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Human welfare and biodiversity are at risk due to the deterioration of water and sediment quality. Particularly, in last few decades, global water and sediment quality degraded due to the rapid industrialization and urbanization. This study aimed to determine the concentration of nine heavy metals and metalloid (Pb, Cr, Cd, Hg, As, Mn, Ni, Cu, and Zn) and assess the ecological risks using different pollution indices (e.g., heavy metal pollution index [HPI], Nemerow pollution index [NI], geo‐accumulation index [Igeo], contamination factor [CF], degree of contamination [CD] and pollution load index [PLI], ecological risk index [ERI]) in water and sediment of the Shitalakshya River, an industrially affected urban river of Bangladesh. For the first time, 20 water and sediment samples were collected across a wider geographical area of the Shitalakshya River during both monsoon and dry seasons and analyzed using the atomic absorption spectrometer. Average concentrations of heavy metals and metalloid in water were within the Bangladesh standard except for Cr (51.69 ppb) and Mn (228.20 ppb) during monsoon season, portraying potential ecological and human health risks. Besides, average concentration of Mn (549.75 and 370.93 ppb), Ni (549.75 and 370.93 ppb), and Cu (45.34 and 36.09 ppb) in sediment during both seasons were above international standard, implying risk to aquatic sediment biota. The average HPI values indicated moderate to high contamination, whereas the NI values implied polluted water in monsoon season with severe pollution in port area of the river. Similarly, Igeo, CF, CD, and PLI elucidated different levels of contamination in the sediment, particularly during dry season. The ERI values also referred moderate ecological risk in the sediment during dry season. Overall, our findings highlight the alarming level of heavy metal pollution in the Shitalakshya River, necessitating immediate action to protect the aquatic environment, sediment biota, and human health. Practitioner points: This study determined the concentration of heavy metals and metalloid in water and sediment of the Shitalakshya River, Bangladesh.The study revealed that the average concentration of Cr and Mn in water exceeded national standard, whereas Mn, Ni, and Cu in sediment exceeded international limit.Potential ecological risk of heavy metals was also assessed using different pollution indices.Calculated pollution indices indicated different degree of pollution, implying critical ecological condition due to heavy metal pollution in aquatic environment and sediment biota. [ABSTRACT FROM AUTHOR]

The present study in the Peenya Industrial Area in Bengaluru, India, carried out to assess the level of heavy metal contamination in the industrial area's soil and groundwater. The study also discusses the potential health risks that inhabitants would suffer from consuming contaminated groundwater. In 116 bore well water samples collected before and throughout the monsoon season, heavy metals including cadmium, chromium, copper, zinc, arsenic, mercury, lead, nickel, and aluminium were examined. Heavy metals concentration (mg/kg) was analysed for 36 soil samples collected in the research area and for heavy metals like chromium, nickel, copper, zinc, arsenic and cadmium. In the current study, the heavy metal pollution index (HPI), hazard index (HQ(ing)) and cancer risk factor (CR) were calculated to assess the potential health risk. The HPI value inside the Peenya industrial area exceeded the critical pollution index value of 100. The hazard index (HQ(ing)) via oral ingestion was found to be > 1.00 in Cr, Hg and As during both seasons, indicating maximum health impacts in the inhabitants of the study area. Cancer index values were > 10-4 in Cr, Ni, Cd, and Pb in the research area, posing cancer risk in people of all ages, from children to adults. Environmental and human health are both put at risk in a polluted region. To assess soil contamination, the following indices were utilized: geoaccumulation (Igeo), single contamination index (PI), and pollution load index (PLI). [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]

Novel functionalized and/or grafted crosslinked chitosan adsorbents were synthesized and used to remove several toxic heavy metal ions such as nickel, lead, chromium, and cadmium ions from contaminated water. The chitosan biopolymer was functionalized by maleic anhydride (CS_MA) acting also as a crosslinking agent. Glutaraldehyde-crosslinked chitosan (CS_GA) grafted with poly(methyl methacrylate) (CS_MMA) was also synthesized. The synthesized adsorbents were characterized using a variety of analytical techniques such as SEM, TGA, and FTIR, which confirmed their chemical structures and morphology. The adsorption capacity of the adsorbents was analyzed under various conditions of contact time, adsorbent dose, initial concertation, temperature, and pH and evaluated against those of pure chitosan (CS) and the crosslinked chitosan(CS_GA). The ultimate removal conditions were 0.5 g/100 mL adsorbent dose, an initial metal ion concentration of 50 ppm, a temperature of 45 °C, and pH 9. CS_MMA had the highest removal percentages for all metal ions, ranging from 92% to 94%. The adsorption was demonstrated to fit a pseudo-first-order model that followed a Langmuir adsorption isotherm. The results highlight the capacity of the synthesized polymers to efficiently remove major toxic contaminants at low cost from contaminated water, present especially in low-income areas, without harming the environment. [ABSTRACT FROM AUTHOR]

In view of water and soil getting polluted by Pb(II), Zn(II), and other heavy metals in tailings and acid mine drainage (AMD), we explored the removal effect of sulfate-reducing bacteria (SRB) on Pb(II), Zn(II), and other pollutants in solution and tailings based on the microbial treatment technology. We used the scanning electron microscope-energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), and X-ray fluorescence (XRF), to reveal the mechanism of SRB treatment of tailings. The results showed that SRB had a strong removal capacity for Zn(II) at 0-40 mg/L; however, Zn(II) at 60-100 mg/L inhibited the growth of SRB. Similarly, SRB exhibited a very strong ability to remove Pb(II) from the solution. At a Pb(II) concentration of 10-50 mg/L, its removal percentage by SRB was 100%. SRB treatment could effectively immobilize the pollutants leached from the tailings. With an increase in the amount of tailings added to each layer, the ability of SRB to treat the pollutants diminished. When 1cm of tailingssand was added to each layer, SRB had the best effect on tailing sand treatment. After treatment, the immobilization rates of SO2-4, Fe(III), Mn(II), Pb(II), Zn(II), Cu(II), and total Cr in the leachate of #1 tailing sand were 95.44%, 100%, 90.88%, 100%, 96.20%, 86.23%, and 93.34%, respectively. After the tailings were treated by SRB, although the tailings solidified into a cohesive mass from loose granular particles, their mechanical strength was <0.2 MPa. Desulfovibrio and Desulfohalotomaculum played the predominant roles in treating tailings by mixing SRB. The S2- and carbonate produced by mixing SRB during the treatment of tailings couldmetabolize sulfate by combining with the heavymetal ions released by the tailings to form FeS, MnS, ZnS, CuS, PbS, Cr2S3, CaCO3, MnCO3, and other precipitated particles. These particles were attached to the surface of the tailings, reducing the environmental pollution of the tailings in the water and soil around the mining area. [ABSTRACT FROM AUTHOR]

The ecological integrity of several freshwater ecosystems has been disrupted by the rapid and unrestrained accumulation of toxic heavy metals (HMs) from various sources. Changes in land use and land cover, in the form of urbanization and industrialization, have significantly affected the surface-water quality of freshwater ecosystems by causing an upsurge in pollutant loads. In addition, agricultural runoff has contributed to the decrease in water quality. Almost 70% of India's surface-water resources have become polluted owing to the discharge of untreated sewage and industrial effluents, according to a recent report by the Central Water Commission (CWC) of India, with 42 rivers containing at least two HMs in concentrations above the permissible limit. The aquatic biota inhabiting contaminated sites can accumulate HMs from the surface water. In high concentrations, these HMs can damage biotic components, predominantly by triggering oxidative stress and becoming bioaccumulated in different trophic levels of freshwater ecosystems. Heavy metal contamination in the aquatic environment can also cause direct potential hazards to humans, mostly through their consumption of fish and waterfowl. Thus, it is recommended that the untreated wastewater discharge from industry, agricultural fields, and households be curtail to improve surface-water quality. In this systematic review, we investigated the probable sources of the HMs, the HM contamination in the important rivers and wetlands of India, the effects of HM toxicity on freshwater food chains, and potential remediation measures. The findings of the present study will improve our knowledge about the spectrum of HM toxicity and the effects of HM contamination on the biota in freshwater bodies throughout India, and will also aid policymakers in building strategic and sustainable freshwater management plans around the globe. [ABSTRACT FROM AUTHOR]

With increasing extreme weather events and urban development, drinking water source areas (DWSAs) face rising water quality pollution incidents. Timely and precise pollution incident early warning is critical. This study integrated the hydrodynamic model and water quality early warning model developed for the Three Gorges Reservoir Area (TGRA)'s DWSA, establishing a water pollution incident early warning system for the TGRA. Assuming a heavy metal zinc (Zn) pollution incident in the TGRA's Heshangshan drinking water source area (HDWSA), the study analyzed pollutant Spatio-temporal variations and the duration of early warning exceedance during different water periods. Results indicated varying durations for pollutant levels to return to background values across the four water periods: 123 min (dry), 115 min (falling), 106 min (storage), and 96 min (flood). Level I early-warning durations ranged from long to short: 68 min (dry), 63 min (falling), 57 min (storage), and 50 min (flood), respectively. The early warning system is scientifically reliable and supports decision-making for DWSA water pollution incidents. [ABSTRACT FROM AUTHOR]

At present, there is relatively little research on the synergistic effects of heavy metals in soil, sediment, and bedrock on heavy metal pollution in water bodies. In this paper, heavy metals in soil, sediment, bedrock, and water of a typical karst watershed in southwest China were investigated. The results indicated that the average values of heavy metals in soil and sediment were relatively higher than those in bedrock except for Ni and As. During the research period, As and Cd were the main heavy metal elements polluting the soil and sediment in the study area, while water bodies were mainly polluted by Ni, As, and Cd. The pollution assessment indicated that there were instances of poor or very poor water quality in the study area during the study period; the soil as a whole was slightly polluted by Cd and As; sediment was subject to moderate Cd pollution and mild As pollution. Analysis of geochemical form for heavy metals showed that heavy metals in soil and sediment were mainly in residual form, and the proportions of exchangeable As and Cd were relatively high. Multiple statistical analysis showed that heavy metals in sediment, soil, and bedrock explained 23.8%, 16. 8%, and 16. 2% of the changes in heavy metals of water, respectively. The research results Can provide scientific basis for the prevention and control of heavy metal pollution in water bodies. [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 contamination of water with heavy metals like arsenic, cadmium, nickel, zinc, lead, and cobalt presents a pressing and formidable challenge for numerous countries. The surge in industrial activities has exacerbated the pollution of freshwater sources, resulting in an alarming escalation of toxic metal concentrations in lakes, rivers, and underground water reservoirs. Consequently, millions of individuals in developing nations face significant health risks associated with heavy metal exposure. Compounding this issue is the limited accessibility to advanced water treatment methods, intensifying the gravity of the situation. Extensive research efforts have been dedicated to investigating low‐cost adsorbents derived from waste materials. It has been observed that the complete removal of heavy metals can be obtained using waste materials like eggshells, neem leaves, red mud, and black tea waste. The objective is to enhance the efficacy of heavy metal removal from water by employing modified waste materials as effective adsorbents. In this comprehensive review, concise and in‐depth information about the utilization of readily available waste materials is provided, including black tea waste, fruit peels, vegetable peels, sawdust, and other similar resources. This review emphasizes the kinetics and mechanisms involved in removing heavy metals. Additionally, the factors that impact the efficiency and extent of heavy metal removal in different waste materials have also been discussed. [ABSTRACT FROM AUTHOR]

This study was executed to investigate the acidification and heavy metal (Cr, Mn, Fe, Ni, Cu, Zn, and Pb) pollution of Tohma stream flowing near Kangal lignite-fired thermal power plant located in Kangal district of Sivas province in the Central Anatolia region of Turkey. All water samples were screened for pH to evaluate the acidification of the Tohma stream. Water samples were found in moderately alkaline according to pH values (8.1–8.7). The average concentrations of Cr, Mn, Fe, Ni, Cu, Zn and Pb in water samples from the Tohma stream were determined as 0.94, 2.27, 13.78, 1.24, 1.98, 0.32 and 0.54 mg L−1 using energy dispersive X-ray fluorescence spectroscopy, respectively. Metal pollution index (MPI) and metal evaluation index (MEI) were estimated to evaluate the pollution of Tohma water samples with heavy metals. The values of MPI and MEI varied from 312 (medium pollution) to 9715 (high pollution) with an average of 4713 (high pollution) and 181(medium pollution) to 317 (high pollution) with an average of 226 (medium pollution), respectively. The results of MPI and MEI revealed that investigated water samples are seriously polluted with toxic heavy metals and inadequate for drinking and irrigation water utilisation. [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]

The urban water environment is seriously affected by human activities. Rivers in highly industrialized areas, which often carry various types of industrial pollutants, such as metals and nutrients, are especially affected. In this study, the water quality of the Pi River, an industrial base that flows through Chengdu, a large city in Southwest China, was tested for one year. Heavy metal concentrations in the water, sediment, and macrobenthic and algal communities in the river were examined. The water pollution index (WPI) and trophic level index (TLI) were employed to measure the water pollution degree and eutrophication status, respectively. The Shannon—Wiener index (H') and Margalef's index (dM) were determined to represent the diversity and richness of macroinvertebrates. The principal component analysis (PCA) was employed to define the main heavy metal influencing factors in the Pi River. Our study showed that the eutrophication status increased with spatial change, and the eutrophication status was the most serious in the downstream reach, which was moderately eutrophic. The water body of the Pi River was seriously polluted by heavy metals, and the content of chromium (Cr) in the sediment and cadmium (Cd) in the water/sediment was far beyond the prescribed limit. In addition, we found that Cd had a serious impact on both the benthic and algal communities, and the benthic community structure was completely changed, destroying the original aquatic environment. We explored the mechanisms of the influence of Cd on aquatic fauna, and this information is of great significance for the future conservation of industrial urban rivers. In this study, the spatial–temporal variations in water quality and aquatic communities revealed the pollution status of a river flowing through industrial areas, which provided a basis for future river conservation and restoration. [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]

Water quality depends on its physicochemical and biological parameters. Changes in parameters such as pH, temperature, and essential and non-essential trace metals in water can render it unfit for human use. Moreover, the characteristics of the local environment, geological processes, geochemistry, and hydrological properties of water sources also affect water quality. Generally, groundwater is utilized for drinking purposes all over the globe. The surface is also utilized for human use and industrial purposes. There are several natural and anthropogenic activities responsible for the heavy metal contamination of water. Industrial sources, including coal washery, steel industry, food processing industry, plastic processing, metallic work, leather tanning, etc., are responsible for heavy metal contamination in water. Domestic and agricultural waste is also responsible for hazardous metallic contamination in water. Contaminated water with heavy metal ions like Cr (VI), Cd (II), Pb (II), As (V and III), Hg (II), Ni (II), and Cu (II) is responsible for several health issues in humans, like liver failure, kidney damage, gastric and skin cancer, mental disorders and harmful effects on the reproductive system. Hence, the evaluation of heavy metal contamination in water and its removal is needed. There are several physicochemical methods that are available for the removal of heavy metals from water, but these methods are expensive and generate large amounts of secondary pollutants. Biological methods are considered cost-effective and eco-friendly methods for the remediation of metallic contaminants from water. In this review, we focused on water contamination with toxic heavy metals and their toxicity and eco-friendly bioremediation approaches. [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]

Water contamination with heavy metals seriously affects water and sediment quality and may affect the aquatic biota. This study assessed the impact of heavy metals on the morphological characteristics of aquatic microorganisms in potentially contaminated water. Different physicochemical parameters and heavy metals contents were analyzed for toxicological assessment along with microbial diversity in the rivers Swat and Kabul. The pH of River Swat water was neutral to slightly alkaline, while River Kabul was neutral to slightly acidic. The results showed substantial variations in heavy metal concentration across different sampling points. In both River Swat and River Kabul water samples, Cu and Zn concentrations were below the permissible limits for surface and drinking water qualities while the rest of the heavy metals exceeded the permissible limit with Cd being the most abundant heavy metal. Similarly, in sediment samples all the heavy metals were below the permissible limits except for Cd that exceeded the Environment Canada (EC) limits in River Swat and EC and NOVA limits in River Kabul. The rest of the heavy metals concentrations were within the permissible limits, with few exceptions. The results showed that in River Swat, most of the contamination was of geogenic origin, while the main source of contamination in River Kabul was anthropogenic. Results of microbial analysis showed that River Swat has more diversity than River Kabul, which may be due to the low contamination profile of River Swat. It was further observed that high heavy metal concentrations negatively impact the morphological characteristics of microorganisms. The heavy metals concentration and microbial diversity were closely related to each other. [ABSTRACT FROM AUTHOR]

Amidst industrialization and urbanization, wetlands face pollution challenges. We investigated the seasonal distribution of five heavy metals (As, Cd, Cr, Pb, and Zn) in the surface water of Harike wetland. The surface water samples were collected from four different stations selected along Harike wetland. Our results indicate As, Cr, and Zn levels were within WHO standards, however, Cd in winter (7.07 µg/L), monsoon (4.45 µg/L), and post-monsoon seasons (3.13 µg/L) exceeded the limits. Pb surpassed the standards in winter (278 µg/L) and monsoon seasons (14.5 µg/L). In winter, Pb and Cd had higher levels, and the pollution level was classified as moderate. Cd, however, was categorized under light pollution status during the monsoon and post-monsoon seasons. The health risk assessment indicated that the hazard quotient (HQ) and hazard index (HI) values for both ingestion and dermal pathways were within the safety limits (HQ < 1 and HI < 1) for both population groups (adults and children). The multivariate statistical analysis reported the correlation and further indicated different sources of heavy metals from nearby industries, agriculture, and mining. This research highlights the importance of continued monitoring and emphasizes the potential for positive environmental changes, as exemplified by the influence of the COVID-19 pandemic. These findings hold global relevance and offer valuable input for the development of precise action plans aimed at elevating water quality standards on an international scale. [ABSTRACT FROM AUTHOR]

Heavy metal pollution in rivers and lakes arising due to rapid economic development has been extensively studied by various countries due to its direct impact on ecological health and human well-being. However, there is a lack of comprehensive and systematic reviews addressing the current research status of this subject. In this study, we conducted a visual metrological analysis of the literature from 2001 to 2021 using the Web of Science (WoS) and China National Knowledge Infrastructure (CNKI) citation databases. The results show that studies conducted in other countries initially outnumbered those in China; after 2010, China emerged as the foremost contributor. Furthermore, both the WoS and CNKI databases indicate active engagement of Chinese researchers through a significant proportion of published papers on metal research, with prominent contributions coming from institutions such as the Chinese Academy of Sciences (CAS) and University CAS. Nevertheless, Chinese research institutions still have relatively low total paper citation numbers and have yet to establish themselves as key players in international scientific research efforts. Additionally, core authors from different countries share substantial similarities in their research directions and focuses. Consistent research hotspots regarding heavy metals in rivers and lakes were identified across both databases, including heavy metal pollution, adsorption, human activities, water quality, and sediment. [ABSTRACT FROM AUTHOR]

Both engineered and non-engineered landfills are used for the disposal of solid waste. Although modern landfills are designed to reduce the negative effects of waste, the generation of leachate remains a problem for landfills due to the potential contamination of groundwater and surface water caused by seepage and diffusion of leachate through soil. Moreover, it is unfortunate that open dumpsites, which are unregulated and illegal landfills, are common in many developing countries. This study aims to assess the impact of leachate from a controlled dumpsite operation in a municipal solid waste landfill on surface water. The study analyzes the main physicochemical, chemical, and heavy metal parameters of surface water samples during the rainy and dry seasons to evaluate the extent of pollution caused by the controlled dumpsite. The surface water samples from various locations surrounding the controlled dumpsite were found to be polluted by leachate. The winter season showed higher pH, BOD5 and COD levels in the surface water compared to the rainy season through surface runoff in the surrounding areas. The ratios of BOD5 and COD in the surface water from four sites near the controlled dumpsite were in the range of 0.51 - 0.89, indicating the controlled dumpsite being in mature stages that can be in the acceptable toxin range; however, its BOD5/COD ratios tended to be more toxic as they decreased in summer and rainy season. The heavy metals with the highest average level in the surface water were Fe, followed by Cr, Cd, Ni, Mn, Zn, Pb, and As, respectively. In addition, every water source had Cr, Cd and Ni concentrations much higher than the WHO standards (exceeding 0.05 mg/L, 0.003 mg/L and 0.02 mg/L, respectively) at the average concentration of 2 mg/L, 0.56 mg/L and 0.48 mg/L, respectively. The results indicated that the leachate from the controlled dumpsite had a detrimental impact on surface water quality due to lack of engineered liners and adequate leachate collection systems. Consequently, there is movement of toxic leachate from leachate ponds with inadequate or no liner into groundwater and surface water. [ABSTRACT FROM AUTHOR]

Climate change has been an alarming global issue over the past twenty years. Iraq is internationally considered the fifth country in the world under the consequences of climate change due to human activities. Thus, the present study has focused on investigating Pollution by heavy metals in the water of marshlands as they are unique habitats and are recorded as natural heritage by UNESCO. The current study aimed to investigate concentration of heavy metals of Cd, Pb and Ni in water of the Dalmaj Marsh, located in AL-Diwaniyah City, in Iraq. This area is characterized as heavily polluted due to wastewater discharge and agricultural activities using fertilizers. Clean plastic containers that had previously been cleaned with distilled water and then with deionized water were used to collect samples. Water samples were gathered in situ from surface water. Digestion by HCL and HNO3, HF and HCIO4 acids have been used and finally, samples were centrifuged to extract heavy metals from collected samples. The results show that there has been a variation in heavy metals in the three studied sites. The mean values of concentrations in water were 1.96, 4.27, and 2.11μg/l for Cd, Pb and Ni, respectively. Pollutants such as pesticides, sewage discharge, irrigation and electronic waste are the main pollutants in the Pollution of freshwater bodies, including marshes. These findings provide crucial background data for further research to obtain better management and protection for Iraqi freshwaters. [ABSTRACT FROM AUTHOR]

In recent years, human impact on the Earth's ecological environment has become increasingly visible, with serious negative consequences. One of the most important pollutants are heavy metals which can easily bind to sediments. Due to their toxic behavior, persistence, lack of biodegradability and bioaccumulation, they are considered key river pollutants that need to be controlled. This study examined two rivers: the Liwiec and Muchawka rivers located in south-eastern Poland. The mouth of the Liwiec River is the Bug River, which is partly the border between Poland and Belarus. In turn, the mouth of the Muchawka River is the Liwiec River. The objectives of the study were the following: (1) To complete a qualitative analysis of heavy metals (Cd, Pb, Cu, Ni, Zn) in the waters and bottom sediments of the Liwiec and Muchawka rivers; (2) To assess the degree of heavy metal contamination; (3) To identify the sources of contamination. The analysis included samples of surface water and bottom sediments collected (16 water and 16 bottom sediment samples were taken from the Muchawka River and 32 water and 32 bottom sediment samples were taken from the Liwiec River) in June and September 2022. The variability of characteristics, such as temperature, precipitation and humidity, contributes to seasonal changes in the distribution characteristics and sources of heavy metals. The study showed that only a small part of the heavy metals entering rivers are present in the water depth in the dissolved state, and most of them enrich the sediment, resulting in much higher concentrations of heavy metals in the sediment than in the water column. The differences in the distribution of some elements in water and sediment are due to the fact that surface sediments retain long-term records. Therefore, sediment can be considered a potential source of heavy metals in the aquatic environment. In general, the content of heavy metals determined in bottom sediments was not high but indicative of anthropogenic human activity. There is a possibility of re-release of heavy metals from the sediment into the water when hydrodynamic conditions or environmental factors (pH, redox potential, etc.) change, which could lead to secondary water pollution. The data obtained will be of great importance to both researchers studying river systems and the population living in the area. [ABSTRACT FROM AUTHOR]

Water hyacinth (Eichhornia crassipes) is a potential accumulator of water pollutants in aquatic ecosystems, and its presence in water systems can affect water quality. This study used different field measurements and laboratory tests of lake water to determine the impact of water hyacinth phytoremediation capacity. A total of eight sampling stations were used for the two lakes: Lake Koka and Lake Ziway, Ethiopia. Sampling stations were selected from sites infested with water hyacinth (low, medium, and high) and non-water hyacinth aquatic plants during wet or rainy and dry or non-rainy seasons to compare the effects of plants on water quality in the two lakes. All the sampled stations had various human interventions. The water samples were tested for the selected physico-chemical properties, namely, phosphate, nitrate, pH, electrical conductivity (EC), the five-day biological oxygen demand (BOD5), water temperature, and heavy metals (Chromium (Cr), Lead (Pb), Cadmium (Cd), Zinc (Zn), and Copper (Cu)). These water quality variables were compared by means of ANOVA. Despite the chemical oxygen demand (COD) of Lake Ziway, this study found no significant (p > 0.05) variation in the concentrations of Cu, EC, pH and water temperature between wet and dry seasons in either lake. Variations in Zn concentration and other physico-chemical parameters (EC, BOD5, COD, nitrate, phosphate) between low, medium, and high levels of water hyacinth were significant in both lakes (p < 0.05). Water hyacinth has shown significant phytoremediation nature during wet and dry seasons. The lowest average heavy metal, phosphate, and nitrate concentrations; and significant pH and temperature variations were observed in Lakes Koka and Lake Ziway, among water hyacinth and other grass-infested sites. These findings suggest water hyacinth plant as a promising nature-based solution for removing undesirable chemicals from contaminated water bodies. [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 heavy metals (HMs) and metalloids such as Cr(VI), As(Ill), and Pb(II) in contaminated water are toxic even at trace levels and have caused devastating negative health impacts on human beings. Hence, the effective adsorption of these heavy metals from contaminated water is important to protect biodiversity, hydrosphere ecosystems, and human beings. In this study, a leachate modular tower (LMT) was developed for the singular purpose of adsorbing HMs. The LMT contained nano-slag as a liner, which was synthesized from slag. The nano-slag was blended in different proportions of 90:10; 80:20, 70:30, 60:40, and 50:50 to the combined mass of clay and nano-slag, to evaluate the most efficient ratio of the blends capable of adsorbing HMs and metalloids with 100% efficiency. A series of leachate tests were performed to evaluate the adsorption capacity of LMT with different embedded liners. Attenuation periods of 2, 5, 7, and 10 days with a temperature of 500 °C were also selected to improve the sorption rate and uptake of HMs. Subsequently, the effluents were subjected to inductive coupled plasma mass spectrometry (ICP-MS) tests to evaluate the concentrations and percentages of adsorbed HMs, which were calculated using a pseudo-first-order adsorption model. The results revealed that the removal of 98%As, 99%Cd, and 99.9% Pb was achieved with a 50%:50% ratio of soil and nano-slag as the liner at 10 days equilibrium period. Furthermore, 98%Zn, 95.45%Cu, 93.3%Fe, 97%Ni, and 89% Hg were achieved upon further investigation using the same dosage of soil and nano-slag and equilibrium conditions. The scanning electron microscopy (SEM) tests demonstrated that some traces of the absorbed HMs and metalloids were found on the liner surfaces, indicating significant changes in microstructure. The results indicated the sorption rate increased significantly due to the elevated temperature, aluminosilicate structure, and prolonged attenuation period, which are also associated with an elevated pH level and higher cation exchange capacity (CEC), of the liner. [ABSTRACT FROM AUTHOR]

Sectorial approach for monitoring heavy metal pollution in rivers has failed to report realistic pollution status and associated ecological and human health risks. The increasing spread of heavy metals from different sources and emerging risks to human and environmental health call for reexamining heavy metal pollution monitoring frameworks. Also, the sources, spread, and load of heavy metals in the environment have changed significantly over time, requiring consequent modification in the monitoring frameworks. Therefore, studies on heavy metal monitoring in rivers conducted in the last decade were evaluated for experimental designs, research frameworks, and data presentations. Most studies (∼99%) (i) lacked inclusiveness of all environmental compartments; (ii) focused on "one pollutant – one/two compartment" or sometimes "one pollutant – one compartment – one effect" approach; and (iii) remained "data‐rich but information poor." An ecological approach with integrative system thinking is proposed to develop a holistic approach for monitoring river pollution. It is visualized that heavy metal monitoring, risk analyses, and water management must incorporate tracking pollutants in different environmental compartments of a river (water, sediment, and floodplain/bank soil) and consider correlating it with riverbank land use. The systems‐based pollution monitoring and assessment studies will reveal the critical factors that drive heavy metals pollutant movement in ecosystems and associated potential risks to the environment, wildlife, and humans. Also, water quality and pollution indexing tools would help better communicate complex pollution data and associated risks among all stakeholders. Therefore, integrating systems approaches in scientific‐ and policy‐based tools would help sustainably manage the health of rivers, wildlife, and humans. [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]

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]

Pollution of industry-adjacent surface water bodies has become a major threat to the environment in Bangladesh. This study examined the health risks of concentrated heavy metals in Tongi, Shitalakkhya, and Dhaleshwari, which receive effluents from wastewater treatment plants. Samples were analyzed for heavy metals such as lead, cadmium, iron, magnesium, manganese, zinc, copper, chromium, and nickel. At all the locations, only Zn, Cu, and Ni did not exceed the Bangladesh standard for drinking water. The health risk was estimated using the hazard quotient (HQ) technique. There was a threat of health risks resulting from the exposure through ingestion, with Pb, Cd, Fe, Mg, and Cr being the main contributors. The orders of decreasing values of mean HQ were Mg . Pb . Fe . Cr . Cd, Mg . Fe . Pb . Cr . Cd, and Cr . Mg . Pb . Fe . Cd via oral intake for both adults and children at Tongi, Shitalakkhya, and Dhaleshwari, respectively. For dermal intake, the mean HQ for only chromium at Dhaleshwari exceeded the limit for both groups. The results emphasize the need for enhancement, proper operation, and maintenance of wastewater treatment facilities in order to meet the discharge quality standard. [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]

Urban rivers in Asian developing countries are becoming increasingly polluted due to industrialization and lacking treatment of wastewater. We investigated toxicity and likely sources of pollutants for the urban Shitalakshaya River, Bangladesh. Physiochemical variables and heavy metals were examined in water and sediment of an urban river section in Narayanganj City. The spatial distribution of quality indices and cluster groups indicates that the river's downstream urban-affected areas are the most contaminated. Water and sediment quality guidelines indicate that COD, TSS, Fe, Pb, Zn in water, and Pb, Co, Ni, Cu, Zn, and particularly Pb and Cu in sediment, pose a serious threat to the aquatic ecosystem and human health in the area. Correlation, principal component (PCA), and cluster analysis (CA) indicate that the sources of Mn and Cd are geogenic, COD, TSS, Pb, Zn, Cu anthropogenic, and Fe, Ni, Co both geogenic and anthropogenic. The main anthropogenic pollution sources of the study area are municipal and industrial wastewater, boat and car traffic, runoff from agricultural areas, and stormwater runoff. [ABSTRACT FROM AUTHOR]

Impacts of nine heavy metals (Cd, Cr, Cu, Ni, Pb, K, Fe, Mn, and Zn) contamination in irrigation water on the soil, shoots, and roots of barely were investigated. Due to freshwater shortages, the use of available and inexpensive urban wastewater with input from local industrial factories containing heavy metals in irrigation is still practiced in the Middle East including Palestine. Barely was grown in plastic pots filled with sandy soil irrigated with simulated treated wastewater during two growing seasons. The metal treatments investigated include one, three, nine, and 15 multiples of the average metal content of treated effluent. Results showed that (i) Barley showed similar growth responses but different metal uptake patterns, (ii) Cd, Fe, Pb, and Zn in roots and shoots of barley were higher than WHO permissible levels, (iii) all metals accumulated in the soil had lower content than WHO permissible levels, (iv) The average value of enrichment factor (EF) for most heavy metals used was around unity indicating poor enrichment to soil and translocation to roots and shoots, (v) The highest Translocation factor (TF = 57.8) and Bioconcentration Factor (BCF = 126.8) was observed for K indicating its role in enhancing barley's tolerance to drought and its effectiveness in using barley in phytoremediation, and (vi) Barley growth and development and soil quality parameters were significantly affected by repetitive and increased irrigation with wastewater containing heavy metals. [ABSTRACT FROM AUTHOR]

The concentrations of eleven heavy metals (Pb, Cd, Cr, Fe, Mn, Zn, Cu, Ni, Co, As, and Ag) were assessed in both groundwater and seawater collected from the ship-breaking industrial area of Bangladesh using an atomic absorption spectrometer. The investigation aimed to estimate the water quality and pollution level employing several indices, and its associated health risks for the first time in that area. This study found that Cd, Cr, Fe, Pb, Mn, and Ni were higher in both groundwater and seawater compared with WHO standards. Based on the WQI (water quality index) and EWQI (entropy water quality index) classifications, the quality of most of the groundwater is extremely poor or unsuitable for drinking purposes. Furthermore, the HPI (heavy metal pollution index), HEI (heavy metal evaluation index), and CD (degree of contamination) values of most groundwater and all seawater samples exhibit a higher degree of pollution. In addition, the results of NI (Nemerow pollution index) come to an end that both groundwater and seawater in the study area are mostly polluted by Fe, Mn, Pb, Cr, and Cd. Although the HI (hazard quotient index) values of almost all studied heavy metals in both cases of adults and children are within the safe limit, the HI value of Cr for an adult is near the threshold limit and the maximum HI value of Cr for children exceeds this limit. The carcinogenic risk reveals that Cr, Pb, As, and Cd produce detrimental effects on local people through the direct ingestion of groundwater. The pollution source is identified using principal component analysis and a Pearson correlation matrix as being primarily anthropogenic and attributed to intensive ship-breaking activities or other industries in the area. [ABSTRACT FROM AUTHOR]

To ensure the ecological security of the basin, data on the heavy metal content in the sediments of the Weihe River Basin were collected to analyze the spatial distribution characteristics of heavy metals based on descriptive statistics and geostatistics. The geoaccumulation index and potential ecological risk assessment were conducted, and the number of pollution sources and the contribution rate were determined by combining correlation analysis, principal component analysis, and APCS-MLR. The results showed that the mean values of As, Pb, Zn, Ni, Cr, Hg, Cu, and Cd were 15.42, 27.27, 88.05, 31.05, 75, 0.13, 29.47, and 1.05 mg·kg−1, respectively. Igeo is in the order of Cd > Hg > As > Cu > Pb > Zn > Cr > Ni. Cd had the highest potential ecological risk factor, followed by Hg with a critical risk proportion of 12.6%. The traceability analysis showed that the heavy metals come from mixed, industrial, and agricultural sources, among which Pb, Zn, Ni, Cr, and Cu are affected by soil-forming parent materials and industrial comprehensive sources, As is affected by agricultural sources, and Hg and Cd are affected by industrial sources. Industrial and living sources are the main sources of the heavy metals. The results of the study can provide a basis for formulating relevant pollution prevention and control measures in the Weihe River Basin. [ABSTRACT FROM AUTHOR]

Mariout Lake is one of the Northern Nile-Delta Lakes in Egypt that receives agricultural, industrial and domestic effluents through several drains. The present study aims to evaluate the levels of some heavy metals (HMs) in water and edible parts of Oreochromis niloticus in Mariout Lake, in addition to studying several pollution indices and potential human health risks. The levels of the studied HMs in water were in the order of Fe > Zn > Mn > Pb > Cu > Ni > Cd. However, results of the pollution index, that concerns the effect of individual metal, concluded that Cd and Pb in water had serious pollution effects for aquatic life, while Cu, Fe, Mn, Ni, and Zn had not any pollution effects at different locations in the lake. The indices of the composite effects of all HMs (Metal Index and Heavy Metal Pollution Index) indicated the high pollution of Mariout Lake water, which may cause adverse effects on fish and different aquatic organisms. On the other side, the bioaccumulation factors of HMs in edible parts of O. niloticus were in the order of Zn > Cd > Cu > Ni > Pb > Mn > Fe. Although the target hazard quotient for all metals was less than the non-hazardous limit (THQ < 1), the non-carcinogenic hazard index (HI = 1.24) was classified in the moderate hazard risk level (1 < HI < 10) indicating low potential adverse effects on the exposed population due to consumption of O. niloticus caught from Mariout Lake. [ABSTRACT FROM AUTHOR]

Mitotic chromosomal aberrations and DNA polymorphism (RAPD marker) were carried out on the Nile tilapia Oreochromis niloticus collected from five sites in Minia governorate, Egypt to test their applicability as biomonitors for heavy metal contaminants of water. The diploid chromosome number of O. niloticus population was 2 n = 44. Different types of chromosomal aberrations were recorded (e.g., deletion, ring, centromeric attenuation, end‐to‐end association, dicentric chromosome, stickiness chromosomes, endomitosis, fragments and chromatid gap). The chromosomal aberrations varied between O. niloticus population collected from five sites, and the most common type was ring (R) chromosomes. Samples obtained from Bahr Yousef and Irrigation drain exhibited the highest aberration frequency. The frequency of chromosomal aberration was positively correlated with the concentration of heavy metals where their concentration in the surface water of Irrigation drain and Bahr Yousef exceeded the limits defined by WHO as well as the concentration of Pb in muscles. The RAPD marker was also used to identify genetic variation among Nile tilapia samples collected from five different water sources. It created polymorphic and unique bands that can be used as genetic markers to track DNA variations. The dendrogram also revealed that exposure to heavy metal pollution causes gradual accumulation of variance, whereas areas subjected to environmental stress showed higher genetic variation and clustered together. [ABSTRACT FROM AUTHOR]

The current research aimed to monitor and assess the heavy metal contamination in the surface water of 53 sampling sites along the selected rivers using principal component analysis and cluster analysis. For this purpose, both physiochemical parameters such as the temperature (T), the potential of hydrogen (pH), total dissolved solids (TDS) and electroconductivity (EC), and heavy metals such as iron (Fe), chromium (Cr), nickel (Ni), cadmium (Cd), lead (Pb) and arsenic (As) are analyzed as potential water contaminants. The average values of pH, TDS, EC and T are found at 7.75, 70.89 mg/L, 139.11 µs/cm and 20.29 °C, respectively, and heavy metals including Cr, Ni, Cd, Pb, As and Fe are observed at 0.04, 0.04, 0.04, 0.03, 0.001 and 0.04 mg/L, respectively. Moreover, it is found that in both rivers hazardous metals, including Cr (100%), Cd (92.30%), Pb (100%), Ni (100%) and Fe (91%), exceed the permissible limits of the WHO. [ABSTRACT FROM AUTHOR]

Increases in population and the expansion of industrial and agricultural operations result in an increase in agricultural and industrial trash as well as residential waste that is dumped directly into rivers and streams. These pollutants typically pollute river or stream water. This study focuses on the effects of domestic, industrial, and agricultural waste water on the water quality of the five main valleys in the left part of Mosul City: Al-Rashediya, Al-Kharrazi, Al-Khosar, Al-Danffilli, and Al-Shoar. Forty-eight samples of the water from these valleys were measured in the field for their physical characteristics (pH, EC, TDS, and Tr). The chemical properties (Ca2+, Mg2+, Na+, K+, HCO₃ -, SO₄ 2-, Cl- and NO₃ -), the heavy elements (Fe, Cu, Pb, Co and Mn) and the organic maters, were analyzed. The results indicated that calcium and bicarbonate are more abundant than other cations and anions, respectively. This mainly indicates the impact of carbonate fragment contents and calcareous cementing materials in the soils that exposed to chemical weathering in the outcrops on water quality. Heavy element pollution factors {The heavy metal pollution index (HPI), Heavy metals rating index (HEL), Metal Index (MI), and Contamination Index (Cd)} generally indicated that the water in the study area is highly polluted and unsuitable for agricultural use. The amounts of pollutants in the rivers of Al-Shoar and Al-Danffilli valleys appear to be higher than those of the other valleys since these valleys are generally the most exposed to waste, especially industrial waste. [ABSTRACT FROM AUTHOR]

Sabore field is characterised by a high level of artisan activities that contributes to water pollution by heavy metals; these heavy metals when present in drinking water can be deleterious to human health. Consequently, in 2018 we investigated the seasonal variations of the water samples from the Sabore vicinity to determine its suitability for drinking. Six metals (Mn, Cu, Cd, Zn, Ni, Pb) were studied, the health risk assessment was investigated using Hazard Index (HI), Hazard Quotient (HQ) and Cancer Risk (CR). The results showed that water from this locality have HI values > 1, Pb and Cd were top contributors to non-carcinogenic risk while Ni and Cd caused concern for carcinogenic health risk making it unsuitable for consumption. The seasonal spread of the metals shows that Mn varied from 148 to 976 µg/L; Cu from 923 to 1676 µg/L; Cd from 1.167 to 22.5 µg/L; Zn from 63 to 118 µg/L, Ni from 37 to 95 µg/L and Pb from 128 to 185 µg/L in the rainy season. For the dry season, Mn shows a spread of 1442–1802 µg/L; 344–776 µg/L for Cu; 57–82 µg/L for Cd; 48–187 µg/L for Zn; 147–242 µg/L for Ni and 79–256 µg/L for Pb. The increased concentration of some metals during the dry seasons could be attributed to the increased human activities around the field, increased evaporation rate, absence of rainfall and runoff water. The heavy metal content of water from some of the sites exceeded the stipulated permissible limits and poses serious health risk to its consumers. [ABSTRACT FROM AUTHOR]

Industrial development has led to increased heavy metal pollution in bodies of water all over the world. Numerous methods are being developed with the aim of detecting and subsequently removing heavy metal ions from water with hopes of reversing pollution. Here, we present a novel and ecological switchable solvent-based liquid phase microextraction (SS-LPME) method that detects Fe (III) in water samples before they can be tested on flame atomic adsorption spectrometry. In this method, 2-(5-Bromo-2-pyridylazo)-5-(diethylamino) phenol was selected as a complexing agent and switchable polarity solvent was formulated with N, N-dimethyl-n-octylamine. Box–Behnken response surface design was used to investigate and optimise factors associated with the extraction recovery. When the optimal conditions were reached, a linear calibration curve was achieved at 0.05–400 µg L−1. The preconcentration factor was 200, the detection limit was 0.015 µg L−1 with the relative standard deviation (RSD) of 2.2% (at 30 µg L−1; n = 8). Water samples and wastewater reference material (SPSWW1) were used to test the applicability and success of the method. [ABSTRACT FROM AUTHOR]

This study assessed the spatiotemporal variability and pollution grades of heavy metals in water and sediments of Bahr El-Baqar drain, Eastern Nile Delta, Egypt, by integration of geochemical analysis, metal pollution indices, correlation, and multivariate statistical analyses. Twenty samples of water and sediments were collected during 2018 and analyzed for heavy metal concentrations using ICP-OES. Heavy metal contents in the water samples followed the order: Fe > Zn > Al > Pb > Mn > Cu > Ni. The drain sediments were highly contaminated with heavy metals that followed the order: Fe > Al > Mn > V > Zn > Cu > Cr > Ba > Ni > Pb > As. Spatiotemporally, most metals in the drain sediments showed a decreasing trend from upstream (south) to downstream sites (north). Results of principal component analysis (PCA) supported those from the Pearson correlation between investigated heavy metals. In water, Mn, Ni, Pb, Zn, Cu, and Fe showed highly significant correlations. In sediments, Ba, Ni, Zn, Fe, Al, Mn, and V showed strong positive correlations indicating that these metals were derived from similar anthropogenic sources. The calculated metal pollution indices: enrichment factor (EF), contamination factor (CF), pollution load index (PLI), degree of contamination (DC), and index of geo-accumulation (Igeo) indicated high loadings of heavy metals in the drain sediments. EFs revealed low, moderate to significant enrichment, whereas CFs showed low, moderate, and considerable contamination. PLI indicated low, baseline, and progressive contamination, while DC indicated low, moderate, and considerable degree of contamination. Igeo of all investigated metals (except for As; class 1) indicated extremely contaminated sediments (class 7). [ABSTRACT FROM AUTHOR]

This study assessed heavy metal contaminations of soils in cultivated fields (or farms) and water samples from rivers, boreholes, and dug-out wells in Nandom District in semi-arid northwestern Ghana. Other parameters of water from the three sources were also measured and then compared to the permissible limits in the literature. The results showed that soils in farms across the study communities significantly (P ≤ 0.05) had higher levels of chromium (Cr = 0.456 ± 0.132 mgkg−1), iron (Fe = 214.8 ± 1.52 mgkg−1), lead (Pb = 0.854 ± 0.03 mgkg−1), nickel (Ni = 2.813 ± 0.4 mgkg−1), and arsenic (As = 1.753 ± 0.42 mgkg−1) when compared to permissible limits set by World Health Organization (WHO) and Food and Agricultural Organization (FAO) for food crops. Water from the study sites significantly (P ≤ 0.0001) had lower levels of heavy metals than the permissible limits set by FAO for irrigation of growing crops. Thus, the water sources appear to be safe for irrigation in the study area. Nonetheless, these sources of water in Nandom District had significantly higher levels of total suspended solids, turbidity, and coliforms that were above the maximum limits indicated in the guidelines of WHO and the Government of Ghana for drinking water. Therefore, treatments of water for drinking are required to minimize any potential threats to public health. [ABSTRACT FROM AUTHOR]

Eutrophic waters experiencing cyanobacterial blooms often contain high levels of heavy metal pollutants, including cadmium (Cd) and zinc (Zn). The transfer mechanisms of Cd and Zn within the water-algae-fish system, however, remain poorly understood. This study investigates the accumulation and transfer of Cd and Zn in a simulated water-algae‑silver carp (Hypophthalmichthys molitrix) ecosystem during Microcystis aeruginosa (M. aeruginosa) blooms. Algae demonstrated significant bioaccumulation of Cd and Zn, with Zn proving more toxic to the algae than Cd. In silver carp, the accumulation of Cd and Zn was strengthened in the intestine, liver, and skin following ingestion of M. aeruginosa enriched with these metals. This resulted in a 31% increase in Cd enrichment in the intestine, liver, and a 72% increase in the skin, compared to systems without M. aeruginosa. Zn enrichment in the liver and skin increased by 53% and 61%, respectively. However, muscle accumulation of Cd and Zn showed only minor increases of 0.59 and 3.93 mg/kg. This study elucidated that algae exacerbated the bioaccumulation of Cd and Zn in silver carp through mechanisms such as digestion, absorption, and skin mucosal contact in ecosystems experiencing M. aeruginosa blooms. The accumulation and food chain amplification of heavy metals in eutrophic water bodies increase the ecological toxicity risk to aquatic organisms and local residents. Measures should be considered to simultaneously control both eutrophication and heavy metal pollution in water bodies, with overall results contributing to the scientific management of eutrophic waters containing heavy metals. [Display omitted] • Algae accumulated cadmium (Cd)and zinc (Zn) in water contaminated with heavy metals. • Cd/Zn enrichment in silver carp intestine/liver was stronger than that in muscle. • Zn accumulation in silver carp intestine mediated via algae was temporary. • Algae enhanced Cd/Zn bioenrichment in fish by digestion, metabolism and skin contact. • Simultaneous control of water eutrophication and heavy metal pollution was proposed. [ABSTRACT FROM AUTHOR]

The bottom sediment of reservoirs has many functions. Among them, matter sorption is a very important one, and results in many side-effects on the reservoir sediment forming the water–bottom sediment system. As a result, bottom sediment can also be an indicator of anthropogenic water pollution. There is only very little knowledge of this situation in the study area. The main objective was the analysis of heavy metal accumulation in bottom sediment, as well as their ability to migrate throughout the water–bottom sediment system and their spatial distribution in the Kapshagay Reservoir in Kazakhstan. Heavy metal concentrations, in the both water samples and the bottom sediment, were determined using the atomic absorption spectrophotometric method. Surfer software was used to visualize the processes of migration and accumulation. Another objective was the development of model maps of the spatial distribution of metals in the reservoir water area, which indicated significant anthropogenic loads. It is obvious that both the transboundary inflow of the Ili River and the inflow from small rivers in the territory of Kazakhstan are the reasons for the anthropogenic water and sediment load. The results of the spectrometric analysis verify the water pollution in the reservoir, revealing increased concentrations of zinc reaching up to 10.8 µg/L and lead up to 32.7 µg/L, transported by the transboundary runoff of the Ili River and by the small rivers on the left bank into the Kapshagay Reservoir. Sediment concentrations close to the central part and dam zone of the reservoir reached the following values: zinc up to 37.0 mg/kg and lead up to 8.8 mg/kg. The results of this study indicate a significant anthropogenic load of the ecological conditions of the Kapshagay Reservoir. This is discussed and compared with other relevant studies. [ABSTRACT FROM AUTHOR]

Water pollution in rivers is still a crucial problem for the countries that use river water as the primary water source. This study aimed to determine the water quality of the Musi river and the content of heavy metals in water, sediment and mussels as well as to predict the water quality of the Musi river in the next five years. The water samples were taken from 18 stations (sampling points) from upstream to downstream to be checked physically, chemically and biologically. Prediction of the river water quality was made using the QUAL2Kw software. The research results show that the Musi River water is categorized as lightly polluted with concentrations of TSS and DO that have passed the threshold. The heavy metals in river water, such as Pb and Cr have also passed the quality standard. The Fe, Mn, and Zn concentrations are pretty high in the sediment. In turn, in mussels, the metals measured were Fe, Cu, and Zn. The prediction results reveal that several values of the river quality parameters will pass the threshold value with the same pattern tendency from each station. [ABSTRACT FROM AUTHOR]

Baia Mare area represents one of the most important mining areas of Romania. Although the mining activities carried out here are currently inactive (since 2012), they generated residual pollution that negatively influences all the environmental factors. The aim of the study is to evaluation of the quality of surface water from the vicinity of the city of Baia Mare, Romania. The surface water samples, collected in two distinct years (2021 and 2022), were analyzed to determine the concentration of heavy metals (Cd, Cr, Cu, Ni, Zn, Pb, Fe, Mn, and As) in order to establish the degree of contamination and the water quality through heavy metal evaluation index (HEI), heavy metal pollution index (HPI), and water quality index (WQI). The pH and the content of cations (Ca, Mg, Na, K) and anions (HCO3−, SO42−, Cl−) were also determined for complex characterization. The results showed that the water in the area had a high degree of pollution with high concentrations of Cr: 0.165–1.57 mgL−1, Ni: 0.01–0.718 mgL−1, and Cu: 0.036–0.195 mgL−1. The pollution indices showed an average level of heavy metal pollution for the collected surface water samples. The quality index demonstrated that all surface water samples in the study area were unfit for irrigation and drinking due to poor and very poor water quality. [ABSTRACT FROM AUTHOR]

Heavy metals affect the suitability of aquatic environment for all purposes; hence, this study evaluated heavy metal contamination in Agodi Reservoir Oyo State, Nigeria. Atomic Absorption Spectrophotometry was used to determine heavy metal concentrations. Heavy Metal Pollution Index (HPI), Water Quality Index (WQI), Pollution Index (PI), Comprehensive Pollution Index (CPI), Contamination Index (CI), Single-Factor Pollution Index (SFPI), Heavy metal Evaluation Index (HEI), and Human Health Risk Assessments (HRA) were used to determine the extent of heavy metal pollution and their impact on the aquatic environment. The order of heavy metal concentrations in both wet and dry seasons was Fe > Mn > Zn > Cu > Cd > Ni > Cr > Pb > Co and Mn > Fe > Zn > Cu > Co > Ni > Cd > Cr > Pb, respectively. WQI for both wet (3182.6) and dry (3649.5) seasons classified the reservoir as "unsuitable for aquatic life." Also, the CPI rated the reservoir to be "severely polluted" in both dry (311.2) and wet (268.7) seasons. Similarly, HEI (951.3 and 2059.7) and Cd (942.3 and 2050.7) rated the reservoir as "highly polluted" in wet and dry seasons, respectively. The Hazard Quotient (HQ ingestion) was in the order of Mn > Cu > Cd > Zn > Fe > Co > Ni > Cr > Pb in the dry season while the order was Cu > Mn > Cd > Fe > Zn > Ni > Pb > Co > Cr in the wet season. The HQ ingestion revealed that Cr (0.00), Ni (0.33; 022), and Pb (0.00; 0.06) were the only metals with HQ values lesser than 1 (HQ < 1) while the values of HQ (dermal) were less 1 (HQ < 1) indicating that there was no health risk in association with the domestic use of the water. The pollution level of the reservoir means that urgent attention is needed from different agencies for the conservation, management, and sustainable development of the reservoir. [ABSTRACT FROM AUTHOR]

Air and water pollution are global environmental problems; thus, bioindicators have become important tools for monitoring various pollutants, including metals and metalloids. Parmotrema arnoldii (Du Rietz) Hale and Tillandsia usneoides L. were evaluated as indicators of heavy metals in the air and Platyhypnidium aquaticum A. Jaeger and Marchantia polymorpha L. as indicators of heavy metals and a metalloid in water. The concentrations of cadmium (Cd), lead (Pb), copper (Cu), manganese (Mn) and zinc (Zn) as air pollutants and aluminum (Al), cadmium (Cd), iron (Fe), manganese (Mn), lead (Pb), zinc (Zn) and arsenic (As) as water pollutants were analyzed within four different zones (control, northern, central and southern) in an Andean city of Ecuador. The level of metal concentrations in the air for P. arnoldii and T. usneoides had the following order of concentration: Zn > Mn > Pb > Cd > Cu. In the case of water, P. aquaticum pointed out a concentration of Al > Mn > Fe > Zn > As > Pb > Cd and proved to be more effective in detecting water pollution than the species M. polymorpha, which had a concentration of Al >Zn > Fe > Cd >As > Mn > Pb. P. aquaticum showed a higher capacity to accumulate heavy metals than M. polymorpha; therefore, it can be used as a model species for passive water quality monitoring. However, P. arnoldii and T. usneoides showed similar heavy metal accumulation related to air quality. The passive monitoring of air quality using bromeliads and lichens as well as bryophytes for water quality proved their effectiveness and applicability in tropical regions such as Ecuador. [ABSTRACT FROM AUTHOR]