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Rice intake represents a significant pathway through which humans accumulate heavy metals. This study presents a comprehensive analysis of heavy metal and pesticide contamination in rice cultivars irrigated with industrial wastewater near Dhaka, Bangladesh, a region heavily influenced by industrial activities. This study employed a unique methodology that not only quantified the concentrations of heavy metals and pesticide residues in rice grains but also extended to evaluating the physicochemical properties of rice stems, husks, soil, and irrigation water. The findings revealed alarmingly high levels of heavy metals such as lead, cadmium, chromium, nickel, and mercury in the soil and irrigation water, with concentrations in some cases exceeding the World Health Organization safety thresholds by 2 to 15 times. Notably, the rice grains also exhibited significant contamination, including substantial amounts of diazinon and fenitrothion pesticides, exceeding the established safety limits. The study employed hazard quotients (HQs) and cancer risk (CR) assessments to evaluate the potential health risks associated with the consumption of contaminated rice. The results indicated HQ values were greater than 1 for rice grains across the sampled fields, suggesting a considerable non-carcinogenic health risk, particularly from lead exposure, which was found at levels twice the standard limit in all the sampling fields. Moreover, the CR values for As, Pb, Cd, Co, and Mn highlighted a significant carcinogenic risk in several instances. [ABSTRACT FROM AUTHOR]

The traditional craft villages in Vietnam in general and in Bac Ninh province in particular have been exposing many negative impacts on the environment. The heavy metal-rich wastes from the metal recycling casting craft villages in the field of metal recycling and metal casting are causing severe heavy metal pollution not only to the air, soils, and sediments but also to the groundwater resources. In Da Hoi iron recycling craft village in Chau Khe ward, Tu Son town, Bac Ninh province, Vietnam, the Holocene aquifer is exposed to the Ngu Huyen Khe River's sediments contaminated with heavy metals Lead, Cadmium, Nickel, and Zinc. Freundlich isotherm parameters of the Holocene aquifer have been selected for finite element modeling of heavy metal transport with high temporal and spatial varying retardation factors to get reliable quantitative heavy metals' distribution in depth and time. Initial and boundary conditions have been augmented to be established. The retardation factors of the advection and dispersion transport in the Holocene aquifer for heavy metals Pb, Zn, Cd, and Ni are very highly none-linear and very much varying in time and space: 8.7–66.4 for Pb, 2.0–12 for Zn, 1.7–4.8 for Cd and 1.1–5.9 for Ni. The results of the numerical modeling show that heavy metal transport in the Holocene aquifer is very fast and the entire aquifer thickness has equilibrium aquifer formation and aquifer water heavy concentrations after around 2–2.5 years for Cd and Ni, around 4 years for Zn and around 27 years for Pb. The heavy metals' fluxes from the Holocene aquifer to the Pleistocene aquifer are maximal and more or less constant from the equilibrium time and would cause severe contamination of the Pleistocene aquifer. [ABSTRACT FROM AUTHOR]

A novel electrochemical sensor based on multiwalled carbon nanotubes (MWCNTs) and 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6) hydrophobic ionic liquid for the rapid detection of Pb2+ and Cd2+ was developed. In this study, the BMIMPF6-MWCNTs composite, as well as BMIMPF6 and MWCNTs, were characterized using SEM. The electrochemical studies were performed using Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS). The BMIMPF6-MWCNTs/GCE exhibited excellent electrochemical activity. The effect of the pH value of 0.1 M NaAc/HAc buffer, deposition potential, and deposition time was investigated. Under the optimal conditions, the linear range for the modified sensors varies from 5 to 1850 µg L−1 for Pb2+ and 22 to 600 µg L−1 for Cd2+. The limit of detection (LOD) for Pb2+ and Cd2+ was 0.9 µg L−1 and 0.5 µg L−1, respectively, and the limit of quantification (LOQ) was 3 µg L−1 for Pb2+ and 1.7 µg L−1 for Cd2+. Moreover, this method showed excellent anti-interference performance, short analysis time, and practicability for determining Pb2+ and Cd2+. The electrochemical sensor was able to determine heavy metal ions in actual water samples without complex pretreatment, with acceptable recoveries from 98 to 110.8% for Pb2+ and 98.6 to 111.3% for Cd2+, demonstrating that the sensor based on BMIMPF6-MWCNTs/GCE can apply for Pb2+ and Cd2+ quantification. [ABSTRACT FROM AUTHOR]

The aim of the present research was to investigate the presence of heavy metals such as lead (Pb), copper (Cu), chromium (Cr), and cadmium (Cd) in blood samples from cows raised with irrigated wastewater, as well as in the wastewater itself, in the North-western region of Pakistan. A total of 60 blood samples were collected from five different locations in Kohat, namely Tappi Road (TR), Pindi Road (PR), Gul Malik Road (GMR), Markaz Road (MR), and a control group. The samples of both i.e. cow blood and wastewater were analyzed for the concentrations of heavy metals. The highest concentration of Cd was detected in the MR site with a mean value of 0.03 mg/L, and the highest concentration of Cu (0.04 mg/L) was recorded in the TR site, while the lowest level was found in the control group with a mean of 0.002 mg/L in blood samples. The highest Cr and Pb concentrations were found at the PR site, with mean values of 0.03 and 0.07 mg/L, respectively, whereas the control group had the lowest concentrations, with mean values of 0.002 and 0.01 mg/L. Similarly, heavy metal concentrations were analyzed in wastewater used for irrigation in the study area. Results indicated elevated concentrations of Cu and Cr in wastewater, although they remained below the World Health Organization (WHO) recommended values except for Cr (0.13 mg/L) in the GMR site, which exceeded permissible limits. Cd and Pb concentrations in wastewater were relatively low, but Cd concentration surpassed WHO limits, particularly with a mean concentration of 0.08 mg/L in the TR site. Comparison between heavy metal concentrations in blood and wastewater revealed higher values of Cd and Pb in blood samples than in wastewater, while Cu and Cr concentrations were higher in water compared to blood. Additionally, elevated levels of Super Oxide Dismutase (SOD), antioxidant enzyme Catalase (CAT), and oxidative stress marker malondialdehyde (MDA) were detected in blood samples. Cluster and principal component analyses were employed to assess heavy metal toxicity among the groups, indicating potential long-term adverse health effects on animals, transfer to humans, and toxicity in living organisms. [ABSTRACT FROM AUTHOR]

The rapid industrial development in the Indian capital region has led to significant waste generation, which, despite undergoing treatment prior to disposal, contributes substantially to water body contamination. Given the diverse nature of these wastes and their potential repercussions across the food chain, a study was conducted to evaluate heavy metal contamination levels in the Ganga and Yamuna Rivers of two major cities. Six heavy metals (Pb, Cd, Hg, Cu, Cr, and Zn) were analyzed in fish, water, and sediment samples by utilizing flame atomic absorption spectrophotometry (Avanta Σ) from March 2019 to February 2020. Results revealed distinct heavy metal distribution patterns, with Cr > Zn > Pb > Cu > Cd > Hg in the Ganga River and Zn > Cr > Pb > Cu > Cd > Hg in the Yamuna River for fish samples. Additionally, levels of Hg in Cyprinus carpio and Sperata oar from the Ganga River, and Pb, Cd, Hg, and Cr in Salmophasia bacaila and Mystus cavasius from the Yamuna River exceeded WHO/FAO permissible limits. In water samples, the predominant heavy metal sequences were Pb > Cu > Zn > Cr > Cd > Hg for the Ganga River and Cr > Zn > Pb > Cu > Cd > Hg for the Yamuna River, with Pb, Cr, Zn, and Cd surpassing WHO standards. Sediment analysis revealed varying heavy metal compositions, with Zn > Cr > Pb > Cu > Cd > Hg in the Ganga River and Cr > Zn > Pb > Cu > Cd > Hg in the Yamuna River. While drinking water and fish from the Ganga River were deemed safe for consumption, those from the Yamuna River were not. Given the toxic nature of heavy metals and their detrimental health impacts, regular monitoring and effective management strategies are imperative. [ABSTRACT FROM AUTHOR]

An electrode modified with phytic acid (PA)-doped polypyrrole (PPy)/molybdenum disulfide (MoS2) nanocomposites for the simultaneous detection of Pb2+ and Cd2+ heavy metal ions in water. On the surface of MoS2 nanosheets PA-doped PPy/MoS2 nanomaterials were fabricated by in situ chemical oxidation polymerization. The PA-doped PPy network was uniformly covered the surface of MoS2 nanosheets which can improve stability of MoS2 and increase electrochemical active sites. The PA-doped PPy/MoS2-modified electrode demonstrated outstanding electrochemical performance compared to the PA-doped PPy and MoS2-modified electrodes. The PA-doped PPy/MoS2 has been proven to detect range of Pb2+ and Cd2+ between 10 and 300 μg/L. The limit of detection (LOD = 3σ/k) for Pb2+ was 1.78 μg/L and for Cd2+ was 2.03 μg/L. The PA-doped PPy/MoS2-modified electrode has good selectivity, reproducibility and stability. In practical tap water applications, good recoveries were achieved. This work illustrated a straightforward, helpful and high performing pathway within the areas of electrochemical detecting Pb2+ and Cd2+. [ABSTRACT FROM AUTHOR]

Kathajodi, the principal southern distributary of the Mahanadi River, is the vital source of irrigation and domestic water use for densely populated Cuttack city which receives anthropogenic wastes abundantly. This study assesses the contamination level and primary health status of urban wastewater, and its receiving river Kathajodi based on the physicochemical quality indices employing inductively coupled plasma mass spectroscopy and aligning with guidelines from the United States Environmental Protection Agency (USEPA) and WHO. The high WQI, HPI, and HEI in the catchment area (KJ2, KJ3, and KJ4) indicate poor water quality due to the influx of domestic waste through the primary drainage system and effluents of healthcare units. A high BOD (4.33–19.66 mg L−1) in the catchment indicates high organic matter, animal waste, bacteriological contamination, and low DO, resulting in deterioration of water quality. CR values beyond limits (1.00E − 06 to 1.00E − 04) in three locations of catchment due to higher Cd, Pb, and As indicate significant carcinogenic risk, while high Mn, Cu, and Al content is responsible for several non-carcinogenic ailments and arsenic-induced physiological disorders. The elevated heavy metals Cd, Cu, Fe, Mn, Ni, and Zn, in Kathajodi, could be due to heavy coal combustion, vehicle exhaust, and industrial waste. On the other hand, Cu, Fe, K, and Al could be from agricultural practices, weathered rocks, and crustal materials. Positive significant (p ≤ 0.05) Pearson correlations between physicochemical parameters indicate their common anthropogenic origin and similar chemical characteristics. A strong correlation of PCA between elements and physiological parameters indicates their role in water quality deterioration. Assessing the surface water quality and heavy metal contents from this study will offer critical data to policymakers for monitoring and managing public health concerns. [ABSTRACT FROM AUTHOR]

Groundwater and surface water quality is of great significance for humanity as they serve as the primary drinking water sources globally. Due to population growth and the need to provide people with necessities that depend on water as an essential resource, these bodies of water are becoming more polluted. The present study involved the collection of groundwater and surface water samples from Kampala and Mbarara districts in Uganda during the dry and wet seasons. Also, concentrations of lead (Pb), manganese (Mn), cadmium (Cd), copper (Cu), and iron (Fe) were analyzed in order to evaluate the toxicity of metals, identify potential sources, and determine the health risk associated with their presence in water. Results showed that metals were observed with higher concentration during the wet season than the dry season. The concentrations of Fe (8.646 ± 0.00 mg/L), Mn (2.691 ± 0.01 mg/L) and Cd (0.090 ± 0.41 mg/L) measured in groundwater were significantly higher than those measured in surface water. However, only Cu was observed with higher concentration (0.322 ± 0.06 mg/L) in surface water during the wet season. Furthermore, the degree of contamination (Cd) and the heavy metal pollution index (HPI) were evaluated for both the wet and dry seasons. Results showed that few samples were found in the category of portable drinking water while majority are within the "poor" and "very poor" classes which require proper treatment before consumption. The oral hazard index (HIoral) results showed that none of the samples are suitable for consumption; therefore, cause potential non-carcinogenic health issues to the consumer (HIoral > 1). Moreover, children are more at risk than adults in the study districts (higher HI values in both seasons). This study recommends frequent monitoring of quality of water and also effluent waste treatment by the major source of pollution. [ABSTRACT FROM AUTHOR]

Among the many heavy metal pollution treatment agents, carbonate materials show strong flexibility and versatility by virtue of their high adsorption capacity for heavy metals and the characteristics of multiple and simple modification methods. It shows good potential for development. This review summarizes the application of carbonate materials in the treatment of heavy metal pollution according to the research of other scholars. It mainly relates to the application of surface-modified, activated, and nano-sized carbonate materials in the treatment of heavy metal pollution in water. Natural carbonate minerals and composite carbonate minerals solidify and stabilize heavy metals in soil. Solidification of heavy metals in hazardous waste solids is by MICP. There are four aspects of calcium carbonate oligomers curing heavy metals in fly ash from waste incineration. The mechanism of treating heavy metals by carbonate in different media was discussed. However, in the complex environment where multiple types of pollutants coexist, questions on how to maintain the efficient processing capacity of carbonate materials and how to use MICP to integrate heavy metal fixation and seepage prevention in solid waste base under complex and changeable natural environment deserve our further consideration. In addition, the use of carbonate materials for the purification of trace radioactive wastewater and the safe treatment of trace radioactive solid waste are also worthy of further exploration. [ABSTRACT FROM AUTHOR]

Accumulation of bioavailable heavy metals in aquatic environment poses a serious threat to marine communities and human health due to possible trophic transfers through the food chain of toxic, non-degradable, exogenous pollutants. Copper (Cu) is one of the most spread heavy metals in water, and can severely affect primary producers at high doses. Here we show a novel imaging test to assay the dose-dependent effects of Cu on live microalgae identifying stress conditions when they are still capable of sustaining a positive growth. The method relies on Fourier Ptychographic Microscopy (FPM), capable to image large field of view in label-free phase-contrast mode attaining submicron lateral resolution. We uniquely combine FPM with a new multi-scale analysis method based on fractal geometry. The system is able to provide ensemble measurements of thousands of diatoms in the liquid sample simultaneously, while ensuring at same time single-cell imaging and analysis for each diatom. Through new image descriptors, we demonstrate that fractal analysis is suitable for handling the complexity and informative power of such multiscale FPM modality. We successfully tested this new approach by measuring how different concentrations of Cu impact on Skeletonema pseudocostatum diatom populations isolated from the Sarno River mouth. [ABSTRACT FROM AUTHOR]

Heavy metals are naturally omnipresent in aquatic systems. Excess amounts of heavy metals can accumulate in organisms of pollution impacted systems and transfer across a food web. Analysing the food web structure and metal contents of the organisms can help unravel the pathways of biomagnification or biodilution and gain insight in trophic linkages. We measured heavy metals and other elements in mussel bank detritus and organisms of the Biesbosch reservoirs (the Netherlands) and linked those to stable isotopic signatures. The heavy metal contents (cadmium, copper, lead, and zinc) were often lowest in benthivorous, omnivorous and piscivorous species (mainly fish); whereas, phosphorus contents were lower in the autotrophs. Mussel bank detritus contained the highest amounts of heavy metals. The heavy metals were negatively correlated with δ15N values. For selenium no clear trend was observed. Furthermore, there was a negative correlation between fish length and some heavy metals. Based on all 20 analysed elemental contents, similarities between species became apparent, related to niche or habitat. This study confirms that elemental contents of species can differ between feeding guilds and/or species, which can be attributed to metabolic and physiological processes. The organisms in higher trophic levels have adaptations preventing metal accumulation, resulting in lower contents. Within the fish species biodilution occurs, as most metal contents were lowest in bigger fish. Overall, the metals did not seem to biomagnify, but biodilute in the food web. Metal analyses combined with isotopic signatures could thus provide insights in metal transfer and possible trophic linkages within a system. [ABSTRACT FROM AUTHOR]

Most of the existing research for heavy metals in water at present is focusing on surface water. However, potential environmental risk of heavy metals in the bottom water of lakes cannot be ignored. In this study, the content, distribution, and speciation of nine heavy metals (As, V, Cr, Co, Ni, Cu, Zn, Cd, and Pb) in the bottom water and sediment of Chaohu Lake were studied. Some pollution assessment methods were used to evaluate the environmental effect of heavy metals. Positive matrix factorization was conducted to investigate the potential sources of heavy metals in sediment. The contents of heavy metals in the bottom water of Chaohu Lake mean that its environmental pollution can be ignored. In sediment, Cd and Zn have showed stronger ecological risk. pH and redox potential are more likely to affect the stability of heavy metals in the bottom water of Chaohu Lake during the dry reason. Industrial sources (16%) are no longer the largest source of heavy metal pollution; traffic sources (33.6%) and agricultural sources (23.4%) have become the main sources of pollution at present. This study can provide some support and suggestions for the treatment of heavy metals in lakes. [ABSTRACT FROM AUTHOR]

This study focuses on the removal of heavy metal ions, such as cadmium (Cd2+), lead (Pb2+), chromium (Cr6+), and zinc (Zn2+) from water. Metals, which are often present in water, can have various origins, i.e., industrial emissions, mining, melting, corrosion, municipal, industrial waste, and agrochemicals. These metals have the potential to cause adverse effects on human health. The study employed activated carbon derived from date palm waste as a means of removing heavy metals. The activated nanoparticles were characterized using various analytical techniques, including SEM, ICP, XRD, BET, Raman, and FTIR analysis. Batch studies were conducted to optimize the metal ion adsorption onto the activated carbon of date palm waste. The adsorption process was evaluated using isotherm models and reaction kinetics under various conditions, including contact time, dosage, pH, and initial concentration. The findings of this study revealed that the prepared activated carbon from date palm waste effectively removed up to 85% of Cr6+, Pb2+, Cd2+, and Zn2+ ions from water. This study highlights the potential of using agricultural waste, to produce effective adsorbents for heavy metal removal. [ABSTRACT FROM AUTHOR]

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 × 10 - 2 , 1.6 × 10 - 2 , 2.8 × 10 - 3 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. [ABSTRACT FROM AUTHOR]

The China-Pakistan Economic Corridor (CPEC) between China and Pakistan passes through the environmentally fragile region of the Himalayas−Karakorum−Hindukush (HKH). Surging human influence in the form of transportation and tourism may pose a potential threat to the socio-environmental sustainability especially, the water resources of the region. Therefore, it is important to evaluate the status and hydrogeochemistry of freshwater in mountainous catchments. For this purpose, water samples were collected from the Hunza, Gilgit, and Indus River Basins from 2019 to 2020. The physicochemical and biological characteristics of surface water were investigated using the water quality index (WQI), multivariate statistics, Piper diagram, and Gibbs plots. The results revealed high seasonal variability in the hydrochemistry of water samples in all basins. Heavy metals (HM) i.e., arsenic (As), and lead (Pb) were detected in more than 50% of total water samples, whereas cadmium (Cd) and mercury (Hg) were detected in less than 15% of total water samples. 82% of water samples collected during summer and 48% in winter were contaminated with bacterial contamination (Escherichia coli (E. coli) and total coliform (T. coli)). Piper diagram and Gibbs plot suggested that rock weathering and dissolution of carbonate rocks are the dominating factors controlling the chemistry of glacial streams and river water. The results of this study have important implications for policymakers, regulators, and practitioners involved in water and environmental management across CPEC. [ABSTRACT FROM AUTHOR]

Luanchuan is rich in molybdenum resources, and mining activities are frequent, but over-mining can cause serious metal pollution to the local environment. To explore the degree of metal pollution caused by mining activities, the content characteristics and spatial distribution of metals in mining areas were studied by measuring the concentrations of Fe, Mn, Zn, Ba, Mo, Cu, Cr, Co, V, and W in surface water and mosses of mining areas. In addition, the metal pollution index (HPI), contamination factor (CF), and pollution load index (PLI) were used to evaluate metal pollution, and factor analysis was used to analyze the sources of metals. The results of the analysis of surface water at the mine site indicate the most abundant element in surface water, with a maximum concentration of 3713.8 μg/L, and its content far exceeds the water quality standard of Class III of the Environmental Quality Standard for Surface Water. The results of the HPI analysis showed that nearly 90% of the surface water was moderately contaminated (HPI ≥ 15). The results of the analysis of atmospheric deposition at the mine site confirm that the metal elements with a high threat to the atmospheric environment are Mo and W. The results of PLI indicate that the level of atmospheric deposition pollution in the study area is severe (PLI > 4). Factor analysis indicated that rock weathering and mining activities were the main sources of metals. This study provides a theoretical basis for the investigation and control of metal pollution in similar metal mining areas. [ABSTRACT FROM AUTHOR]

The detection of heavy metals in water, especially Pb2+ ions, is important due to their severe hazardous effects. To address this issue, a highly controlled hexagonal TiON/TiO2 heterostructure has been synthesized in this study. The fabrication process involved the utilization of atomic layer deposition and direct current sputtering techniques to deposit TiO2 and TiON layers onto a porous Al2O3 membrane used as a template. The resulting heterostructure exhibits a well-ordered hollow tube structure with a diameter of 345 nm and a length of 1.2 µm. The electrochemical sensing of Pb2+ ions in water is carried out using a cyclic voltammetry technique under both light and dark conditions. The concentration range for the Pb2+ ions ranges from 10–5 to 10–1 M. The sensitivity values obtained for the sensor are 1.0 × 10–6 in dark conditions and 1.0 × 10–4 in light conditions. The remarkable enhancement in sensitivity under light illumination can be attributed to the increased activity and electron transfer facilitated by the presence of light. The sensor demonstrates excellent reproducibility, highlighting its reliability and consistency. These findings suggest that the proposed sensor holds great promise for the detection of Pb2+ ions in water, thereby facilitating environmental monitoring, water quality assessment, and safety regulation across various industries. Furthermore, the eco-friendly and straightforward preparation techniques employed in its fabrication provide a significant advantage for practical and scalable implementation. [ABSTRACT FROM AUTHOR]

Heavy metals accumulated in the sediment constitute a potential source of pollution having a higher pollutant load than the overlying seawater. In order to determine anthropogenic impacts on the heavy metal enrichment and contamination in surface sediments, either reference/background values of the metals in the pristine condition or reference metal values of the earth's crust are widely used. In this study, the metal pollution indices Enrichment Factor, Geoaccumulation Index, Contamination Factor and Pollution Load Index were used to determine the levels and sources of metal pollution (Chromium, Manganese, Iron, Nickel, Copper, Zinc, Cadmium and Lead) in the coastal surface sediments of the Mersin Bay. The study findings indicated that the coastal surface sediments of the Mersin Bay are highly enriched by Chromium, Nickel and Cadmium due to anthropogenic pressures and weathering and erosion of the rocks. [ABSTRACT FROM AUTHOR]

Heavy metal and pesticide pollution of freshwater ecosystems, i.e., rivers, raises significant concerns worldwide, where practical solutions to reduce the threats become urgent need. Heavy metals and pesticides are top of the list of environmental toxicants endangering nature; therefore, pesticides and heavy metals were measured at 10 stations along the Al-Zennar agricultural drain and the Nile River at Assiut city in Upper Egypt, to assess potential negative impact on the water/sediment's quality. The sediment of the streambed is a sink for pesticides and heavy metals, where both water and sediments have higher contamination factor (CF) for Cd, Pb, Cr, Cu, and Zn. In addition, the Nile water is highly contaminated by PCBs. The distance to the point source and hydrodynamics (flow rate and stream gradient) has major influences in pollutant concentrations as indicated by regression models. Dilution effect and rapid sedimentation may comment on the lower concentrations of the pollutants in the Nile comparatively to the drain and on the water comparatively to the sediments. The physiochemistry of the stations has minor effect on the metal/pesticide concentration, where the variable importance of projection (VIP) of the partial least square model indicated that total dissolved solids (TDS), total suspended solids (TSS), SO42−, and BOD/TOC/COD are the main contributors to the metal/pesticide concentration. Concentrations were not correlated between water and sediment suggesting a historical accumulation in sediments and temporal variation in the pollution load in the Al-Zennar drain. Bray–Curtis clustering confirmed that heavy metals have the same anthropogenic source in contrast to natural source of both Mn and Fe. [ABSTRACT FROM AUTHOR]

The primary natural resource we use in our daily lives for a variety of activities is freshwater for drinking and various developmental goals. Furthermore, the pace of human population increase worldwide is rising rapidly and has a great impact on the Earth's natural resources. Natural water quality has diminished owing to various anthropogenic activities. Water is crucial to the life cycle. On the other hand, chemical and agricultural industries pollute heavy metals. Acute and chronic diseases caused by heavy metals, such as slow metabolism and damage to the gills and epithelial layer of fish species, are divided into two categories. Pollutants can also harm liver tissues and result in ulceration as well as diseases such as fin rot, tail rot, and gill disease. The most prevalent heavy metals are As, Cr, Pb, and Hg, which are systemic toxicants that affect human health. These metals are categorized as carcinogens by the US Environmental Protection Agency and the worldwide agency for cancer research because they cause organ damage even at low exposure levels. The focus of the current study is to review various freshwater sources of heavy metal pollution. [ABSTRACT FROM AUTHOR]

Zipingpu Reservoir, located in the upper reaches of the Minjiang River Basin in the middle section of Longmen Mountain in western Sichuan, is a large-scale water control project mainly for irrigation and water supply, with comprehensive benefits such as power generation, flood control, environmental protection, tourism and so on. The area of the reservoir area is 18.16 square kilometers. In May 2021, the group has carried on the detailed survey sampling in the scope, including five parts, the surface water sediment sample 6, 3 pieces of rock samples, respectively, the water of heavy metal measurement and analysis of characteristics of phytoplankton community structure, sediment measurement of heavy metals, petrophysical parameters and microscopic thin section identification, etc. Through the qualitative and quantitative analysis of the geological structure, hydrogeological conditions, it is considered that the reservoir area has the conditions for the occurrence of structural earthquakes; And the lateral percolation of the water body in the reservoir area is not strong. The environmental quality of surface water in the reservoir area is good, which is much lower than the standard limits of surface water resources class I and centralized drinking water; the content of heavy metals in surface sediments is generally between the limit of grade I and grade II of soil environment (alkalinity); the element accumulation index of the sampling site is between −4.30–0.37, indicating that there is no pollution; In which the individual samples of Cu, Cd, Cr and Pb elements 0 < Igeo < 1, and the accumulation indexes of Fe, Mn, Ni and Zn are all less than zero; the dominance index of phytoplankton in the sampling area varies from 0.00 to 0.14, with more dominant species; the range of phytoplankton density at sampling sites is 4585.9 −321019.1 cells/L, and the Shannon-Wiener diversity index is between 3.6874–4.1508, indicating that the water quality in the sampling area is relatively good, showing micro-pollution or non-pollution. It will be a hot topic to apply the methods of structural geology, environmental geology, ecological geology and so on to water environmental quality assessment. [ABSTRACT FROM AUTHOR]

The aim of the work was to establish the effect of anthropogenic activities and seasonality on physico-chemical parameters and heavy metal levels of River Yala (RY) within RY Basin of Lake Victoria (LV), as well as the associated ecological risks. Analyses were done on the collected samples in order to establish the levels of EC, pH, DO, temperature, conductivity, turbidity, acidity, alkalinity, BOD, COD, DOC, TOC and heavy metals (Cu, Fe, Pb, Mn, Zn, Cr and Cd) in RY water and sediments adjacent to Agricultural Farms during dry and wet seasons. The levels in terms of μg/mL, μS/cm (EC), NTU (turbidity) of analyzed parameters in the Agricultural Farms in water ranged from 0.01±0.00 to 121.75±15.23 (Upstream pristine sources of RY - S), 0.02±0.01 to 184.83±23.43 (Nandi Tea Estate and Kaimosi Agricultural Farms - N), 0.02±0.01 to 149.67±22.77 (Subsistence Farms - Sub), 0.02±0.01 to 209.33±18.09 (Lake Agro Limited Agricutural Farms and Yala Swamp – D) and 0.01±0.00 to 164.25±30.33 (Terminal of RY - T). The levels in μg/g of analyzed parameters in sediments ranged from 7.2±1.46 to 3342.8±538.7 (S), 9.12±0.2 to 4063.2±90.4 (N), 3.15±1.14 to 5998.5±588.4 (Sub), 2.03±0.76 to 4519.8±194.9 (D) and 2.13±0.75 to 5514.4±201.4 (T). The significant differences in the levels of analyzed parameters in water between dry and wet seasons were computed as; EC (+20.54 μS/cm), alkalinity (-2.85 μg/mL), DOC (+0.24 μg/mL), Fe (+0.58 μg/mL), Pb (+0.11 μg/mL), Zn (+0.07 μg/mL) and Cd (+0.01 μg/mL) while that for Mn in sediment samples was +163.8937 μg/g. The significantly (p ≤ 0.05) positive values indicated that wet season had more impact on the levels than dry season. There was positive correlation of zinc in water and sediments during dry and wet season. Chromium correlated positively in water and sediments during wet season. Copper and cadmium correlated negatively during dry and wet season while Mn only wet season. Results of geostatistical indices (CF, Cd, mCd, PLI, Er and RI) indicated that sediments located at regions N, D and T were highly contaminated with the heavy metals. However, a wetland at the mouth of Lake Victoria cleaned the water before it drained into the lake. Therefore, despite contamination of RY through anthropogenic activities, wetland mitigation protects LV from pollution by the river, indicating the important ecological and restorative functions played by wetlands. [ABSTRACT FROM AUTHOR]

Environmental pollution arises from the myriad of chemicals in current and historic applications. In Nigeria, the fate of pollutants among other factors relies on water runoffs with pollution implications on the flooded environment. In addition, there is a need for applications of pesticides against disease vectors in a flood-prone environment, therefore increasing pollution complications in the environment. Literature information is missing regarding the levels and public health risk implications of contaminants such as heavy metals and organochlorine pesticide (OCP) residues in groundwater and residential soils within the selected flood-prone residential locations in Lagos, Nigeria. This study was hence targeted at examining the levels and health risks of heavy metals and OCP residues in residential soils and groundwater sources of the targeted environment. Seven heavy metals comprising Cd, Zn, Fe, Pb, Cu, Ni, and Co were detected in the water samples with high concentrations of iron (mean = 22,000 mg/kg) and Zn (mean = 810 mg/kg). Only Fe (mean = 5.8 µg/L) and Zn (mean = 2.6 µg/L) were detected in the groundwater samples. Fifteen OCP residues were observed in the soil samples within the concentration range of 7.9 to 13 (mean = 11) mg/kg while seven OCP residues were reported in the groundwater samples within the concentration range of 0.19 to 0.35 (mean = 0.24) mg/kg. There was a concern about high contamination of dieldrin and heptachlor epoxide in the groundwater sources with concentrations exceeding the WHO (2017) drinking water guideline. A significant Pearson correlation (< 0.05) was obtained for endrin and endosulfan I in water and soil samples indicating potential contamination of groundwater from soil sources. The diagnostic ratio indicated possible applications of endosulfan and some other OCP residues. Overall, our data indicated low health risk implications for all the targeted contaminants. We recommend continuous investigation of newly listed priority chemicals such as dicofol and more public engagement on the implication of environmental pollution and health impacts of regulated chemicals. [ABSTRACT FROM AUTHOR]

Industrial effluents have caused water bodies to suffer from accumulation of heavy metals such as cadmium (Cd), lead (Pb), and mercury (Hg). This study focuses on determination of the potential use of mycofiltration in the removal of heavy metals, the effect of contact time, and the efficiency of mushroom species in mycofiltration from an artificial wet pond. In search of effective biosorbents, mycofilters were developed by adding spawns of P. ostreatus and A. bisporus, which were left for incubation and then installed in synthetic ponds for a certain period. Thereafter, mushrooms were harvested, post treated and their biosorption rate was analyzed through atomic absorption spectrophotometer. Significant differences were evaluated in the biosorption rate of mycofilters of P. ostreatus and A. bisporus. A dependent relationship was also established between biosorption and the temperature, namely, an increase in biosorption with an increase in temperature. The comparison of all results for the two species revealed that P. ostreatus showed superiority in the biosorption capacity for Pb 9–189 mg g–1 and Cd 1–21.4 mg g–1 over A. bisporus. However, A. bisporus has shown significant results in the case of Hg 0.6–10 mg g–1 absorption. Overall, in this study, P. ostreatus demonstrated the highest range in biosorption efficiency for metals Pb 99–100% and Cd 97–100% as compared to A. bisporus. At the same time, A. bisporus showed a slightly higher level of removal efficiency in the case of Hg 85–100%. Considering these findings, industrialists may use this cheap and ecofriendly treatment technology for the uptake of heavy metals. [ABSTRACT FROM AUTHOR]

Industrial effluents reaching to the aquatic ecosystem is one of the major causes of environmental pollution and exposure to industrial effluents containing harmful substances may be a serious threat to human health. Therefore, the present study aimed to determine the sub-lethal (1/5th of predetermined LC50) impact of industrial effluents from Sundar Industrial Estate on Oreochromis niloticus with proper negative control. The physicochemical analysis of industrial effluents showed enormous loads of inorganic pollutants and exhibited high mean levels of heavy metals, Mn, Fe, Pb, Ni, Cr, Hg, As, Zn and Fe with statistically significant differences at p < 0.05. Highest level of Mn and Fe was detected in effluent's samples as 147.36 ± 80.91 mg/L and 90.52 ± 32.08 mg/L, respectively. Exposure led to increase in serum biochemical parameters alanine aminotransferase + 25%, aspartate aminotransferase + 20% and alkaline phosphatase + 7% over control although superoxide dismutase, catalase, glutathione peroxidase and reduced glutathione significantly increased as 3.42, 2.44, 4.8 and 8 folds, respectively in metabolically active tissue brain which indicated stress caused by industrial effluents. The results concluded that industrial effluent has potent oxidative stress inducers on one hand whereas histoarchitectural and physiological toxicity causing contaminants on the other. This condition may adversely affect the health of aquatic organisms, the fish and ultimately the human beings. [ABSTRACT FROM AUTHOR]

Carbamazepine is a widely used antiepileptic drug to control and treat a variety of disorders that is frequently detected in surface water, and in municipal and urban wastewater. This recalcitrant pollutant could be removed by alternative advanced oxidation technology such as heterogeneous photocatalysis. Ce-modified ZnO and Pd-modified TiO2 were synthesized by a microwave-assisted sol–gel method. According to the characterizations (Raman spectroscopy, UV–Vis diffuse reflectance spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy), a mixture of oxides was determined in both materials: CeO2/ZnO and PdO/TiO2. Photocatalytic degradation of carbamazepine in pure water under visible light (3 h) was assayed. The degradation percentage obtained with each catalyst was 80%, 53%, 20%, and 9% for ZnO, Ce-modified ZnO, TiO2, and Pd-modified TiO2, respectively. The leaching of Zn as a possible source of water contamination was tested, finding the lowest value for Ce-modified ZnO by adjusting the initial pH up to neutrality. Later, an environmentally relevant concentration of carbamazepine (228 µg L−1) was assayed, using local surface water (pH = 8.3). Despite the presence of other compounds in the real water matrix, after 5 h of photocatalysis, a 56% of degradation of the pharmaceutical and low leaching of Zn were achieved. The use of Ce-modified ZnO activated by visible light is a promising strategy for the abatement of pharmaceutical active compounds. [ABSTRACT FROM AUTHOR]

Contamination of water with heavy metals as lead (Pb2+) is a relevant problematic issue. In this work, we have tested different types of dendritic materials for lead removal from water and further recovery. The systems employed are magnetic nanoparticles (MNP) modified with monocarboxylate and dendritic carboxylate ligands, and they are compared to pristine MNP and carbosilane dendrimers. They are all effective at removing Pb2+, but the key variations are in their recyclability. The usage of a filtering membrane was required for dendrimers, which was significantly degraded by the acidic media. In terms of MNP, those that were covered by dendritic molecules were clearly less damaged in acidic media. Finally, isotherm analysis revealed that Pb2+ interacts differently with unmodified and modified MNP. [ABSTRACT FROM AUTHOR]

We have carried out studies to examine the possibility of using biosorbents: the epigeic mosses Pleurozium schreberi (Willd. ex Brid.) Mitt., and the epiphytic lichens Hypogymnia physodes (L.) Nyl. in active biomonitoring of heavy metal pollution of surface waters. The dried sea algae Palmaria palmata (L.) Weber & Mohr were used as the third biosorbent. The studies were conducted in the waters of the Turawa Reservoir, a dam reservoir with a significant level of eutrophication in south-western Poland. Incremental concentrations of Mn, Ni, Zn, Cu, Cd, and Pb were determined in the exposed samples. It was shown that a 2-h exposure period increases the concentration of some metals in the exposed samples, even by as much as several hundred percent. High increments of nickel concentrations in the algae Palmaria palmata (mean: 0.0040 mg/g, with the initial concentration of c0 < 0.0016 in the algae) were noted, with negligible increments in concentrations of this metal in mosses and lichens. In contrast, mosses and lichens accumulated relatively high amounts of Cd (mean: 0.0033 mg/g, c0 = 0.00043 mg/g) and Pb (mean: 0.0243 mg/g, c0 = 0.0103 mg/g), respectively. [ABSTRACT FROM AUTHOR]

The deltaic areas of the Mahanadi River basin are densely populated and are prone to contamination due to sewage, industrial waste, and agricultural runoff. The present study offered a systematic approach to evaluate the degree of heavy metal pollution in sediment and its impact on human health. The granulometric study revealed a relatively violent energy condition in the study region. Statistical parameters such as cluster dendrogram analysis and principal component analysis revealed a mixed source at Kujang and the dominance of a mafic source at Subala. The mean concentration of Co (47.25 ppm) and Pb (44.70 ppm) at Kujang and Co (37.03 ppm) and Pb (61.27 ppm) at Subala exceeded the global average value. The geo-accumulation index suggested Co and Pb contamination (each varying from 1 to 2) in the study region. The enrichment factor (EF) showed a moderate to significant enrichment of Co (EF = 8.5) at Kujang and a moderate enrichment of Co (EF = 2.2), Pb (EF = 3.6) and Zn (EF = 2.3) at Subala, indicating anthropogenic pollution, possibly from agriculture land due to heavy use of pesticides in the investigated region. The exposure pathway for both non-carcinogenic and carcinogenic risk was via oral ingestion. The human health risk suggested no significant non-carcinogenic risk for adults and children in the study region. However, the carcinogenic risk in children due to Cr posed a mild threat. Therefore, each day's intake of these chronic metals must be examined as their collective effect could result in various health complications for children and adults. [ABSTRACT FROM AUTHOR]

Today, water pollution has become one of the serious environmental issues need of global concern. The excessive intake of toxic heavy metals causes very harmful effects on living organisms. So, researchers across the world are unceasingly searching to find promising technologies for the treatment of wastewater and the removal of heavy metals. Adsorption is recognized as the most suitable and affordable method for the treatment of wastewater with high competence. Owing to their exclusive structural characteristics and attractive physicochemical properties, nowadays graphene-based materials have attained considerable attention as effective adsorbents. So, developing promising graphene complexes via the surface modification using various functional groups, nanoparticles, or polymers is a consistent challenge. Synthesis of a large number of complex derivatives of graphene is progressively reported, but the removal of contaminants and mechanisms of adsorption are still difficult to be completely elucidated. In this article, synthesis methods of graphene and various graphene-based composites, their adsorption mechanism, and all the significant studies regarding the adsorption of toxic heavy metals such as mercury, lead, cadmium, chromium, and arsenic using graphene and its subsidiaries under different experimental conditions have been reviewed and the relevant results have been produced. An outlook on future research requirements and challenges involved while developing excellent adsorbents using graphene and its derivatives are emphasized. Therefore, it can be ensured that the contaminated water in the environment should be noticed with the minimum heavy metal content so that the effects of heavy metals on the ecosystem can be reduced. [ABSTRACT FROM AUTHOR]

Uncontrolled artisanal and semi-mechanized mining activities generate growing pressure on water resources. This work investigated the water quality status and the metal contamination of the Lom River water in the vicinity of gold mining area of Bekao, Adamawa region of Cameroon using water quality index (WQI) and five pollutions indices, supported by multivariate statistical analyses (MSA) that include factor analysis (FA), hierarchical cluster analysis (HCA), and Pearson's correlation analysis. For this purpose, a total of thirty-two (32) water samples were systematically collected in four campaigns during the rainy and dry seasons in order to determine physicochemical parameters, major ions, and trace elements and heavy metals (Cu, Cr, Cd, Pb, Ni, As, Fe, and Hg). The results obtained were compared with (2017) WHO standards. The results indicated that the water samples were acidic to neutral (4.54–7.12), very turbid (583.00–130.99 NTU), and weakly mineralized (27.40–36.12 μS/cm) with high levels of suspended solids (42.21–532.68 mg/L). The predominant water facies was CaMg-HCO3, with no dominant cation and high proportions of bicarbonate. The elements concentration decreased in the following order: Fe ˃ As ˃ Pb ˃ Cu ˃ Cr ˃ Ni ˃ Hg ˃ Cd whereas the mean concentration of Pb, Ni, As, Fe, and Hg exceeded the maximum allowable limits defined by the World Health Organization (WHO) guidelines. The WQI values demonstrated that about 56.25% of samples were unfitted for domestic purposes. The heavy pollution index (HPI), the heavy metal evaluation index (HMEI), and the contamination index (CI) suggested a high level of heavy metal pollution, resulting mainly from gold mining washing and panning processes. Strong correlations (R ≥ 0.70) were observed between PO43−-Cu (R = 0.70), PO43−-Cd (R = 0.73), Ca2+-PO43− (R = 0.72), Ca2+-Cu (R = 0.76), Mg2+-Cu (R = 0.73), Mg2+-Ca2+ (R = 0.78), Cu-Pb (R = 0.73), and Cu-As (R = 0.73). The MSA also allowed to identify anthropogenic activities as the major source of the Lom River water pollution: (i) most of major ions were originated from crops activities and domestic sewage of temporal dwellings of artisans and also from agricultural, and (ii) heavy metals were released mainly from gold mining exploitation activities, especially from washing, panning, and refining steps. [ABSTRACT FROM AUTHOR]

The intense pollution due to increased anthropogenic load on the water catchment areas is a problem of small rivers. Changes in the hydrochemical regime of small rivers have an impact on large rivers as well, since the former feed the latter with transfer of pollutants from the land. Agricultural and communal water pollution of small rivers can be the cause of degradation of the river system. Therefore, systematic monitoring and comprehensive evaluation of the water quality of small rivers against the background of climatic changes and low water is an urgent problem for the water management of Ukraine. This study is aimed at assessing the ecological state of the Umanka River (the left tributary of the Yatran' River) in a certain period of time, which makes it possible to follow changes in water quality under the influence of anthropogenic factors and natural and climatic conditions of low water. Based on the results of analytical measurements of water samples of the Umanka River bed, the following block indices of water quality are calculated: index I1 of contamination by the components of the saline composition (the sum of the Cl– and ions); ecological and sanitary index I2 ( , , , PO, and pH); and index I3 of specific indicators of toxic action (Fetot, Cd, Pb, Cu, and Zn). According to hydrochemical parameters, the Umanka River water—which is a potential source of drinking water supply—is contaminated with nitrogen compounds , , and , and with Cd and Pb, and has a high level of permanganate oxidation exceeding the fourth class level of surface water quality. A comprehensive ecological assessment of the river water with values ranging from 3.51 to 4.36 along the stream is carried out, and the water quality is characterized as transitioning from "good" and "fairly pure" to "satisfactory" and "slightly polluted" with a tendency to approach "mediocre" and "moderately polluted", while the Umanka River water in 2004 was classified as "good" and "fairly pure". [ABSTRACT FROM AUTHOR]

The anthropogenic impact of metals on aquatic environments is a risk for biota, and thus their levels must be controlled. Callitriche cophocarpa Sendtn. belongs to a genus with a potential for accumulation of elevated metal levels. Thus, it may provide consolidated evidence of contamination. Therefore, the aim of this investigation was to determine Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in this species collected together with water and bottom sediments from rivers with various levels of pollution. Of these rivers, one less polluted and one more polluted was selected for the collection of C. cophocarpa for an experiment to compare its Cu and Zn concentration potential. Both metals were supplemented at concentrations 0.01, 0.02, 0.03, 0.05, 0.08 and 0.14 mg L−1 of Cu as CuSO4 × 5H2O and 0.4, 0.6, 0,9, 1,35, 2.03 and 3.04 mg L−1 of Zn as ZnSO4 × 7H2O, and in the binary design containing (mg·L−1) 0.01Cu + 0.4Zn, 0.02Cu + 0.6Zn, 0.03Cu + 0.9Zn, 0.05Cu + 1.4Zn, 0.08Cu + 2.03 Zn and 0.14Cu + 3.04Zn. The upper concentrations of Cr, Cu, Mn and Zn in C. cophocarpa shoots from both types of rivers as well as of Ni and Pb in shoots from more polluted rivers were higher than the values typical for toxicity thresholds with no visible harmful effects, which may indicate accumulation abilities of C. cophocarpa for these metals. Both roots and shoots of C. cophocarpa may be included in the group of macroconcentrators for bottom sediments with respect to Cd, Co, Cr, Cu, Fe, Mn, Ni and Zn and deconcentrators of Pb. Greater accumulation of most metals in roots than in shoots indicates their restricted mobility and translocation by C. cophocarpa to shoots. C. cophocarpa from the less polluted river and exposed to all experimental solutions contained significantly higher levels of Cu and Zn than that from the more polluted river exposed to identical experimental solutions. The plants collected from the more polluted river influenced by surplus of metals and living under chemical stress could probably limit further accumulation by developing a resistance mechanism. Cu and Zn contents in C. cophocarpa were higher when treated with separate metals than for binary treatment both in the more and less polluted river. Such research presenting the impact of a combination of metals could be important for understanding and explaining the interactions of these elements which may influence their bioavailability in nature as well as importance in the evaluation of the risk of environmental toxicity. [ABSTRACT FROM AUTHOR]

In this study, the occurrence and distribution of 49 antibiotic resistance genes (ARGs) and two integrase genes (intl1, intl2) in three major rivers of Hainan Island, China, were investigated in July 2021, and to explore the spatial distribution of the target genes in the three rivers with the potential influencing factors such as regional characteristics and environmental factors. The results showed that a total of 46 ARGs and two integrase genes were detected in water and sediment, and the absolute abundance of ARGs ranged from 1.16 × 103 to 2.97 × 107 copies/L and 3.34 × 103–1.55 × 107 copies/g. ARGs of macrolides, aminoglycosides, and sulfonamides were this study's main types of ARGs. The aadA2, tetE, ermF, tetX, aac(6′)-Ib, tetW, and qnrS genes are predominant ARGs in the water and sediment of the three rivers. The relative abundance of ARGs shows higher abundance in the midstream and downstream and lower abundance in the upstream and estuarine. After conducting a correlation analysis, it was found that there was a significant positive correlation between the ARGs detected in the water of the three main rivers. However, in sediment, tetC was negatively correlated with tetQ, macB was negatively correlated with ermF and ereA (p < 0.05), while the remaining ARGs showed positive correlations. Specifically, there was no significant positive correlation between tetQ and tetC, macB and ereA, and ermF in the sediments. Among the nine environmental factors studied, pH was found to be the main factor associated with the occurrence of ARGs in the aquatic environment, but it was also significantly associated with only nine ARGs. Among the detected heavy metals, only Cd and Zn showed significant correlations with the two ARGs in the water bodies of the three main rivers. It indicated that the pollution of ARGs in the three major rivers was in the initial stage, the detection abundance was low, the influence of environmental factors was small, and the interaction between ARGs seemed to be the main driving force. This study provides a scientific basis for further understanding the occurrence of ARGs and their influencing factors in a tropical island environment, and lays a foundation for subsequent management. [ABSTRACT FROM AUTHOR]

Contamination of heavy metals and antibiotics would threaten the water and soil resources. Phytoremediation can be potentially used to remediate metal and antibiotics contaminated sites. The current study was carried out over a period of 12 months to assess the efficiency of the macrophytes Typha domingensis and Cyperus papyrus with different substrate materials to remove heavy metals and two antibiotics, roxithromycin and levofloxacin, from wastewater for reuse in agriculture. The concentrations of seven heavy metals (copper, nickel, iron, cadmium, zinc, lead, and chromium) in water and plant tissues were determined. The results showed that C. papyrus had a greater capacity than T. domingensis to remove biochemical oxygen demand (BOD) (80.69%), chemical oxygen demand (COD) (69.87%), and ammonium (NH4+) (69.69%). Cyperus papyrus was more effective in retaining solid pollutants. The bioaccumulation factors (BCF) roots of C. papyrus were higher levels of most metals than those of T. domingensis. The highest root–rhizome translocation factor (TF) values of C. papyrus were higher than T. domingensis. The bacterial indicators (total and fecal coliforms, as well as Faecal streptococci) and the potential pathogens (Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa) showed removal efficiencies ranging between 96.9% and 99.8%. The results indicated that the two systems could significantly reduce the concentration of antibiotics in wastewater, with roxithromycin showing higher elimination rates than levofloxacin. The results showed maximum removal of the heavy metals in constructed wetlands CWs planted with T. domingensis. The presence of zeolite and C. papyrus in the effluent of CWs significantly improved treatment capacity and increased pollutant removal efficiency. [ABSTRACT FROM AUTHOR]

The present study was carried out, first, to evaluate the quality of urban wastewater. For this purpose, sampling campaigns of wastewater were carried out at the domestic (R1), industrial (R2), and hospital (R3) levels. The results showed that the metallic trace elements recorded at the three sites comply with the national standards. The quantitative distribution of the metallic trace elements contents follows the same order at sites R1 and R3: Fe > Pb > Zn > Ni > Cd > Cr > Cu, while at site R2 it is as follow: Fe > Zn > Pb > Cd > Ni > Cr > Cu. Statistical analyses using principal component analysis have allowed to reduce the database size by collecting as much information as possible about its trends. Second, this study focuses on the evaluation of the quality of sediments of Oued Defali and their degree of contamination by four heavy metals (Cr, Cu, Pb and Zn). Sediment samples were taken at four stations (S1–S4). The results show low levels of Cr, Cu and Zn and highlight the presence of contamination by Pb. The analysis of the contamination factor, the pollutant load index and the geoaccumulation index revealed unpolluted sediments in terms of Cr, Cu and Zn, as well as moderate pollution by Pb. [ABSTRACT FROM AUTHOR]

Heavy metal contamination in surface water is widespread throughout the world as a result of numerous anthropogenic activities and geo-genic mechanisms. This contamination is also affecting aquatic life, as fish have the potential to acquire heavy metals in their tissues making them vulnerable. Worldwide lakes are an important source of water for the inhabitants of the area. So, in the present study, we have focused on the Satpara Lake to check the extent of heavy metal pollution and their accumulation in fish to provide baseline data for metal pollution management. Samples were collected from three locations (inflow, center, and outflow sites) during two seasons (summer and winter). Inductively coupled plasma optical emission spectrometry (ICP-OES) was applied to analyze heavy metals concentration. Among the metals, Cd, Pb, As, and Fe revealed relatively higher concentrations. The highest concentration of heavy metal found in water and fish was of Cd, i.e., 8.87 mg L−1 and 18.19 mg L−1 in summer season, respectively. Arsenic concentration was also higher than the permissible limits in both water (0.76) and fish (1.17 mg L−1). The water quality assessment showed that in the summer season, the HPI (heavy metal pollution index) value 253.01 was more than 100, indicating the bad quality of water for drinking purposes. However, the HPI value 35.72 was less than 100 in winter. Toxicity hazard calculation of fish in summer seasons gives Hi values greater than 10.0, indicating the acute effect on human health as compared to winter. [ABSTRACT FROM AUTHOR]

The Niger River, Bamako's population's primary drinking water source, is threatened by human activities. This study examines the Niger River pollution trend using heavy metals pollution indexes and Bamako's population's non-carcinogenic and carcinogenic related health risks. Parameters were monitored at fifteen sampling locations in low and high flow seasons. pH (7.30–7.50) and fluoride (0.15–0.26 mg/L) were within the normal drinking water range. Among seven heavy metals (copper, zinc, cadmium, nickel, iron, manganese, and lead), the latter three were above the drinking water standard. The degree of contamination was negative, pointing to better water quality. However, the heavy metal evaluation index (HEI) was below the mean (5.88), between the mean and twice the mean, indicating a low and medium degree of pollution. Besides, heavy metal pollution indexes (HPI) were above the standard value (100), explaining a low-medium pollution level. High values of HPI could be explained by the industrial units' intensive activities coupled with the runoff effect. The hazard index (HI) indicated a low and medium non-carcinogenic health risk for adults and children. The probability of cancer risk (PCR) of nickel showed a cancer risk. Therefore, the river was polluted with trace elements and could not be used for drinking water without any treatment. [ABSTRACT FROM AUTHOR]

Nanyi Lake is a tributary in the lower reaches of the Yangtze River and the largest freshwater lake in southern Anhui. Anthropogenic activities have significantly affected the lake with the rapid development of the surrounding economy in recent years. This study collected a total of 39 × 2 water samples of surface water and overlying water, detected the heavy metal concentrations (As, Cr, Cu, Mn, Ni, Pb, Sb, Zn, Fe, Cd), and analyzed the spectral characteristics of the dissolved organic matter (DOM). The results demonstrated that the concentrations of heavy metals (As, Cr, Cu, Mn, Ni, Pb, Sb, Zn, Fe, Cd) in the surface water were 1.00–7.78, 0.40–5.59, 0.20–4.52, 20.00–269.50, 0.40–5.56, 0.20–5.06, 1.00–7.64, 20.00–252.50, 60.00–590.00, and 0.04–0.60, respectively (unit: μg L−1). The risk assessment showed that the carcinogenic risks of heavy metals (As, Cr, Cd) through drinking water were ranged from 10−7 to 10−4a−1 in Nanyi Lake, and Cr was the main carcinogen which should be the focus of environmental health risk management. The average personal non-carcinogenic risks of heavy metals (Cu, Mn, Ni, Pb, Sb, Zn, Fe) were ranged from 10−9 to 10−13a−1, and considered to be acceptable risk level. The contour map of spatial distribution demonstrated different degrees of heavy metals (except Zn) enrichment near the Langchuan River in the East Lake District. Parallel factor analysis showed that the main components of DOM in Nanyi Lake were tryptophan like, fulvic acid like, and tyrosine like, and the dissolved organic matter was primarily derived from autogenous endogenous sources. The heavy metals Cr, Ni, Pb, Fe, Cd, and HIX in the surface water of West Lake were significantly positively correlated, among which Ni, Fe and C2 were significantly negatively correlated (P < 0.05), Mn and BIX demonstrated extremely significant positive correlations (P < 0.01), while no significant correlation was observed between heavy metals and the DOM indexes in the surface water of the East Lake. The principal component and correlation analysis showed that the heavy metals in Nanyi Lake were primarily derived from the production wastewater discharged by the surrounding industrial and mining enterprises through the rivers input, followed by the non-point source runoff input of the surrounding agricultural production and lake aquaculture. [ABSTRACT FROM AUTHOR]

Groundwater is the only freshwater source for agriculture and domestic use in the Khulais region of Saudi Arabia (SA). Anthropogenic activities, particularly agricultural runoff and lithogenic sources cause groundwater contamination, posing health risks to all generations (infant, child, and adult) via ingestion, dermal, and inhalation exposure routes. The configuration of non-carcinogenic and carcinogenic health concerns posed by contaminated water is, thus, a time-sensitive requirement. This study uses multivariate statistical techniques to assess health risks and to identify health impacts and pollution sources. Sampling of groundwater at nineteen sampling sites was carried out in two seasons (winter and summer) of 2021. The samples were analyzed for major ions and toxic metals. Results show that the average hazard quotient (HQ) and health hazard index (HHI) in infants was higher than 1 for most of toxic metal in both the seasons. The health risks associated with ingestion were significantly higher than those associated with the dermal and inhalation pathways. The aquifer's carcinogenic risk ranged from high to extremely high in terms of chromium (Cr), nickel (Ni), and lead (Pb) concentrations. The estimated health risk values may have a negative impact on people's health, which suggests that active aquifer management should be implemented. Multivariate statistical analyses were accomplished to determine the primary contamination sources in the aquifer system. The total dissolved solid (TDS) correlated strongly among chloride (Cl−), sulphate (SO42−), sodium (Na+), potassium (K+), magnesium (Mg2+), calcium (Ca2+), iron (Fe), strontium (Sr), fluoride (F−) and bromide (Br−), which caused by seawater intrusion within winter and summer seasons. The hierarchical cluster analysis (HCA) identifies two clusters and one independent case within the summer and winter seasons. One-way analysis of variance (ANOVA) showed significant variations in the concentrations of Mg2+, Aluminum (Al), Cobalt (Co), Cr, Ni, and Pb in winter, while TDS, electrical conductivity (EC), Cl−, SO42−, Na+, Mg2+, Ca2+, Sr, F− and Br− in summer. This research demonstrates that aquifer cleanup and management protocols should be implemented, encouraged, and maintained. Applying the best hygienic practices and pre-clean-up of polluted groundwater is recommended before application for different purposes. [ABSTRACT FROM AUTHOR]

Water is polluted via various means; among these, heavy metal (HM) contamination is of great concern because of the involvement of metal toxicity and its effect on aquatic environment. The significance and novelty of this study is that it focuses on assessment of HMs in the surface water of Indian rivers only from 1991 to 2021. For this, multivariate studies were used to find multiple sources of HMs. The average concentrations of Fe, Cr, Pb, Ni, Cd, Mn, Hg, Co, and As in surface water of rivers were found to far exceed the permitted limits established by both World Health Organisation and Bureau of Indian Standards. The HM indices like HM pollution, degree of contamination, evaluation index, water pollution, and toxicity load data all indicated that the rivers under investigation are heavily polluted by HMs. In this study, health risk assessment indicated non-carcinogenic effects of Fe, Cr, Cu, Pb, Cd, Mn, Hg, Co, and As in children and those of Fe, Cr, Pb, Cd, Hg, Co, and As in adults. Values investigated for Cancer index were higher for Cr, Pb, Ni, Cd, and As indicating a high risk of cancer development in adults and children via the ingestion pathway than the cutaneous pathway. Moreover, children are more prone to be exposed to both non-carcinogenic and carcinogenic effects of HMs than adults. To reduce human dangers, remediation approaches, such as environment-friendly, cost-effective adsorbents, phytoremediation and bio-remediation, as well as tools like bio-sensors, should be included in river management plans. [ABSTRACT FROM AUTHOR]

Heavy metal contamination has severe detrimental impacts on the entire river ecosystem's quality and causes potential risks to human health. An integrated approach comprising deterministic and probabilistic (Monte Carlo simulation) models with sensitivity analysis was adopted to determine heavy metals' chronic daily intake (CDI) and their associated health risks from the riverine ecosystem. Both carcinogenic and non-carcinogenic risks of water and sediment were estimated through multi-exposure pathways. The analytical results indicated that the concentration patterns of heavy metals in sediment (Fe > Mn > Sr > Zn > Cr > Cu > Cd) were slightly different and higher than in water (Fe > Zn > Cr > Sr > Mn > Cu > Cd). The potential carcinogenic risks of Cr and Cd in sediment (5.06E-02, 5.98E-04) were significantly (p < 0.05) higher than in water (9.08E-04, 8.97E-05). Moreover, 95th percentile values of total cancer risk (TCR) for sediment (1.80E-02, 3.37E-02) were about 22 and 143 times higher than those of water (8.10E-04, 2.36E-04) for adults and children, respectively. The analysis of non-carcinogenic risk revealed a significantly higher overall hazard index (OHI) for both sediment (adults: 1.26E+02, children: 1.11E+03) and water (adults: 3.26E+00, children: 9.85E+00) than the USEPA guidelines (OHI ≤ 1). The sensitivity analysis identified that the concentration of heavy metals was the most influencing input factor in health risk assessment. Based on the reasonable maximum exposure estimate (RME), the study will be advantageous for researchers, scientists, policymakers, and regulatory authorities to predict and manage human health risks. [ABSTRACT FROM AUTHOR]

The occurrence of heavy metals including chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb) was investigated in paired samples of hair and nails collected from 121 volunteers in 16 cities, China. Results showed that the mean concentrations of Zn, Cu, As, Pb, Cr, Ni and Cd were 205, 18.0, 7.79, 6.18, 3.54, 2.02, 0.533 μg g−1 in hair and 103, 8.09, 0.760, 7.27, 6.07, 8.81, 0.485 μg g−1 in nails, respectively. The concentrations of Zn, Ni, Cr, Cd and Pb were positively correlated in paired samples of hair and nails, whereas a negative correlation was found for Cu and As between hair and nails. Higher concentrations of heavy metals were found in northern China than southern China. The multivariate analysis of variance revealed that dwelling environment was the dominant factor influencing the levels of Cd in hair (p < 0.05), while age was the dominant factor influencing the levels of Cr in nails (p < 0.05). Moreover, industrial pollution and smoking were also the important factors leading to the accumulation of heavy metals in human body. Principal component analysis (PCA) showed that industrial pollution and decoration material immersion were the main factors for the high concentrations of Cr and Ni in hair, accounting for 62.9% of the total variation; As in hair was dominantly related to groundwater pollution. The concentrations of heavy metals were within the recommended ranges in nails from this study. However, the mean levels of Cr, Ni and As in hair exceeded their recommended reference values, indicating potential health risks from heavy metals for residents in China. [ABSTRACT FROM AUTHOR]

Exponential industrialization and anthropogenic activities have resulted in water contamination by various heavy metals in Kanpur city, India. Heavy metal pollution, an issue of great concern, is not only affecting river water, but contamination of groundwater is creating health issues and worries. In the present investigation, blood samples were collected from selected volunteers, water and sediment samples from four sites of river Ganga and drinking groundwater samples from 23 locations of Kanpur city. Heavy metals analysis in river water, sediment, and human blood, was done by inductively coupled plasma optical emission spectroscopy (ICP-OES) and atomic absorption spectroscopy (AAS) was used for groundwater samples. Human blood showed a high concentration of arsenic (As) (66.6 ± 0.00 and 76.9 ± 0.01 μg L−1 in males and female subjects, respectively) and thallium (Tl) (13.4 ± 0.004 and 16.6 ± 0.005 μg L−1 in males and female subjects, respectively) with higher concentrations in females than males. Other heavy metals (Nickle, Beryllium, Cadmium, Cobalt, Chromium, Lithium, Molybdenum, Lead) were not observed in any of the tested human blood samples. However, in groundwater sampling, iron (Fe), copper (Cu), and arsenic (As) were detected, one sample had the presence of chromium (Cr), and two samples showed lead (Pb) contamination. River water [Cu (32–125 μg L−1), Cr (19–725 μg L−1), Cd (1–59 μg L−1), Pb (37–163 μg L−1), As (32–153 μg L−1), Th (26.75 μg L−1)] showed a high level of the heavy metals, as compared to reference values of BIS, CPCB (2016a), WHO, EPA and USEPA. River sediment [Cu (4168–34,470 μg Kg−1), Cr (4040–145,650 μg Kg−1), Cd (326–5340 μg Kg−1), Pb (1840–19,350 μg Kg−1), As (103–188 μg Kg−1)] also showed high concentration when compared to reference values of USEPA and PASS. River site 4, with high Cr (725 μg L−1), also showed Cr levels (19.8 μg L−1) in the groundwater samples, indicating Cr contamination in groundwater while Pb was observed at groundwater samples close to two industrial sites. Drinking water might be the primary exposure pathway for As and Tl to enter the human body. The study recommends periodic monitoring of river water, sediment, groundwater, and human blood samples for contamination of heavy metals. [ABSTRACT FROM AUTHOR]

Chemoecological studies were carried out in the water areas of the Kagau and Longtau rivers in the Can Gio Biosphere Reserve (Vietnam). Mass-spectrometry analysis was used to determine the concentrations of 15 microelements (heavy metals and metalloids) in water and bottom sediments. The overall pollution level in the Can Gio rivers was found to be moderate. However, the concentrations of some heavy metals in several cases exceeded the maximum permissible concentration at short-time exposure; also, the limits of safe concentrations at chronic exposure were exceeded for some elements. The concentrations of some heavy elements amount to 30 to 80% of the MPC for water bodies used for fishery. Primarily, these are copper, zinc, arsenic, vanadium, iron, and molybdenum. It was found that, according to the Regulations of Vietnam, the waters of the examined water areas showed concentrations of suspended matter in excess of the standards for category A1 sources, and the concentration of dissolved oxygen in water was below the standard. The obtained results suggest the need to monitor the chemical–ecological conditions of rivers in Can Gio as protected natural objects, which are also used to some extent for social and economic purposes. [ABSTRACT FROM AUTHOR]

The study employed an integrated application of electrical resistivity tomography (ERT), soil classifications, and physicochemical parameters of water samples to map the extent and dynamics of leachate migration from the municipal waste dump and its potential impact on groundwater in a crystalline basement complex area, Malete, Nigeria. The ERT model revealed leachate dispersion beneath poorly graded inorganic silt-sand topsoil to about 2 m, hoisting low resistive moisturized soil within the range 1.8 × 10 - 3 to 6.4 × 10 - 1 Ωm and underlain by an impervious thin silty-clay layer (about 0.5-m thick) and weathered basement downward. The imprint of induced near-surface leachate percolation is revealed with increased (but acceptable) turbidity, conductivity, DO, and BOD within the shallow wells but prevented by the impervious silt–clay liner from vertical migration to the deeper water source. The concentrations of As, Cd, Cr, Fe, Pb, Zn, and Cu in the water samples and the acceptable TDS and TSS parameters; with low nitrate, sulfate and phosphate concentration are within the recommended range approved by WHO permissible limit for potable water and could have no adverse effects on the public's health. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the contamination level of Abzana water in Asano district. Five water samples were collected from different point of Abzana water. Some physicochemical parameters and four heavy metals (Cd, Pb, Cr and Mn) concentration were analyzed using standard procedures, and the results were compared with World Health Organization guideline values. The results of the present study have shown the temperatures of all sampling station range between 18.9 and 19.2 °C. The pH was found to be of range from 6.54 to 7.11, whereas the electrical conductance was 1.745 × 102 to 2.06 × 102 (µS/cm). In addition, the lowest value of total dissolved solids was 1.314 × 102 mg/L and the highest was 1.401 × 102 mg/L. In contrast, four heavy metals were analyzed and compared with standards of drinking water. The results indicate that the mean concentration of Cd (6.64 × 10−3 mg/L) exceeded the standards, but the mean concentration of Mn, Pb and Cr was founds within the standard limit at 7.608 × 10–2, 8.10 × 10–3 and 3.5442 × 10–2 mg/L, respectively. The concentrations of the investigated metal (Cr, Pb and Mn) and all physicochemical result of Abzana water from Asano kebele were found below the guidelines for drinking water. However, the concentration of Cd in Abzana water sample was found above the permissible limit of World Health Organization standards. Therefore, it was not safe for drinking and health effect according metals what we have studied here. [ABSTRACT FROM AUTHOR]

The article presents the results of research on the leachability of selected heavy metals (cadmium, nickel, chromium, cobalt, lead, and copper) from solid waste obtained in laboratory processes involved in the industrial treatment of wastewater generated in metal surface treatment plants. The test sludges were precipitated using sodium hydroxide solution, calcium hydroxide suspension, 45% solution sodium trithiocarbonate (Na2CS3), 15% solution trimercapto-s-triazine, sodium salt (TMT), and 40% solution sodium dimethyldithiocarbamate (DMDTC). The precipitates were treated with artificial acid rain and artificial salt water. After 1, 7, 14, and 21 days of leaching, the concentration of Cd, Co, Cr, Cu, Pb, and Ni in the leachate was determined. Artificial acid rain leached Ni and Cd to a maximum concentration of 724 mg/L and 1821 mg/L, respectively, from the sludge obtained after the application of Na2CS3, while artificial salt water leached Ni in the maximum amount of 466 mg/L and Cd—max. 1320 mg/L. When Ca(OH)2/NaOH was used, the leaching of Cr reached a similar level for both leaching agents, i.e., the maximum for artificial acid rain was 72.2 mg/L and the maximum for artificial salt water 71.8 mg/L. The use of Na2CS3 or Ca(OH)2/NaOH poses a risk of some heavy metals entering the environment, which may have a negative impact on living organisms, whereas the sludges obtained with the use of DMDTC and TMT as precipitants were the most stable under the experimental conditions and did not pose a potential environmental hazard. [ABSTRACT FROM AUTHOR]

Surface and groundwater are the most common sources of water in Nigeria's rural communities, which are used for a variety of purposes ranging from farming to industrial processes and other domestic household activities including drinking. Water that contains heavy metals in excess of the maximum permitted levels poses a risk to human health. This study aims to evaluate the levels of heavy metals in surface and groundwater in Ifite Ogwari, a rural community in Anambra State, Southeast Nigeria, as well as their ecological indices and human health risks assessment. The concentration levels of Ni, Cr, Cd, Pb, Zn, Fe, Mn, and Cu were determined in fifteen water samples from the major water sources in the study area, viz., streams, river, and hand-dug wells. The water samples were collected using precleaned 500 cm3 glass bottles and were analyzed using Atomic Absorption Spectroscopy (AAS) technique. The results showed that four metals (Cr, Cu, Mn, and Pb) out of the eight heavy metals were not detected in all the samples. The concentration levels of total Ni had a range of 0.029–0.11 mg/L with highest concentration occurring at Isiachala stream, Onowulugbe well, and Omambala river (0.11 mg/L). The Cd levels in the water samples had a range of 0.001–0.036 mg/L, with Isiachala and Iyiutu having the highest values (0.036 mg/L). The concentration of Fe ranged from 0.01 to 0.047 mg/L. Mn was detected at a concentration level of 0.003 mg/L in Iyiutu stream only. The Pearson correlation deduced a strong correlation (> 0.75) and a medium correlation (0.50–0.75) for sample locations and analytes, while three factors (principal component analysis) were produced, which indicates the influence of anthropogenic release rather than natural release. Ecological indices showed the impact of multi-elemental matrices on the ecology, while health risk assessments showed that there was no adverse cancer risk or non-cancer risk across respondents (adults and children). The obtained results showed that anthropogenic release has an extensive mobility influence on the natural level of metals in surface and ground water in Ifite Ogwari, and so proper treatment is advocated. This study has shown that the water sources from Ifite Ogwari pose no adverse health risk to the residents. Consequently, additional research on Ifite Ogwari water is needed to characterize "forever chemicals," per- and polyfluoroalkyl substances (PFAS) which are ubiquitous, cancerous and have been linked to reproductive and immune system harm, and suggest routes for remediation. [ABSTRACT FROM AUTHOR]

Zinc (Zn) was identified as one of the most toxic heavy metals and often found contaminating the water sources as a result of inefficient treatment of industrial effluent. A green emulsion liquid membrane (GELM) was proposed in this study as a method to minimize the concentration of Zn ions in an aqueous solution. Instead of the common petroleum-based diluent, the emulsion is reformulated with untreated waste cooking oil (WCO) collected from the food industry as a sustainable and cheaper diluent. It also includes Bis(2-ethylhexyl) phosphate (D2EHPA) as a carrier, Span 80 as a surfactant, sulfuric acid (H2SO4) as an internal phase, and ZnSO4 solution as an external phase. Such formulation requires a thorough understanding of the oil characteristics as well as the interaction of the components in the membrane phase. The compatibility of WCO and D2EHPA, as well as the external phase pH, was confirmed via a liquid–liquid extraction (LLE) method. To obtain the best operating conditions for Zn extraction using GELM, the extraction time and speed, carrier, surfactant and internal phase concentrations, and W/O ratio were varied. 95.17% of Zn ions were removed under the following conditions; 0.001 M of H2SO4 in external phase, 700 rpm extraction speed for 10 min, 8 wt% of carrier and 4 wt% of surfactant concentrations, 1:4 of W/O ratio, and 1 M of internal phase concentration. [ABSTRACT FROM AUTHOR]