Metal Concentrations In Water Research Articles

Health Risk Associated with Copper Intake through Vegetables in Different Countries

Sustainable development goals aim to attain food security by 2030. To attain food security, it becomes extremely important to target various aspects of food security where safety of food is a major factor. In order to meet the growing population demand, efforts are being made to increase production of food and thus the safety aspect is often ignored. Irrational anthropogenic activities have impacted and deteriorated the ambient environment. Degradation of soil and water has resulted in buildup of contaminants in these spheres and further transfer of contaminants into the food chain. Increase in heavy metals in our surroundings is reported in many parts of the world. Further, increase in concentration of metals in soil and water result in the transfer of these metals into food chain. Unlike other metals copper is although is an essential element for living organisms but excessive consumption of copper is known to cause toxic impacts to living organisms. Green leafy vegetables are considered as hyperaccumulators for copper. The excessive concentration of copper in vegetables is not limited to any one region of the world. The present review summarizes the reports of copper content in vegetables in various parts of the world and health effects associated with it.

Bioconcentration of heavy metals by three plant species growing in Golmarz wetland, in northwestern Iran: The plants antioxidant responses to metal pollutions

In the present study heavy metal contaminations in water and sediments of the Golmarz wetland in northwestern Iran were determined. Moreover, bio-monitoring of metal pollution in the aquatic ecosystem and evaluating the role of some plant species in bioaccumulation and remediation of heavy metals from the environment were performed. The metal(loid) concentrations in water, sediment and plant samples were measured by inductively coupled plasma-mass spectroscopy (ICP-MS). It was established that there was no metal contamination in water samples, but the sediments were highly contaminated by Se and As. Typha latifoila was able to accumulate large amount of Cd, Pb, Ni, and Zn in its root and the amount of its enrichment coefficient of root for the elements was more than 1. Due to its large biomass and its high potential in elements uptake, T. latifolia was a suitable species for metal’s phytoremediation. Panicum maximum was capable to uptake and transporting Pb and Cd to its above-ground parts. Moreover, Scirpus lacustris showed good potential to accumulate of Cd and Pb in its root. The obtained results indicated that the activity of antioxidant enzymes and the amounts of phenol and flavonoids in three plant species were high in the most polluted sampling sites. Therefore, the plants try to adapt the existence of heavy metal by induction of their defense systems. • Determination of water and sediment pollution in Golmarz wetland. • Evaluation of phytoremediation potential of the indigenous plants. • Physiological responses of the plants in the polluted environment.

Evaluation and Health Risk Assessment of Five Toxic Metals Concentration in Soil, Water and Seasonal Vegetables and Fruits from Pakistan-Afghanistan Border, Torkham

Heavy metals are of serious concern for human health and food security. The risk to human health is directly related to soil and water pollution, which enter the food chain (vegetables and fruits). The current study was designed to investigate the heavy metals (Cr, Pb, Ni, Cd, and Zn) concentrations in five vegetables (Potato, Tomato, Turnip, Onion & Taro) and five fruits (Banana, Apple, Grapes, Pomegranate, and Guava) samples. We also estimated metal concentrations in water and soil samples. Torkham, a border region between Afghanistan and Pakistan, was selected for the purpose. The analysis was performed on Atomic Absorption Spectroscopy (AAS, Perkin- Elmer 700). In vegetables, the highest Pb and Ni were recorded in Potatoes (0.34 ± 0.066) and Onions (0.278 ± 0.021). While in tomatoes, the highest concentrations of Cd (0.90± 0.115), Zn (0.726 ± 0.008), and Cr (1.761 ± 0.028) were noted. While, in fruits the highest levels of Pb (0.32± 0.03), Cd (0.61 ± 0.0119), Zn (0.357 ± 0.0047) and Ni (0.111 ± 0.0128), while in apples we noted the highest Cr levels (0.789 ± 0.0452). We compared the metal concentrations with permissible limits set by World Health Organization/Food and Agricultural Organization (WHO/FAO). In the majority of the samples, the metal levels exceeded the permissible limits, while few were found within the safe limits. Based on heavy metals concentrations in soil, water, vegetables, and fruit samples. We calculated the health risk assessment, i.e., daily intake of metals (DIM) estimated daily intake (EDI), target hazard quotient (THQ), total target hazard quotient (TTHQ), carcinogenic risk (CR), health risk index (HRI) and contamination factor (CF). The EDI for Ni and Zn was in the safest region. While for Cd and Pb, the highest EDI was recorded in tomatoes (0.394) and guava (0.303), respectively. Similarly, Cr poses’ serious risk with the highest EDI in tomatoes (0.771), apples (0.563), turnip (0.393), guava (0.282), and banana (0.263). If HRI, THQ THQ, and TTHQ are less than one (< 1), it means the exposed populations are not at risk. In the present HRI, THQ and TTHQ were found to be less than one. The contamination factor for Ni and Zn was found to be considerable (CF<6), while Pb, Cd, and Cr presented the highest contamination degree (CF>6). This study suggested that some samples may impose a certain degree of potential health risk. It is required that proper action should be taken to avoid chronic exposure and consequent adverse health effects.

Responses of marine zooplankton indicators after five years of a dam rupture in the Doce River, Southeastern Brazil

Since November of 2015, when ore tailings from a dam rupture reached the Atlantic Ocean, researchers are trying to assess the degree of impact across the Doce River and adjacent coastal area. This study aims to use the zooplankton dynamics as a tool to evaluate the environmental impact in the coastal region, five years after the rupture, during periods of low and high river flow. Doce River flow varied from 49 to 5179 m3/s and structured the zooplankton community between periods of low and high river flow, but salinity and chlorophyll-a had stronger correlation with depth (r = 0.40 and − 0.40 respectively) than with the Doce River discharge variation along the sampling period (r < 0.2). On the other hand, inorganic particles in the water and total metal concentration (dissolved + particulate), used as tracers of the iron enriched tailing (Al, Cd, Cr, Cu, Fe, V), were correlated with fluvial discharge and showed to be the main factor driving the zooplankton community dynamics. For assessing the degree of environmental impact, we tested the ecological indexes for the zooplankton community. Margalef Richness, Pielou Evenness and Shannon-Wiener Diversity varied from 2.52, 0.40 and 1.39 (all registered during high river flow period) to 9.02, 0.85 and 3.44 (all registered during low river flow period), respectively. Along with those community indicators, we evaluated the response of representative taxonomical genera such as Paracalanus, Oikopleura and Temora, regarding the Doce River flow, and found population patterns that established a baseline for future monitoring in the region. Our results showed that the zooplankton community is more fragile when the river discharge is stronger, and this pattern is confirmed by all indicators tested.

Prognosis of metal concentrations in sediments and water of Paraopeba River following the collapse of B1 tailings dam in Brumadinho (Minas Gerais, Brazil)

In January 25, 2019, the B1 dam of Córrego do Feijão mine located in Brumadinho municipality (Minas Gerais, Brazil) collapsed and injected nearly 2.8 Mm3 of iron (Fe)- and manganese (Mn)-rich tailings in the Paraopeba River. This study assessed the contribution of tailings to the contamination of sediments and water by those metals. The dataset was built through daily to weekly samplings executed in the two years following the event, at 27 sites located along the Paraopeba plus 9 sites located at the confluence of main tributaries. The results evidenced a distinct contribution in the sectors “Anomalous” (8.6–63.3 km downstream from the dam) and “Natural” (115.8–341.6 km). The “Anomalous” sector presented large Fe/Al (12.2 ± 6.4) and Mn/Al (0.33 ± 0.19) ratios in sediments, thus being rich in tailings, while the “Natural” sector presented small ratios (2.4 ± 1.0; 0.06 ± 0.03) comparable to the natural sediments. A 500–700 m3/s stream flow discharge in the Paraopeba caused pronounced drops to the Fe/Al and Mn/Al ratios in the “Anomalous” sector, attributed to the mixture of contaminated sediments from the main water course with uncontaminated sediments injected by the tributaries during the event. Non-linear regressions showed Fe/Al and Mn/Al declines in the “Anomalous” sector, related with tailings mobilization downstream. The concentrations of Fe and Al in the sediments correlated positively with the corresponding concentrations in the Paraopeba water, conditioned by raising discharge rates and variations in the water pH. The contribution of tailings to the Fe correlation was demonstrated. No direct relation was established between the Mn concentrations in water and stream discharge, because manganese is associated with fine particles in the tailings that are mobilized to the water column even under low flows. The preliminary results of Seasonal Autoregressive Integrated Moving Average models predicted the return of Paraopeba to a pre-collapse condition in 7–11 years.

An integrated study of the plankton community after four years of Fundão dam disaster

Mining activities can affect the environment either by the tailings releasing or dams failures. The impact of the tailings can last decades and cause chronic effects due to their toxicity. The Fundão dam collapse, a relevant environmental disaster, occurred in November 2015 in Southeastern Brazil. Tailing rich in metals reached the Doce River and arrived in the Atlantic Ocean. Previous studies revealed the acute impact of the tailings in the marine planktonic community near the Doce River mouth. The current study aims to characterize the structure of planktonic assemblages in the impacted area after four years of the disaster. Sampling occurred in November 2018, January, April, and July 2019 at 32 stations located at the marine coastal area near the Doce River mouth. Our study detected high metal concentrations in the surface waters during January 2019, when the lowest diversity and abundance of phytoplankton, lowest zooplankton diversity, and low ichthyoplankton abundance were recorded. The zooplanktonic community was structured by environmental parameters and ichthyoplankton assemblages in November 2018, January and April 2019. Nutrients and metals, mainly iron from the tailing carried by the Doce River waters to the marine environment changed the plankton community, confirming the impact of the Fundão Dam collapse in the coastal area near the Doce River mouth. The phytoplankton community, influenced by the nutrients and to a lesser extent metals concentrations, was not decisive in the zooplankton community structure. The environmental variability was driven by the meteoceanographic conditions and the Doce River flow. There was a high correlation between the zooplanktonic community and ichthyoplanktonic assemblage and the environmental factors and metals. These relations indicate the impact of the tailings from the collapse of the Fundão Dam on these communities, even after four years of the Mariana disaster.

Analysis of Heavy Metals Concentration in Water and Sediment from Bori River, Naldurg Maharashtra

Analysis of Heavy Metals Concentration in Water and Sediment from Bori River, Naldurg Maharashtra

The Danubian cryptic invader Theodoxus fluviatilis (Gastropoda: Neritidae) in the River Rhine: a potential indicator for metal pollution?

Metal pollution poses a major threat to aquatic systems especially in anthropogenic influenced areas, in as much as metals are persistent in the environment. The freshwater snail Theodoxus fluviatilis has often been used as an indicator species for the ecological status in river monitoring. In the River Rhine, the native Northern-European form of T. fluviatilis is nowadays extinct, whilst the Danubian form is spreading along the river. The aim of our study was to investigate if the cryptic invader is affected by metal exposure present in the River Rhine and to discuss its potential as an indicator for metal pollution. Several environmental abiotic (14 water environmental variables plus five common metal concentrations in water and biofilm) and biotic parameters (biofilm mass) were measured across 23 sites along the River Rhine. Five population and six histopathological parameters were evaluated on snails collected at all 23 sites. Aqueous chromium concentration was positively correlated to the damage of male reproductive organs of T. fluviatilis, and higher ammonium concentration was correlated to a decrease in snail size and an increase in the proportion of juveniles. None of the analysed snail parameters was negatively correlated to concentrations of other metals measured, like copper and zinc. Therefore, based on the parameters evaluated, our results indicate that the Danubian form of T. fluviatilis is only restrictedly suitable as an indicator for metal pollution in the River Rhine system. Further field and laboratory investigations including other stressors are necessary to evaluate the indicator potential of the cryptic invader holistically.

Predicting Heavy Metal Adsorption on Soil with Machine Learning and Mapping Global Distribution of Soil Adsorption Capacities.

Studying heavy metal adsorption on soil is important for understanding the fate of heavy metals and properly assessing the related environmental risks. Existing experimental methods and traditional models for quantifying adsorption, however, are time-consuming and ineffective. In this study, we developed machine learning models for the soil adsorption of six heavy metals (Cd(II), Cr(VI), Cu(II), Pb(II), Ni(II), and Zn(II)) using 4420 data points (1105 soils) extracted from 150 journal articles. After a comprehensive comparison, our results showed that the gradient boosting decision tree had the best performance for a combined model based on all the data. The Shapley additive explanation method was used to identify the feature importance and the effects of these features on the adsorption, based on which six independent models were developed for the six metals to achieve better model performance than the combined model. Using these independent models, the global distribution of heavy metal adsorption capacities on soils was predicted with known soil properties. Reversed models, including one combined model for all the six metals and six independent models, were also built using the same data sets to predict the heavy metal concentration in water when the adsorbed amount is known for a soil/sediment.

Tracing iron along the flowpath of East Australian Current using iron stable isotopes

The mechanisms delivering iron (Fe) to Southern Ocean surface waters and resulting capacity for the oceanic drawdown of CO2 are important to constrain in a changing climate. The East Australian Current (EAC) is a major western boundary current flowing south along the eastern margin of Australia, hypothesized to play an important role in entraining Fe from a variety of potential sources and supplying Fe to large annual spring phytoplankton blooms in HNLC waters. We report Fe concentration and Fe isotope (δ56Fe) profiles for both dissolved and particulate phases at stations within the EAC, in the frontal mixing zone, and in subantarctic waters along the southward flowpath of the EAC in early spring. Mixed layer dFe concentrations declined from EAC source waters (0.32–0.53 nmol kg−1) into subantarctic waters (0.27–0.42 nmol kg−1) with a concurrent deepening of the ferricline. Particulate trace metal concentrations indicate robust inputs of lithogenic particles to subtropical EAC waters, potentially impacted by advection of shelf sedimentary particles and evidence of a significant supply from local aerosol deposition. The isotopic composition of pFe in the EAC (0.3 ± 0.1‰) is similar to prior reports of aerosol δ56Fe and upper ocean δ56pFe in the western Pacific and isotopically heavier than average values for the bulk continental crust. In EAC surface waters, isotopically light δ56dFe values (0.11–0.16‰) are observed likely due to reductive release of dFe from lithogenic particles in the photic zone with a particle-dissolved phase fractionation (Δ56FedFe–pFe) of −0.1 to −0.4‰. At depth, elevated dFe concentrations and a heavy δ56dFe signature suggest a non-reductive release of dFe from lithogenic particles via desorption or dissolution processes with a Δ56FedFe–pFe of +0.3‰. During southward transit of EAC waters, mixed layer dFe pools become increasingly heavy due to biological uptake through the frontal mixing zone and into subantarctic waters. We also observe differences in particulate trace metal concentrations in intermediate waters between subantarctic stations that could result from entrainment of sedimentary particles during transit over the relatively shallow South Tasman Rise.

Seasonal Dynamics of Heavy Metal Concentrations in Water, Fish and Sediments from Haor Region of Bangladesh

Heavy metal concentrations in water, fish, and sediments from Bangladesh's haor region were investigated. Fish and sediment samples were taken once a season and evaluated using standard methods, while water samples were collected monthly. Results showed that metals in water (mg/L) were found in order of Mn (0.1694) > Cu (0.0189) > Zn (0.0045) > Pb (0.0040) > Cd (0.0028) within the maximum permissible level of Environment Conservation Rules (ECR). Mean concentrations of metal in fish (mg/kg–dry wt.) found in order of Zn (56.16) > Cu (25.47) > Mn (4.36) > Pb (2.19) > Cd (1.27) that were higher than maximum allowable level of Food and Agricultural Organization (FAO) except Cu. Metal in sediments (mg/kg) found in order of Mn (127.61) > Zn (32.51) > Pb (10.09) > Cu (5.40) > Cd (0.43), and except Cu all metal concentrations were lower than the Environmental Protection Agency's (EPA) probable effect concentrations. In water and sediments, pollution indices revealed a critical pollution threshold for water, and a range of unpolluted to highly polluted for sediments. Sampling sites had low potential ecological risk, despite the fact that metals were showing signs of a negative impact on people' health. Furthermore, bio-concentration factor for fish and water was low to extremely high, but for fish and sediment was low. The level of heavy metal contamination in haor shows the situation is alarming for biota and residents of the region. The relevant authority should control and monitor the aquatic ecology in order to protect it.

Assessment of Heavy Metal Concentration from a Lead-Zinc Mined Pit at Ebonyi State, Nigeria

This study assessed the concentrations of heavy metals in soil and surface water from a Lead-Zinc mined pit at Enyigba, Ikwo Local Government Area in Ebonyi State, Nigeria. Soil samples were collected and analysed from different soil depths (0 – 15 cm) and (15 – 30 cm) at a tailing down (marked as TD) and refuse dumpsite (marked as RD) and a vegetation site 50 km away which was used as the control site. Surface water samples were collected from the Enyigba River from three (3) points (marked as point A, B, and C) and were analysed using routine laboratory procedures. The following parameters were analysed for soil: particle size distribution, pH, available phosphorus, total nitrogen, organic carbon, organic matter content, calcium, magnesium, potassium, sodium, exchangeable acidity, and effective cation exchange capacity. The results for mean values of soil samples obtained at both depths were 58.86% (sand), 11.73% (silt) and 34.04% (clay). Mean values obtained for heavy metals from the soil for Iron (Fe) ranged from 3.31 to 2.24 mg/kg: Zinc (Zn) 0.70 to 0.62 mg/kg and Lead (Pb) 0.01 to 0.01 mg/kg). Results obtained for surface water around the mined pit showed mean values for Iron (Fe) 0.57 mg/L, Magnesium (Mg) 151.6 mg/L, Calcium (Ca) 76.62 mg/L, Chlorine (Cl2) 416.6 mg/L and Lead (Pb) 0.01 mg/L. The high concentrations of chlorine make the water unsuitable to be discharged on any agricultural land as plants could accumulate these metals and when consumed could pose serious threat to humans. The discharge from the mining site increased the already slightly high turbidity of the water to a much higher and undesirable level. The mining activity at Enyigba Ikwo LGA, Ebonyi State has negatively impacted the environment through the introduction of heavy metals in soil and surface water, thereby causing an increase in the pollution of the environment. It is recommended that further studies and monitoring should be carried out in the study location for possible remediation.

Heavy Metals Concentration In Underground Water And Its Environmental Health Effects: A Case Study Of Solous Dumpsite, Igando, Lagos

Introduction: Contaminated water is linked to diseases worldwide. Aims: To investigate the heavy metals concentration in underground water around the Solous dumpsite in Igando Lagos State, Nigeria and its effect on human. Materials and Methods: water samples from 12 different locations within a distance range of 0.07 - 0.72 km was collected. And a structured questionnaire was administered to 120 respondents to find out their perceptions about the dumpsite environment and ill-health effect of their drinking water. The physicochemical parameters was measured and heavy metals concentration of the water samples were determined using Flame Atomic Absorption Spectrometer. Results: The water samples from the 12 sites contains heavy metals concentrations: Lead (Pb) (0.08-1.20mg/L), Cadmium (Cd) (0.03-0.08mg/L), Iron (Fe) (1.4-12.3mg/L), Nickel (Ni) (0.08-0.19mg/L), Zinc (Zn) (0.05-0.13mg/L) and Manganese (Mn) (0.01-0.04mg/L) respectively. It was revealed that age, educational qualification and year of living in the community of the respondents explain a significant amount of the variance in the value of the perception of the respondents on effect of heavy metal contamination. The result shows that over 75% of the respondents was not sure of any prior ailment linked to any heavy metal contamination affecting anyone among them. Conclusion: all water samples collected were contaminated by heavy metals and respondents using this water are ignorant of the danger. Thus, there is a need for proper provision of safe alternative water supply to the dumpsite community for domestic use and awareness on environmental heavy metal toxicity from drinking water to avert global health challenges.

The peat bog at Zinnwald-Georgenfeld revisited after 25 years: Geochemical investigation of water, Sphagnum moss and peat cores

From 1992 to 1994, trace metal concentrations of bog water, Sphagnum mosses and peat cores of the bog “Georgenfelder Hochmoor” at Zinnwald-Georgenfeld in the Eastern Ore Mountains (Germany) were investigated. A sampling campaign in September 2019 allows the comparison of the older measurements with today's trace metal concentrations. No changes were found in the bog waters, while the trace metal concentrations of the Sphagnum mosses have decreased significantly. Due to the low growth rate of the peat and despite certain heterogeneity between the peat cores, the investigated elemental data for the peat sampled in the 1990s and in 2019 are in the same concentration range. The maximum concentrations are measured in the upper samples of all peat cores for the analysed elements (except sulphur). Compared to upper crustal data, a different behaviour of the elements is observed: Cr, Sc, Ti, and V, rare earth elements show crustal ratios, while Al and Si are also influenced by crust-air fractionation. Cd, Cu, Ni, Pb, and Zn are additionally enriched by anthropogenic atmospheric inputs from industry and transport. These results confirm the assumption that peat cores record past atmospheric deposition.

Impact of Green Stormwater Infrastructure Age and Type on Water Quality

Green stormwater infrastructure (GSI) has become increasingly common to mitigate urban stormwater runoff. However, there is limited research on the impact of age and type of GSI. This study evaluated nutrient and metals concentrations in the soil water of five different GSI systems located at the University of Portland in Portland, Oregon. The GSI systems included a bioretention curb extension (part of Portland’s Green Street project), a bioretention basin, a bioretention planter, an infiltration basin, and a bioswale ranging in age from 2 to 11 years. Samples were taken from each system during rain events over a 10-month period and analyzed for copper (Cu), zinc (Zn), phosphate (PO43−), and total phosphorus (TP). Copper and zinc concentrations were found to be impacted by GSI age, with lower concentrations in older systems. The same trend was not found with PO43− and TP, where almost all GSI systems had soil water concentrations much higher than average stormwater concentrations. Age likely played a role in phosphorus soil water concentrations, but other factors such as sources had a stronger influence. Phosphorus is likely coming from the compost in the soil mix in addition to other sources in runoff. This study shows that GSI systems can be effective for copper and zinc, but changes to the soil mix design are needed to reduce high levels of PO43− and TP in soil water.

Probability of Heavy Metals Mobility from Dumped Sediments in a Quarry

Dregs from the former Texcoco Lake were used to build the new international Mexico City airport and pumped in a quarry. The dredged sediments could have heavy metals (HMs) capable of polluting water bodies. The study’s objective was to evaluate the content of Cu, Zn, Cd, Ni, and Pb of the sediments deposited in the quarry, their transfer to the runoff water and the adsorption of Cu, Zn, Ni, and Pb in the subsoil. Other variables measured were water infiltration rate, HM in sediments, water runoff, and the HM adsorption in the subsoil. The infiltration rate in sediments is low (≤ 10-7 cm/h). HMs in sediments are within the maximum permissible limits by Mexican regulations, for sewage sludge. The HMs in the runoff from the sediments are in the range of the Mexican regulations for the discharge into rivers and for irrigation purposes of agricultural soils. They are also within safe limits for irrigation use considered by FAO and EPA. The materials adsorption capacity of Pb (1250 mg kg-1), Zn (588 mg kg-1), and Cu (1250 mg kg-1) is higher than the concentration of metals in the runoff water, so the movement of HMs down into the subsoil is unlikely.

Terzialan Göleti’nin (Çan, Çanakkale) sulama suyu kalitesi açısından mevsimsel değişimlerinin değerlendirilmesi

Determining the water quality of agricultural irrigation ponds has great importance both for agricultural production and for aquatic organisms. In this study, seasonal changes of the physico-chemical parameters and metal concentrations of water in Terzialan Pond were investigated. In 2019, physico-chemical analysis of the water samples taken from four sampling points are made according to APHA (2012) standard method, determining metal concentrations with ICP-OES. The water quality of the pond is evaluated according to YSKYY, ITASHY and TS266 classes. Terzialan Pond, according to Surface Water Quality Management Regulations is found to be second quality in terms of phosphate concentration and first quality in other parameters. The pond can be used as agricultural irrigation water being in C2-S1 class according to US Salinity Laboratory diagram and very good- good class according to Wilcox diagram. Changes in water quality are observed due to anthropogenic effects depending on seasonal agricultural and recreational activities, besides natural effects. Periodic monitoring of the pond will be beneficial for environmental management.

Evaluation of lead (Pb) concentration in animal tissue, soil, and water samples from grazing pasture near mining industry in southern part of Mongolia

Lead (Pb) is a substance that can cause serious damage to the brain and kidneys, soften bones, adverse effect to the reproductive system, and can be fatal. Long-term exposure to the substance can damage not only children, but also adults' nervous systems. Lead does not belong into the category of toxic substances due to its effects on the human body. It is considered as a harmful substance. In this study, we analyzed lead concentration in liver and kidney of cattle, horse, sheep, and goat from the mining areas located in the Ulaanbadrakh, Zuunbayan, and Airag soums of Dornogovi province. As a result, the level of lead in the liver of sheep and goat Zuunbayan soum of Dornogovi province was slightly higher than in other soums. The content of heavy metals in water and soil samples did not exceed the international standard average.

Assessing Heavy Metal Contamination Risk in Soil and Water in the Core Water Source Area of the Middle Route of the South-to-North Water Diversion Project, China

The Middle Route Project of China’s South-to-North Water Diversion Project (SNWDP) is a national-level water source protection zone and the ecological safety of its water quality and surrounding soil is of great significance. In this study, heavy metals in the surface water and topsoil in the core water source area were quantitatively analyzed using a geographic information system (GIS) and geostatistical techniques combined with environmental pollution and ecological risk assessment models to determine their environmental contamination levels, ecological risk levels, and spatial distribution patterns. Cd was identified as an essential factor responsible for the overall slight heavy metal pollution in the topsoil layer. Heavy metal contamination in surface water was primarily driven by alert-level concentrations of Hg and was consistently distributed in areas with high concentrations of Hg in the topsoil. Applying the potential ecological risk index (RI) revealed two key results. First, surface water showed no ecological risk. The concentrations of heavy metals in surface water met the goals set by relevant authorities in China. Second, overall, the topsoil was at low ecological risk, with a spatial pattern primarily influenced by Cd and Hg. Some heavy metals might have similar pollution sources and originate from human activities such as industrial activities, mining and smelting, and pesticide and chemical fertilizer applications. The study is important for improving the soil and water ecology in the reservoir area and ensuring the northward diversion of high-quality water. In addition, it provides a sound basis for making decisions about local heavy-metal remediation and treatment projects.

QUESTIONS ON OPTIMUM DEVELOPMENT OF COMPLEX FOR MULTI-POINT CONTROL AND EVALUATION OF CONTAMINATION OF WATER BASINS POLLUTED BY WASTE WATER OF MINING AND PROCESSING PLANTS

The paper is devoted to questions on optimum development of complex for control and evaluation of contamination of water basins used for collection of industrial waste water. The purpose of the paper is development of scientific-methodical basics for development of measuring system for control and evaluation of contamination of natural water basins with heavy metals using method of attenuation of irradiation of dissolved organic matters excited by external irradiation. The task on optimization of operational regime of measuring complex for control and evaluation of contamination of natural water basins by waste water of large scale point type polluter of environment with heavy metals. The known model of Shtern-Volmer is used as a basis which assumes non-linear relationship between formed complex and fluorescent irradiations attenuation degree. It is noted that potential possibilities of Shtern-Volmers model are used not fully till now. So that in known researches the water objects polluted by several same sources are mainly researched. It is shown that Shtern-Volmer model is also applicable for analysis and estimation of pollution of water basins by single strong polluter that is mining and processing plants. For analysis the suggested special parameter, inversely proportional to concentration of heavy metals in water is used. Integration of this parameter on all possible values of heavy metals concentration and imposition of special limitation condition on the searched for function of dependence of attenuated part of fluorescent irradiation on maximum concentration of heavy metals make it possible to formulate and solve the task on searching of optimum type of this function providing for the optimum regime of operation of the complex.