Water Environmental Risk Research Articles

Water Environmental Risks Encountered during Urbanization in Valley Areas and the Potential Mitigation Effects of Utilizing Reclaimed Water

Since urbanization poses risks to regional environments, assessing and mitigating these risks is a challenge inherent to the urbanization process. The present study employs an adapted methodology based on the water environmental capacity (WEC) to assess the risks associated with the water environment in an urbanizing area located in a valley of the Chongqing municipality in Southwestern China, with a particular emphasis on its representative regional river. By utilizing hydrological data and planned parameters specific to this region, this study estimates the spatial and temporal distribution of the WEC and pollution loads in the river under various urbanization scenarios. It also explores the potential of the utilization of reclaimed water to mitigate these water environmental risks. The results indicate that the extent of urbanization exerts significant influences on the water environment and, therefore, requires meticulous planning. Areas experiencing higher levels of urbanization in the middle reaches of the river are associated with greater environmental risks compared to those observed in the lower reaches, while minimal risk is observed in the headwater. Due to the pollution loads brought about by precipitation, there is a higher level of environmental risk during the wet season (May–October) compared to the dry season. Utilizing reclaimed water can effectively reduce the pollution loads discharged into the river and is the most efficient means of mitigating environmental risks. To effectively manage environmental risks during urbanization in this valley area, further studies should prioritize examining the correlation between the scale of urban expansion and the river’s environmental carrying capacity. Additionally, it is imperative to establish realistic targets for the river water’s quality and discharge standards for the effluent from wastewater treatment plants. Furthermore, it is crucial to determine an appropriate level of utilization of reclaimed water and delve into the mechanisms behind the method used to assess the water environmental capacity. Despite these challenges, analyzing the spatial and temporal distribution of risk during urbanization and evaluating the mitigative effect of utilizing reclaimed water based on adapted assessments of the water environmental capacity hold reference value for the formulation of environmental management strategies and environmental planning. There is significant potential for this approach to have various applications.

Degradation of ribavirin by Fe2+/PS oxidation technology: performance, mechanism and toxicity control

During the COVID-19 pandemic, the extensive use of ribavirin (RBV) raised concerns about its environmental residues and associated risks, necessitating remedial actions. This study investigates the degradation efficiency, mechanism, and biotoxicity of RBV using ferrous (Fe2+) activated persulfate (PS) advanced oxidation technology (Fe2+/PS oxidation). Experiments conducted under various conditions revealed that at pH = 3, PS concentration of 4 mM, PS/Fe2+ molar ratio of 2:1, and citric acid of 0.5 mM with Fe2+ added twice, the degradation rate of RBV reached 98.70 %. The degradation process of RBV by Fe2+/PS from 0 to 5 mins followed a first-order reaction kinetics model. The presence of halide ions (Cl-, Br-, I-) was found to inhibit the degradation efficiency. The active species involved were identified as SO4-·, ·OH, 1O2, and FeO2+, with SO4-· and ·OH being the most significant. Moreover, the products of ribavirin were determined and their degradation pathways were proposed. Dehydration, deamidation, C-N bond breaking and hydroxylation were the major pathways. Additionally, toxicity assessment showed that Fe2+/PS oxidation reduced the inhibition rate of bioluminescence in Vibrio fischeri from 31.58 % to 3.88 %, effectively controlling RBV toxicity during the reaction. This study provides insights into managing water environmental risks associated with pharmaceutical residues in the post-pandemic era.

Spatial and Temporal Distribution and Risk Assessment of Heavy Metals in Surface Water of Changshou Lake Reservoir, Chongqing

To understand the water pollution status and environmental risks of Changshou Lake, the concentrations of heavy metals (Cr, Cu, Zn, As, Cd, and Pb) in the water were collected and analyzed during different seasons. The study investigated temporal and spatial variations, distribution characteristics, pollution levels, and health risks associated with heavy metals in Changshou Lake. The results showed that all six heavy metals were below than the Class Ⅰ standard of the Surface Water Environmental Quality Standard (GB 3838-2002), but recent years have witnessed an increasing trend, with Cu, As, and Pb showing a significant increase (P<0.05). The temporal and spatial distributions of these heavy metals were different. Temporally, Cr and Cd concentrations in surface water were higher in summer, As and Zn were higher in spring, and Pb and Cu were higher in autumn and winter. Spatially, the concentrations of Cr, As, Cu, Zn, and Pb showed higher concentrations in the southern outlet of the reservoir, the northwestern Longxi River inlet, and the central part of the reservoir, whereas Cd was higher in the northern stagnant area. The overall levels of heavy metals in the water body of Changshou Lake were low, with Cr and Cu slightly polluted, while other heavy metals were identified as having an insignificant pollution level. Drinking water was the primary exposure pathway to carcinogenic and non-carcinogenic heavy metals in surface water bodies. The health risk values of Cr and As in water bodies were high, ranging from 6.2×10-10 to 3.0×10-4 and 5.1×10-8 to 3.9×10-5, respectively. The corresponding contribution rates for children and adults to the total health risk were high, with Cr accounting for 87.18% and 87.20%, respectively, while As accounted for 12.73% and 12.71%, respectively. Therefore, it is crucial to prioritize environmental risks associated with Cr and Cu, as well as the health risks associated with Cr and As in Changshou Lake These findings provide a scientific foundation for water pollution control and environmental quality improvement in Changshou Lake, and rational development and utilization of water resources.

Improving Analytic Hierarchy Process inside the Analytic Group Decision-Making Approach Method with Two-Dimensional Cloud Model for Water Resource Pollution Risk Warning Evaluation: A Case Study in Shandong Province, China

This study proposes a water resource pollution risk warning evaluation method. Firstly, an evaluation system is constructed, consisting of 15 secondary indicators in four aspects: water quality, ecology, utilization protection, and water disasters. Then, an improved AGA-AHP method and coefficient of variation method are used to determine the weights of each indicator. Cloud models are employed to describe the characteristics of standard clouds and evaluation clouds, establishing a two-dimensional cloud model with risk probability and hazard level as variables. Taking a certain region in Shandong Province, China, as an example, the quantitative analysis results indicate that the water pollution risk level in the area is classified as Level IV, with particular attention needed for water quality and management indicators. Simultaneously, a series of measures such as source control, monitoring and early warning, emergency response, and public participation are proposed to further reduce the risk. The research findings demonstrate the following: (1) The establishment of a comprehensive indicator system for multidimensional assessment; (2) The combination of the AGA-AHP method and cloud model for quantitative analysis; (3) The practicality of the method validated through the case study; (4) Providing a basis for subsequent decision-making. This study provides new insights for water environmental risk management, but a further optimization of the model to enhance predictive capability is required when applied in practical scenarios. Nevertheless, the preliminary validation of this method’s application prospects in water resource risk monitoring has been achieved.

Environmental risks assessment of the Kogylnyk River nutrient pollution based on probit functions

The relevance of the study is associated with the need to determine the risks of high and catastrophic levels of water pollution of the Kogylnyk River. The water quality of this river affects the environmental condition of the northern part of Sasyk lake and reservoir. This artificial reservoir that was created as part of the estuary used to be one of components of the Danube-Dniester irrigation system in the past and can be used for irrigation in the post-war period in the future. As the North-Western Black Sea region is an agricultural region of Ukraine, the article focuses on the pollution of the river by specific nutrients (ammonium, nitrite, nitrate, phosphate). The subject of the study covers the environmental risks assessment of the Kogylnyk River present-day pollution. Hydrochemical observations of the State Water Resources Agency of Ukraine were used as input materials of the research. Such observations were carried out across the upper (below the border with the Republic of Moldova) and lower sections of the river. The number of samples taken in the upper section was 80, and 56 – in the lower section. Water quality was assessed using a modified water pollution index (WPI). The risks of nutrient pollution were evaluated based on a statistical approach using a probit function. It was found that the water quality in the upper section is worse than the one in the lower section. The research indicated a close correspondence between water quality indicators and environmental risk values. In the upper section, the risks of catastrophic pollution have a probability of their occurrence that is equal to 46.1%, and the risks of high pollution – 41.1%, with 87.2% constituting a total percentage. In the lower section, the probability of a high level pollution risk is equal to 33.3%, with no critical risk identified during the observation period. The trophic status of the water body along the river length varies from hypertrophic and polytrophic on the upper course to eutrophic and mesotrophic on the lower course. The decrease in pollution levels in the river's lower section is due to the processes of biological, physical and chemical self-purification of the aquatic ecosystem. Since nutrients have a predominantly anthropogenic origin, the water quality improvement of the Kogylnyk River across the territory of Ukraine is associated with the reduced flow of municipal and agricultural wastewater entering the river. Nutrient pollution requires implementation of additional measures such as improving the culture of farming taking place in the catchment area (for example, during conservation of fertilizers and their application).

Buoys are non-indigenous fouling hotspots in marinas regardless of their environmental status and pressure

Marinas contribute to the degradation of coastal ecosystems, constitute non-indigenous species (NIS) hotspots and function as steppingstones in invasion processes. These often enclose highly modified water bodies that promote the concentration of pollutants and propagules, favoring NIS abundance. In these habitats, floating structures are often the most invaded by fouling NIS. This study aims to address the effect of floating substrate (buoys vs pontoons) on fouling assemblages, with special focus on NIS, in 6 marinas of Cadiz Bay during summer and winter seasons. Since the effect substrate type can depend on the water physicochemical conditions and environmental state and pressures of marinas, an environmental assessment was carried out for each marina using literature, physicochemical water measurements and environmental risk assessments. Despite the registered seasonal variation in fouling assemblages and the environmental variability among the studied marinas, the type of substrate played a key role in fouling assemblages' structure and abundance. The higher abundance of fouling assemblages in buoys than pontoons favor NIS prevalence in marinas and increase the risk of NIS dispersal, particularly considering that buoys are more likely to detach and drift at sea than pontoons. The results indicate that high-risk consideration should be given to this substrate type and that the potential environmental effects of biological pollution must be considered in risk assessments.

Unveiling the Nexus the link between water quality index and phthalic acid ester concentrations in Tigris River

Monitoring water quality in an aquatic system is a crucial objective in pursuing sustainable development, despite the challenges posed by water scarcity and the impact of climate change. The objective of the present study was to examine the water quality of the Tigris River along its course from the point of entry into Baghdad city to its exit, particularly in the presence of Phthalic Acid Esters (PAEs). In both dry and wet seasons and from five sites of the river, nine environmental factors (Turbidity, Total dissolved solids, pH, dissolved oxygen, Chloride, nitrate, phosphate, sulfate, and Biological oxygen demand) and three PAEs (di-n-butyl phthalate (DBP), di-isononyl phthalate (DiNP), and di-2-ethyl hexyl phthalate (DEHP)) were investigated. Results revealed that the river has high levels of turbidity and Total dissolved solids, slightly alkaline, and well-aerated (dissolved oxygen >7 mg/L). Chloride, nitrate, phosphate, and sulfate values varied between seasons, as high values were recorded in the wet season. Biochemical oxygen demand levels were higher during the dry season. The highest value of total PAEs (2.20 μg/L) was observed during the dry season, and the lowest value was in the wet season (1.16 μg/L). The HQ results revealed that the river was ranked as a moderate risk area. However the water quality index and environmental risk index classified the water quality as a poor category, with a high-risk score in the study sites within Baghdad city. Therefore, despite the acceptable limit of PAEs in the river's water (<3 μg/L), its presence is an early alarm to withdraw attention to its environmental risk. These findings highlight the need for appropriate measures to control and remove pollutants to ensure a safe and healthy water supply in the Tigris River.

Study on coupling of typical elements in surface water and groundwater in the middle reaches of the Yangtze River, China

Understanding the coupling relationship of typical elements between surface water (SW) and groundwater (GW) is helpful to the prevention of regional water environment pollution. In this study, the coupling of typical elements (C, N, P) of SW and GW in the middle reaches of the Yangtze River was comprehensively analyzed using multiple statistics and hydrogeochemical modeling methods. SW chemical characteristics was found similar with that of GW in the middle reaches of the Yangtze River with cluster analysis, and all sampling points was divided into two principal components based on principal component analysis. One principal component was more affected by the water-carbonate mineral interaction, the other one was greatly affected by anthropogenic activities. More interestingly, no fixed replenishment and discharge relationship was found between SW and GW in different seasons, which laid a foundation for the coupling of typical elements between SW and GW. Cl- in SW and GW had the same major source. In addition, almost identical water-carbonate reactions was found occurred in phreatic water (PGW) and confined water (CGW). As a link between SW and CGW, PGW may accept the supplies of the two waters at the same time, resulting the concentrations of δD, Cl-, DOC and HCO3– in PGW ranking between SW and CGW. Furthermore, Nitrogen and phosphorus were found to migrate between SW and GW, and a potential ammonium source in shallow aquitard which generated a large amount of ammonium. The coupling effect of nitrogen source input and transformation occurred in the process of nitrogen coupling between SW and GW, which increased the ecological risk of water environment. This study provided a scientific basis for the control of SW-GW pollution in the middle reaches of the Yangtze River, and supported the security of the water ecological environment in the Yangtze River Basin.

Urbanization and the Emerging Water Crisis: Identifying Water Scarcity and Environmental Risk with Multiple Applications in Urban Agglomerations in Western China

Urbanization and climate change have combined to exacerbate water shortages in cities worldwide. While rapid urbanization is faced with the risk of water resource shortage, there are few studies on the impact of water resource shortage and the ecological environment in mega-regions. Taking the three major urban agglomerations in Western China as an example, the spatial–temporal agglomeration pattern and driving force for the risk of water shortage are analyzed. First, a new comprehensive index system for environmental risks of water resources has been established, which can be used to assess spatial changes in water resource shortage risks. Secondly, the relationship between water resource shortage and the urban agglomeration effect is discussed in regards to water resource vulnerability, exposure, and recoverability. The results showed: (1) From 2000 to 2018, the risk of total water shortage in 12 provinces (cities) in Western China decreased from 3.42 to 2.59; the risk of total water shortage in the Guanzhong Plain urban agglomeration dropped the fastest, with an average annual decline rate of 10.57%. (2) Water resource shortage in different cities of the three major urban agglomerations is out of sync in time and space; the risk level of water shortage is high in the north and low in the south. (3) Geological environmental change is an important influencing factor of water resource shortage; the negative impact of industrial water use on the risk of water shortage is the largest, with a contribution of 24.9%. In addition, this paper also puts forward policy suggestions to alleviate the risks of water shortage in the urbanization process in the western region. This research can provide a scientific basis for the sustainable development of urban water resources.

An integrated approach using multi-source data for effective pollution risk monitoring of urban rivers: a case study of Hangzhou.

With the rapid urbanization of cities, water pollution has emerged as a major challenge to their sustainable development. To tackle this problem, we developed a river pollution risk management system that integrates multi-source data and includes risk identification, early warning, and control. We applied this system to a case study of urban rivers in Hangzhou, China. The results indicated that the measured and effect values of urban river water quality in Hangzhou were 1.01 and 1.14, respectively, indicating mild pollution levels. NH3-N is the main risk factor, with poor supervision and land use being the main risk sources. River pollution risk in different drainage zones demonstrated stratification. Since 2012, the measured risk of water quality in Hangzhou has been decreasing, mainly concentrated in the built-up area; however, the effect risk has been increasing, especially in the new center and sub-center of the city. Based on these findings, three strategies for urban river pollution control are suggested: water ecology source rehabilitation, water environment process supervision, and water pollution end management. The results of this study extend the understanding of urban water environment risk and provide implications for sustainable urban planning.

Searching for pharmaceutically active products and metabolites in environmental waters of Peru by HRMS-based screening: Proposal for future monitoring and environmental risk assessment

The presence of pharmaceutical active products (PhACs) in the aquatic environment is a matter of current concern, and there is an increasing trend to include these compounds in water quality monitoring programs and environmental risk assessments. Several studies have reported the presence of PhACs in environmental waters worldwide, but only a few studies have focused on Latin American countries. Thus, available information on the occurrence of parent pharmaceuticals, especially their metabolites, is very scarce. Peru is one of the less monitored countries in terms of contaminants of emerging concern (CECs) in waters, and only one study has been found, which was focused on the quantification of selected PhACs in urban wastewater and surface water. The aim of this work is to complement the previous data reported on PhACs in the aquatic environment by application of a wide-scope high-resolution (HRMS)-based screening, making use of target and suspect approaches. In the present work, 30 pharmaceuticals, drugs or other compounds (sweeteners, UV filters, etc.) and 21 metabolites have been identified, with antibiotics (and metabolites) being the most prevalent compounds. The use of liquid chromatography (LC) coupled to ion mobility-HRMS allowed the tentative identification of parent compounds and metabolites, for which the analytical reference standard was not available, with a high level of confidence in their identification. Based on the results obtained, a strategy for the monitoring of PhACs and relevant metabolites in environmental waters from Peru and for subsequent risk assessment is proposed. Our data will also help to focus future studies to evaluate the removal efficiency of wastewater treatment plants and the impact of treated water in receiving water bodies.

Stagnant water environmental management in urban river networks: An integrated risk analysis involving hydraulic potential dissipation

Rapid urbanization has led to water stagnation by temporal and spatial imbalances of the hydrodynamics in urban river networks, which further entails environmental risks to drinking and recreational water supplies. The establishment of a succinct hydraulic potential dissipation (HPD) index to indicate the spatiotemporal stagnant water environmental risks quickly and intuitively is of vital significance to urban river networks with complicated water regimes and diversified water diversion measures. On this basis, an integrated stagnant water environmental risk analysis model (ISWERA) was established by coupling the process-based model and stochastic process to comprehensively and accurately assess risks, which has been calibrated and validated against the real data of 11 monitoring stations from May 3 to May 11 in 2017 and November 28 to December 10 in 2020, respectively. To represent the rationality of stagnant water environmental risks assessment using HPD, ISWERA was used to evaluate the temporal- and spatial-varying stagnant water environmental risk intensity and probability of 270 water diversion schemes formed by the combination of water diversion duration, flow, route, and potential in the Changzhou urban river network along the Yangtze River. For time-varying results, it revealed that cumulative risk intensity was reduced by nearly 15%, and risk probability was significantly reduced by nearly 50% with the increase of diversion duration to 5 days in general. For spatial-varying results, most of the rivers reached the low-risk grade under the optimized diversion duration, flow, route, and potential. While the rivers adjacent to densely populated areas still presented a moderate-risk state. The positive correlation was significant between HPD and stagnant water environmental risk intensity and probability results, with R2 = 0.86 and 0.74 respectively. When the HPD of upstream channels are below 63.4%, 74.1%, and 57.7% and the downstream HPD of S1 to T1, S2 to T2, S2 to T3, and S3 to T4 are below 40.6%, 32.9%, 22.4%, and 19.1%, respectively, the stagnant water environmental risk is lower. Arguably, this study could provide a scientific reference and foundation for water environmental management of similar urban stagnant water systems.

Integrated Assessment of Water Environmental Health Risk through Drinking Water Ingestion in Lhasa River Basin: Quantitative Analysis and Environmental Significance.

An integrated assessment of water environmental health risk through drinking water ingestion in Lhasa River has been implemented. The health risks caused by different pollutants in different age groups (children, juvenile and adult groups) are in the order of 10-8 ~ 10-7, 10-7 ~ 10-5 and 10-13 ~ 10-8 a-1, respectively. The total health risks for all age groups are lower than the International Commission on Radiation Protection recommended value and the U.S. Environmental Protection Agency recommended value at all points except LS4, LS12 and LS13. The total health risk levels in different age groups at most points are class III or II, which means that there are low or negligible negative effect in these points and age groups. It is more important to monitor the arsenic concentration. The water environment quality protecting in Lhasa River Basin must be consistent with the clear water and blue sky protecting in Tibet Autonomous Region and the national ecological security barrier construction on the Tibetan Plateau.

Health risk study of cadmium, chromium, lead and arsenic in reservoir water of Changzhou, China

Accurately assessing the health risks of human exposure to heavy metals via water is of great importance for performing targeted health risk prevention measures. To better understand the concentration characteristics and potential harm to human health of cadmium, chromium, lead and arsenic in the main drinking water-type reservoirs of Changzhou city, we collected samples from the Haidi Reservoir, Dongjin Reservoir, Xinfushan Reservoir, Maodong Reservoir and Xiangyang Reservoir of Changzhou in the summer of 2019. The results showed that the daily average comprehensive exposure level of metals was much lower than the provisional tolerated daily intake (PTDI), i.e., Cd: 1 µg kg−1 d−1; Cr: 3 µg kg−1 d−1; Pb: 3.57 µg kg−1 d−1; and As: 2.14 µg kg−1 d−1. The comprehensive non-carcinogenic risk levels of four metals under water-drinking exposure and water-skin exposure routes ranged from 4.68E − 3 to 1.69E − 1, and the carcinogenic risk ranged from 2.09E − 5 to 7.30E − 5, which were all at acceptable risk levels. Although lead and chromium were present at acceptable health risk levels, they still represented the main pollutants of potential health risk in the local water environment from a non-carcinogenic or carcinogenic perspective, and they should be listed as the primary targets for water environmental risk management.

The Main Problems of the Water Ecological Environment and Protective Countermeasures in the River Basin of the Altay Region, Xinjiang

This study systematically sorted out the situation of the water ecological environment in the river basins of the Altay region, and analyzed the main problems that exist concerning water environmental quality, water ecology, water resources, and other aspects. The Altay region has three major river systems: the Irtysh River, the Ulungur River and the rivers of Jimunai County. The water environmental quality of major rivers in the region remained stable, and the total amount of water resources in the Altay region is at the forefront of Xinjiang. However, insufficient ecological flow in the Altay basin, serious water ecological damage and water environmental risks are still prominent. Based on the main problems which were identified and the distribution of the river system, the Altay region would be divided into four areas: the Irtysh River Basin, the Ulungur River Basin, the river basins of Jimunai County, and the desert control unit in the south, and the four areas was divided into eleven water ecological environment control units. In order to provide scientific and technological support for the improvement of the water ecological environmental quality of the river basins in the Altay region, general ideas and countermeasures are put forward for protecting the water ecological environment of the river basin from the three aspects of enhancing water pollution prevention and control, strengthening the protection of water resources, and reinforcing water ecological protection and restoration.

Study on water environment risk of city size increase under the integration of Yangtze River Delta: A case study of Hefei city

Study on water environment risk of city size increase under the integration of Yangtze River Delta: A case study of Hefei city

Water Environmental Pollution Risk Assessment and Water Pollution Dispersion Simulation by Integrating GIS and Random Forest Algorithm

Water Environmental Pollution Risk Assessment and Water Pollution Dispersion Simulation by Integrating GIS and Random Forest Algorithm

Exploring the Influences of Stream Network Structure and Connectivity on Water Environment Risk in China

Stream networks are the transportation channels of pollutants that can significantly influence water environment risk (WER). However, the influences of stream network structure and connectivity (SC) on WER at the national scale and its regional variability have been rarely investigated in China. In this study, the WER was assessed from the grey water footprint of nitrogen and phosphorus in 214 catchments in China. The relationship between WER and SC and its regional variability were analyzed using correlation and grey relational analysis. Results showed that the water environment risk index (RI) in some catchments located in the Hai and Liao River Basins was the highest in China (RI &gt; 0.8). On national scale, longitudinal connectivity (Cl) and cyclical connectivity (Cc) had the strongest influences on WER with grey relational degree index (GRAI) of 0.68 and 0.67, respectively. The average slope (Sr) was the most important in humid zones, whereas Cl and water surface ratio (Rw) had a stronger influence in arid zones. In zones with intensive human activities, Cc, river density (Rd), and the node connection ratio (Rnc) mostly affected WER. The main influenced factors varied significantly among nationwide and different zones, which indicated that climate and human activities played an important role in the spatial variation of the relationship between WER and SC. This study highlights the important role of SC on WER and that the relationship between WER and SC varies with climate and human activities.

Assessment and Analysis of Water Environmental Risk Using Pressure-state-response Model in Ningbo, China

Assessment and Analysis of Water Environmental Risk Using Pressure-state-response Model in Ningbo, China

Inter-basin water transfer enhances the human health risk of heavy metals in the middle and lower Han River, China

The ecological and human health issues caused by inter-basin water transfer have drawn wide attention. To illustrate the spatial and temporal distribution of heavy metals (HMs) in the middle and lower Han River (MLHR), a 1D hydro-environmental model was developed, calibrated, and validated based on the observed data. Three simulation scenarios were conducted to analyze the human health risks resulting from heavy metal pollution. The results show that the water flow reduction after water transfer enhanced the heavy metal pollution in the MLHR. The total health risk of HMs in surface water of the MLHR basin was 4.69 × 10−5 a−1 for adults and 7.82 × 10−5 a−1 for children without the water transfer, while it increased to 4.77 × 10−5 a−1 and 7.95 × 10−5 a−1 when the South-to-North Water Transfer Project (SNWTP) was put into operation. The Yangtze to Han River Water Transfer project (YHWTP) can partially offset the adverse SNWTP influences. However, the human health risk is still higher than those without SNWTP operation. The health risks in the MLHR basin are main from carcinogens As, which should be prioritized as the main targets for water environment risk management in the Han River basin.