Search

Navigation channels provide a vital link in the supply chain of inland transport. Excavation of sediment from the river bed and fluvial islands is necessary to make the large braided river navigable for transportation. Present research work investigates the feasibility of dredging operations in the mid-sand bars of the Brahmaputra River (Assam, India) for navigation purposes. Pernicious metal (Cu, Zn, Fe, Mn, Ni, Co, Cr, Pb, Cd) concentrations were assessed at 42 sampling locations, covering a reach length of approx. 600 km (reaches 1 and 2). Vertical samples were obtained from 0 cm, 50 cm, and 100 cm of the mid-sand bar. Various indices were evaluated to quantify the contamination level in the mid-sand bars. Based on the enrichment factor (EF), reach 2 was highly enriched with toxic metal-limiting dredging operation. Conversely, reach 1 was found suitable for dredging operations, owing to the low EF value. Various anthropogenic activities are likely to be the causative factor for the heavy metal enrichment in reach 2, including effluents from pharmaceutical industries, oil refineries, and industrial and domestic runoff. Statistical analysis also endorsed those heavy metals possess similar anthropogenic origins. Overall, the dredging can be feasible for reach 1 and at localized zones for reach 2 across the Brahmaputra River. Further, the study tries to present a suitable mitigation measure to carry out dredging operations and manage contaminated dredged sediment for reach 2. [ABSTRACT FROM AUTHOR]

The giant panda (Ailuropoda melanoleuca) is recognized worldwide as an icon for wildlife conservation. The Qinling subspecies (Ailuropoda melanoleuca qinlingensis) inhabiting the Qinling Mountains is more endangered. Previous studies have indicated that Qinling pandas are potentially at risk from environmental pollutants, which they are exposed to via food and drinking water. However, there is little information about the surface water quality in the Qinling Mountains, and it is unknown whether drinking water is an important pollutant source for pandas. Water samples were collected from five different nature reserves in Qinling, each of which is home to a population of pandas. The samples were analyzed for five essential metals of copper (Cu), zinc (Zn), manganese (Mn), chromium (Cr), and nickel (Ni) and four non-essential metals of lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg). The concentrations of all heavy metals (HMs) were higher in buffer zones than in the core areas and were highest in Foping and Niuweihe nature reserves. The concentrations of mercury exceeded the water quality standard in the core zone of three reserves, suggesting that NWH (Niuweihe), THS (Tianhuashan), and PHL (Pingheliang) giant panda populations were at risk from mercury toxicity. The accumulation of other elements over time could also pose a serious risk to pandas. Three main sources of pollution were identified: coal combustion, waste incineration, and fertilizer use; traffic-related activities; and metal mining. Environmental pollution is compromising the efforts to conserve the giant panda, and measures need to be put in place to control pollution sources. [ABSTRACT FROM AUTHOR]

Submarine groundwater discharge (SGD) dynamically links land‐ and ocean‐derived chemical constituents, such as metals, in the coastal ocean. While many metals are sediment‐bound, changing environmental conditions, particularly along the coast, may lead to increased release of metals to their dissolved and more bioavailable form. Here, we review metal behavior, speciation, and drivers of mobilization in the coastal environment under anthropogenic influence. We also model global metal contamination risk to the coastal ocean via SGD considering anthropogenic and hydrogeologic pressures, where tropical regions with high population density, SGD, and acid sulfate soils (4% of the global coast) present the highest risk. Although most SGD studies focus on other analytes, such as nutrients, this review demonstrates the importance of considering SGD as a critical pathway for metals to reach the coastal ocean under rapidly changing environmental conditions. [ABSTRACT FROM AUTHOR]

Fluvial sediment analysis and water quality assessment are useful to identify anthropic and natural sources of pollution in rivers. Currently, there is a lack of information about water quality in the Pixquiac basin (Veracruz state, Mexico), and this scarcity of data prevents authorities to take adequate measures to protect water resources. The basin is a crucial territory for Xalapa, the capital city of Veracruz state, as it gets 39% of its drinkable water from it. This research analyzed 10 physicochemical parameters and 12 metal concentrations in various rivers and sources during two seasons. Dissolved metals presented average concentrations (µg/L): Al (456.25) > Fe (199.4) > Mn (16.86) > Ba (13.8) > Zn (7.6) > Cu (1.03) > Pb (0.27) > As (0.12) > Ni (0.118) (Cd, Cr and Hg undetectable). Metals in sediment recorded average concentrations (ppm): Fe (38575) > Al (38425) > Mn (460) > Ba (206.2) > Zn (65.1) > Cr (29.8) > Ni (20.9) > Cu (16.4) > Pb (4.8) > As (2.1) (Cd and Hg undetectable). During the rainy season, Water Quality Index (WAWQI) classified stations P17 and P18's water as "unsuitable for drinking" with values of 110.4 and 117.6. Enrichment factor (EF) recorded a "moderate enrichment" of Pb in sediment in P24. Pollution was mainly explained by wastewater discharges in rivers but also because of erosion and rainfall events. Statistical analysis presented strong relationships between trace and major metals which could explain a common natural origin for metals in water and sediment: rock lixiviation. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the quality of water and fish meat of Sarpa salpa and to determine the water pollution index based on the physicochemical parameters in El-Kala waters, Algeria. The sampling of water and fish was carried out in 2020 at three stations (New Harbor, Maudite Islands, and Messida). The results of pollution index “PIj” calculation at coastal waters El-Kala were classified as lightly polluted (New Harbor and Messida waters) with the pollution index values of 3.24 to 1.33, respectively. It was important to notice that the levels of Cd, and Pb had exceeded the International Security standards in the coastal areas. The values of the bioconcentration factor “BCF” of the whole and of the dosed ETMs oscillate were between 18.31 and 175.41. At the three stations, the distribution of ETMs according to their BCF values were sequenced in the following decreasing order: cadmium˃ lead˃ zinc. The average concentrations of TME in water and fish meat decreased in the following order of stations: New Harbor> Messida> Maudite Islands, regardless of the metal. The analyses carried out made it possible to identify the samples from the New Harbor and Messida stations as the most contaminated with cadmium found in fish and cadmium and lead found in water. The high levels of cadmium and lead in water and fish tissues can be a real indicator of the degree of contamination of the site by these metals. [ABSTRACT FROM AUTHOR]

Drinking water samples were collected from natural sources (groundwater and surface water) in rural villages in southeastern Nigeria, and the results were compared to WHO and Nigerian drinking water quality criteria. To meet the study's goal, 21 drinking water samples were collected from sparsely populated rural settlements in Ebonyi State (Ugwulangu, Okposi, and Uburu). pH, temperature, turbidity, conductivity, salinity, total dissolved solids, total hardness, alkalinity, chlorides, nitrates, sulphates, phosphates, and metals were all measured in the water samples. This study looked at eight metals: Ca, Mg, Fe, Zn, Pb, Cr, Mn, and Ni. Except for turbidity, conductivity, alkalinity, Pb, and Ni, all metrics were found to be within allowed ranges. The metal concentrations followed the order: Ca > Mg > Pb > Fe > Zn > Ni > Mn > Cr. Metal index, degree of contamination, and hazard index were all calculated using the metal concentrations. The metal index and degree of contamination results showed that the water sources were safe to drink. The hazard index assessed children's and adults' chronic risk levels. By ingesting metals in water samples, the Hazard Index assessed the risk that users of water are prone to. Children are more at risk than adults from drinking untreated water from Ugwulangu, Okposi, and Uburu, according to the findings of a hazard index study. To safeguard children's health, it is strongly advised that they be provided with alternative drinking water. [ABSTRACT FROM AUTHOR]

To determine the sources and pathways of lead (Pb) and zinc (Zn) in river sediments contaminated with metals from mining and smelting activities, metal concentrations and Pb and Zn isotope ratios were measured in river water and sediment, and potential metal contaminant samples (imported Zn concentrates, smelting wastes, soils around the smelter, mine ores, and riverside tailings). Zn and cadmium (Cd) concentrations in river water and sediment samples were 30- and 11–25-fold higher, respectively, near the smelter than upstream, while a 6-fold increase in sediment Pb concentrations was detected over the same region. Sediment samples near the smelter (207Pb/206Pb = 0.8638 and 208Pb/206Pb = 2.0960) were observed to have a different Pb isotopic composition from upstream of the smelter (207Pb/206Pb = 0.8322 and 208Pb/206Pb = 2.0502), with δ66Zn values increasing from –0.01 to 0.82‰. Analysis of Pb and Zn isotopes and concentrations revealed that dust-contaminated soils were a major Pb source, and baseline sediments were found to be contaminated by regional mining tailings. For Zn in sediments, the main Zn sources were groundwater-derived Zn (δ66Zn = 1.02 ± 0.43‰, n = 4), dust-contaminated soils (δ66Zn = –0.18 ± 0.08‰, n = 3), and tailings-contaminated sediments (δ66Zn = 0.01 ± 0.07‰, n = 10). Endmember mixing model results showed that dust-contaminated soils contributed 78% and 64% of sediment Pb and Zn, respectively, within 2 km of the Zn smelter, decreasing to negligible levels after 47.1 km downstream. Downstream of the smelter, groundwater-derived Zn contributed 54% of sediment Zn, whereas tailings contaminated sediments contributed 70% and 25% of Pb and Zn, respectively. [ABSTRACT FROM AUTHOR]

This study conducted experimental investigations into the effects of electrode material and potential gradient on the effectiveness of electro-osmotic consolidation (EO) in strengthening soft soils. Seven laboratory tests were conducted on high-water-content marine clayey soils through EO. In these experimental tests, four different types of electrodes made of steel, copper, aluminum, and composite carbon fiber (CCF) were employed in four tests each to evaluate the consolidation effectiveness. Additionally, four tests, one was the comparitive study for different eletrode materials, were carried out to determine the optimal gradient for the EO using CCF electrode. Several critical properties of the tested soils were examined and evaluated in this study, including the effective voltage utilization, potential distribution, water discharge, discharge rate, energy consumption, and soil bearing capacity. The test results indicated that the CCF electrode had superior performance in water discharge, discharge rate, and average soil water content compared to metal electrodes. Furthermore, CCF led to uniform enhancement of soil strength, with treated soil bearing capacities 6.3 to 12 times higher than initial values, and 1.9 to 2.5 times higher than those attained with metal electrodes. Additionally, an effective potential gradient of 1 V/cm was identified for the EO with the CCF electrode, providing a higher discharge rate and a larger soil strength in a uniform distribution. Moreover, the use of CCF electrode significantly reduced corrosion compared to metal electrodes during the consolidation process, further contributing to improved consolidation efficiency. This study offers valuable insights and recommendations for the utilization of CCF in marine clayey soils, effectively addressing the challenges posed by electrode corrosion and high energy consumption in EO applications. [ABSTRACT FROM AUTHOR]

Discharge of untreated wastewater into water bodies pollutes the receiving waters. This study assessed the impact of abattoir and Kampala designers' effluent discharge on the water quality of the Yemoja River in Abeokuta, Nigeria. Twenty-seven water samples collected at three points, covering 180 m length, for 6 months were assessed for physicochemical parameters and metals and compared with the World Health Organization (WHO) and Standard Organization of Nigeria (SON) permissible standards. Most discharge point levels were found to be higher than their corresponding upstream and downstream values. Temperature, turbidity, magnesium, alkalinity, DO, TSS, phosphate, lead, BOD and potassium were found to be higher than normal levels for river water as prescribed by the WHO and SON while parameters like TDS, TS, calcium, chloride, nitrate, sulphate, iron and COD were lower than the standards. The total coliform values were higher than both national and international permissible limits, indicating contamination by human sewage or animal droppings. The water quality index indicated polluted water that is unfit for consumption. Findings from this research indicate that butchering and tie-and-dye activities have impacted river Yemoja water quality. Therefore, wastewater from the abattoir and textile industries be treated before discharge into water bodies. [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]

Many contaminants can enter the environment via dentistry. Some of the materials including heavy metals may present some problems to the environment. Amalgam waste in dental clinics is the main source of mercury pollution in the environment. Apart from mercury, other amalgam constituents such as Ag, Sn, Co, Cu, and Zn in dental clinics’ wastewater have just been reported in a few previous kinds of literature. This study aimed to measure the concentrations of mercury, cobalt, zinc, copper, tin, silver, chromium, and nickel in the influent and effluent of dental units of some dental clinics. Samples were collected over 6-month period from 5 dental clinics and three samples were collected from each clinic at the end of the working day, within a week as the effluent sample. Metal concentration was also detected in the influent of the dental units and samples were analysed for metals using the atomic absorption spectrophotometry (AAS) technique for statistical analysis. Data were analysed with Wilcoxon and Kruskal – Wallis tests within SPSS 18 software. The concentration of all the metals in influent water was at the level of the national standard in all samples. In comparing influent and effluent values, the P-values for Hg, Zn, Cu, and Sn (0.001), Cu (0.003), Ag (0.028), Cr (0.007), and Ni (0.016) as shown significant differences between influent and effluent values for all the sample. Based on the obtained findings from the study, wastewater has an undesirable level in terms of heavy metals. Thus, dental clinic wastewater might be considered hazardous waste that should be properly treated before it discharges into the environment. [ABSTRACT FROM AUTHOR]

Purpose: The levels of metal(loid)s at the beginning of the coastal pelagic food web, providing an insight into accumulation in the suspended particulate matter (SPM) and size-fractionated plankton, were studied in the shallow coastal marine environment of the Gulf of Trieste (northern Adriatic Sea) affected by the metal polluted Isonzo/Soča River as a result of historical Hg, and Pb and Zn mining activities in the hinterland. Materials and methods: Levels of metal(loid)s were investigated in suspended particulate matter (0.45–20 µm) and fractionated plankton (20–50 µm, 50–200 µm, > 200 µm) collected monthly at the Marine Biology Station oceanographic buoy Vida in the southern part of the Gulf of Trieste. Results and discussion: Concentrations of meta(loid)s showed the following order Al,Fe > Zn,Mn > Ni > Cu,Cr > As,Pb,V > Co > Se > Cd > U > Hg and were similar to those of dissolved metal(loid)s of the gulf waters (Al,Fe > Zn > Cu > V > Mn > As > Ni,Se > U,Cr > Cd > Hg) where Hg, Cu, Cr and Se were significantly associated with colloidal organic matter (< 0.2 µm, > 5 kDa). The partition of metal(loid)s between their particulate phase and free ion and inorganic complexes in the water (Kpd) confirmed a strong binding of Hg, Al, Mn, Fe, Cr and Pb onto seawater particles. In general, the metal(loid) data for SPM and plankton showed high levels in the 50–200 µm microplankton fraction. Larger plankton fractions, especially > 200 µm, contain a lower amount of metal(loid)s associated with mineral particles originating from sedimentary pelite resuspension and riverine inflows. Variations of metal(loid)s levels in SPM and plankton fractions were related to their biomass (ash free dry weight—AFDW) and organic matter, and mineral (inorganic) content, which is difficult to separate from biogenic particles including organisms, and to the taxonomic composition and feeding behaviour of organisms in various fractions. Conclusions: The Redfield's stoichiometric concept including metal(loid)s in the coastal marine plankton (SPM and mesozooplankton) appears unreliable. The bioconcentration factors (log BCFs) of the studied metal(loid)s, ranging between 4 and 6 for Hg, Fe, Mn, Cr, Pb, Co, Zn, Ni, As, Cu and V and lower for Se and U both in micro- and mesoplankton, can possibly be used in micro- and especially in mesoplankton fraction less impacted by mineral metal(loid)s. This should be considered when establishing the metal(loid)s levels at the base of the coastal and estuarine food webs, at the onset of marine bioaccumulation, to provide information for marine organisms consumed by humans. [ABSTRACT FROM AUTHOR]

The heavy metal speciation analysis in sediments helps us understand and evaluate essential and unavoidable issues in terms of both health and environmental hazards imposed by these metals in our lives. Analyzing the total content of heavy metals enables us to understand only the quantity of the contaminants. To understand the different species or the chemical forms of heavy metals available in the sediments, we must study their speciation. Speciation studies help us determine their possible sources as well as their environmental stability in terms of availability to plants and other organisms. The heavy metals in this study were specified using four-stage sequential extraction, also known as the BCR technique. This study mainly highlights the quantification of metal contamination of Cu, Zn, Pb, Ni, Cd & Cr, and chemical forms as species in sediment samples collected from different Pune District, Maharashtra sites. Heavy metal contamination from the collected samples was analyzed with the use of flame atomic absorption spectrometry. This study indicated that Zn and Ni are among the most abundant metals in the sediment samples; however, Cu and Cd belong to the least abundant category. The oxidizable and residual forms (immobile and cannot be used by the organisms readily) appeared dominant for most heavy metals. Very significant differences were observed in the speciation of heavy metals from sample to sample, which was probably due to differences in water/soil composition and the agrochemicals like pesticides, weedicides, and fertilizers used in agricultural practices; the wastewater generated from different pharmaceuticals, chemical processing and manufacturing industries as well as the improper wastewater treatment methods. [ABSTRACT FROM AUTHOR]

This study closely analyzes the water quality dynamics of Teceu Lake, situated in a Natura 2000 protected area in Romania. The research investigates seasonal variations and interconnections with groundwater, assessing various ecological impacts. The main physico-chemical indicators of water, such as electrical conductivity (EC), dissolved oxygen (DO), oxygen saturation (OS), temperature, pH, turbidity, ammonium concentration (NH4+), nitrates (NO3−), nitrites (NO2−), orthophosphates (PO43−), water hardness, alkalinity (A), and chlorides (Cl−), were measured over the January–December 2022 period. Metal concentrations for both major metals (Na, K, Ca, Mg, Al) and trace metals (Li, Ga, Fe, Mn, Pb, Cu, Zn, Ni, Ti, Mo, Sr, Ba) were assessed. The evolution of the physico-chemical indicators revealed an increase in nutrient compounds (ammonium and phosphates) during the spring and autumn months. The EC values ranged from 180–444 μS/cm for the lake and 1575–2480 μS/cm for groundwater. The pH values (7.12–7.96) indicated a slightly alkaline environment. DO levels (6.79–11.21 mg/L) indicated good water quality. Chlorides exceeded levels in drinking water in some instances. Water hardness varied due to pH, temperature, and atmospheric pressure. Metal composition revealed diverse levels of aluminum, barium, nickel, copper, zinc, and manganese, which carries implications for environmental and human health. The water quality index (WQI) score, which is based on major ions, indicated that 93% of the groundwater samples were classified as excellent and good for drinking. WQI, based on the main physico-chemical indicators, revealed that 79.17% of the Teceu Lake-water samples and 41.66% of the groundwater samples gathered were classified as good quality; the difference indicated poor quality, especially in autumn. Q- and R-mode cluster analyses revealed distinct clusters for seasonal months and sampling points, suggesting shared sources and geological influences. Notable connections between physico-chemical indicators and metal content were identified, emphasizing the need for a tailored conservation strategy. Correlation analyses highlighted both positive and negative relationships between metal pairs. Understanding these parameters is vital for water resource management and preserving biodiversity in the region. The results of this study are important for monitoring pollution in Lake Teceu and might prompt local communities and authorities to take measures to reduce and prevent pollution. [ABSTRACT FROM AUTHOR]

Ocean pollution poses a significant issue in the marine ecosystem. Coastal areas are particularly impacted by this pollution, and consequently, organisms associated with these coasts bear the brunt of its effects. Therefore, the presence of robust bioindicators, such as the shrimp species Palaemon elegans, is critically important. In this study, 20 P. elegans specimens were examined in each of the five areas on Gran Canaria Island. Water samples were collected to assess the potential existence of elevated concentrations. Significant discrepancies were observed in the levels of Al and Li across all zones, except those previously mentioned. The highest concentrations were recorded in Arguineguín (Southern sector), reaching 49.14 ± 4.51 mg/kg (Al) and 47.64 ± 2.86 mg/kg (Li). The authors contend that P. elegans proves to be a reliable bioindicator for tourist and port-related pollution, specifically for the metals Al, Zn, Cd, Pb, Ni, Fe, B, and Li analyzed in this research. [ABSTRACT FROM AUTHOR]

The article discusses the impact of climate change on indigenous communities in the Arctic region. It highlights how rising temperatures and melting ice are affecting the traditional way of life for these communities, including hunting and fishing practices. The article also emphasizes the importance of recognizing and respecting indigenous knowledge and perspectives in addressing climate change. It concludes by calling for collaborative efforts between indigenous communities and policymakers to mitigate the effects of climate change and protect the cultural heritage of these communities. [Extracted from the article]

The submerged surface sediment of the artificial lake at Jordan University of Science and Technology in Irbid, Jordan, was investigated to evaluate its contamination with trace metals. Chemical characterization was applied to leachates of sediment samples collected from 11 sampling stations at the study zone. The metal concentration (Pb, Cu, Cr, Cd, Ni, Zn, Fe, and Hg) in the sediment samples was matched to the limits set by the Jordanian standard for water-sludge-uses of treated sludge and sludge disposal. According to the results obtained via thermal decomposition, mercury amalgamation, and inductively coupled plasma—atomic emission spectrometry (ICP-AES), most metals were below the detection limit. Several metals were found to be below the limits fixed by the Jordanian standards except for stations 10 and 11 which connected the wastewater channels to the lake. At these two stations, Pb recorded contents were 439 and 335 mg/kg dry matter, respectively, and thus exceeded the limits set by the Jordanian standard. Thus, the overall results were in favor of the environmental safety of the JUST lake for setting up a fish aquaculture. [ABSTRACT FROM AUTHOR]

In Ghana, small-scale mining (SSM) has been carried out for many years, generating employment and income. Currently, illegal artisanal mining ('galamsey') has impacted the environment negatively, resulting in land degradation and water pollution. The government of Ghana, responding to public outcry against the negative effects of 'galamsey', placed a ban on illegal small-scale mining activities in March 2017. This ban stopped both 'legal' small-scale and the illegal artisanal miners from carrying out any such activity. In July 2018, this study was carried out to examine the status of water and sediment quality in eight endemic regions of illegal mining to ascertain the outcome of the ban on the water quality of the rivers. Methodologies in the Standard Methods for the Examination of Water and Wastewater were followed. Results of the study indicated that the rivers were high in total suspended solids (TSS), turbidity and colour, suggesting inflow of wastewater from the illegal mining activities and some run-off. Colour had a strong correlation with turbidity (r = 0.95) and TSS (r = 0.94), suggesting that the pollution originates from the same sources. Low levels of metals were found in both water and sediment. However, very high concentrations of Fe were detected in both water and sediment. Mercury concentrations were low in the water column but relatively higher in the sediment. A comparison of the general water quality status of the water bodies in the Pra Basin in 2013 and 2018 using the Water Quality Index (WQI) showed a marginal improvement in quality in 2018 over 2013 in the Pra Basin. The improvement of water quality in 2018 is attributable to the ban. [ABSTRACT FROM AUTHOR]

Sediments from three rivers in south-western Poland and their tributaries were used in a laboratory experiment on metal (Al, Cu, Ni, Cd, Zn, Fe, Mn) release. Metal migration was studied under different pH (pH 3.93, pH 7.29, pH 9.59) during 96 h. Al concentration was the highest in Bystrzyca and lowest in Strzegomka; other metal concentrations were highest in Nysa Szalona and lowest in Strzegomka. The values of pH and electrolytic conductivity increase throughout the experiment in acidic and neutral environments. Water pH decrease was observed under alkaline conditions, but conductivity reached higher values with time. The aluminum release showed an increase in values followed by a decrease. The highest aluminum amounts were released from the sediment from Nysa Szalona and the lowest from Strzegomka. The greatest aluminum migration was observed in the acidic medium. Similar observations were made for Mn and Zn: Strzegomka < Nysa Szalona < Bystrzyca. For Cu, Cd, Fe and Ni, the highest values were recorded in sediments in alkaline conditions. The amount of metals migrating from sediments to water remains at a similar level as presented by other researchers. More metals are released under acidic conditions. The most intensive migration of metals is noted at the beginning of the experiment. This experiment shows the existing trend of metals migration from the sediments to the over-bottom water, which is important from the point of view of the use of water for drinking purposes. Satisfactorily, the sediments in varied environments behave predictably enough that the quality of raw water under these conditions is not compromised, which is confirmed by environmental and health standards. The research performed concerns a specific area of southwestern Poland, for which this type of research has not been conducted. [ABSTRACT FROM AUTHOR]

Macroalgae are widely used for bioindication and assessment; however, in the case of pollutants of different origin, it is still unclear which contaminants in thalli can be regarded as indicative because too many factors influence the ability of algae to uptake them. The present study is a part of an international HAZLESS project and was conducted in the eastern Gulf of Finland (GoF). The main goal of our study was the application of metal concentrations in macroalgae as a tool for environmental quality assessment. To achieve this goal, we calculated the threshold metal concentrations in macroalgae (Cladophora glomerata) and compared our obtained values with actual concentrations. We found significant Spearman correlations in May between metals in sediments and pore water (−0.73 for Zn, −0.62 for Cd, 0.85 for Pb) and also between metals in algae and metals in pore water (1 for Cu and Cd, 0.98 for Zn and Pb). In July, Pb in algae were significantly correlated with Pb in pore water (0.88). The application of the calculated environmental quality standard (EQSMPC) for macroalgae has shown moderate pollution by Cu and Pb in the coastal zone of the eastern GoF. This was confirmed by an assessment based on the comparisons of metal concentrations in water with Environmental Quality Standards for water (EQSw). However, differences in the bioaccumulation factor and EQSMPC between May and July have shown that it is necessary to compare samples taken during the same period every year for adequate results in long-term monitoring. Considering the sensitivity of accumulating processes to the surrounding environment, we believe that in the case of habitats with diverse conditions, even for the same species of algae, threshold values should be calculated and used individually for every habitat. Our results have shown that this approach can be widely used for an assessment of environmental quality via metal concentrations in opportunistic macroalgae and can be recommended for further use. [ABSTRACT FROM AUTHOR]

A laboratory experiment was performed to find out the potential bioaccumulation of metals (Al, Cu, Cd, Ni, Pb, Fe, Mn) in aquatic plants acting as natural biosorbents in the environment depending on the variation of water pH. Two plants were selected for the study: branched bur-reed—Sparganium erectum L., as a representative of emergent plants; and river water-crowfoot—Ranunculus fluitans Wimm., 1841, as a representative of submergent plants. The bioaccumulation of metals in plants relative to water (BCFW) was determined, and the metal pollution index (MPI) was calculated. The metal content in water and plants before the experiment was arranged in the following series of increasing values: Cd = Ni < Cu < Pb < Mn < Al < Fe (water) and Cd < Cu < Ni < Pb < Al < Fe < Mn (in both plants). The lowest concentration of cadmium was found in water both at the end and beginning of the experiment. In turn, aluminum level increased, and its concentration was the highest in both acidic and alkaline water. This suggests that aluminum is definitely more available to the organisms living in it under such conditions, and in higher concentrations may be a limiting factor for them. Bioaccumulation of metals (BCFW) in neutral and alkaline environments was higher in branched bur-reed, and in acidic conditions in river water-crowfoot. This may provide a basis for using specific plant species to selectively accumulate metals depending on the range of water pH. This is also supported by the MPI values, which indicate that they have a very high and often the highest impact on metal pollution levels. The observed variability of metals bioaccumulation against the condition of hydromacrophytes makes it possible to consider these plants as biosorbents used in constructed biological treatment plants, which, depending on the species placed there, can selectively absorb particular trace elements. The plants used in the experiment are common hydromacrophytes of Europe, so they can be used in the construction of artificial wetlands across the continent. The apparent diversity of metal accumulation in relation to hydromacrophytes indicates that this type of site can be inhabited by specific species, which can significantly improve the purification of natural or anthropogenic water reservoirs, i.e., those that are intended to perform a filtering function. [ABSTRACT FROM AUTHOR]

There are few studies on the simultaneous behavior of chromium (Cr), molybdenum (Mo), and tungsten (W) belonging to group VIB of the periodic table. Herein, based on high-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) technology, the vertical distribution characteristics of DGT-labile and soluble Cr, Mo, and W in two lakes of Nansi Lake (Weishan Lake and Dushan Lake) were analyzed. In addition, the net diffusion fluxes and R-value (CDGT/Csol) were used to evaluate the mobility and release risk of metals at the sediment-water interface. The results showed that the DGT-labile concentrations of the three metal elements (Cr, Mo, and W) in Weishan Lake were higher than those in Dushan Lake, both in overlying water and sediment. This is mainly due to the dredging of the Dushan Lake area, which can permanently remove the polluted sediment in the lake. Meanwhile, the exogenous input is relatively high near the tourist area of Weishan Island. The net diffusion fluxes indicate that the W has a potential release risk of diffusion to the overlying water in Dushan Lake. The release of Cr, Mo, and W is thought to be related to the reductive dissolution of Fe/Mn (hydr)oxides based on Pearson correlation coefficients. The R-values of Cr and W indicate that Cr and W belong to the partial continuity case. The R-value of Mo was lower than the minimum value, meaning that Mo belongs to the single diffusion type and it is difficult for Mo sediments to supply pore water. [ABSTRACT FROM AUTHOR]

The lower Nile River is a vital drinking and irrigation water source in Egypt. Human activities adjacent to rivers deteriorate the quality of such water resources. The water quality profiles of 23 sites along the Nile were calculated in accordance with the model (Canadian Council of Ministers of the Environment–Water Quality Index [CCME-WQI]). The WQI results indicated that 65%, 100%, and 96% of the Nile River water samples were suitable for drinking, irrigation and aquatic life uses, respectively. These results indicated slight effects on the Nile water quality profile due to different activities, including agricultural runoff and potential industrial and municipal effluents. The metal quality and pollution indices were calculated to assess the contamination with metals (Fe, Mn, Ni, Co, Cr, Cu, Zn, Pb, and Cd). The metal index results for agriculture purposes indicated that the water quality in all collected samples was in the excellent category and had no adverse effect. Moreover, the study showed that the water quality profile of Nile River water had different metal pollution components, notably Pb for drinking and Pb, Co, Cu, and Cd for aquatic life usage, respectively. [ABSTRACT FROM AUTHOR]

Introduction: The concentration of metals in sediments, their correlation and causality in the surface waters of hydrographic basins are evaluated. Monitoring information from six Peruvian watersheds was used, carried out in surface water as well as in sediments, obtaining the concentration of 31 metals in each sampled point. Objective: To evaluate the concentration of metals in sediments and warn if there is causality in the concentration of metals in surface waters, with respect to any metal of environmental relevance. Materials and Methods: Monitoring carried out by the National Water Authority of Peru was used. IBM Statistics SPSS V.29 software was used. Results and Discussion: Of 31 metals evaluated in both sediments and surface water from rivers, there is only a moderate correlation in four metals. Regarding causality, there is only a high trend for arsenic with an R² of 0.729. This indicates that 72.9% of the arsenic concentration in water is caused by the concentration of arsenic present in the sediments, with 27.1% attributable to other factors such as anthropic factors in the specific study areas. Conclusions: It is shown that the presence of arsenic in the waters is mainly due to the fact that it is found in the sediments in the study area. Therefore, it is necessary to take actions to control the effects that it may have on the environment and the human being, if it is used for consumption or productive activities such as agriculture. [ABSTRACT FROM AUTHOR]

The study assess concentration of nine metals in the abiotic (water and sediment) and biotic components (aquatic plant and benthic Rita rita and benthopelagic Ctenopharyngodon idella fish) of River Ganga at Ganga Barrage, Kanpur. Amounts of all elements in river water and aquatic plant exceeded the permissible limit recommended by the world health organization and USEPA except for Zn in the aquatic plant. Heavy metals concentrations in critical organs (kidneys, liver, muscles and gills) of fish were estimated and health risk post consuming contaminated fishes from study area was evaluated through target hazard quotient and hazard index. The result revealed that the children were more prone to health risks than adult by consuming the fish. The geoaccumulation index (Igeo) values were contributed by Cu having value of 1.58 in water and 1.003 in sediments than their desired limit of one. Similarly, Cd also has value of 1.152 in water and Pb have the value above 2 in both water (2.172) and sediment (2.218) reflecting their main contribution in pollution of the Ganga river and its sediments. The contamination factor (CF) and ecological risk (Er) were due to Cd and Pb in Ganga River water and sediment respectively at Ganga Barrage, Kanpur. The pollution load index (PLI) and potential ecological risk index (PERI) values were within the safe levels of the abiotic community. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Botanical Research is the property of Bulletin of Botanical Research Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study a battery of bioassays, both in vivo (metals and metalloids concentrations, erythrocyte morphometry, comet assay, micronucleus assay, and histopathological analyses) on vimba bream Vimba vimba (L., 1758) and white bream Blicca bjoerkna (L., 1758), and in vitro (treatment of HepG2 cells with native water samples) was applied to assess the harmful potential of untreated wastewater. Faecal indicator bacteria were quantified to assess the microbiological water quality. Vimba bream had significantly higher Fe concentrations in both liver and muscle, while white bream had higher Ca and Cu concentrations in liver. Vimba bream had a significantly higher level of DNA damage in both liver and blood cells, in comparison to white bream. Low levels of micronucleus and nuclear abnormalities were observed in both species. Erythrocytes morphometry did not show significant interspecific differences. Histopathological analyses revealed a similar response of the studied species, with a significantly higher presence of ceroid pigments in the liver of vimba bream. Treatment of HepG2 cells revealed the high genotoxic potential of water downstream of the discharge point. The results of this study clearly demonstrate the importance of effect-based monitoring, in order to enforce more efficient management of natural resources and implementation of wastewater treatment systems. [ABSTRACT FROM AUTHOR]

Amphibians are subject to several stressors in the aquatic and terrestrial environments, and human activities have profoundly impacted this vertebrate group. The aim of the present study was to analyze physicochemical parameters, metals and pesticide residues, and the toxicity of water and sediment samples from an environment with high agricultural activity (S1: Salto stream; S2: drainage channel downstream from S1) by means of bioassays using Rhinella arenarum (Amphibia: Anura) larvae. Metals and pesticides were analyzed in water and sediment samples by fluorescence spectrometer of X‐ray by total reflection and ultra‐high‐performance liquid chromatography‐MS/MS, respectively. For lethality bioassays, 10 larvae (in triplicate) were exposed for 504 h to water and sediment samples. Also, 50 larvae were exposed for 96 h (in triplicate) to water and sediment samples for the evaluation of biomarkers of neurotoxicity, oxidative stress, and genotoxicity. Twenty‐six different pesticides (mainly herbicides) were detected in both sites, and Cu, Zn, and Pb exceeded the limit for protection of aquatic life. Lethality was observed in larvae exposed to water and sediment samples from both sites at chronic exposure. Oxidative stress was observed in larvae exposed to both sites. In larvae exposed to samples from S1, alterations in the neurotoxicity biomarkers were observed. These results alert about the degradation of the sites and highlight the need to monitor and control the use of pesticides. Practitioner Points: Twenty‐six pesticides were detected in water and sediment from Salto stream basin.Significant mortality was observed in larvae exposed to samples from all sites.Sublethal effects were observed mainly in larvae exposed to samples from Salto stream.The degraded quality can be associated with the agricultural activities of the area. [ABSTRACT FROM AUTHOR]

This study reports: a) the content of Ca, Cd, Co, Cr(III), Cr(VI), Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn in wastewater from metal industries and rivers that flow near the metal processing industries; b) the possibility of quantitative determination of Cr(III) and Cr(VI) in the presence of the following cations: Fe3+, Cu2+, Ca2+, Mg2+, Ni2+, Mn2+; and Zn2+ and anions Cl-, NO3-, and SO4 2-; c) speciation of Cr(III) and Cr(VI) on silica gel modified with Nb2O5 . Metals were determined by flame atomic absorption spectrometry, except for Na and K, which were determined by atomic emission spectrometry, and Cr(VI) by ultraviolet-visible spectrophotometry. When the concentration of cations is higher than Mg2+ (>25 mg/L), Ni2+ (>100 mg/L), Fe3+ (>250 mg/L), Zn2+ (>500 mg/L), and Mn2+ (>1000 mg/L), an error greater than 10 % is obtained in the measurement of Cr(III) . Silica gel modified with Nb2O5 can be considered as an effective solid phase extraction adsorbent for speciation of Cr species and simultaneous concentration of Cr(III). The proposed method was successfully applied to the speciation and determination of Cr(III) and Cr(VI) in the analyzed samples. The content of almost all analyzed metals has been below the permitted values for wastewaters. [ABSTRACT FROM AUTHOR]

The effect of varying process parameters during the bio-catalyzed leaching of metals from end-of-life printed circuit boards (PCBs) was investigated in [[4]]. The achieved results offer possibilities for further studies at higher pulp densities that would advance the bioleaching approach such that it facilitates economical and environmentally friendly technology for the urban mining of non-ferrous metals. References 1 Serga V., Zarkov A., Shishkin A., Elsts E., Melnichuks M., Maiorov M., Blumbergs E., Pankratov V. Study of Metal Leaching from Printed Circuit Boards by Improved Electrochemical Hydrochlorination Technique Using Alternating Current. [Extracted from the article]

Safe and clean water is an indispensable component for all kinds of living beings. An attempt was taken to examine the drinking water, particularly the groundwater quality of Savar Upazila under the Dhaka District of Bangladesh by assessing some physicochemical parameters such as pH, total dissolved solids (TDS), electrical conductivity (EC), and temperature and the levels of different heavy metals (Cu, Cd, Cr, Fe, Mn, and Zn). To measure the concentration of the six selected metals from the groundwater samples collected from 38 different locations of Savar Upazila, Atomic Absorption Spectrophotometry (AAS) was used. Our results showed that the pH, TDS, EC, and temperature ranged from (6.56-7.72), (73-437 mg/L), (117-654 µS/cm), and (27.7-30.5°C), respectively which were found within the limit of water standards recommended by national and global regulatory authorities. The mean concentration of different studied metals in the reported water samples of Savar Upazila followed the order of Fe > Zn > Mn > Cr > Cu > Cd. The average concentration was 0.136±0.188 mg/L, 0.121±0.289 mg/L, 0.033±0.060 mg/L, 0.015±0.0096 mg/L, 0.0104±0.005 mg/L, and 0.0022±0.0019 mg/L for Fe, Zn, Mn, Cr, Cu, and Cd, respectively. In this study, Water quality index (WQI) was also calculated for the studied samples and it was observed that the groundwater of Savar Upazila belonged in the good to excellent categories and can be recommended as suitable for drinking purposes. [ABSTRACT FROM AUTHOR]

The present study was conducted to determine the current state of water quality parameters and concentration of metals in the water and fish of Balu River. Samples were collected from three sampling sites in both wet and dry seasons. Temperature, color and odor, pH, electrical conductivity (EC), total dissolved solids (TDS), total solids (TS), optical density, salinity, and dissolved oxygen (DO) of water were tracked. Five fish species (Puntius ticto, Channa punctatus, Glossogobius giuris, Amblypharyngodon mola, and Mystus vittatus) were tested for metal concentrations (Cu, Pb, Cd, Zn and Cr). During the dry season, the river's water was slightly black, light grey, and black in color, and it smelled strongly pungent. Waterborne life was fatally affected by the DO values. The TDS, EC, and TS of water were higher in the dry than in the wet season. The trends of metal concentrations were Zn > Cu > Pb > Cr > Cd in water and Zn > Cu, Pb > Cr > Cd in fish species. During the dry season, the Cu in G. giuris; Pb, Cr, and Zn in A. mola, and the Cd in C. punctatus were the highest among the fishes investigated. However, during the dry season, A. mola had the highest total metal bioaccumulation while P. ticto had the lowest. When opposed to the wet season, the water had a significantly worse quality during the dry season, which may have been brought on by nearby industrial pollutants. [ABSTRACT FROM AUTHOR]

Gold mining (GM) is a major source of metals and metalloids in rivers, causing severe environmental pollution and increasing the exposure risks to the residents of surrounding areas. Mining in Ecuadorian Amazonia has dramatically increased in recent years, but its impacts on Indigenous local populations that make use of rivers are still unknown. The aim of this study was to assess the risks to adults and children caused by the exposure to metals and metalloids in freshwater ecosystems contaminated with tailings released by GM activities in 11 sites of the upper Napo River basin, Ecuador. We selected a carcinogenic and a noncarcinogenic risk assessment method to estimate the hazard index (HI) and total cancer risk (TCR). The concentration of Ag, Al, As, Cd, Cu, Fe, Mn, Pb, Zn, B, and V in water and sediment samples was considered to assess the risks to human health. The calculated HI was 23–352 times greater than the acceptable limits in all sites for both children and adults. Mn and Fe were the main contributors (75% in water and 99% in sediment) to the total calculated risk based on the HI. The calculated TCR for children and adults exceeded approximately one to three times the permissible threshold in all sites. As and Pb contributed up to 93% of the total calculated risk based on TCR for both children and adults. This study demonstrates that the emission and mobilization of metals and metalloids caused by mining activities increase the risk to human health, to which we recommend further monitoring of freshwater contamination in the area and the implementation of preventive health management measures. Integr Environ Assess Manag 2023;19:706–716. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Key Points: Areas affected by gold mining in Amazonia have high concentrations of metals and metalloids in the water and sediments.The noncarcinogenic risk, as calculated by the hazard index, was 23–352 times greater than the acceptable limits for both children and adults.The carcinogenic risk to both children and adults exceeded by up to three times the permissible threshold.Our human health risk assessment indicates that Indigenous populations living close to mining areas are exposed to health risks. [ABSTRACT FROM AUTHOR]

Lonar Lake is a highly saline inland water body created by a crater in Maharashtra, India. A rare occurrence of the colour change of lake water from green to brown and eventually to pinkish-red was observed in Lonar in June 2020. This phenomenon attracted the attention of researchers, academicians and interestingly legal fraternity to understand the causes of colour change. The literature studies coupled the phenomenon of colouration of water to three aspects: the presence of halophilic Halobacterium salinarum or an algal species of Dunaliella (Dunaliella salina) or oxidization of metals (Fe and Mn) present in water. A comprehensive study was done to understand and assess the change in the colour of Lonar Lake water. The green colour of the lake is primarily due to the dominance of chlorophyll-a pigment in the algae population. The stressed condition in June 2020 adversely affected the photosynthesis activity of Dunaliella sp. resulting in the red colouration of the species. This red colour of Dunaliella sp. is due to the formation of a pigment named carotenoid which is similar to that in halophilic bacteria. This pigment completely hides the green chloroplast, and water turns pinkish-red. This study describes detailed investigations of environmental and climatic parameters to determine possible causes of abiotic stress on the algae population of the lake. The major factors contributing to the stressed conditions are high dissolved solids, alkalinity and alkaline pH due to salts in the lake water due to evaporation losses and limited rainfall over the months. The study further verified whether the colour change is a cyclic event and predicted possible lake conditions for the event of colour change to occur in the future. [ABSTRACT FROM AUTHOR]

Mine water containing copper and zinc exceeding the permissible discharge limit has been discharged from the S mine site in South Korea. To evaluate the feasibility of applying passive treatment methods for treating water discharged from this mine, bench-scale experiments were conducted by using columns simulating successive alkalinity-producing systems (SAPS) and bioreactors. As substrate materials, limestone and spent mushroom compost (SMC) were applied, with their structures and mixing ratios varied. The efficiency of metal removal for each column was then evaluated. SAPS (column B) and bioreactors (columns C and D) exhibited Cu removal efficiencies of 99.7%, 98.0%, and 97.1%, respectively, while the limestone reactor (column A) had an average removal efficiency of 81.3%. Except for the re-dissolution events, Zn removal efficiencies were 99.5%, 97.6%, and 88.4%, respectively, while the limestone reactor had an average removal efficiency of 29.2%. Facilitated by a pH increase caused by the dissolution of limestone, the bacterial sulfate reduction (BSR) reaction was shown to be effective at removing metal in the SAPS and bioreactor columns; the process was revealed through the presence of sulfide in the effluent. When comparing bioreactors with different compost mixing ratios, columns with greater SMC ratios had higher removal efficiencies, as well as higher alkalinity, which shows the importance of SMC in metal removal. Overall, this study will be helpful in determining on-site treatment methods for Cu- and Zn-rich mine water by reusing waste materials, SMC, through bacterial metal reduction reactions, as well as considering the potential lifespan of the treatment facility. [ABSTRACT FROM AUTHOR]

The study was conducted to estimate the spatial and temporal variations, pollution levels, and potential sources of some heavy metals in the south coastal areas of Vietnam, using data obtained from the national monitoring stations from 2015 to 2021. The concentrations of As, Cr, Cu, Fe, Mn, Pb, and Zn in surface and bottom water samples at seven monitoring sites were analysed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for heavy metal pollution indexing. Results indicated that concentrations of almost all the heavy metals (As, Cr, Cu, Pb, Mn, and Zn) were lower than the threshold limits. In exception, Fe concentrations were 1.0 - 12.8 fold higher than the standard level of seawater quality in Vietnam. The highest concentrations of Fe, Cu, Mn, Pb, and Zn were observed in Dinh An and Rach Gia sites, which may be due to the influence of strong discharges from local rivers. The Contamination Factor (CF) and Contamination Degree (CD) values were far below 1, indicating that the seawater in these sites is at a low contamination level. The principal component analysis indicated that heavy metal concentrations in Ganh Rai, Dinh An, Rach Gia, and Ha Tien sites might be affected by natural factors; while it might also be caused by anthropogenic activities in Nha Trang, Phan Thiet, and Song Doc sites. [ABSTRACT FROM AUTHOR]

The accumulation of heavy metals in rivers' sediments near industrial wastes and mining activities has been a serious issue in developing countries including Rwanda and it has caused different environmental impacts on aquatic and terrestrial lives. Environmental studies have reported heavy metals pollution (lead, manganese, copper, zinc, nickel, iron, and cadmium) in major Rwandese rivers such as Mpazi, Rusine, and Nyabugogo. The increase in heavy metal concentrations in the environment results in abnormal enrichment, which in turn, affects the surrounding environment. This study aimed to investigate the heavy metals in Nyabarongo sediments, Mageragere sector using both X-ray fluorescence (XRF) and Atomic Absorption Spectrometer (AAS) instruments. Sediments samples were collected systematically on four sampling stations and the results showed that the Cadmium (Cd), Lead (Pb), and Manganese (Mn) concentrations among the investigated heavy metals are above the Rwanda Standard Board (RSB) and World Health Organization (WHO) guidelines for soils and sediments, meaning that those metals are the measure pollutants in the sediments of Nyabarongo River and the study has recommended the people around the river to reinforce the erosion control measures and not to use Nyabarongo water for domestic use and animal farming activities because of the concentration of heavy metals it contains that are toxic to animals, plants and micro-organisms. [ABSTRACT FROM AUTHOR]

Pykara Lake was formed as a result of the dam and power plant built on the river, and it is surrounded by a rich green shola forest. It is a popular tourist site that is situated in the Western Ghats. The trace metal contamination history of Lake Pykara was investigated utilizing a 210Pb-dated core sediment sample and EDXRF over the calendar year 1910–2019 AD. The metal concentrations (Mn, Cr, Cu, Cd, Ni, Zn, As, Pb, and Co) were found to vary significantly over time, implying a contribution from both geogenic and human causes such as nearby rocks, fossil fuel combustion, sewage, and agrochemicals. The average sedimentation rate of the Lake Pykara sediment core was calculated to be around 0.70 cm year−1, corresponding to an age of 109 years. The contamination factor (Cf) suggested a low to very high level of contamination in the study area. Sediment samples with moderate-high potential toxicity levels were detected using sediment quality guidelines (SQGs). Assessment of the ecological risk of the sediments revealed a considerable ecological risk in the study area. It is evident that continual monitoring and control are necessary to avoid serious pollution from sewage, agriculture, and commercial operations in the regions surrounding the lake. [ABSTRACT FROM AUTHOR]

The rupture of the Fundão dam released about 50 million m3 of mining tailings in the Doce river basin. To assess the potential for environmental contamination and the risks of residual exposure of the human population generated by these tailings, water and fish samples from the Doce river were collected 25 days after the accident and analyzed the physicochemical parameters of the water and levels of metals by ICP-MS, in addition to the temporal variability of the concentration of these elements through other studies. This was the first study to carry out an assessment of the health risk associated with the consumption of fish contaminated by metals from the areas affected by the disaster. The values of turbidity (5460 NTU), electrical conductivity (74.8 μS cm−1), total dissolved solids (892 mg L−1) and total suspended solids (772 mg L−1) were above the maximum limit allowed by Brazilian legislation, due to the presence of large amounts of solid materials released after the dam rupture. The analysis of metals in water samples indicated high concentrations of Al (1,906.71 μg L−1), Mn (370.32 μg L−1), Fe (8,503.50 μg L−1) and Hg (34.25 μg L−1), while for the fish samples, only As (1,033.98 μg kg−1) and Hg (herbivorous: 505.32 μg kg−1; predatory: 1,184.09 μg kg−1) presented levels above those established by Brazilian legislation. The health risk assessment showed that the estimated daily intake for Hg was higher than the reference dose, reinforcing the need for monitoring the area affected by the disaster. [ABSTRACT FROM AUTHOR]

In order to assess the metal pollution in the Wujiang River, concentrations of Cu, Zn, Fe, Mn, Pb, Cd, As, and Hg in the water, sediments, and two fish species Cyprinus carpio and Pelteobagrus fulvidraco from the middle reaches (Tuomugang, TMG) and lower reaches (Wulong, WL) of the Wujiang River were examined. The results indicated that all metal concentrations were lower than the values for grade one water quality according to the Environment Quality Standard for Surface Water of China (GB 3838–2002). The bioavailable fraction concentrations of Zn, Fe, Mn, Pb, and Hg in WL were significantly higher than those in TMG (p < 0.05), indicating that these metals in sediments of WL have higher bioavailability and mobility. The Cu, Zn, Fe, Pb, As, and Hg were mainly related to the residual fraction, while the Mn and Cd were mainly associated with the non-residual fraction. The risk assessment code (RAC) and the secondary phase to the primary phase (RSP) values indicated that Mn and Cd have a high risk of secondary release. The mean metal concentrations in the liver of the two fish species were higher than those in muscle. The higher metal concentrations of fish in WL suggested that bioaccumulation of metals in fish could be influenced by metal bioavailability. No identical relationships between metal concentrations and fish length were manifested in the present study. The values of target hazard quotient (THQ) and hazard index (HI), and carcinogenic risk (CR) of metals for the consumption of C. carpio and P. fulvidraco indicated that the anglers would likely not experience significant non-carcinogenic risk, but the carcinogenic risk of As cannot be ignored. Thanks to prohibited commercial fishing in the Wujiang River, the metal pollution will probably not pose a health risk to the general public for wild fish consumption. [ABSTRACT FROM AUTHOR]

Background. Estuaries are transitional coastal ecosystems that are threatened by multiple sources of human pollution. In 2015, mining tailings from an upstream dam failure caused massive metal contamination that impacted benthic assemblages on the Brazilian Rio Doce estuary. Methods. In this study, we investigate and compare meiofaunal assemblages with eDNA metabarcoding 1.7 years (2017) and 2.8 years (2018) after the initial contamination by mine tailings in order to evaluate the continued impact of sediment mine tailing contaminants on the structure of benthic assemblages after the disaster. Results. The community was dominated by Arthropoda and Nematoda 1.7 yr after the impacts (42 and 29% of meiofaunal sequence reads, respectively) but after 2.8 years Arthropoda (64.8% of meiofaunal sequence reads) and Rotifera (11.8%) were the most common taxa. This continued impact on meiofaunal assemblage revealed a lower phylogenetic diversity (7.8-fold) in 2018, despite overall decrease in metal concentration (Al, Ba, Cr, As, Fe, Zn, Mn, Pb, Cd, Co) in sediments. Our data suggests that differences in benthic assemblages and loss of diversity may be influenced by contaminants in sediments of this estuary, and indicate that broad eDNA assessments are greatly useful to understand the full range of biodiversity changes in dynamic estuarine ecosystems. [ABSTRACT FROM AUTHOR]

In this study, some physicochemical properties, concentrations of metals (Pb, Cd, Cu, Zn, Fe, and Mn), and the overall water quality from Bomadi Creek in the Niger Delta of Nigeria were assessed over two seasons. Water samples were collected from designated areas along the course of the river and were prepared for analysis by standard procedures. The ranges of the mean values for some water quality indicators were found to be as follows: pH: 7.40–8.17, turbidity (NTU): 20.5–42.3, total dissolved solids (mg L−1): 27.5–44.7, total suspended solids (mg L−1): 34.1–61.7, dissolved oxygen (mg L−1): 3.07–6.53, biochemical oxygen demand (mg L−1): 0.13–2.77, total hardness (mg L−1): 28.3–60.0, and nitrate (mg L−1): 0.37–0.92. Only the turbidity values exceeded the permissible limit of 5 NTU. The concentration ranges (mg L−1) for the six metal ions determined were: Pb: 0.01–0.02, Cd: 0.01–0.03, Zn: 0.1–0.3, Cu: 0.03–0.07, Fe: 0.6–0.9, and Mn: 0.01–0.05. There were no significant variations in many of the locations between the wet and dry seasons. The comprehensive pollution index values indicated severe pollution of the Creek, with Cd, Fe, and turbidity, identified as the major contributors to the deteriorated water quality. The sources of high loads of Cd, Fe, and turbidity in this river system include discharges from oil production activities, speed boats, illegal bunkering, and domestic waste dumps. Principal component and cluster analysis were used to establish relationships between the various parameters and sites. The risk assessment indicated adverse non-carcinogenic and carcinogenic risks arising from human consumption of the water. The risk is higher for children than adults. Therefore, the Bomadi water is considered unsuitable for drinking and other domestic purposes, and remediation is required. [ABSTRACT FROM AUTHOR]

Highlights: The sediments from all water bodies near the landfill are heavily polluted with Cr; Ecotoxicological studies on the sediments and water demonstrated the highest toxicity to tested species came from the nearest site to the slag heap; Noncancer and cancer risk calculations indicate possible adverse health effects for all sediments taken from the three water bodies; There is a high risk of possible health problems for fish consumers. This study assessed the possible impact of a former ferrochromium plant in Siechnice (Lower Silesia, Poland) on water reservoirs and living organisms. The metal concentrations (Zn, Cu, Pb, Fe, and Cr) in the sediments were determined, along with ecotoxicological studies that were conducted on both the sediments and the surface water of three water bodies that border the slag heap. The samples of the sediments and water were taken at different distances from the landfill area. The studies also covered a human health risk assessment. The highest concentrations of all the studied elements were observed in the sediments taken from the water reservoir closest to the landfill. In the case of the sediments, a 30% death rate for Heterocypris incongruens (Ostracodtoxkit F) was recorded at the same site. Additionally, at this site, the ecotoxicological studies on the surface water revealed the highest mortality for Daphnia magna (Daphtoxkit F magna) and the lowest values of LC50 for algae (Algaltoxkit). The health risk assessment of the sediments was estimated by calculating the noncarcinogenic health risk using the hazard quotient (HQ) and hazard index (HI), and the carcinogenic risk was calculated using the excessive risk of cancer development (ECR) measurement. The hazard index (HIing) for Cr exceeded 1 for children, which suggests that possible adverse health effects might occur for humans. The ECR values calculated for Cr and Pb were above the range limit of 10−6. The value for Cr was the highest for the sediments from the closest water reservoir to the landfill for both children and adults. Studies prove that the water reservoirs located near landfills pose potential ecological risks, and the risk is the highest where the distance is the shortest from the slag heap. In prospective human health risk assessments, the sediments from the closest water body pose a potential carcinogenic health risk to humans, especially to fish consumers, i.e., the residents of neighboring areas who might experience severe health problems from the intake of Cr and Pb through fish consumption. Significant steps should be taken to reduce Cr concentrations in the sediments to minimize the risk of human health adverse effects. [ABSTRACT FROM AUTHOR]

The surface and groundwater are the main sources for human consumption, and the groundwater is being used as a supplement where the surface water is not adequate due to insufficient accessibility and contamination. Fast growing population, anthropogenic activities creating serious environmental concerns on the deterioration of groundwater. The quality of drinking water has a significant effect on human health. Contaminated surface and groundwater may be the cause of a number of diseases in 3rd world countries. According to the survey conducted by Pakistan Council of Research in Water Resources (PCRWR) in 22 districts of Sindh, the weathering of rocks and anthropogenic activities are viewed as principal natural and artificial sources of heavy metals (HM). The aim of this research was to investigate concentration of heavy metal (Co, Cd, Cr, As, Cu, Mn, Ni, Zn, Pb, and Fe) and the quality of the groundwater of district Hyderabad, Sindh, Pakistan. The research examined the possible health risk of the population triggered by consuming heavy metals (HM). HM concentrations were analyzed by flame air-acetylene atomic absorption spectroscopy (FAAS) using standard burner head with 800 (Perkin Elmer, Singapore). The results were compared with the permissible limit of the WHO, and samples of reference water (Rfw) were collected from a water supply scheme of Hyderabad city. The health risk assessment of hazard quotient (HQ) and chronic daily intake (CDI) was calculated based on the concentration of HM. The CDI values for groundwater Hyderabad rural (GWHR) and groundwater Hyderabad city (GWHC) were higher than the threshold value of 1.00 shown in decreasing order Zn > Fe > Ni > Pb > Mn > Cu > Cd > Cr > Co and Fe > Zn > Cr > Mn > Ni > Co > Pb > Cu, respectively. The HQ values of GWHR and GWHC were found greater than 1.00 in lowering order: Cd > Co > Pb > Cu and Co > Cd > Pb and Cr, respectively. The results of CDI and HQ values were calculated greater than the safe limit 1.00 for multiple metal ions and may be a cause of indicated health risk for the consumers of the district of Hyderabad. This study confirmed that specific methods are required for the incorporated evaluation of the groundwater pollution and affords a systematic foundation for the strategic destiny making plans and complete management for the availability of hygienic water for the habitants of the study area. [ABSTRACT FROM AUTHOR]

Wastewater reuse in irrigation is an integral part of water resource management (IWRM) that aims to cover agricultural water requirement in water-scarce regions. Taken the example of Yemen, recent study assesses the quality of Sana'a municipal wastewater for irrigation use and addresses the degree of health risk of consuming crops irrigated with wastewater. More than 50 samples from wastewater discharge canal and also from leaves, grains, and fruits were analyzed for physicochemical parameters, heavy metals, and pathogen content. The average of the physicochemical concentrations is 1808 μs/cm, 9.88 meq/L, 7.8, 125, 81.3, 34.9, 360.3, 36.5, 10.93, 94.7, 315, 609, and 215 mg/L for EC, Na, pH, NH3, Ca, Mg, T.H, K, NO3, SO4, BOD5, COD, and SS, respectively. ANOVA test indicates a significant difference between the sampling groups with p value of 0.02. The physicochemical concentrations were high in the influent group and gradually decreased at different distances from the wastewater treatment plant, which may attribute to the role of natural processes (sunlight, air temperature, aeration), and the contact of wastewater flow with earth materials in minimizing their concentrations. Heavy metals, on the other hand, are not at high levels. Their average concentrations in the sampling groups are 0.04, 0.002, 0.20, 0.06, 0.008, and 0.011 ppm for Mn, Cu, Ni, Zn, Cd, and Pb, respectively. The result of fecal contamination, mainly fecal coliforms (FC) and the total coliforms (TC), demonstrated beyond question that pathogen content is extremely high. After treatment, the pathogen number decreases considerably in all sampling groups along the discharge canal with p value of 0.00. Comparison between crops irrigated with wastewater (WW) and those irrigated with groundwater (GW), T-test showed great variation in the number of FC and TC between both fields with p value of 0.03. Increasing the time between irrigation and harvesting has resulted in a massive decrease of pathogen number. After 10 days from the irrigation day, fecal (FC) and total coliforms (TC) decreased to 85% on vegetables, such as cabbage, onion, barley, and leek, and up to 80% on alfalfa. Moreover, the quality of Sana'a wastewater for irrigation use is varied from one site to another. Group two (G2), group four (G4), and group five (G5) displayed lower number of pathogen content and showed acceptable physicochemical concentrations. Thus, water from these locations can be reused to irrigate salt-tolerant vegetables and cocked-eaten crops such as the examples presented in this study. [ABSTRACT FROM AUTHOR]

The primary goal of this study was to determine and evaluate the concentration and contamination of heavy metals like (As, Cd, Pb, and F) in the groundwater of Umerkot city in Sindh Pakistan. The groundwater samples were collected using 22 hand pumps installed at different public locations in the Umerkot city; the latitude and longitude readings of all the sampling points were noted. The EPA ICP-MS Method 200.8 was adopted for determination of heavy metals such as arsenic, cadmium, and lead. The EPA 8029 SPADNS method was used to determine the fluoride concentration in groundwater samples; the DR-900 Multi parameter Portable Colorimeter was used. The spatial distribution thematic maps of each metal were constructed by interpolating the spatial variation of each groundwater quality indicator using the spatial interpolation IDW tool. The concentrations of arsenic and fluoride in groundwater range from 0.6 to 23 ppb and 0.6 to 3.2 mg/L, respectively. The anthropogenic factors, such as lack of drainage patterns and municipal waste, as well as the mineral composition of the subsurface strata originating from the A-type granites and ferromagnesian minerals present in sedimentary rocks (e.g., biotite and amphibole) contribute to the elevated concentration of these toxic metals in the subsurface aquifer system of the study area. Due to high concentrations of arsenic and fluoride, much of the groundwater in Umerkot city stands unsuitable for drinking. [ABSTRACT FROM AUTHOR]

Kalpani River, Pakistan is an important stream that collects more than two third of the untreated domestic, commercial, industrial, and sewerage water, agricultural overflow, and other unwanted effluents of the surrounding area. These effluents have degraded the overall quality of this river water. The current study aims to examine the concentration of selected heavy metal (HM) contamination in Kalpani River sediments. The HMs studied were Pb, Cd, Zn, Ni, Fe, and Cu. Sediment samples were taken from nine selected locations (labeled as P1, P2, P3, ... P9) and tested for HM contamination. The HMs contamination level in the sediment was computed using the contamination factor (CF), pollution load index (PLI), and geo-accumulation index (Igeo). All three indicators revealed that the Kalpani River in Mardan city is polluted with hazardous HMs such as Cd, Pb, and Zn. Pb, Ni, Fe, and Cu CF levels in sediment samples ranged from low (< 1) to moderate (1–3). However, the CF values for Cd and Zn indicated being highly polluted (> 6). The PLI values along the Kalpani River varied considerably and were observed lower upstream (P1 and P2, i.e., 0.821), highest (1.229) at the middle course, and lower (0.897) downstream. The Igeo for the studied HMs ranged from moderately to strongly polluted. The primary anthropogenic sources responsible for HM pollution in the Kalpani River were improper waste dumping, untreated sewage urban and industrial wastewater into the river, and excessive pesticide usage. [ABSTRACT FROM AUTHOR]