Metal Concentrations In Water Research Articles

Study on spatial distribution, potential sources and ecological risk of heavy metals in the surface water and sediments at Shanghai Port, China

Heavy metal concentrations in surface waters and sediments of Shanghai port were measured to analyze the spatial distribution characteristics, sources and pollution degrees. The southern Shanghai port was heavily polluted by Cd, Pb, Cr and Cu in water, and the concentrations of Pb, Hg and Zn in sediments exceeded Effects Range Low. Cu, Pb, Cd and Cr in water were positively correlated in group, and they probably derived from industrial and domestic sewage, fossil fuel burning and vehicular pollution and represented 82.47 % of the contribution. Zn, Hg and As contaminations represented industrial and agricultural effluent sources and accounted for the remaining 17.53 %. Heavy metal pollution of Yangshan Port water was at high pollution, and the remaining sites were at low pollution. Most of the sampling sites were at moderate ecological risk in sediments, and the pollution of Cd, Hg and Zn were serious.

КОМПЛЕКСНИЙ ПІДХІД ДО ОЦІНКИ ЗАБРУДНЕННЯ ВАЖКИМИ МЕТАЛАМИ ЕКОСИСТЕМ МАЛИХ РІЧОК ЗАХІДНОГО ПОДІЛЛЯ

The metal content (Ferrum, Cobalt, Manganese, Zinc, Copper) in water, bottom sediments and tissues of freshwater fish (carp, crucian carp, pike, perch) from small rivers of Western Podillya (Seret, Strypa, Zolota Lypa) was studied. High concentrations have been found in the water and bottom sediments of the Ferrum and Manganese, which is probably due to the inflow of these metals from the bottom sediments in conditions of oxygen deficiency. The high content of mobile form of Ferrum, Cobalt, Manganese in the bottom sediments of the Zolota Lypa can lead to secondary pollution of the water column and pose a potential danger to aquatic organisms. Individual mechanisms of accumulation and distribution in the body of fish were established for different metals. Higher concentrations in the liver and gills of the studied fish species of Ferrum, Manganese and Zinc and significantly lower contents of Cobalt and Copper were observed. The metal content in fish tissues was characterized by high variability, had a pronounced tissue and species specificity. Correlation relations between metal content in water, bottom sediments and fish tissues from small rivers of Western Podillia are analyzed. Positive correlations have been established between the content of the gross form of Ferrum in the bottom sediments, in the gills of crucian carp, perch and pike and the liver of perch and pike. The amount of Manganese in the water correlated with the metal content in the gills of carp and pike. The increase in the amount of Zinc in the bottom sediments (gross form) led to its accumulation in the gills of all fish species, as well as in the liver of perch and pike, as evidenced by the high positive values of Pearson's coefficients (0.71-0.91). The Copper content in water and bottom sediments (gross form) correlated with their amount in the liver of perch and pike, which may serve as a bioindication of pollution of aquatic ecosystems by this metal.

Assessment of seasonal changes in biochemical composition of freshwater bivalve, Parreysia cylindrica in relation to heavy metal pollution of Jayakwadi reservoir (M.S.), India

The objective of present study is to determine seasonal changes in biochemical content of freshwater bivalve, Parreysia cylindrica in relation to heavy metal pollution of Jayakwadi reservoir. Heavy metal concentrations were determined seasonally from surface water, soil sediment and soft body tissues of freshwater bivalve, Parreysia cylindrica. The heavy metal concentrations in surface water, soil sediment and soft body tissues of Parreysia cylindrica were highest during summer season than winter and monsoon season. The Protein, DNA, RNA and Ascorbic acid content were estimated during summer, monsoon and winter season from mantle, gills, digestive glands and whole soft body tissues. In the present study Protein, DNA, RNA and Ascorbic acid content were highest during monsoon than summer and winter season.

Heavy metal concentration in water, soil and cultivated vegetables at the edge of Kashaf Roud River, Mashhad, Iran: ecological risk assessment and bioaccumulation factor

ABSTRACT The entrance of heavy metals through human activities causes pollution of water, soil, and plants. The aim of this study was to measure the heavy metals concentration (Hg, Pb, As, and Cd) and their ecological impacts on water, soil, and vegetables in the Kashaf Roud River basin. Hence, 72 samples of irrigation water, 72 samples of soils, and 216 samples of vegetables (dill, leek, and basil) were collected. The contamination levels were evaluated by several ecological indices including Ecological Risks index (ERI), Heavy Metal Evaluation Index (HEI), Contamination factor (Cf), Pollution Index (PI), geo-accumulation index (Igeo), Potential ecological risk index (RI), Pollution load index (PLI), and modified degree of contamination (MDC). Based on obtained results, concentrations of heavy metals in water and soil samples were in the order of Pb>As>Cd>Hg. In addition, Pb and As had the highest concentration in vegetables with the mean total concentrations of 1.60 and 0.08 mgkg−1 wet weight, respectively. According to ERI value (238), water sampling site no. 3 had higher pollution than other places and was classified in the considerable ecological risk. Among the soil samples, the Cf average values followed the declining order of Cd (7.78)>Pb (6.91)>Hg (4.26)>As (2.68), so that Pb and Cd presented high contamination levels. Moreover, all soil samples of the studied region possessed PLI>1, which confirms their contamination with heavy metals. Finally, the trends in the BAF values for heavy metals in various vegetables were in order of Hg>Cd≈Pb>As for Leek and Hg>As> Pb>Cd for Dill and Basil. Concentrations of heavy metals in soil and water samples were within the national and international standard ranges. However, the concentrations of these metals in some vegetable samples exceeded the national and international levels. The utilisation of standard quality effluent for agricultural irrigation requires control measures and good organisational performance.

Heavy Metal Pollution Characteristics and Risk Assessment of Golden Snub-nosed Monkey (Rhinopithecus roxellana) Habitat in Shennongjia Mountains

The golden snub-nosed monkey is one of the most endangered animal species endemic to China. In order to explore the characteristics and health risks of golden snub-nosed monkeys exposed to heavy metals, we collected the plant food sources, soil, and water samples from the golden snub-nosed monkey habitat in the Shennongjia Mountains; examined the contents of seven heavy metals (Cu, Zn, Pb, Cd, Cr, Ni, and As); and adopted the comprehensive pollution index, potential ecological risk index, and Nemerow index to evaluate pollutants in the water, soil, and food plants. At the same time, the Target Hazard Quotient method was used to assess heavy metals in the food plants. The results showed that the heavy metal concentration of the habitat water was 0.004-1.220 μg·L-1. The water comprehensive pollution index showed that the habitat water was safe. In addition, the ω(Cd)(0.162-0.822 mg·kg-1) in the soil was 2.71 times the background value of the soil in Hubei province, indicating a moderate risk of ecological harm. The over-standard rates of Pb, Cd, Cr, and Ni in food plants were 29%, 29%, 18%, and 35%, respectively; the pollution indexes of lichen and bark were 6.038 and 7.709, which were at a heavy pollution level; and the pollution indexes of Abies fragesii and Vicia cracca were 2.716 and 2.034, which indicated a moderately polluted level. The rest of the plants were at a safe level. Our health risk analysis showed that the risk of lichen and bark were higher than that of leaves, followed by fruits. Among the seven metals, As most threatened the health of the golden snub-nosed monkeys (THQ>1). In general, heavy metals had polluted the habitats of the golden snub-nosed monkeys in the Shennongjia Mountains, and we are certain that the heavy metal pollution was associated with human activities. Thus, human activities in the Shennongjia Mountains should be reasonably restricted in the future. Our results can provide scientific support for the population conservation of golden snub-nosed monkeys in China and provide research samples in the health risk valuation of heavy metals in endangered animals through food plants.

Heavy Metals (Hg, Cd, Pb, Cu) in Greenback Mullets (Planiliza subviridis Valenciennes, 1836) from Bojonegara coastal waters, Banten Bay, Indonesia

Waste from industrial activities can be a source of pollution for the waters of Banten Bay. One source of these pollutants are heavy metals. High concentrations of heavy metals in waters can pollute the aquatic environment, endangering all organisms. Heavy metals can accumulate in aquatic environments and living organisms such as fish. The greenback mullet Planiliza subviridis (Valenciennes, 1836) is known as a fish for human consumption. Heavy metals that are contained in mullets can move to a higher trophic level within the food chain and endanger the health of humans. This study aims to analyze the accumulation of heavy metals, such as Hg, Cd, Pb, and Cu, in the flesh of greenback mullets at Bojonegara Waters of Banten Bay. The research was carried out for five months (August - October 2020 and March - April 2021). Samplings were taken from Terate River and Wadas River, which are mullet fishing areas and natural habitats of these mullets. Data analysis consisted of descriptive and quantitative analyses. The results showed that the Hg, Cd, Pb, and Cu contents were below the quality standards based on Government Regulation of the Republic of Indonesia (PP RI) No. 22 of 2021. The greenback mullets have experienced a moderate accumulation rate. The different rates of Cu metal accumulation in each month indicate a variation in catches with low to moderate accumulation rates. The water conditions in Bojonegara can still be seen as tolerable and still suitable for mullets usable for human consumption in a reasonable amount. Monitoring and evaluation activities need to be carried out periodically for the management of the aquatic environment in Bojonegara.

Evaluation of heavy metal pollution from coastal water of Nizampatnam Bay and Lankevanidibba, East Coast of India

Thirty locations in the Coastal area of Nizampatnam Bay and Lankevanidibba were studied for heavy metals and their concentrations in the Coastal water. The samples were analysed for Cd, Co, Cr, Fe,Mn,Pb, and Zn to evaluate metal concentrations in coastal water. The concentration of metals Cd, Co, Cr, Fe, Mn, Pb, and Znwere determined by ICP-OES, in coastal water. The concentration of Cd (Cadmium) is demonstrating elevated contamination in all the sampling sites. The coastal wateris polluted by heavy metals like,Mn and Zn. It acts as a sink for the multitude of anthropogenic sources in the study area.The metals were identified in allcoastal water samples were proxies of pollution,Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-OES-Perki Elmer-Optima 4300 DV) is an analytical technique used for elemental determinations and instrument was utilized for water analysis. Based on the order of accumulation the metal content was more and as a result pollution was more in the coastal water due to release of industrial wastes and anthropogenic activities.The comparison of Premonsoon and post monsoon is given.Premonsoon:Pb (16.049 μg/L), Zn (7.998 μg/L), Mn (15.976 μg/L), Ni (8.827 μg/L), Fe (10.028 μg/L), Cd (9.221 μg/L), Cu (11.744 μg/L), Cr (10.486 μg/L), post monsoon: Pb (15.952 μg/L), Zn (8.084 μg/L), Mn (20.437 μg/L), Ni (8.583 μg/L), Fe (0.763 μg/L), Cd (4.837 μg/L), Cu (12.116 μg/L), Cr (8.008 μg/L).

Heavy Metal Concentrations in the Surface Water of a Crater Lake in Southern China

Heavy Metal Concentrations in the Surface Water of a Crater Lake in Southern China

Determination of Heavy Metals Concentration in Water and Soil at Various Locations in Lahore and their Harmful Impacts on Human and Plants life

Heavy metals poisoning of soil and water has resulted from industrial expansion in Lahore, Pakistan, creating a significant environmental hazard. As a result, monitoring the contamination of soil and water around industrial sites is critical. The fact that higher concentrations of heavy metals have a negative influence on both plants and human life and this cannot be ignored. Higher heavy metal concentrations have a direct impact on human health due to their presence in drinking water. Consumable plants and vegetables cultivated in these polluted areas may collect higher concentrations of heavy metals from soil and water via the phytoremediation process. Its worth mentioning that the accumulation of toxic metals in edible plants and vegetables also has a direct negative impact on human and animal health. The purpose of this study is to find the heavy metals concentration in the soil and ground water in the Lahore area. Five industrial zones were evaluated for water and soil throughout the research period of December 2021 to January 2022 (pre-monsoon). pH and heavy metals content measurements were performed on the collected soil and water samples. We discovered that the water had a higher pH and that the soil was heavily contaminated with significantly higher concentrations of toxic heavy metals. According to the research, there is a gangrenous influence of pollution caused by industrial waste and the surrounding environment on soil and water resources, which affects living creatures. Keywords: Environmental Pollution, Heavy Metal, Pollution, Water pollution, Soil pollution

The antioxidant defense capacities and histological alterations in the livers and gills of two fish species, Oreochromis niloticus and Clarias gariepinus, as indicative signs of the Batts drain pollution

The impacts of the Batts drain on two chronically exposed fish (O. niloticus and C. gariepinus) were assessed using multiple biomarkers. Concentrations of metals in water and sediments (Cu, Zn, Fe, Cd, Pb, and Al) showed significant elevations near the Batts discharges (site 2) compared to the reference site (site 1). The liver and gills of fish collected from site 2 showed marked elevations in the catalase, superoxide dismutase, glutathione peroxidase, and thiobarbituric acid reactive substance levels. In addition, significant reductions in glutathione-reduced contents were also recorded. Tissue and species-specific antioxidant responses were associated with excessive generations of reactive oxygen species, which were visualized fluorescently. Various histological alterations were observed in the gills and livers of both species. These alterations varied between compensatory responses (ex: epithelial thickening and lifting) and irreversible damage (ex: necrotic degeneration). Based on the level of lipid peroxidation and the frequency of histopathological modifications, O. niloticus demonstrated greater resistance to the same level of pollution than C. gariepinus. Using integrated biomarkers to evaluate the real impacts of untreated discharges of the Batts drain is applied for the first time on the selected fish species at the studied sites.

Concentration of Heavy Metals in Sediment and Water of Përlepnica Lake, Kosovo

Concentration of Heavy Metals in Sediment and Water of Përlepnica Lake, Kosovo

Risk Assessment of Heavy Metal in Soil Content and Portable Water: A Review of the Literature

Extant studies have revealed that water and soil pollution are among the major global challenges that society must address in the 21st century aiming to improve water quality and reduce human and ecosystem health impacts. Industrialization, climate change, and expansion of urban areas produce a variety of water and soil contamination. In this study, the authors discussed some of the relevant findings in extant literature related to the release of heavy metals into water and soil content, that is affecting agricultural practices, and hence, serve as possible risks for human health. Thus, the aim of this study is to review previous research work done by other authors on heavy metals in water and soils, detection, poisoning, damages to human health and treatments of agricultural soils as noted in some studies. The study adopts an extensive review of literature such as conference papers, journal articles, internet sources, books to find out concentration of heavy metals in agricultural soils and water. After analysis and review of such secondary articles, the current studies found that heavy metal in portable water and soil is a source of major concern and should be regularly checked and monitored by appropriate regulatory agencies. In addition, some previous researchers found that anthropogenic activities are identified as the main source of the increasing amounts of heavy metals found in water and soil. Some of the health hazards derived from repeated exposure to traces of heavy metals, including lead, cadmium, nickel, and zinc, were also reported in this study. The authors also stated the methods in which this contamination occurs and ways to prevent future contamination as discussed by various authors. This study concluded that heavy metals are the main cause of water pollution and impact human health worldwide. Keywords: Heavy Metal: Water: Contamination: Pollution: Human Health: Anthropogenic Factors: Nigeria.

Concentration, Health Risk, and Hydrological Forcing of Heavy Metals in Surface Water Following Water-Sediment Regulation of the Xiaolangdi Dam in the Yellow River.

Water and sediment regulation aimed at aquatic ecosystems and preserving reservoir capacity to minimize the negative consequences of dams can fundamentally change the distribution of heavy metals (HMs) in the reservoir and downstream reaches. However, the effects of water and sediment regulation on variation in HMs are still poorly understood. In this study, the variations in concentration, contamination, human health risk, potential sources, and influencing factors of the metalloid As and HMs (Cr, Hg, Ni, Pb, and Zn) in surface water in the reservoir and the downstream reach of the Xiaolangdi Dam (XLD) following the operation of the water-sediment regulation scheme (WSRS) were determined. These results indicate that HM concentrations in the two post-WSRS seasons were much lower than the water quality standards, but were significantly increased over time due to the trapping effects of the XLD (p < 0.05, except for Zn). However, As concentration in the reservoir was significantly lower than that observed in downstream reaches, likely due to anthropogenic input from agricultural activities. Meanwhile, HM concentrations varied with distance to the dam, which displayed a distinct accumulation closer to the dam in the post-WSRS II season. The contamination of HMs, the carcinogenic risk of exposure to As, and the noncarcinogenic risks associated with exposure to Hg, Ni, Pb, and Zn via the direct ingestion pathway of drinking water were all within acceptable levels following the WSRS, but increased over time. The carcinogenic risk of Cr in the post-WSRS II season was at an unacceptably high level, particularly at sites near the dam. Hydrological characteristics (water level and flow rate) were the dominant factors in determining the distribution of HMs. These results can provide new insight for a better understanding of the variations in HMs following the water and sediment regulation practices, and guide future management in regulating the trapping effects of dams.

Assessment of heavy metal concentrations as indicator of pollution in Clarias gariepinus (African catfish) of Warwade reservoir, Dutse, Jigawa State-Nigeria

Pollution status of Warwade reservoir was assessed using heavy metals bioaccumulation in water, gills and liver samples of C. gariepinus between July and December, 2019. Heavy metals analyses were carried out using microwave plasma atomic spectroscopy (MP-AES). Water and fish were sampled fortnightly from the three sites coded as upstream (A), midstream (B) and downstream (C) between 7:00 – 7:30am for period of six months. The results revealed that heavy metal concentrations in water followed the order: Cr (2.15mg/L)&gt;Cu (1.40mg/L) &gt; Pb (0.89mg/L)&gt; Cd (0.68mg/L). Bioaccumulation Factor (BAF) of heavy metal concentration in water decreased in the order of Cr &gt; Pb &gt; Cu &gt;Cd. In the fish organs, gills had the highest value of Cr, followed by Pb, Cu and Cd recorded the lowest. The BAF in liver tissues decreased in the order of Cu &gt; Pb &gt; Cr &gt;Cd. BAF for Cu was highest in liver tissue (2.90) while the lowest was obtained in the gills (1.04). Lead (Pb) had its highest value in liver (2.16) and the lowest value (1.33) was obtained in the gill. BAF in Cr had its highest value of 2.15 in water and the lowest was obtained in the gills. Heavy metals bioaccumulation differed significantly (p&lt;0.05) between the sampling sites and seasons with the exception of cadmium which did not differed significantly (p&gt;0.05). It can be deduced that heavy metals bioaccumulation in the fish tissue is attributed to the influx of chemicals into the reservoir as a result of agrochemicals input among other anthropogenic activities. It is recommended that indiscriminate release of the xenobiotic compounds should be minimized in order to avert degradation of the reservoir in the long run. Intervention by appropriate authorities to curtail the effects of heavy metals on fish species among other important biota is recommended.

Assessment of heavy metal contamination levels and health risks in environmental media in the northeast region

• Analyze heavy metal contamination levels in soil, water, and air. • Heavy metals from media are hazardous to human health in many ways. • Major pollution is affected by industry and agriculture. • Characterization of human contamination by heavy metals in human hair. • Environment causes health hazards to humans and makes sustainability suggestions. Rapid development in Northeast China has brought serious heavy metal pollution to the environmental media (soil, surface water and air). This paper presents a study on the spatial and temporal distribution, source analysis, potential ecological risk and human health risk assessment of heavy metals in environmental media in Northeast China, aiming to provide a theoretical foundation for controlling and reducing heavy metal pollution. The study shows the following results:1. Developed cities in Jilin Province (Changchun and Jilin) have the most serious heavy metal pollution. 2. The main sources of heavy metals in soil are metallurgical production and agricultural production. The main sources of heavy metals in surface water are industrial production, domestic waste, and sewage. The main sources of heavy metals in the air are vehicle emissions, biomass combustion and coal burning for winter heating. The sources of heavy metals are listed in order of decreasing significance in all three cases above. 3. Soil, surface water and air heavy metal concentrations all have a significant impact on human health. 4. Heavy metals in soil, surface water and air are an ecological risk and already pose a carcinogenic risk to humans.

DETERMINATION OF HEAVY METALS STATUS IN OSARA DAM

Environmental risk assessment and water quality management are becoming increasingly important issues, particularly in view of the large number of contaminants entering the aquatic environment that are harmful to the functioning of an ecosystem. Interest in metals like Zn, Cu, Fe and Mn, which are required for metabolic activities in organisms, lies in the narrow "window" between their essentiality and toxicity. Other heavy metals like Cd, Hg, Cr and Pb may exhibit extreme toxicity even at low levels under certain conditions, thus necessitating regular monitoring of sensitive aquatic environments. The study determines the heavy metal concentrations of water from Osara dam in Kogi central area, as well as their sediments and edible parts of two fish species using ICP-OES. Water samples were collected from eight selected sampling sites from Osara dam. There results were below or within the range of the recommended limit of WHO and other recognized regulatory bodies. Similarly, the head, gills, muscle, and liver of the two fishes sample collected from Osara dams were found to contain all the analysed heavy metals (Mn, Cu, Pb, Cd, Fe, Zn, Cd, Cr, Ni, and Hg) at different levels. Some of the determine metals in the parts of the fishes may not be harmful to consumers because the observed values of heavy metals were below the permissible limits issued by WHO and other recognized regulatory bodies for human consumption however, elements like Cr, Ni and Pb call for serious concerned. Finally, Pearson’s correlation at 95% confidence levels of significance was calculated for finding relationship between elements content in water and fish sample. Significantly positive and negative correlation was observed between different elements in water and fish samples.

Effects of Trace Metals and Municipal Wastewater on the Ephemeroptera, Plecoptera, and Trichoptera of a Stream Community.

Simple SummaryMayflies (Ephemeroptera), stoneflies (Plecoptera), and caddisflies (Trichoptera) (EPT) are aquatic insects that are well known to the general public and are commonly used as indicators of environmental quality in water management. Knowledge of how EPT communities react to human-induced gradients in real environments can be important, for example, during the assessment of the implications of newly planned or currently active human disturbances for natural or cultural landscapes. We sampled a stream ecosystem affected by mining and smelting industries and communal wastewaters with pronounced concentrations of cadmium, lead, and zinc, as well as high levels of pesticides, pharmaceuticals, illegal drugs, and sewage-derived organic matter. Changes in other environmental factors such as increases in temperature were also studied at the affected sites. The abundance and species richness of stoneflies fell rapidly at the study sites. The richness of mayfly families also declined, from four to one, even though overall mayfly abundance was not affected. Conversely, the abundances of caddisflies were higher at the affected sites, and their richness did not decrease. This study will provide feedback for ecotoxicologists who perform better controlled and manipulated tests in laboratories, although any such test results are limited by simple artificial environments.Abundances of EPT larvae sampled in a Central European locality affected by mining and smelting, as well as by the continual inflow of treated communal wastewaters (WWs), were recorded. High concentrations of trace metals in water (maximum 1200 µg·L–1 for zinc) and sediments (maximum 140,000 mg·kg–1 in dry weight for lead) were found at the most contaminated sites. The highest loads of pesticides, pharmaceuticals, and illegal drugs were found under the WW effluent. Other associated factors such as the physicochemical parameters of the water and alterations to microhabitats were also evaluated and taken into account. Although EPT richness was lower at affected sites, abundances did not fall. Stoneflies were dominant at unaffected sites, while caddisflies dominated at affected sites. Only baetid mayflies were detected at the sites contaminated by trace metals and WWs; ephemerellid, heptageniid, and leptophlebiid mayflies were absent from these sites. The site contaminated by trace metals was also inhabited by numerous limnephilid caddisflies, in which limb malformations were detected in up to 11.8% of all specimens of a single taxon. Downstream from the entrance of the WWs, the locality was dominated by hydropsychid caddisflies. The increasing prevalence of predator or passive filter-feeding strategies in these EPT communities was significantly related to increasing water conductivity and acute ecosystemic exposure to ‘poorly treated’ WWs.

Short−Term Assessment of Heavy Metals in Surface Water from Xiaohe River Irrigation Area, China: Levels, Sources and Distribution

The aims of this study were to determine the pollution characteristics of heavy metals and their potential harm to human health in the surface water of agricultural irrigation areas, China, over a short term. In this study, Cu, Zn, Pb, Hg, Ni, Cr, Cd, and As in surface water of the Xiaohe River irrigation area were detected and analyzed. The results showed that the concentrations of Pb, Hg, Ni, Cr, Cd, and As exceeded the national environmental quality standard for surface water in varying degrees. The concentrations of heavy metals in surface water in October were significantly lower than that in November and December due to the impact of extreme precipitation events. Point source pollution (industrial sewage, etc.) was the main factor affecting the spatial distribution of heavy metals. The main source of heavy metals in October was domestic sewage. Domestic sewage and industrial sewage were the main sources of heavy metals in November. The sources of heavy metals in surface water in December were relatively diverse, and industrial sewage was the main source. The temporal variation of heavy metal pollution sources changed significantly. Industrial sewage was the main pollution source of heavy metals in surface water in the study area. The impact of urban domestic sewage and agricultural activities cannot be ignored. The health risk of heavy metals in surface water mainly depends on Cr, Cd, and As. Policy recommendations were also proposed for better control of heavy metal pollution in the surface water of river ecosystems involving agricultural irrigation areas.

From sediments to soils: changes in pore water metal bioavailability

The use of sediments as soils is an area of interest for Beneficial Use of dredged sediments. In this study the impact of the transition from sediments to soils is researched by looking at the seasonal and long year (10 year) change in pore water metal chemistry of sediments which are considered clean (class A) according to the Dutch soil directive. This study is based on a combination of geohydrological, geochemical and ecotoxicological risk models and validated against measured pore water concentrations for metals over an dry/wet period. The pore water metal concentrations are compared against standards and expressed as at Risk Characterization Ratio’s (RCR) values. The RCR values are high (> 1) during the first 3 years after the application of sediments as soil, especially at the end of the summer. The multi substances Potentially Affected Fraction (ms-PAF) shows a similar trend as the RCR values, although it takes 5 years before the combined calculated potential ecotoxicity is below the legal 40% threshold level. Translated to land use, it is advised to restrict land use for farming on soils where these clean (class A) sediments are applied for a five-year transition period.Article HighlightsBeneficial Use of sediments should take into account the different conditions when used as soils.Use of sediments as soils lead to a predicable seasonal and multiple year trend in metal concentrations in pore water.The predicted results in metal pore water concentrations are translated into an advice for temporal land use.

Assessing the Environmental Impact of Artisanal Gold Mining Activities on the Waters and Sediments Around Meli, Northwestern Tigray, Ethiopia

The paper presents the environmental impact of artisanal gold mining activities on the waters and sediments around Meli, northwestern Tigray, Ethiopia. Stream sediment, water, and tailing samples were collected in the dry season in January of 2019 and analyzed for heavy metals Cu, Zn, Pb, and As. The physicochemical parameters (pH, EC, major cations, and anions) of a few water samples were also measured. Flame atomic absorption spectrometry was used to determine the level of the metals in stream sediments. The results show that tailing has the highest concentration of metals followed by the stream sediments. The least concentrations are recorded in water for all metals. Pb has the highest mean concentration of all heavy metals in stream sediments, waters, and tailing samples. The mean Geo-accumulation Index (Igeo) and Contamination Factor (CF) suggest that the sediment represents uncontaminated to moderately contaminated classes. Concentrations of Cu and Zn in the water samples are generally within the maximum allowable concentration of the WHO, whereas concentrations of Pb and As are above the limit. Metal Index for surface and groundwater suggests that the area is polluted with heavy metals Pb and As. The main sources of the metals are assumed to be the sulfide ores facilitated by natural weathering processes and artisanal mining activities like excavations, crushing, grinding, and amalgamation processes. The Gibbs and Durov plots show that major hydrogeochemical processes controlling the water chemistry are water-rock interactions with considerable mixing of water types.&#x0D; &#x0D;