Metals In River Water Research Articles

Assessment of hydrochemical characteristics and trace metals of Punpun River water – a tributary of the Ganga River

ABSTRACT This manuscript presents the first inventory of dissolved ions (cations and anions) and trace metals (Pb, Mn, Cr, Co, Ni, Cu and Zn) in the Punpun River water to assess its irrigational suitability, pollution sources and hydrogeochemical processes. For this, the physicochemical parameters and trace metals in river water were analysed in the pre- and post-monsoon seasons. The results showed that the concentrations of cations and anions were Ca2+ > Na+ > Mg2+ > K+ and HCO3− > SO42- > Cl− > NO3− > PO43-, respectively, in both the pre- and post-monsoon seasons. However, trace metal concentration in pre- and post-monsoon followed the trend of Pb > Mn > Cr > Ni > Cu > Zn > Co and Pb > Ni > Mn > Cr > Zn > Co > Cu, respectively. The results reveal that combined effects of rock weathering and evaporation-concentration influence hydrochemistry, along with anthropogenic factors like industrial effluents, urban domestic sewage and agricultural runoff. Piper and Durov plots suggest that the river water is dominated by Ca–Mg–HCO3− type, and the processes were governed by simple ion dissolution and mixing. However, the Gibbs plot shows that silicate and carbonate weathering govern the hydrochemical properties. Irrigational indices like sodium adsorption ratio, %Na, residual sodium carbonate, Kelly's ratio, magnesium hazard, and trace metals indicate that most of the water samples are suitable for irrigation. Comprehensive pollution index values suggest that the river water quality ranges from sub-clean to slightly to moderately polluted.

Spatial and temporal distribution of geochemical elements and their processes in different size fractions–Miri River (NW Borneo)

The toxicity, persistence, and propensity for accumulation of metals in aquatic environments have raised significant concerns globally. Expansion of urbanization with the growth of industrial and agricultural sectors in Miri City results in a high concentration of pollutants that flow directly into the Miri River. Hence, this study provides a comprehensive analysis of the Miri River water quality, focusing on spatial and temporal variations. River water samples were collected in two different time periods and analysed for physico-chemical parameters includes major ions, nutrients, metals and isotopes. Particularly, the metals were analysed in different size fractions (particulate and colloid) of the suspended solids. Geochemical plots, pollution index, geochemical modelling and factor analysis were used for the data analysis. Interpretation of data reveals that the mean concentration of metals in river water were increased from downstream to the upstream of the river irrespective of the seasons. Major ions were mostly derived from the chemical weathering of source rocks, which was supported by the Gibbs plot. Piper plot indicates the seasonal shifting of water types from Ca–Mg to Na–Cl. Isotopic signatures reveal direct atmospheric precipitation and evaporation were the major origins of river water. Fe was the dominant metal concentration in river water irrespective of the seasons (mean concentration 1.05 mg/L). Fe and Zn were the dominant metal concentration observed in all the 3 size fractions of suspended solids. Industrial activities and seawater influx dominate in the downstream, whereas weathering and agricultural inputs are significant in the upstream of the river. Particulate and colloidal fractions are the major contributors for the metal transport in the midstream and downstream of the river. The outcome of this study offer a thorough understanding of the seasonal elemental distribution at different size fractions, geochemical behaviour and the pollution status of the Miri River. With this knowledge, sustainable management strategies can be developed for this crucial water resource to the benefit of Miri community.

DEVELOPMENT OF TRACE METALS CONCENTRATION MODEL FOR RIVER: APPLICATION OF PRINCIPAL COMPONENT ANALYSIS AND ARTIFICIAL NEURAL NETWORK

Rapid development along the Kuantan River was long perceived as the rivers serve many communities in terms of drinking water source, domestic, fisheries, recreation, and agricultural purposes. Due to the rapid changes in technology and upsurge in chemical usage, pollutant alterations turn out to be more drastic with respect to space and time. Research on the trace metals in river water is quite limited in Malaysia, probably due to their ppb-level existence and the need for special handling techniques. Hence, the aim of this study is to forecast heavy metals concentration in Kuantan River waters using a collective of 10 years (2007 – 2016) dataset of heavy metals that provided by the Department of Environment, Malaysia. Principal Component Analysis (PCA) was used to compute the data, which showed that As, Cr, Fe, Zn and Cd explain 67.3% of the total variance through three principal components. For ANN computation, those significant metals extracted from rotating PCA was selected and used in ANN model. The developed approaches were trained and tested using 80% and 20% of the data, respectively. Then, the coefficient of determination (R2) was executed to calculate the model performance. Out of five metals, only As shown acceptable R2 for ANN models with 0.8690 and 0.8088 for training and testing, respectively, probably due to the model’s limitation. Generally, this study illustrates the usefulness of PCA and ANN for analysis and interpretation of complex data sets and understanding the temporal and spatial variations in the Kuantan River for effective river water management.

Pollution Characteristics and Health Exposure Risks of Heavy Metals in River Water Affected by Human Activities

Under the influence of human activities, surface water quality has been significantly affected, which threatens human health and sustainability. In order to clarify the potential risks of heavy metal pollution to human health in river water, two tributaries of the Tumen River with significant differences in human activity interference were selected for investigation. Comparative analysis of the contents of chromium (Cr), cuprum (Cu), arsenic (As), cadmium (Cd), mercury (Hg), and plumbum (Pb) in the surface water of the two tributaries showed that the concentrations of As and Hg in some sampling sites exceeded the pollution standard values, and the Buerhatong River had a higher pollution level. Further analysis of the health risks revealed that the hazard quotient values of Cr, Cu, As, Cd, Hg, and Pb were <1, but the cumulative risk value of the Buerhatong River was higher than 1 for children, indicating adverse effects on human health. The As levels under the fish ingestion scenario had unacceptable carcinogenic risks, while the Cr in the Buerhatong River for adults and Cr and Pb in the Buerhatong River and Hunchun River for children had acceptable carcinogenic risks. Moreover, the As in the incidental water ingestion scenario also had acceptable carcinogenic risks. Therefore, the increase in human activity intensity can promote the increase in the health exposure risk of heavy metals in river water, and fish ingestion was the main exposure pathway, while children had higher exposure risks than adults.

Distribution of Cr, Cd, Cu, Pb and Zn in organs of three selected local fish species of Turag river, Bangladesh and impact assessment on human health

The current study estimates the contamination status of heavy metals in fish organs of three local fish species including Amblypharyngodon microlepis (Mola), Trichogaster chuna (Chuna Khalisha) and Annaldale Loach (Gutum fish) which were collected from Turag river during the months from January to March 2022. The heavy metal concentrations of river water and fish organs were assessed through Atomic Absorption Spectrophotometer (AAS). Heavy metals in river water was detected in the order of Ni > Zn > Cu > Cd > Pb > Cr while metal accumulation in the fish organs were detected in the order of Zn > Cr > Cu > Pb > Cd, Zn > Cu > Cr > Pb > Cd and Zn > Cu > Cr > Pb > Cd for Trichogaster chuna, Amblypharyngodon microlepis and Annaldale Loach respectively. Among the detected heavy metals, highest contamination factor (CF) of Zn (1.104198) in intestine and lowest CF of Cu (0.00315) was detected in muscle of Amblypharyngodon microlepis (Mola). On the other hand, highest CF of Cd (1.072772) in liver and lowest CF of Zn (0.0225016) in gill of Trichogaster chuna (Chuna Khalisha) was detected. In case of Annaldale Loach (Gutum fish), highest CF of Cu (0.304122) in liver and lowest CF of Zn (0.002593) in intestine was detected. The total target hazard quotients (TTHQ) values of Amblypharyngodon microlepis in liver (1.18816) exceeded allowable threshold of 1 while TTHQ values in the muscle (1.8862) and liver (1.03995) of Annaldale Loach (Gutum fish) surpassed the acceptable standard limit as well. The TTHQ values (Gill- 0.18764, Muscle- 2.1633, Intestine- 1.68741, liver- 1.03995, kidney- 1.82188) for all of the organs of Trichogaster chuna (Chuna Khalisha) exceeded the acceptable standard limit which indicated possible non-cancer risk for all consumers and some of the fishes found unsafe if they are consumed for a longer time. However, the target cancer risk (TCR) values indicated no potential cancer risks by consumption of those fishes. The regulatory authorities should pay more attention to reduce the river water contamination through industrial effluents which might affect public health.

Dissolved Heavy Metal Pollution and Assessment of a Karst Basin around a Mine, Southwest China.

Karst water quality is one of the most important environmental issues in karst areas. The study's purpose was to investigate dissolved heavy metal pollution and health risk assessment in karst water basins around mines. River water and groundwater samples were analyzed by principal component analysis, correlation analysis, water quality index, hazard quotient, and hazard index. Median concentrations of dissolved heavy metals in the Sidi River were similar to the world average with a slightly alkaline characteristic. The concentrations of most dissolved heavy metals in river water were higher than those in groundwater. The concentrations of Zn, Pb, and Cd around the mine exceeded the limits of drinking water indicators. The poor water quality samples with high water quality index values were distributed around the mine. Lead (Pb), Zn, As, Cd, and Cr were potentially threatening metals in the study area. The pollution level of dissolved heavy metals in the Sidi River was at a medium level compared with other rivers worldwide. Principal component analysis and correlation analysis showed that Cu, Pb, Zn, Cd, Mn, Fe, As, and Sr mainly came from mine drainage; Ca2+, Mg2+, and Cr mainly came from the contribution of carbonate rocks; Na+ and K+ were related to local human agricultural activities. The concentrations of dissolved heavy metals in groundwater were affected by karst aquifers. The results of this study can provide a data reference for water resources prevention and human health protection in the Sidi River's karst basin and similar karst basins.

Study of Heavy Metal contents of Kundalika River water at Roha, Dist. Raigad (M.S.) India

A study was carried out to assess the water quality in terms of the heavy metal content of Kundalika River near Roha, Dist. Raigad (Maharashtra), India. Heavy metals are probably harmful and insidious pollutants because of their non biodegradable nature. Most of the heavy metals are toxic to many aquatic organisms and for human being. A study was therefore undertaken to assess the variation in some of the heavy metal contents of Kundalika river water near Roha. Samples were collected mainly from this area in the year 2019-20 and brought to the laboratory for the analysis purpose. Selected metals like Ni. As, Pb, Cd, Zn and Cr are estimated by using atomic absorption spectrometer, Perkin Elmer AA200. It was found that the concentration of few heavy metal of Kundalika river at Roha site exceeds the permissible limit slightly, whereas metal like Cd and Ni were below the permissible limits. The presence of heavy metal concentration in traces can be attributed to regular sand dredging activity in the river. Overall water quality of river at sampling location can be considered as supportive to the aquatic life. The quality of heavy metals in river water should be checked time to time; as heavy metal accumulation will cause numerous problems to living being. Therefore, passing awareness is needed for the betterment of water quality for the sake of its use.

Study of Heavy Metal contents of Kundalika River water at Roha, Dist. Raigad (M.S.) India

A study was carried out to assess the water quality in terms of the heavy metal content of Kundalika River near Roha, Dist. Raigad (Maharashtra), India. Heavy metals are probably harmful and insidious pollutants because of their non biodegradable nature. Most of the heavy metals are toxic to many aquatic organisms and for human being. A study was therefore undertaken to assess the variation in some of the heavy metal contents of Kundalika river water near Roha. Samples were collected mainly from this area in the year 2019-20 and brought to the laboratory for the analysis purpose. Selected metals like Ni. As, Pb, Cd, Zn and Cr are estimated by using atomic absorption spectrometer, Perkin Elmer AA200. It was found that the concentration of few heavy metal of Kundalika river at Roha site exceeds the permissible limit slightly, whereas metal like Cd and Ni were below the permissible limits. The presence of heavy metal concentration in traces can be attributed to regular sand dredging activity in the river. Overall water quality of river at sampling location can be considered as supportive to the aquatic life. The quality of heavy metals in river water should be checked time to time; as heavy metal accumulation will cause numerous problems to living being. Therefore, passing awareness is needed for the betterment of water quality for the sake of its use.

Effect-based water quality assessment of rivers receiving discharges from legacy mines by using acute and chronic bioassays with two cladoceran species

Abstract Information about the ecotoxicological impacts of surface waters that receive discharges from legacy mines is valuable to infer the ecological impacts on natural environment for managing mine discharges. In this study, we investigated behavioural and reproductive responses of two cladoceran species Ceriodaphnia dubia and Daphnia magna to water samples collected from metal-contaminated and reference rivers near legacy mines in Japan. The toxicity identification evaluation (TIE) of water samples that caused D. magna immobility was conducted to evaluate the key metals causing acute toxicity. The results of our water quality assessment performed using two cladoceran species demonstrated modest to significant adverse effects on their behaviour and reproduction, suggesting the potential for ecotoxicological impacts on natural populations and communities at several contaminated sites that received mine drainage. The results of TIE of water samples that caused D. magna immobility indicated likely contributions of Zn and Cu. These results imply that effect-based water quality assessments such as ours can provide direct and unique evidence of the ecotoxicological impacts of metals in river waters, which will be useful for better understanding and predicting the ecological effects of these metals in the natural environment.

Chemical and ecological quality of water and bottom sediments in small rivers of Belgorod oblast

Belgorod Oblast has limited water resources. The paper explores the chemical and ecological characteristics of water and bottom sediments in the Oskol River tributaries. In samples of water taken from small rivers, Maximum Allowable Concentrations (MAC) for pollutants was excessive, including suspended matter, ammonium ions, nitrite ions, phosphate ions, BOD5 and mineral elements. A hydrochemical water pollution index (WPI6) ranges from 1.0 to 1.9, which characterizes water bodies in the categories from clean to moderately polluted watercourses. A comparatively high WPI6 index is recorded in summer for the Kotel River – 1.4, for the Belenkaya River – 2.3, which is attributed to a high concentration of ammonium ions, nitrites and phosphates found to be present in the water. This indicates recent pollution and a changing trophic status of the reservoir. The amount of metals in river water exceeds the MAC norms: for iron – 1.7 -6 MAC; for copper – 1.6 - 8 MAC; for manganese – 0.8 - 22 MAC; for zinc – 1.9 - 9.9 MAC. Concentrations of micronutrients are subject to significant seasonal fluctuations. No excess of lead is found to be present in surface waters. In the samples of bottom sediments taken from the Oskol River tributaries, no excess of MAC values is found, except for lead (1.1 - 2.9 MAC), manganese (1.6 - 2.2 MAC), copper (1.2 - 1.6 MAC) and phosphate ions (1.3 - 2.3 MAC). It is obvious that the sources of pollution for small rivers are runoffs from agricultural land, livestock farms and household wastewater of nearby settlements.

The Long-Term Effect of Industrial Waste Landfill on Surface Water. An Example from Central Poland

Water resources are influenced by many anthropogenic pollutants, which may migrate into the environment. The Bzura River is one of the rivers strongly impacted by human activity e.g., waste landfills and former industrial plants. The objective of this study was to assess the spatial-temporal variability of trace metals in river water and sediments and to recognize the main sources of pollution. An investigation was carried out on the 120 km section, during two hydrological years. Concentrations of Ni, Pb, Cd, Cu, Zn, Fe, and Mn were determined by atomic absorption spectrometry (AAS). The basic statistics were supported by principal component analysis (PCA) and cluster analysis (CA). Generally, only part of the results exceeded the WHO, USEPA, and Polish threshold values. However, one hotspot burdened by nickel was found. The spatial trend of Ni indicates long-distance migration. The PCA and CA confirmed that the Ni mainly comes from the old industrial waste landfill. Variability of the remaining metals was affected by more mixed sources. None of the metals showed any consistent temporal pattern. The PCA revealed that the anthropogenic factor explained over 50% of the variability in both years; therefore, intensive monitoring of the water river quality is still required.

Assessment of trace metals and its pollution load indicators in water and sediments between Upper and Grand Anicuts in the Cauvery

This study focuses on the contamination level of trace metals in river water, its sediments, the surrounding groundwater and its soil sediments. The region stretching between Upper Anicut and Grand Anicut in the Cauvery delta in Trichy District, Tamil Nadu, India, was chosen for study. This stretch of the river Cauvery experiences maximum quantum of water flow during the monsoon season. Once a perennial river, in recent decades, it experiences only seasonal flow. The Cauvery is the lifeline of millions of people and various flora and fauna. The Cauvery irrigates thousands of hectares of cultivable land, and its delta has sustained the enviable name—the ‘Granary of the South.’ However, the contamination of water and sediments poses grave threat to all life forms. In this study, by using atomic absorption spectrophotometer (AAS) the presence of seven trace metals Cd, Cr, Cu, Ni, Fe, Pb and Zn in water and sediments was ascertained. The trace metal contamination level in sediments was predicted by pollution load indicators such as pollution load index (PLI), geo-accumulation index (Igeo), enrichment factor (EF) and contamination factor (CF).The concentration level of trace metals in water and sediments was determined for four different seasons of a year, at 11 locations (five from river sites and six from land sites) along the Cauvery. A higher-level concentration of Fe 2.18 mg/l and 2.95 mg/kg was found in water and sediments, respectively, during the four different seasons. It was also found to have a low-level concentration of Ni with a range of 0.09 mg/l and 0.24 mg/kg in water and sediments, respectively, for four different seasons. Based on pollution load indicators, the PLI values of trace metals in sediment samples in all four seasons were less than zero; the Igeo values of trace metals in sediment in all four seasons were less than zero; the contamination factor (CF) values of all heavy metals except cadmium in sediments samples in all seasons were less than zero; the enrichment factor (EF) value of trace metals in all sediment in all four seasons was higher than 40. Eventually, it was disclosed that the study area was lightly contaminated by the presence of the trace metals Fe and Cd than other trace metals. It is a known fact that all living organisms need some trace metals including cobalt, copper, iron, manganese, molybdenum, vanadium, strontium and zinc. When the levels of essential metals exceed the desirable limit, they prove to be detrimental to the organisms. Similarly, the presence of nonessential metals like cadmium, chromium, mercury, lead, arsenic and antimony in water bodies causes undesirable effects on human and aquatic life. Once these metals enter into the system, they are capable of reacting with a variety of binding sites in the human body. Thus, this study assumes significance.

Investigation of Heavy Metals in River Water, Sediments, and Fish in Krueng Geumpang, Pidie Regency, Aceh Province

The environmental problems throughout the world have become a concern, especially regarding environmental pollution. Environmental pollution can be caused by various industrial and daily human activities. The primary objective of this study is to analyse the level of contamination and accumulation of heavy metals such as Pb, Hg, Cu, and Fe distributed by heavy metals in water, sediments, and fish in Geumpang River. The data samples used such as water, sediment, and fish were collected from Geumpang River, Pidie Regency, Aceh Province. The study conducted several sample tests at the Banda Aceh Unsyiah Laboratory. The sample test results show that heavy metal Fe was the highest for all water samples analysed with a total of 0.244 mg/L. In addition, the most top-heavy metals for sediments were also recorded in Fe heavy metals for the whole areas tested. However, there is almost no Pb metal found in the whole areas. The results show that the highest heavy metal was found fish at 14,018 mg/g, i.e. Channa striata species. In addition, rivers experiencing pollution hugely affect living things and biota in water. It is suggested that the government policies and future supervision are needed so that environmental pollution, especially in rivers, can be reduced.

The influence of natural weathering on the behavior of heavy metals in small basaltic watersheds: A comparative study from different regions in China

This paper investigates the dynamics between basalt weathering and heavy metal accumulation through a comparative study of 37 small basaltic watersheds within different climate zones in the Yungui (the Pearl River Basin in southwest China), Xuyi (the Huaihe River Basin in east China) and Leiqiong regions (Hainan Island in south China). From a comprehensive sampling regime of stream water, riverbed sediments and bedrock, this study shows that the concentrations of heavy metals in river water are far below the national surface water quality standard and WHO quality standard for drinking water, indicating no significant ecological risk for water body in these basaltic areas. In contrast, the riverbed sediments exhibit varying degrees of heavy metal enrichment in the process of weathering from bedrock to sediments: without enrichment for Cr, Ni, Cu and Zn, but significant enrichment for Cd, As and Pb. Cd exhibits the largest ecological risk of all the heavy metals in the basaltic watersheds especially in the Yungui region, which can be mainly attributed to the high geological background values in this area. Comparative studies of some major basalt watersheds in the world show that temperature, runoff and elevation differences significantly affect the chemical weathering rates and thus the accumulation of heavy metals.

Analysis of Concentration of Heavy Metal (Pb) and Cadmium (Cd) In Waterfish (Eichhornia crassipes) in Indragiri River, Riau

Research has been conducted to determine the concentration of Lead (Pb) and Cadmium (Cd) heavy metals in water hyacinth (Eichhornia crassipes) in the Indragiri River Waters of Indragiri Hilir Regency in May-July 2016. Determination of the research station was carried out by purposive random sampling by considering environmental conditions based on community activities around the river and the existence of Eichhornia crassipes. The main parameters in this study include the concentration of heavy metals Pb and Cd in river water, sediments and Eichhornia crassipes, and physico-chemical parameters as supporting parameters. The results showed that the average concentration of Pb heavy metals in river water was 0.276 ppm and Cd was 0.126 ppm. The average concentration of heavy metals Pb in sediments was 4.61 ppm and Cd of 0.75 ppm. The accumulation of Pb and Cd Eichhornia crassipest heavy metals is included in the low category, namely the average concentration of Pb heavy metals in the root organ is 3.02 ppm, on the leaf stalk 2.61 ppm, and on the leaves 2.09 ppm. The concentration of heavy metal Cd at the root was 0.47 ppm, at the leaf stalk 0.39 ppm, and at the leaves 0.362 ppm

Heavy Metals and Related Human Health Risk Assessment for River Waters in the Issyk-Kul Basin, Kyrgyzstan, Central Asia.

The water resources of Central Asia play an important role in maintaining the fragile balance of ecosystems and the sustainable development of human society. However, the lack of research on the heavy metals in river waters has a far−reaching influence on public health and the sustainable development in Central Asia. In order to reveal the possible sources of the heavy metals and to assess the associated human health risks, thirty−eight water samples were collected from the rivers of the Issyk−Kul Basin during the period with low river flow (May) and the period with high river flow (July and August), and the hydrochemical compositions and major ions of heavy metals were analyzed. No changes in hydrochemical facies were observed between the two periods and the river water type was calcium bicarbonate. Carbonate dissolution and silicate weathering controlled the variation of cations and anions in river waters from the Issyk−Kul Basin. There were some differences in the sources of heavy metals in water bodies between the two periods. During the period with low river flow, heavy metals (Cr) were closely clustered with major ions, indicating that they were mainly affected by water–rock interactions. During the period with high river flow, all heavy metals studied in this paper had different sources of major ions, and the heavy metals maybe influenced by human activities. From the human health risk assessment, the hazard quotients for all samples were less than 1, reflecting that there was no noncarcinogenic risk in the river waters of the Issyk−Kul Basin during the two sampling periods. However, the water samples with carcinogenic risk of arsenic exceeding the threshold (10−4) accounted for 21.1% of the total, indicating that there were some certain carcinogenic hazards for human health via water drinking with direct oral ingestion. The results are of certain significance for the utilization and protection of water resources in the basin as well as the protection of public health.

Investigation for heavy metals in river waters in the federal capital territory, North Central of Nigeria

Water is a universal solvent that has the ability to dissolve any compound. It is of great importance to the existence of mankind, as it serves as a means of drinking, clean energy, irrigation, recreation, livestock farming and many more. However, Human activities such as industrialization and the improper waste management around water body introduce toxic metallic substances which could have great effect on human health and aquatic life when in high concentration (above standard). Hence, this study was carried out to determine the level of pollution of the river waters in and around Abuja city as rapid emerging city in Nigeria and to detect the concentration of ten (10) heavy metals (Cu, Pb, Ni, Zn, Cr, Co, Cd, Fe, Mn, and Mg), respectively. The four water samples were collected along rivers at different points and analyzed at the Chemistry Advanced Laboratory, Sheda Technology and Generation complex, Abuja. Atomic absorption spectrophotometer (AAS) was used to detect the concentration of heavy metals in the water samples. The results indicated the low level concentration in Cu, Pb, Zn, Cd and Mn when compared with the World Health Organization standard. The maximum desirable concentration specified for Ni and Cr by World Health Organization is exceeded in the river waters, while Mg is very low comparable with World Health Organization standard. This study shows that the river waters are not suitable for human consumption and hence recommended that microbiological investigation should be carried out on the river waters as soon as possible to save both lives and aquatic livings.

Histological and Histochemical Studies on the Liver of Nile Tilapia (Oreochromisniloticus) at Different localities of Delta Barrage, Egypt

The aquatic environment is particularly suffered from the various contaminants due to industry, urbanization and agriculture activities. The present study was carried out to study histological structural of liver in the freshwater fish, Oreochromisniloticus, which collected from different localities and exposed to different pollutants. Histological, histochemical, and Immunohistochemical alterations were examined in liver .Samples from El-Riah El-Menoufy and downstream of El-Rahawy area, indicated that, the Last one is more suffered from many histopathological changes than those collected from El-Qanater El-Khyria.As well as, a decrease in carbohydrates distribution, an elevation of different types of fiber and a strong caspase-3 expression are detected. The histopathological damages were related to the discharge of water loaded with sewage in El-Riah El-Menoufy and El-Rahawy drain, which consequently may affect fish and human health. The present study also investigated the concentrations of some heavy metals in river water (iron, copper, zinc and cadmium) and their effects on Nile Tilapia obtained from the same investigate sites. Accordingly, there is a necessity to treat the sewage effluents before discharging to the Rosetta branch.

ESTIMATION OF THE GEOECOLOGICAL STATE OF THE LEFT INFLOWS OF THE DNISTER RIVER (MOHYLIV-PODILSKY SITE)

The results of hydrochemical, lithogeochemical tests of surface waters, bottom sediments and soils of the coastal zone of the left inflows of Podolsk part of the Dnister river within the limits of Mogilev-Podolsky site are given. Among the investigated elements common to bottom sediments, water and soils from the banks of watercourses are Mn, Ni, Ti, V, Cr, Mo, Zr, Nb, Cu, Ba, Pb. The main attention is paid to the concentration of lead, chrome, manganese and copper in surface waters, bottom sediments and soils of the coastal zone of rivers Dnister, Zhvan, Karaets, Lyadova, Serebrya, Nemiia, Derlo. The content of the indicated elements there are less maximum permissible concentrations (MPC) of sanitary toxicological requirements and MPC of standard in water of the investigated reservoirs. In the soils and bottom sediments of the Dnister river, insignificant concentrations of most metals (at the average concentrations for river waters) were detected. The results of researches on the distribution of concentrations of chrome, lead, copper and manganesein water, bottom sediments of rivers and soils selected from their shores for better visibility are represent in the form of diagrams for each chemical element. Complex research of water, bottom sediments and soils of the coastal zone made it possible to obtain a coherent picture of the geoecological state of the rivers within their ancestral part. Taking into account that the content of the majority of investigated elements in watercourses does not exceed the MPC and answers to the average concentrations of metals in river waters of Ukraine, then it is possible to draw conclusion about the satisfactory state of reservoirs and the catchment area. It has been found that such complex and systematic studies have not been carried out in the past, so it is not possible to compare the results with the results of research in previous years. Also sharply the problem of null information costs about the geoecological state of right inflows of Dnister (the territory of the Republic of Moldova) common to both countries of the transboundary water.

Multivariate Analyses and Human Health Assessments of Heavy Metals for Surface Water Quality in the Xiangjiang River Basin, China

Pollution by heavy metals in river water is becoming a major subject of global drinking water concern, and the Xiangjiang River is one of the most heavily polluted rivers in China. Water samples were collected from 17 sites spanning the entire Xiangjiang watershed from 2005 to 2016 to investigate spatial-temporal distributions and potential human health risks related to 8 metal pollutants (As, Cd, Hg, Cr, Cu, Pb, Zn, and Se). The results of spatial-temporal distribution analyses proved that most metals were below the guideline limits the majority of the time. However, the hazard index and carcinogenic risk analyses indicated that As and Cr were associated with a potential risk of cancer, although noncarcinogenic heavy metals in general and carcinogenic risk declined year by year. A nonparametric seasonal Mann-Kendall's test revealed that there were notable decreasing trends in As, Cd, Zn, Cu, Cr, and Pb for most sites, whereas Se and Hg significantly increased in some areas over the targeted 12 yr. The results of principal component analysis agreed with those of dual hierarchical cluster analysis in the identification of pollution sources, the results of which are as follows: 1) As, Cd, Pb, Hg, and Zn were mainly derived from anthropogenic activities and the smelting industry; 2) Cr and Cu mainly originated from agricultural or industrial activities; and 3) Se was predominantly from natural erosion. The present study will be conducive to optimizing the distribution of water monitoring stations and drafting remediation strategies pertaining to the protection of public health in metal-polluted areas. Environ Toxicol Chem 2019;38:1645-1657. © 2019 SETAC.