution levels across all stations. Irrigation water quality was largely adequate, as shown by the magnesium hazard (MH), sodium adsorption ratio (SAR), Na%, and Kelly's ratio (KR). The total hazard index (THI) values consistently remained below 1, indicating no non-carcinogenic health risks. However, at station 10 (city center), the cancer risk (CR) for adults due to arsenic was slightly above the threshold (1.44E-04). Using principal component analysis (PCA), positive matrix factorization (PMF), and geographic information system (GIS) mapping, the study determined that most PTEs originated from natural geological formations or a combination of natural and human sources, with minimal impact from human activities. These findings highlight the safety and reliability of the groundwater sources studied, emphasizing their potential as a long-term, safe water supply for nearby populations.

Appropriate supply of sulfur alleviates lead toxicity and stimulates its accumulation in hyperaccumulator Arabis alpina

Widespread lead (Pb) contamination of agricultural soils is a global issue stemming from human activities. The remediation of Pb-contaminated soils used for agricultural purposes is critically important to safeguard food crop safety. Despite the modulating effects of sulfur (S) on plant responses to toxic heavy metals, the ecological, physiological, and molecular mechanisms driving such modulation in the Pb hyperaccumulator Arabis alpina L. remain unclear. Here, we investigated the effects of five S concentrations (0, 50, 100, 150, and 200 mg kg-1) on A. alpina grown in Pb-contaminated soil from a lead-zinc mining area. Under S50 (i.e., 50 mg kg-1) and S100 treatments, the Pb concentration in both shoots and roots of A. alpina significantly decreased compared to the control (S0). Specifically, the S50 treatment significantly enhanced Pb accumulation, plant biomass, and plant height, indicating that low S applications facilitate Pb accumulation from the soil and alleviate Pb toxicity. Additionally, S50, S100, and S150 treatments significantly improved photosynthetic rate, stomatal conductance, and intercellular CO2 concentration in A. alpina. Transcriptomic analysis showed that S50 and S100 treatments increased the expression of the LHCA, LHCB, psa, and psb genes, which had a significant impact on photosynthetic efficiency. S50 and S100 boosted glutathione (GSH) levels in A. alpina roots, and the increased expression of GST gene enhanced tolerance to environmental stress. In summary, these results suggest that an appropriate supply of S (S50 and S100) not only alleviates Pb toxicity by enhancing plant biomass, height, photosynthetic features, and sulfur metabolites but also stimulates Pb accumulation in the hyperaccumulator A. alpina. Our study elucidated the specific concentrations of sulfur that optimally enhance both Pb accumulation and stress tolerance in the hyperaccumulator A. alpina, providing novel insights into the practical application of sulfur in phytoremediation strategies and advancing our understanding of the underlying molecular mechanisms.

Spatial Distribution and Pollution Assessment of Metals in Sediments of the Babon River, Central Java, Indonesia

Background

The Babon River is one of the drainage channels in Semarang, Indonesia, that is used for drinking water, irrigated agriculture of paddy fields and gardens, fish farming media, and the disposal of industrial wastewater. This study aimed to assess the spatial distribution of metals in the sediment of the Babon River through the utilization of different pollution indices. These indices included concentration factor (Cf), contamination factor (CF), enrichment factor (EF), geoaccumulation index (Igeo), sediment pollution index (SPI), threshold effect level (TEL), and probable effect level (PEL).

Methods

Seven sampling locations were sampled for water and sediment in April, June, and September of 2021. The measurement of the metal was conducted using an atomic absorption spectrophotometer.

Results

The findings of the study demonstrated that sediments with a predominant sand texture exhibited higher levels of Cd and Pb, while the sediments characterized by a predominant clay texture had a higher concentration of Cr. Upon analyzing the Cf, CF, EF, Igeo, and SPI data, it has been confirmed that the sediment in the Babon River has substantial levels of Cd, Cr, and Pb. According to the TEL and PEL values, it can be observed that the presence of Cd and Pb has detrimental effects on the biological health of the benthic biota.

Conclusions

The aquatic biota and the benthic environment may be subject to adverse effects in the event where the concentration of metals in the sediment is higher than the natural concentration of metals.

Toxicological risk assessment using spring water quality indices in plateaus of Giresun Province/Türkiye: a holistic hydrogeochemical data analysis

Water scarcity is a growing concern due to rapid urbanization and population growth. This study assesses spring water quality at 20 stations in Giresun province, Türkiye, focusing on potentially toxic elements and physicochemical parameters. The Water Quality Index rated most samples as "excellent" during the rainy season and "good" during the dry season, except at stations 4 (40° 35' 12″ North/38° 26' 34″ East) and 19 (40° 44' 28″ North/38° 06' 53″ West), indicating "poor" quality. Mean macro-element concentrations (mg/L) were: Ca (34.27), Na (10.36), Mg (8.26), and K (1.48). Mean trace element values (μg/L) were: Al (1093), Zn (110.54), Fe (67.45), Mn (23.03), Cu (9.79), As (3.75), Ni (3.00), Cr (2.84), Pb (2.70), Co (1.93), and Cd (0.76). Health risk assessments showed minimal non-carcinogenic risks, while carcinogenic risk from arsenic slightly exceeded safe limits (CR = 1.75E-04). Higher arsenic concentrations during the rainy season were due to increased recharge, arsenic-laden surface runoff, and human activities. Statistical analyses (PCA, PCC, HCA) suggested that metals and physico-chemical parameters originated from lithogenic, anthropogenic, or mixed sources. Regular monitoring of spring water is recommended to mitigate potential public health risks from waterborne contaminants.

Lead induced cerebellar toxicology of developmental Japanese quail (Coturnix japonica) via oxidative stress-based Nrf2/Keap1 pathway inhibition and glutathione-mediated apoptosis signaling activation

Lead (Pb) is a heavy metal that has been recognized as a neurotoxin, meaning it can cause harmful effects on the nervous system. However, the neurotoxicology of Pb to birds still needs further study. In this study, we examined the neurotoxic effects of Pb exposure on avian cerebellum by using an animal model-Japanese quail (Coturnix japonica). The one-week old male chicks were exposed to 50, 200 and 500 mg/kg Pb of environmental relevance in the feed for five weeks. The results showed Pb caused cerebellar microstructural damages charactered by deformation of neuroglia cells, granule cells and Purkinje cells with Nissl body changes. Moreover, cerebellar neurotransmission was disturbed by Pb with increasing acetylcholine (ACh) and decreasing acetylcholinesterase (AChE), dopamine (DA), γ-Aminobutyric Acid (GABA) and Na+/K+ ATPase. Meanwhile, cerebellar oxidative stress was caused by Pb exposure represented by increasing reactive oxygen species (ROS) and malondialdehyde (MDA) as well as decreasing catalase (CAT), glutathione peroxidase (GPX), glutathione (GSH) and superoxide dismutase (SOD). Moreover, RNA-Seq analysis showed that molecular signaling pathways in the cerebellum were disrupted by Pb exposure. In particular, the disruption of nuclear factor erythroid-2-related factor 2 (Nfr2)/kelch-like ECH-associated protein 1 (Keap1) pathway and glutathione metabolism pathway indicated increasing cell apoptosis and functional disorder in the cerebellum. The present study revealed that Pb induced cerebellar toxicology through structural injury, oxidative stress, neurotransmission interference and abnormal apoptosis.

Metals and phosphorus in the sediments of streams emptying into the Çanakkale strait (Dardanelles): Spatial distribution, pollution status, risk assessment and source identification

The Çanakkale Strait is exposed to various pollutants due to its strategic location. It is thought that stream inputs may contribute significantly to metal and phosphorus (P) accumulation in the strait. In this study, the spatial distribution, pollution status, ecological risks and possible sources of twelve metals and P in the sediments of seven important streams emptying into the strait were analyzed. The results showed that Zn (226 mg/kg), Ba (67.2 mg/kg) and Pb (10.4 mg/kg) concentrations were higher in the Umurbey Stream due to mining activities, while P concentration (295 mg/kg) was higher in the Çanakkale Stream due to both agricultural activities and domestic wastewater discharges. Modified hazard quotient (mHQ), enrichment factor (EF) and contamination factor (Cf) values revealed that Zn and Pb showed high and moderate contamination in the US3 and US4 sampling sites of the Umurbey Stream, respectively. Similarly, P showed moderate contamination in the ÇS3 site of the Çanakkale Stream. Nemerow pollution index (NPI) showed that the US3 (2.41) and US4 (4.28) sites of the Umurbey Stream were slightly and moderately polluted, respectively. Toxic risk index (TRI) values demonstrated that the sediments in only the US4 site (5.17) of the Umurbey Stream may pose a low toxic risk due to high Zn content. Similarly, based on comparison results with sediment quality guidelines (SQGs), it was found that high Zn content may lead to adverse effects on sediment-dwelling organisms in the US4 site. In addition, the PEC-quotient value in the US4 site exceeded 0.5, confirming the finding that the sediments in this site could be toxic to benthic organisms. Finally, correlation, cluster and factor analyzes were used to determine possible sources of elements. Mining activities, natural sources and mixed sources (agricultural activities and natural sources) were identified as the main sources of elements in the sediments of the streams. This study can provide an important reference for evaluating stream sediment pollution and managing marine pollution.

Ecotoxicological effects of tungsten on celery (Apium graveolens L) and pepper (Capsicum spp.)

Background

Tungsten (W) is an emerging heavy metal pollutant, yet research remains scarce on the biomonitor and sensitive biomarkers for W contamination.

Methods

In this study, celery and pepper were chosen as study subjects and subjected to exposure cultivation in solutions with five different levels of W. The physiological and biochemical toxicities of W on these two plants were systematically analyzed. The feasibility of utilizing celery and pepper as biomonitor organisms for W contamination was explored and indicative biomarkers were screened.

Results

The results indicated that W could inhibit plants' root length, shoot height, and fresh weight while concurrently promoting membrane lipid peroxidation. Additionally, W enhanced the activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and total antioxidant capacity (TAOC) to counteract oxidative damage. From a physiological perspective, pepper exhibited potential as a biomonitor for W contamination. Biochemical indicators suggested that SOD could serve as a sensitive biomarker for W in celery, while TAOC and POD were more suitable for the roots and leaves of pepper. In conclusion, our study investigated the toxic effects of W on celery and pepper, contributing to the understanding of W's environmental toxicity. Furthermore, it provided insights for selecting biomonitor organisms and sensitive biomarkers for W contamination.

A Monte Carlo simulation-based health risk assessment of heavy metals in soils of the tropical region in southern China

The disturbance of ecological stability may take place in tropical regions due to the elevated biomass density resulting from heavy metal and other contaminant pollution. In this study, 62 valid soil samples were collected from Sanya. Source analysis of heavy metals in the area was carried out using absolute principal component-multiple linear regression receptor modelling (APCS-MLR); the comprehensive ecological risk of the study area was assessed based on pollution sources; the Monte-Carlo model was used to accurately predict the health risk of pollution sources in the study area. The results showed that: The average contents of soil heavy metals Cu, Ni and Cd in Sanya were 5.53, 6.56 and 11.66 times higher than the background values of heavy metals. The results of soil geo-accumulation index (Igeo) showed that Cr, Mo, Mn and Zn were unpolluted to moderately polluted, Cu and Ni were moderately polluted, and Cd was moderately polluted to strongly polluted. The main sources of heavy metal pollution were natural sources (57.99%), agricultural sources (38.44%) and traffic sources (3.57%). Natural and agricultural sources were jointly identified as priority control pollution sources and Cd was the priority control pollution element for soil ecological risk. Heavy metal content in Sanya did not pose a non-carcinogenic risk to the population, but there was a carcinogenic risk to children. The element Zn had a high carcinogenic risk to children, and was a priority controlling pollutant element for the risk of human health, with agricultural sources as the priority controlling pollutant source.

Metal pollution assessment in the surface sediments of a river system in Türkiye: Integrating toxicological risk assessment and source identification

This study investigates potentially toxic elements (PTEs) in the surface sediments of the Abdal River system, a critical water source for Samsun province, Türkiye, due to the presence of the Çakmak Dam. PTE concentrations, measured in mg/kg, show significant variability: Hg (0.03) < Cd (0.26) < As (10.98) < Pb (13.88) < Cu (48.61) < Ni (62.45) < Zn (70.97) < Cr (96.28) < Mn (1015) < Fe (38357). Seasonal variations were observed, in particular increased concentrations of As, Cd and Pb in summer (p < 0.05). Contamination and ecological risk indices (mHQ, EF, Igeo, CF, PLI, Eri, mCd, NPI, PERI, MPI, and TRI) indicate moderate to low levels of contamination, suggesting potential ecological effects. Health risk assessments suggest minimal risks to human health from sediment PTEs. Statistical analyses (PCC, PCA and HCA) improve the understanding of the sediment environment and contamination sources, while the coefficient of variation assists in source identification.

Appraisal of metallic accumulation in the surface sediment of a fish breeding dam in Türkiye: A stochastical approach to ecotoxicological risk assessment

This study examines the levels and patterns of potentially toxic elements (PTEs) in surface sediment of Almus Dam Lake (ADL), a key fish breeding site in Türkiye. PTE concentrations in sediment were ranked: Hg (0.05 ± 0.01) < Cd (0.16 ± 0.01) < Pb (9.34 ± 1.42) < As (18.75 ± 15.65) < Cu (63.30 ± 15.17) < Ni (72.64 ± 20.54) < Zn (86.66 ± 11.95) < Cr (108.35 ± 36.40) < Mn (1008 ± 151) < Fe (53,998 ± 6468), with no significant seasonal or spatial differences. Ecological risk indices (mHQ, EF, Igeo, CF, PLI, Eri, mCd, NPI, PERI, MPI, and TRI) showed low contamination levels. Health risk assessments, including LCR, HQ, and THI, indicated minimal risks to humans from sediment PTEs. Statistical analyses (PCA, HCA, SCC) identified natural, transportation, and anthropogenic PTE sources, with slight impacts from agriculture and fish farming. This research underlines contamination status of ADL and emphasizes the need for targeted management strategies, offering critical insights for environmental safeguarding.

Ecological and human health risk from exposure to metal contaminated sediments in a subtropical river affected by anthropogenic activities: A case study from river Yamuna

Heavy metal enrichment in river sediments poses a significant risk to human and aquatic health. The Yamuna River faces severe challenges due to untreated industrial and domestic wastewater discharge. The study evaluates sediment metal content, ecological and human health risks, and potential sources. Results showed Cd and Pb exhibited moderate to severe contamination and displayed ecological risk based on contamination factor, enrichment factor, and potential ecological risk. According to synergistic indices (pollution load index, PINemerow, toxic risk index, contamination security index, mean probable effects level quotients, and probability of toxicity), the sediment in the Yamuna River doesn't seem to have a risk or enrichment from combined metals. Cd and Pb mainly originate from anthropogenic sources. Hazard index (< 1) and carcinogenic risk (2.2 × 10-7 to 4.7 × 10-5) assessments suggest metal didn't pose any risk to humans exposed to sediment. The present study aids in developing pollution control strategies for the Yamuna River.

Enhancing water quality and ecosystems of reclaimed water-replenished river: A case study of Dongsha River, Beijing, China

The use of reclaimed water for urban river replenishment has raised concerns regarding its impact on water quality and aquatic ecosystems. This study aims to reveal the improvements seen in an urban river undergoing a practical water eco-remediation after being replenished with reclaimed water. A one-year monitoring of water quality, phytoplankton, and zooplankton was carried out in Dongsha River undergoing eco-remediation in Beijing, China. The results showed that compared to the unrestored river, the concentrations of COD, NH4+-N, TP, and TN decreased by 28.22 ± 7.88 %, 40.24 ± 11.77 %, 44.17 ± 17.29 %, and 28.66 ± 10.39 % in the restoration project area, respectively. The concentration of Chlorophyll-a in the restoration area was maintained below 40 μg/L. During summer, when algal growth is vigorous, the density of Cyanophyta in the unrestored river decreased from 46.84 × 104cells/L to 16.32 × 104cells/L in the restored area, while that of Chlorophyta decreased from 41.61 × 104cells/L to 11.87 × 104cells/L, a reduction of 65.16 % and 71.47 %, respectively. The dominant phytoplankton species were replaced with Bacillariophyta, such as Synedra sp. and Nitzschia sp., indicating that the restoration of aquatic plants reduces the risk of Cyanophyta blooms. Zooplankton species also changed in the restoration area, especially during summer. The density of pollution-tolerant Rotifer and Protozoa decreased by 31.06 % and 27.22 %, while the density of clean water indicating Cladocera increased by 101.19 %. We further calculated the diversity and evenness index of phytoplankton and zooplankton within and outside the restoration area. The results showed that the Shannon-Weaver index for phytoplankton and zooplankton in the restoration area was 2.1 and 1.91, which was higher than those in the river (1.84 and 1.82). This further confirmed that aquatic plant restoration has positive effects. This study can provide a practical reference and theoretical basis for the implementation of water ecological restoration projects in other reclaimed water rivers in China.

Functional metabolomics reveals arsenic-induced inhibition of linoleic acid metabolism in mice kidney in drinking water

Arsenic (As) is a heavy metal known for its detrimental effects on the kidneys, but the precise mechanisms underlying its toxicity remain unclear. In this study, we employed an integrated approach combining traditional toxicology methods with functional metabolomics to explore the nephrotoxicity induced by As in mice. Our findings demonstrated that after 28 days of exposure to sodium arsenite, blood urea nitrogen, serum creatinine levels were significantly increased, and pathological examination of the kidneys revealed dilation of renal tubules and glomerular injury. Additionally, uric acid, total cholesterol, and low-density lipoprotein cholesterol levels were significant increased while triglyceride level was decreased, resulting in renal insufficiency and lipid disorders. Subsequently, the kidney metabolomics analysis revealed that As exposure disrupted 24 differential metabolites, including 14 up-regulated and 10 down-regulated differential metabolites. Ten metabolic pathways including linoleic acid and glycerophospholipid metabolism were significantly enriched. Then, 80 metabolic targets and 168 predicted targets were identified using metabolite network pharmacology analysis. Of particular importance, potential toxicity targets, such as glycine amidinotransferase, mitochondrial (GATM), and nitric oxide synthase, and endothelial (NOS3), were prioritized through the "metabolite-target-pathway" network. Receiver operating characteristics curve and molecular docking analyses suggested that 1-palmitoyl-2-myristoyl-sn-glycero-3-PC, linoleic acid, and L-hydroxyarginine might be functional metabolites associated with GATM and NOS3. Moreover, targeted verification result showed that the level of linoleic acid in As group was 0.4951 μg/mL, which was significantly decreased compared with the control group. And in vivo and in vitro protein expression experiments confirmed that As exposure inhibited the expression of GATM and NOS3. In conclusion, these results suggest that As-induced renal injury may be associated with the inhibition of linoleic acid metabolism through the down-regulation of GATM and NOS3, resulting in decreased levels of linoleic acid, 1-palmitoyl-2-myristoyl-sn-glycero-3-PC, and L-hydroxyarginine metabolites.

Evaluation of pollution levels in sediments from Lake Edku, Egypt using laser ablation inductively coupled plasma mass spectrometry

The concentrations of 11 heavy metals in sediments from Lake Edku, Egypt were determined using LA-ICP-MS. The average concentrations of elements occurred in the order of Fe > V > Cr > Zn > Ni > Cu > Co > Pb > As > Sn > Mo with respective values of 4.67 %, 104.8, 77.9, 76.6, 59.2, 52, 27.8, 19.8, 4.14, 2.24, and 1.45 μg/g. Several pollution indices were used to evaluate individual and cumulative contamination levels. All HMs were found to be in the deficiency to minimal enrichment range based on the enrichment factor. The contamination factor indicated low contamination levels of Cr and As, low to moderate contamination levels of Fe, Ni, Zn, Mo, Sn, and Pb, and moderate contamination levels of Co and Cu. The pollution load index and contamination degree indicated the sediments to be polluted and moderately polluted, respectively.

Effects of land use/cover change on heavy metal distribution of soils in wetlands and ecological risk assessment

This study aimed to determine the impact of land use/cover changes on the heavy metal content in the Sultan Marshland and surrounding area and assess the pollution status. 54 topsoil samples (0-20 cm) were collected from the Rangeland, Farmland, Scrubland, Southern Marshland, Northern Marshland, and Dry Lake areas. The heavy metal contents of the soil samples (Cr, Pb, Fe, Zn, Cu, Co, Mn, Cd, Mo, As, and Ni) were determined using ICP-MS and ICP-OES devices. The impact of land use/cover change on soil heavy metal content was evaluated using variance analysis, while differences between groups were identified using the Duncan test. Principal Component Analysis (PCA) was conducted to identify potential sources of heavy metals. The contamination status of the soils was evaluated based on land use/cover using the Contamination Factor (Cf), Pollution Load Index (PLI), Ecological Risk Factor (Er), and Potential Ecological Risk Index (PERI). Changes in land use/cover around the Sultan Marshlands affected heavy metal distribution of the soils except for Cd. Among all land use/cover types, Fe concentration was the highest in the soils, while Cd concentration was the lowest. Soils in Southern Marshland exhibited higher average concentrations of Cr, Fe, Zn, Co, Cu, and Ni compared to other land uses/covers. Farmlands and rangelands had higher concentrations of Cd, As and Pb. Land use/cover was ranked based on the total heavy metal load in the following order in terms of average values: Southern Marshland > Scrubland > Farmland > Rangeland > Northern Marshland > Dry Lake. According to Cf, the soils in the Dry Lake were exposed to considerable levels of As contamination. Based on PLI, half of the soil sampling points in the Southern Marshland soils showed a degradation in environmental quality. Er indicated that all land uses moderately polluted with Cd. According to the average PERI, all soils under different land use/cover types were categorized as having a low ecological risk. It was believed that heavy metals originated from both natural and human activities. To ensure the sustainability of the ecosystem and to mitigate the risk of heavy metal pollution entering the food chain, it is recommended to manage farming and mining activities and land use habits.

New insights into the role of sediments in microplastic inputs from the Northern Dvina River (Russia) to the White and Barents Seas

The Northern Dvina River is one of the main sources of microplastic pollution entering to the White and Barents Seas. The coastal and bottom sediments of this river play an important role as a transfer link of microplastics. With Py-GC/MS and μFT-IR methods, it was found that the sediments contain up to 350 mg/kg or 650 particles/kg of microplastic (dry weight). The unique hydrologic conditions of the river branching area contribute to the formation of a microplastic pollution hotspot. The hotspot accumulates >30 % of microplastic pollution, mainly ABS plastic particles smaller than 0.3 mm with roughness and cracks, which increases the hazard class (from II to IV) of microplastic pollution. Obtained data and high annual variability of pollution indicates that this area acts as a place of accumulation, degradation and gradual release of microplastics into the White and Barents Seas, i.e. into the Arctic region.

Ecological and public health risk assessment of potentially toxic elements in the surface sediments of the Pasur river estuary, Bangladesh

Potentially toxic elements (PTEs) in the surface sediments of the Pasur river estuary was investigated to assess its distribution, potential sources, and current dangers to ecological and public health. The Pasur River is a tidal, meandering, perennial river in south-western Bangladesh with a considerable number of fisheries and industrial activities. Sediment samples were collected from seven sampling points from January to December 2022 to assess the contamination level of six potentially toxic elements (Pb, Cr, Cd, As, Cu and Zn). Flame Atomic Absorption Spectrophotometer was utilized to detect the concentration of PTEs by following some sequential analytical procedure. Concentration of PTEs followed the reducing trend of Zn > Cr > Pb > As > Cu > Cd with the mean value of 61.04 > 49.15 > 26.58 > 10.28 > 6.28 > 1.59 mg/kg, respectively. The principle component and cluster analyses justified the anthropogenic source of the studied PTEs. The mean values of contamination factor (CF), geo-accumulation index (Igeo) and enrichment factor (EFc) showed that Pb and Cd were highly responsible for sediment (uncontaminated to moderate) contamination. Pollution load index (PLI) indicated higher pollution of sediments near the port areas. Potential ecological risk index (PERI) indicated low to moderate risks due to the contaminated sediment. However, the contamination of sediment was not associated with the non-carcinogenic (HQderm and HI < 1) and carcinogenic (CRderm < 10-6) risks due to the dermal contact. Although the risks were within the tolerable limit, regular monitoring is suggested to reduce the risk of PTEs contamination.

Theoretical Health Risk Assessment Based on Potentially Toxic Element Profiling of Cosmetic Products in Istanbul Street Bazaars

Toxic elements that pose a potential threat to human health are found as impurities in various cosmetic products. In this study, the inorganic profile of 19 elements (Li, B, Mg, Al, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Sr, Mo, Cd, Sb, Ba, Hg, and Pb) in 90 cosmetic products (lipsticks, lip glosses, lip pencils and eye shadows) were detected by inductively coupled plasma-mass spectrometry after microwave acid digestion method and hazard indices (HI) of 9 toxic elements (Pb, Cd, Cr, Ni, Co, As, Hg, Sb, and Al) were calculated for the assessment of theoretical health risk. Satisfactory method performance parameters were found for each analyte. The results were compared with the maximum permissible limits set by regulatory agencies; 38 of 41 lip products (92.68%) and all eye shadows (n = 49) exceeded the established limits. The HI was found to be ≥ 1 in 82.76% of lip products for oral exposure, whereas HI was ≤ 1 for dermal exposure in all lip products (n = 41) and only one eye shadow sample was ≥ 1 (2.04%). Remarkable results were also detected for 19 elements in this study, which conducted a comprehensive inorganic profiling for the first time. Wide-range concentrations of Mg, Al, Ba, Mn, Cu, Zn, and Sr elements were remarkable. HI values were firstly brought out in this study, although Al, as a well-known toxic element, has not been listed in regulations yet. In conclusion, it is obviously seen that continuous monitoring of cosmetics is crucial not only for toxic elements but also for other essential or non-toxic elements to prevent consumers from long-term exposure.

Mapping specific groundwater nitrate concentrations from spatial data using machine learning: A case study of chongqing, China

Groundwater resources is not only important essential water resources but also imperative connectors within the intricate framework of the ecological environment. High nitrate concentrations in groundwater can exerting adverse impacts on human health. It is imperative to accurately delineate the distribution characteristics of groundwater nitrate concentrations. Four different machine learning models (Gradient Boosting Regression (GB), Random Forest Regression (RF), Extreme Gradient Boosting Regression (XG) and Adaptive Boosting Regression (AD)) which combine spatial environmental data and different radius contributing area was developed to predict the distribution of nitrate concentration in groundwater. The models use 595 groundwater samples and included topography, remote sensing, hydrogeological and hydrological, climate, nitrate input, and socio-economic predictor. Gradient Boosting Regression model outperforms the other models (R2 = 0.627, MAE = 0.529, RMSE = 0.705, PICP = 0.924 for test dataset) under 500 m radius contributing area. A high-resolution (1 km) groundwater nitrate concentration distribution map reveal in the majority of the study area, groundwater nitrate concentrations are below 1 mg/L and high nitrate concentration (>10 mg/L) proportion in southeast, northeast and central main urban area karst valley regions is 1.89%, 0.91%, and 0.38% respectively. In study area, hydrogeological conditions, soil parameters, nitrogen input factors, and percentage of arable land are among the most influential explanatory factors. This work, serving as the inaugural application of utilizing effective spatial methods for predicting groundwater nitrate concentrations in Chongqing city, furnish decision-making support for the prevention and control of groundwater pollution, particularly in areas primarily dependent on groundwater for water supply and holds profound significance as a milestone achievement.

Magnetic susceptibility in the assessment of toxic heavy metal elements in the surface sediments of Inner Ambon Bay, Maluku province, Indonesia

The Inner Ambon Bay (IAB) is an important area for the economic development of the city of Ambon, one of only a few urban areas in eastern Indonesia. This study is intended to monitor the anthropogenic impact on IAB by employing combined rock magnetic and geochemical analyses on 20 samples collected from IAB and the surrounding rivers. Magnetic susceptibility values of samples in the IAB averaged 26.37× 10-8 m3/kg, which is relatively high and comparable to that of contaminated coastal environments. Magnetic susceptibility correlated positively with certain metals such as Cr, Co, Ni, and Mn but negatively with Hg. Geochemical analyses showed that Hg and Ag contents were relatively high but pose only moderate risk to the environment based on the geo-accumulation index. Furthermore, the potential ecological risk index (PERI) showed that there were two points that showed moderate ecological risk. Multivariate statistical analysis (principal component analysis (PCA), Pearson's correlation coefficient (PCC), and hierarchical cluster analysis (HCA)) outlined that the metallic accumulation in the sediments of IAB was related to lithological, geological, and anthropogenic impacts. Therefore, oil spills and household waste are likely major reasons for anthropogenic pollution in the sediments of the IAB.

Effects of lakeshore landcover types and environmental factors on microplastic distribution in lakes on the Inner Mongolia Plateau, China

Microplastic pollution in freshwater environments has received increasing attention. However, limited research on the occurrence and distribution of microplastics in plateau lakes. This study investigated the microplastic characteristics and influencing factors in lakes with different land cover types on the Inner Mongolia Plateau. Results showed that microplastic abundance ranged from 0.5 to 12.6 items/L in water and 50-325 items/kg in sediments. Microplastics in water were predominantly polypropylene (50.5%), fragments (40.5%), and 50-200 µm (66.7%). High-density (27.9%), fibrous (69.3%), and large-sized microplastics (47.7%) were retained primarily in lake sediments. The highest microplastic abundance in water was found in cropland lakes and grassland lakes, while that in sediments was in descending order of desert lakes > cropland lakes > grassland lakes > forest-grassland lakes. Differences among lake types suggest that agriculture, tourism, and atmospheric transport may be critical microplastic sources. Microplastic distribution was positively correlated with farmland and artificial surface coverage, showing that land cover types related to human activities could exacerbate microplastic pollution in lakes. Redundancy analysis showed that ammonia nitrogen and pH were the key physicochemical factors affecting microplastic distribution in lakes, indicating the potential sources of microplastics in lakes and the uniqueness of microplastic occurrence characteristics in desert saline-alkaline lakes, respectively.

Multimedia distribution, partitioning, sources, comprehensive toxicity risk and co-occurrence network characteristics of trace elements in a typical Chinese shallow lake with high antibiotic risk

Although the combined pollution of trace elements and antibiotics has received extensive attention, the fate and toxicity risk of trace elements with high antibiotic risk are still unclear. The multimedia distributions, partitioning, sources, toxicity risks and co-occurrence network characteristics of trace elements in surface water (SW), overlying water (OW), pore water (PW) and sediment (Sedi) samples of 61 sites from Baiyangdian (BYD) Lake were investigated. The trace elements in the SW and OW are derived mainly from traffic and agricultural sources, and those in PW and Sedi samples are primarily from lithogenic and industrial sources. The total toxicity risk index (TRI) of nine trace elements (ΣTRI) in Sedi samples showed a very high toxicity risk (18.35 ± 8.84), and a high combined pollution toxicity risk (ΣΣTRI) was observed in PW (149.17 ± 97.52) and Sedi samples (46.37 ± 24.00). The co-occurrence network from SW to PW became more vulnerable. Generally, total antibiotics and TP may be keystones of trace elements in water and sediment. The high antibiotic risk significantly influenced ΣΣTRI in water samples but not in Sedi samples. The findings provide new implications for the monitoring and control of combined antibiotic-trace element pollution in shallow lakes.

Sediment-associated microplastics in Chilika lake, India: Highlighting their prevalence, polymer types, possible sources, and ecological risks

The primary objective of this research was to assess microplastics (MPs) in the sediments of Chilika lake. MPs were extracted from 22 sediment samples using the density separation method combined with vacuum pump filtration. A stereo-zoom microscope and Raman spectroscopy were employed to identify the sediment-associated MPs. The total MPs collected from all 22 sites was 440 ± 3.53 particles kg-1 wet sediments, with sizes ranging between 50 and 500 μm. In terms of morphology, fibers and fragments emerged as the dominant MP types, with counts of 210 ± 1.66 and 175 ± 1.76 particles kg-1 wet sediments, respectively. Raman spectroscopy verified the presence of various MP polymers in the sediments, predominantly HDPE (37 %), followed by PS (20 %), PET (18 %), PA (11 %), PP (7 %), and PC (7 %). A notable color variation was observed in MPs; black being the most prevalent (38.8 %), succeeded by blue (19.5 %), green (11.8 %), white (11.5 %), red (10.6 %), and transparent (7.5 %). ANOVA results indicated significant (p > 0.05) variations in MP abundance across the 22 sampling locations. However, principal component analysis (PCA) and multiple regression analysis indicated that water quality parameters did not significantly influence MP abundance, yet it was found that MP retention was higher in fine-grained sediments like clay and silt. The leading sources of MPs in Chilika lake were found to be aquafarming, trailed by river and sewage discharges, fishing activities, antifouling coatings and tourism. Additionally, the pollution load index (PLI) was employed to gauge the ecological risks, categorizing the lake under risk category 1, which implies a minimal level of MPs pollution. This research aims to serve as an early warning system for MPs pollution in productive brackish water habitats globally, including Chilika lake, guiding policymakers towards appropriate management strategies and preventive measures.

Season-dependent physiological behavior of Miscanthus x giganteus growing on heavy-metal contaminated areas in relation to soil properties

Miscanthus x giganteus is often considered as a suitable plant species for phytomanagement of heavy metal polluted sites. Nevertheless, its physiological behavior in response to the level of metal toxicity throughout the growing season remains poorly documented. Miscanthus x giganteus was cultivated on three sites in Belgium (BSJ: non-polluted control; CAR: slightly contaminated; VM strongly polluted by Cd, Pb, Cu, Zn, Ni and As). The presence of Miscanthus improved soil biological parameters assessed by measurement of enzyme activity and basal soil respiration on the three considered sites, although to a lower level on VM site. Heavy metal accumulation in the shoot was already recorded in spring. It displayed a contrasting distribution in the summer leaves since heavy metals and As metalloid accumulated mainly in the older leaves of CAR plants while showing a uniform distribution among leaves of different ages in VM plants. Comparatively to plants growing on BSJ, net photosynthesis decreased in plants growing on CAR and VM sites. The recorded decrease was mainly related to stomatal factors in CAR plants (decrease in stomatal conductance and in Ci) but to non-stomatal factors such as decrease in carboxylation efficiency and non-photochemical quenching in VM plants. Stomata remained open in VM plants which presented lower instantaneous and intrinsic water use efficiencies than CAR and BSJ plants. High proportions of heavy metals accumulated in CAR plants were bound to the cell wall fraction while the soluble and organelle-rich fractions were proportionally higher in VM plants, leading to a decrease in cell viability and cell membrane damages. It is concluded that not only the intensity but also the nature of physiological responses in Miscanthus x giganteus may drastically differ depending on the pollution level.

Biochar supported nanoscale zerovalent iron-calcium alginate composite for simultaneous removal of Mn(II) and Cr(VI) from wastewater: Sorption performance and mechanisms

Heavy metal pollution in water caused by industrial activities has become a global environmental issue. Among them, manganese mining and smelting activities have caused the combined pollution of Cr(VI) and Mn(II) in water, posing a serious ecotoxicological risk to ecological environments and human health. To efficiently remove Cr(VI) and Mn(II) from wastewater, a novel biochar supported nanoscale zerovalent iron-calcium alginate composite (CA/nZVI/RSBC) was synthesized by liquid-phase reduction and calcium alginate embedding methods. The adsorption performance and mechanisms of Cr(VI) and Mn(II) by CA/nZVI/RSBC were investigated. The maximum adsorption capacities of Cr(VI) and Mn(II) onto CA/nZVI/RSBC fitted by the Langmuir model were 5.38 and 39.78 mg/g, respectively, which were much higher than the pristine biochar. The iron release from CA/nZVI/RSBC was comparatively lower than that of nZVI/RSBC. Mn(II) presence enhanced the reduction of Cr(VI) by CA/nZVI/RSBC. The results of XRD, XPS, and site energy distribution analysis indicated that redox was the predominant mechanism of Cr(VI) adsorption, while electrostatic attraction dominated Mn(II) adsorption. This study provides a novel alternative way for the simultaneous removal of Cr(VI) and Mn(II) in wastewater.

Mobile genetic elements affect the dissemination of antibiotic resistance genes (ARGs) of clinical importance in the environment

The prevalence of antibiotic resistance genes (ARGs) in the environment is a quintessential One Health issue that threats both human and ecosystem health; however, the source and transmission of ARGs, especially clinically important ARGs (CLIARGs), in the environment have not yet been well studied. In the present study, shotgun metagenomic approaches were used to characterize the microbiome, resistome, and mobilome composition in human feces and six different environment sample types in South China. Overall, the resistome harbored 157 CLIARGs, with specific ARG hotspots (e.g., human feces, wastewater treatment plants, livestock manure and wastewater) excreting significantly higher abundance of CLIARGs compared with the natural environment. A redundancy analysis (RDA) was performed and revealed that the bacterial community compositions and mobile genetic elements (MGEs) explained 55.08% and 34.68% of the variations in ARG abundance, respectively, indicating that both bacterial community and MGEs are key contributors to the maintenance and dissemination of CLIARGs in the environment. The network analysis revealed non-random co-occurrence patterns between 200 bacterial genera and 147 CLIARGs, as well as between 135 MGEs and 123 CLIARGs. In addition to numerous co-shared CLIARGs among different sample types, the source tracking program based on the FEAST probabilistic model was used to estimate the relative contributions of the CLIARGs from potential sources to the natural environment. The source tracking analysis results delineated that mobilome, more than microbiome, contributed CLIARG transmission from those ARG hotspots into natural environment, and the MGEs in WWTPs seem to play the most significant role in the spread of CLIARGs to the natural environment (average contribution 32.9%-46.4%). Overall, this study demonstrated the distribution and dissemination of CLIARGs in the environment, and aimed to better inform strategies to control the spread of CLIARGs into the natural environment.

The detrimental effects of heavy metals on tributaries exert pressure on water quality, Crossocheilus aplocheilus, and the well-being of human health

The escalating presence of heavy metals (HMs) in the Panjkora River water and their impact on fish pose a significant challenge to both the ecological community and human health. Consequently, a study was conducted with the primary aim of elucidating their influence on human health-related issues. To address this, the concentrations of heavy metals, including arsenic (As), cadmium (Cd), iron (Fe), manganese (Mn), lead (Pb), and zinc (Zn), in both water and the fish species Crossocheilus diplocheilus were investigated across various locations within the study area. The quantification of HMs concentration was carried out utilizing an atomic absorption spectrophotometer. The highest concentration in water was found as 0.060 mg/L for Pb and lowest for Fe, whereas the highest concentration in fish was 2.028 mg/kg for Pb and lowest for As. Human health risk associated with fish eating was evaluated by using health risk indices (HRI) for non-carcinogenic health risks and targeted cancer risk (TR) for carcinogenic health risks. The values of the health risk index (HRI) were found greater than 1 except Fe (0.0792), Zn (0.782), and Mn (0.541). The highest mean HRI > 1 was recorded for As (62.99), Cd (26.85), and Pb (10.56). This implies that fish consumption from river Panjkora is not safe up to some extent. Similarly, the TR value for As, Cd, and Pb was found 2.8 [Formula: see text], 1.6 [Formula: see text], 2.8 ×[Formula: see text] which showed cancer risk. There is a detected risk to human health associated with the consumption of fish from the Panjkora River. The government must implement adaptive measures to address this significant issue of water pollution in the study area. Additionally, there is a need for further extensive and prolonged research studies in this context.

Evaluation of physical and chemical characteristics of wastewater and sludge of Zahedan urban wastewater treatment plant for reuse

Following the water shortage in the world, the use of wastewater as a sustainable resource has been considered in large volume. The study conducted to evaluate the physical and chemical characteristics of the wastewater and sludge of the Zahedan urban wastewater treatment plant showed that the wastewater and sludge treatment system of the treatment plant has high efficiency and effectiveness in removing the investigated parameters. The investigated parameters in the effluent included Chemical oxygen demand (COD), Biochemical oxygen demand (BOD), and Total suspended solids (TSS), turbidity, temperature, nitrate, nitrite, phosphate, pH, zinc, cobalt, lead and copper. Also, the investigated parameters in the sludge included Mixed liquor suspended solids (MLSS), Mixed liquor volatile suspended solids (MLVSS), pH, electrical conductivity and heavy metals. The results showed that the average concentration of metals in the treated effluent is Zn > Mn > Cu > Pb > Ni > Cr > Cd ،and Chemical oxygen demand and Biochemical oxygen demand in the effluent of this treatment plant are on average 171 and 44.4 mg/L, respectively, and its discharge in surface water is limited, but it can be applied for agriculture. Also, the purified sludge had the necessary standards and could be used as soil or household fertilizer and compost for agricultural land.

A catchment-wide microplastic pollution investigation of the Yangtze River: The pollution and ecological risk of tributaries are non-negligible

The Yangtze River is an important global channel for plastics and microplastics (MPs) to enter the sea. However, the existing research on MPs in the Yangtze River has primarily focused on the mainstream region, without regarding the occurrence, spatial distribution, and ecological risks associated with tributaries, as well as their relationship with the mainstream. To address this knowledge gap, we conducted a large-scale catchment-wide investigation of the surface water in the Yangtze River, encompassing MPs (48 µm-5 mm) of the mainstream and 15 important tributaries. Tributaries and upstream regions exhibited relatively higher levels of MPs compared with the mainstream and different sections of the river. The distribution of MPs is primarily influenced by the emission of arable land and the pH of water. Notably, the upstream tributary areas demonstrated the highest ecological risks associated with MPs. Further analysis highlighted that the tributaries accounted for a contribution ranging from 16% to 67% in quantity and from 14% to 90% in mass of the microplastics observed in the mainstream. Our results suggest that the pollution of tributaries and their associated ecological risk migration must be effectively regulated.

Assessing industrial wastewater effluent toxicity using boosting algorithms in machine learning: A case study on ecotoxicity prediction and control strategy development

Trace heavy metals have a tendency to persist in the effluent of industrial wastewater treatment facilities, leading to toxic effects on downstream water bodies. Traditional assessment methods relied on animal testing, but ethical concerns have rendered them unacceptable. An alternative solution is to evaluate wastewater toxicity using trophic-level aquatic organisms as bioassays. However, these bioassay methods involve costly and time-consuming chemical and biological analytical experiments. In this study, an artificial intelligence-powered water quality assessment (AiWA) approach is proposed for predicting industrial effluent ecotoxicity to further enhance the quick and cost-effective ecotoxicity assessment process. Initially, 99 samples were collected from industrial wastewater treatment plants representing 21 different industries in the Republic of Korea. Fourteen parameters were measured, encompassing both physicochemical and ecotoxicological aspects. Boosting algorithms, especially extreme gradient boosting (XGBoost) and adaptive boosting (AdaBoost), were employed for model development. XGBoost outperformed AdaBoost in terms of model performance. Feature selection analysis revealed that conductivity, copper, lead, selenium, pH, and zinc concentrations were the most suitable inputs for training the boosting model. The innovated XGBoost-based AiWA model demonstrated significantly higher performance (i.e., up to 80%) compared to conventional models with an R2 value of exceeding 0.94 and root mean square error of 3.5 toxicity unit for predicting the integrated toxicity unit (ITU). Additionally, pH and conductivity emerged as crucial indicators for reflecting ecotoxicity levels. Specially, this case study indicated that non-toxic/directly dischargeable levels (TU ≤ 1) were achieved when the pH ranged from 6.8 to 8.4 and the conductivity remained below 1651 μS/cm. These findings are expected to facilitate rapid and cost-effective detection of heavy metal ecotoxicity in industrial wastewater effluents, aiding decision-making in wastewater management.

LC-MS/MS Investigation of nitrosamine impurities in certain Sartan group medicinal products available in Istanbul, Türkiye

Nitrosamines (NAs) are molecules that include the nitroso functional group. In 2018, the US Food and Drug Administration (FDA) received its first report of NAs in pharmaceuticals. The fact that NA impurities are likely human carcinogens is relevant to these compounds. Furthermore, prolonged exposure to NA contaminants above safe limits may raise the risk of cancer. The goal of this article was to assess the amounts of six different NAs in Sartan group medicines purchased from formal pharmacies in Istanbul, Türkiye, using a validated LC-MS/MS assay. An LC-MS/MS-based analytical assay was undertaken. The separation was performed with a HR ODS 150mm×3.0mm and 5-analytical columns, providing effective separation of major peaks from NA impurities. In mobile phase A, formic acid was 0.10% in water, while in mobile phase B, formic acid was 0.10% in methanol. The flow rate was 0.4mL/minute, and the total runtime was 18minutes with the gradient elution mode. The validation was conducted in line with ISO/IEC 17025 requirements. Up to 100μg/L, linearity was determined using correlation coefficients (r2>0.995) for all NAs. The limit of quantification values for all NAs analyses were below 1.0μg/L. The mean recovery value obtained during the spike experiment was 95.18%, demonstrating the accuracy of the procedure. In addition, the accuracy was shown by a certified reference analysis, which yielded relative standard deviation and relative error values of 1.82% and 3.34%, respectively. During the intermediate precision testing, bias and relative standard deviation were 0.96 and 2.87%, respectively. Of the 75 study samples involving Sartan group medical products, no nitrosamine impurities were detected, demonstrating that pharmaceutical companies have adequate medication safety precautions in place in accordance with FDA and European Medicines Agency (EMA) regulations published to prevent NA contaminants in human medicinal products.

Separation and identification of snuff constituents by using GC-MS and ICP-OES as well as health risk assessment of some existing heavy metals

The identification of volatile organic components in snuff was accomplished using GC-MS analysis in this study. The findings of the GC-MS analysis revealed the presence of nicotine, its derivatives, and several other toxic chemicals that are hazardous to human health. Furthermore, the content of 34 elements in four brands of snuff consumed in Neyshabur City was determined by ICP-OES analysis (with five repetitions). The health hazards of measured heavy elements were examined from two perspectives: carcinogenic (7 heavy elements were checked) and non-carcinogenic (4 heavy elements were checked). The investigation of non-carcinogenic hazards from inhalation was based on the computation of the hazard quotient (HQ) factor, and the results indicated that inhaling five heavy metals, Cu, Pb, Ni, Zn, and Cd, does not represent a substantial health risk ((HQ < 1). In contrast, the computed HQ factors for Cr and As were relatively high (1 < HQ < 10), indicating a substantial health risk from breathing these two elements. The carcinogenic factor (CR value) results revealed that the degree of carcinogenic risk for Cd was very low (CR value less than 1 × 10-6) and did not pose a concern to the consumer population. However, the risk of As, Cr, and Ni exposure is considerable in the carcinogenic risk range (CR values between 1 × 10-6 and 1 × 10-4).

Depth-dependent microbial communities potentially mediating mercury methylation and various geochemical processes in anthropogenically affected sediments

Metal contamination and other geochemical alterations affect microbial composition and functional activities, disturbing natural biogeochemical cycles. Therefore, it is essential to understand the influences of multi-metal and geochemical interactions on microbial communities. This work investigated the distributions of total mercury (THg), methylmercury (MeHg), and trace metals in the anthropogenically affected sediment. The microbial communities and functional genes profiles were further determined to explore their association with Hg-methylation and geochemical features. The levels of THg and MeHg in sediment cores ranged between 10 and 40 mg/kg and 0.01-0.16 mg/kg, respectively, with an increasing trend toward bottom horizons. The major metals present at all depths were Al, Fe, Mn, and Zn. The enrichment and contamination indices confirmed that the trace metals were highly enriched in the anthropogenically affected sediment. Various functional genes were detected in all strata, indicating the presence of active microbial metabolic processes. The microbial community profiles revealed that the phyla Proteobacteria, Bacteroidetes, Bathyarchaeota, and Euryarchaeota, and the genera Thauera, Woeseia, Methanomethylovorans, and Methanosarcina were the dominant microbes. Correlating major taxa with geochemical variables inferred that sediment geochemistry substantially affects microbial community and biogeochemical cycles. Furthermore, archaeal methanogens and the bacterial phyla Chloroflexi and Firmicutes may play crucial roles in enhancing MeHg levels. Overall, these findings shed new light on the microbial communities potentially involved in Hg-methylation process and other biogeochemical cycles.

Deciphering the dysbiosis caused in the fish microbiota by emerging contaminants and its mitigation strategies-A review

The primary barrier to nutrient absorption in fish is the intestinal epithelium, followed by a community of microorganisms known as the gut microbiota, which can be thought of as a hidden organ. The gastrointestinal microbiota of fish plays a key role in the upholding of overall health by maintaining the homeostasis and disease resistance of the host. However, emerging contaminants as the result of anthropogenic activities have significantly led to disruptions and intestinal dysbiosis in fish. Which probably results in fish mortalities and disrupts the balance of an ecosystem. Therefore, we comprehensively seek to compile the effects and consequences of emerging contaminations on fish intestinal microbiota. Additionally, the mitigation strategies including prebiotics, probiotics, plant-based diet, and Biofloc technology are being outlined. Biofloc technology (BFT) can treat toxic materials, i.e., nitrogen components, and convert them into a useful product such as proteins and demonstrated promising elevating technique for the fish intestinal bacterial composition. However, it remains unclear whether the bacterial isolate is primarily responsible for the BFT's removal of nitrate and ammonia and the corresponding removal mechanism. To answer this, real time polymerase chain reaction (RT-PCR) with metagenomics, transcriptomics, and proteomics techniques probably provides a possible solution.

Pollution characteristics, sources and health risks assessment of potentially hazardous elements in sediments of ten ponds in the Saros Bay region (Türkiye)

Pollution of lentic ecosystems by potentially hazardous elements (PHE) due to human activities has become a global concern. In this study, the contents of eight PHEs in the sediments of 10 most important ponds located in the Saros Bay region (Türkiye) were evaluated. The contents of PHEs in the sediments of the ponds ranged from 0.14 mg/kg for Cd to 274 mg/kg for Mn. According to the enrichment factor (EF) results, ponds P3, P8 and P9 for Cd and pond P8 for Pb showed "moderate enrichment". However, the pollution load index (PLI) results indicated that all ponds were in a "baseline contamination" state due to the combined effect of all PHEs. Similarly, based on ecological risk assessment indices, no ecological risk from PHEs was identified. In addition, Cd, Zn, As, Cr, Cu and Pb contents in all ponds were found below threshold effect concentrations. The results of the health risk assessment indicated that non-carcinogenic and carcinogenic risks were not expected for recreational receptors due to exposure to the PHEs in the sediments via incidental ingestion and dermal contact. Correlation and cluster analysis results indicated that although agricultural activities contributed slightly to the As content, all PHEs mainly originated from natural sources.

Estimation of selected elemental impurities by inductively coupled plasma-mass spectroscopy (ICP-MS) in commercial and fresh fruit juices

The main objective of the study is the estimation of elemental impurities in selected packaged commercial fruit juices and fresh fruit juices available in Ahmedabad, Gujarat. Estimation of seventeen samples (9 commercial fruit juices and 8 fresh fruit juices) was carried out for elemental impurities which include lead, cadmium, arsenic, mercury, methyl mercury, nickel, chromium, tin, copper, and zinc. Inductively coupled plasma-mass spectroscopy (ICP-MS) with microwave-assisted sample digestion was used to determine the element content of samples. The ICP-MS method was confirmed for accuracy by performing validation with validation parameters such as linearity, precision, and accuracy. The method's trueness was confirmed with single-element standards. The results were compared with Food Safety and Standards Authority of India (FSSAI) standards. Arsenic, mercury, methyl mercury, tin, and copper were within permissible limits in all samples of fruit juices. The concentration of lead was found to exceed limits in 5 samples of commercial fruit juices which were 0.07, 0.13, 0.18, 0.21, and 0.38 mg/kg, respectively. The concentration of nickel was found to be above permissible limits in 5 samples (1.26, 1.72, 1.95, 3.24, and 4.07 mg/kg) of commercial fruit juices and 6 samples of fresh fruit juices (0.19. 0.21, 0.21, 0.42, 0.66, and 2.42 mg/kg). The concentration of chromium was found to be above permissible limits in 5 samples (3.13, 3.51, 4.29, 5.91, and 6.02 mg/kg) of commercial fruit juices and 6 samples of fresh fruit juices (0.80. 0.88, 0.98, 0.99, 1.16, and 8.95 mg/kg). Health risk assessment was performed for elemental impurities. Target hazard quotient and health risk index for elemental impurities were found to be less than 1 which is considered safe for consumers. Hazard index for elemental impurities was found to be more than 1 in two samples which can cause serious non-carcinogenic risk to consumers. Target carcinogenic risk was found within acceptable levels for all elemental impurities in all samples of fruit juices. Essential elements like copper and zinc are required by the human body for various body functions but heavy metals like lead, arsenic, and cadmium are highly toxic to human beings due to their adverse effects and it needs to be controlled. Lead poses a significant health risk to human health. It is essential to further monitor the levels of elemental impurities on a regular basis in commercial and fresh fruit juices.

Imperative assessment on the current status of rubber wastewater treatment: Research development and future perspectives

The environment has been significantly impacted by the rubber industry through the release of large quantities of wastewater during various industrial processes. Therefore, it is crucial to treat the wastewater from the rubber industry before discharging it into natural water bodies. With the understanding that alarmingly depleting freshwater sources need to be preserved for future generations, this paper reviews the status of the rubber industry and the pollution caused by them, focusing mainly on water pollution. The review pays special attention to the recent advancements in wastewater treatment techniques for rubber industry wastewater categorizing them into pre-treatment, secondary, and tertiary treatment processes while discussing the advantages and disadvantages. Through a comprehensive analysis of existing literature, it was determined that organic content and NH4+ are the most frequently focused water quality parameters, and despite some treatment methods demonstrating superior performance, many of the methods still face limitations and require further research to improve systems to handle high organic loading on the treatment systems and to implement them in industrial scale. The paper also explores the potential of utilizing untreated or treated wastewater and byproducts of wastewater treatment in contributing towards achieving several United Nations sustainable development goals (UN-SDGs); SDG 6, SDG 7, SDG 9, and SDG 12.