WQI Values Research Articles

Principal Component Analysis and the Water Quality Index—A Powerful Tool for Surface Water Quality Assessment: A Case Study on Struma River Catchment, Bulgaria

The water quality assessment of the surface water bodies (SWBs) is one of the major tasks of environmental authorities dealing with water management. The present study proposes a water quality assessment scheme for the investigation of the surface waters’ physicochemical status changes and the identification of significant anthropogenic pressures. It is designed to extract valuable knowledge from the Water Frame Directive (WFD) mandatory monitoring datasets. The water quality assessment scheme is based on the Canadian Council of Ministers of the Environment water quality index (CCME-WQI), trend analysis of estimated WQI values, and Principal Component Analysis (PCA) using calculated excursions during the determination of WQI values. The combination of the abovementioned techniques preserves their benefits and additionally provides important information for water management by revealing the latent factors controlling water quality, taking into account the type of the SWB. The results enable the identification of the anthropogenic impact on SWBs and the type of the corresponding anthropogenic pressure, prioritization and monitoring restoration measures, and optimization of conducted monitoring programs to reflect significant anthropogenic pressures. The proposed simple and reliable assessment scheme is flexible to introducing additional water quality indicators (hydrological, biological, specific pollutants, etc.), which could lead to a more comprehensive surface water quality assessment.

Hydrochemical Characteristics and Water Quality of Shallow Groundwater in Desert Area of Kunyu City, Southern Margin of Tarim Basin, China

The Tarim Basin in Xinjiang is located in the northwest inland arid region of China, but research shows that the region is rich in groundwater resources. To understand the hydrochemical characteristics and water quality of shallow groundwater in the desert area of the southern margin of the Tarim Basin, the groundwater was systematically sampled and tested. The ion characteristics and evolution mechanism of groundwater were analyzed by mathematical statistics, Schukarev classification, Piper three-line diagram, Gibbs model and ion ratio. Water quality was evaluated by the water quality index method (WQI) and irrigation water suitability-related parameters. The results indicated that the dominant cation in the study area is Na+, and the main dominant anions are SO42− and Cl−. According to total dissolved solids (TDS), the groundwater mainly belongs to brackish water and semi-saline water. The hydrochemical chemistry types are mainly Cl·SO4-Na·Mg type, followed by Cl-Na type, and the ion source is mainly the weathering and dissolution of evaporation rock, silicate and sulphate. The hydrochemical process is primarily controlled by evaporation concentration and rock weathering, and the cation exchange is weak. Furthermore, the WQI spatial distribution map shows that the groundwater in the middle of the study area is unsuitable for drinking and there are two areas with high WQI values greater than 500. In contrast, the good-excellent groundwater is scattered in the East. The groundwater generally has high to very high salinity, with significant changes in alkalinity. In addition, 54% of the water samples exceed the magnesium hazard (MH) limit. Therefore, certain measures should be taken before irrigation. This study has important implications for the rational development and reasonable utilization of local groundwater.

Hydrogeochemical characteristics of Kodku River of Lalitpur District, Nepal

Abstract Hydro-geochemical characteristics of Kodku River of Lalitpur, Nepal were determined through analysis of physicochemical parameters including major anions and cations. This study also characterizes and evaluates the suitability for drinking and irrigation. The results showed that river water is slightly alkaline toward the downstream. The concentration of BOD, COD, and total coliform was much higher than its prescribed limits for drinking purposes in downstream, whereas a few samples in upstream are fit for drinking with reference to WQI value. The estimated sodium percentage (Na%), sodium adsorption ratio (SAR), permeability index (PI), magnesium adsorption ratio (MAR), and Kelly's ratio (KR) depict the excellent and safe categories for irrigation purposes. The obtained Wilcox diagram also revealed that river water falls under the C1S1 category which is safe for crops. Hydrogeochemical facies in Piper diagrams signifies the dominance of Ca–HCO3 type. Similarly, Gibbs maps indicate mineral (rock) weathering, whereas mixing diagram reveals carbonate weathering as the main controlling factor of major ion species. This study provides information on the hydrogeochemical properties of the river and its suitability for drinking and irrigation. Despite the comprehensiveness, the study can be an effective approach for countries with similar levels of water resources management.

Water Quality Assessment of Al-Najaf City Potable Water Network

Water is an essential aspect of life and important in evolution. Recently the potable water quality topic has received much attention. The study aims to determine drinking water quality in Al-Najaf City by collecting samples throughout Al-Najaf city and comparing the results with the Iraqi guidelines (IQS 417) and World Health Organization (WHO) guidelines, as well as to calculate the WQI. Samples were tested in the laboratory between December 2021 and June 2022. The results showed that multiple parameters exceeded the allowable limits during both testing periods; during winter months, the results of TDS and turbidity exceeded the upper limits in multiple locations. Total hardness values also exceeded the limit of 500 ppm for all samples taken in the winter period. For magnesium and calcium, summer measurements were mainly within limits, unlike winter period measurements which mostly exceeded the limits. Residual chlorine tests in winter had higher concentrations, generally ranging from 0.25 to 0.8 mg/l. While During summer, concentrations dropped below the allowable limit in multiple sampling points. The study concluded that the majority of the water samples gathered during the winter months were of poor quality as the total WQI values were between (99-110), While the total WQI values for water samples collected during the summer period were rated as good quality water ranged between (75-81).

Risk Assessment of Dissolved Trace Elements and Heavy Metals in the Upper Reaches of the Yangtze River, China

The Yangtze River Basin, one of China’s five major watersheds and a primary source of drinking water for the country, is experiencing serious environmental pollution as heavy metals are discharged into its rivers. To evaluate the water quality of the river, determined water quality parameters were compared with the maximum permissible limit values recommended by the World Health Organization and Chinese drinking water standards. Physical and chemical analyses were conducted on water samples taken from 19 locations along the river’s path. The study quantified the contents of sodium (Na), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), lithium (Li), cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), scandium (Sc) and mercury (Hg). The results show that the average values of Mg, Sr, Co, Cu, Fe, Mn and Sc are higher than the historical background values. Moreover, through a correlation analysis it was concluded that these nutrients and trace metals have high values due to anthropogenic pollution in the study area. The computed WQI values range between 9.59 and 20.26, indicating excellent water quality in the river basin. Finally, hazard quotient (HQ) values show that exposure to the detected pollutants will have no adverse effects on human health and does not pose a potential non-carcinogenic risk.

Ground Water Quality Evaluation with Using WQI of Selected wells in Mandali Area, Diyala Governorate, East Iraq

Groundwater is necessary to ensure the safety of Mandali's water supply. Groundwater samples were collected from various parts of the city for this study. Two aquifers have been identified: the first is a free bed made up of Quaternary deposits. The second is the primary bed that conveys water, belonging to the Bai Hassan Formation. Nineteen groundwater samples were collected from wells and examined for physicochemical parameters in the current study during October 2021. Samples were analyzed for main cations Ca2+, Mg2+, Na+, and K+; anions HCO3- , SO42- , Cl- and NO3-, pH, Electrical Conductivity, and Total Dissolved Solids. Results indicated that the Samples water is neutral to slightly alkaline. The TDS classifications show that the groundwater samples are classified as fresh to slightly fresh water. All water samples are severely mineralized, except sample W17 which is highly mineralized due to the water feeding from the deep aquifer of Bai Hassan formation. Dominant cation is Na+ followed by Ca2+, Mg2+ then K+, whereas dominant anion SO42 ̶ followed by Cl¯ then HCO3¯. The water type of 8 samples 42% is NaCl type, seven samples 37% is MgSO4 type, three samples 16% is Na2SO4 type, and 1 sample 5% is CaSO4. The diversity in water is because the sediments of the Quaternary age derived from neighboring formations such as Fatha and other formations. According to Piper's diagram, Groundwater samples are mostly earth alkaline water with an increased amount of alkali, high sulfate and chloride. The groundwater in the study area has a wide range of WQI ranging from excellent (W17) while classified as good water (W1, W3, W4, W5, W6, W7, W8, W9, W11, W12, W13, W14, W16, W18, W19) and classified as Poor water (W2, W10, W15) because of the high values of WQI values computed.

ASSESSMENT OF IRRIGATION AND WATER QUALITY INDICES OF INDUSTRIAL EFFLUENT AND SURFACE WATER IN ALETO ELEME, RIVERS STATE

x The study assessed the irrigation water quality indices of industrial surface water in Aleto Eleme, Rivers State, Nigeria. A total of 9 samples of water effluents and surface water were collected and taken to laboratory to test for the level of concentrations of the physico-chemical parameters using standard laboratory analyses as recommended by the American Society for Testing and Materials for physico-chemical properties and descriptive statistics were employed for the data analysis. Findings revealed that Sodium Absorption Ration (SAR) values ranged from 0.32 to 12.39; Soluble Sodium Percentage (SSP) values ranged from 23.39 to 80.62; PI values ranged from 24.79 to 889.8; KR values ranged from 0.39 to 4.16, Residual Sodium Carbonate(RSC) values ranged from -585.3 to 9.9. Also, the different classes of salinity hazard in the USSL diagram include low, C1 (EC < 250 μS/cm); medium, C2 Electrical Conductivity (EC 250–750 μS/cm); high, C3 (EC 750 -2250 μS/cm); and very high, C4 (EC > 2250 μS/cm), as shown in figure 4. Also, the sodium hazard classes include: low, S1 Sodium Absorption Ratio (SAR < 10); medium, S2 Sodium Absorption Ratio (SAR 10 -18); high, S3 (SAR 18–26); and very high, S4 (SAR > 26). Thus, the quality of river water in the area had WQI values (WQI > 300), rating the water as unsuitable for drinking. The study recommended that the water quality should be improved for domestic purposes by making sure that regulatory bodies monitor the level of water pollution everywhere in Rivers State. More studies on water quality should also be conducted periodically.

Studies on Nile river pollution and water quality indicators in Egypt

The Nile River is an important natural and exclusive source of fresh water in Egypt. Water samples were taken monthly from twelve sites from 2015 to 2020 in El Beheira Governorate and eighteen physicochemical parameters were measured. The results show that the Rahawy drain recorded the highest values for most of the physicochemical parameters. The HPI and MI indicators in Rahawy drain were higher (70 % & 100 %) than in other sites, especially in the summer and winter seasons. The Rahawy WQI values were classified as poor quality. The IWQI results indicate that the water quality for the Rahawy was within the "severe restriction" class, with many restrictions to be used in agriculture. The water quality of the Nile River in the south of Egypt is better than that of the north and the water quality recovery takes more time and distance.

Assessment of Some Water Quality Parameters in the Storm Sewer Network at Ramadi City, Iraq

This study aims to assess the quality of storm sewer water in Ramadi city before its discharge into the Euphrates River and Al-Warrar Canal. Several samples were taken from the storm sewer in two different periods October and April months. Samples were tested in laboratories which included (PH), electrical conductivity (EC), alkalinity (Alk), total hardness (T.H), calcium (Ca), biological oxygen requirements (BOD5), chemical oxygen requirements (COD), nitrate (NO3). sulfate (SO4) dissolved solids (TDS), suspended solids (TSS), and some heavy metals such as copper (Cu) and zinc (Zn). In this study, the authors suggested a new approach for calibrating WQI values using the multiple linear regression (MLR) model and coefficients analysis The results showed that the (MLR) model is acceptable, the multiple linear regression analysis (MLP) was applicable to calibrate WQI values, and new WQI equation with four variables was developed (SO4, BOD5, TSS and TDS), The results showed that the MLR model has a coefficient of R2 equal to (0.859), which indicates that 85.9% of the variance of the data was explained as well as obtaining significance values greater than 0.05 for each of the absolute WQI value. According to analysis, SO4 is the parameter that has the greatest effect on WQI.

Groundwater quality assessment using principal component analysis modified water quality index in the Huangbizhuang, Northern China Plain

This study was carried out to evaluate the groundwater quality in Huangbizhuang town, which is an important water source for Shijiazhuang and Beijing, China. Fifty-six geo-referenced water samples were collected from pumping and monitoring wells from July to September 2018. The study investigated the applicability of two weighting methods, the expert weighting method, and the principal component analysis weighting method, to water quality assessment and evaluated the water quality status and the leading causes of groundwater pollution by chemical analysis index and multivariate statistical methods. The results show that the overall quality is good, and shallow and deep groundwater in the study area is generally suitable for drinking and irrigation. The WQI of the expert weighting method reveals that 74.36% of the shallow groundwater and 58.82% of the deep groundwater is excellent. Shallow groundwater has a close hydraulic connection with surface water, and the water quality of shallow groundwater is superior to that of deep groundwater. Compared with the expert weighting method, the weight of natural factors is larger, and the WQI value is higher in PCA weighting. Since no subjective factor is involved, the PCA weighting method is more objective and more suitable for the study area. In addition, multivariate statistical calculation results show groundwater pollution is due to both point source pollution, industrial activities, and non-point source pollution, such as agricultural activities.

Geochemical Characterization of the River Waters in the Pumqu Catchments, Central Himalayas

Pumqu is the biggest river in the Qomolangma National Natural Reserve in China. It is one of the headwaters of the river Ganges and is an important international river in southern Tibet Autonomous Region (T.A.R). However, there are a lack of systematic studies on Pumqu’s geochemical properties. In this study, water samples were collected systematically from all the river catchments in different seasons in 2021, the spatiotemporal variations of the geochemical characteristics of the catchments and their controlling factors were studied, and the overall water quality of the river was also evaluated. Overall, the results showed that the water from the Pumqu catchments was slightly alkaline, with an average pH of 8.22. The number of total dissolved solids was comparable to the other rivers on the Tibetan Plateau and showed a similar variation over the year. Affected by the natural geothermal spring water discharge, the values of oxidation reduction potential at some sampling sites were negative in the wet season. Generally, Ca2+ and HCO3− were the dominant ions. Carbonate weathering was the main factor affecting the geochemical features of the studied catchments. The results of correlation analysis showed the influence of rock weathering, glacial meltwater, geothermal water discharge and riverine physicochemical processes on the trace elements. The natural geothermal water discharge was particularly responsible for the elevated Li, which appeared in some of the sampling sites and resulted in relatively high WQI values in the sites. The overall water quality of the Pumqu catchments was excellent. This study provides first-hand information on the overall spatial and temporal span of the physicochemical characteristics and water quality of all the catchments of the river Pumqu, one of the major water systems in the central Himalayas.

Risk Analysis of Heavy Metals and Groundwater Quality Indices in Residential Areas: A Case Study in the Rajanpur District, Pakistan

Continuous monitoring of drinking water quality is essential in terms of the levels of heavy metals and toxic substances, especially in developing countries like Pakistan. Therefore, this study aimed to investigate groundwater quality in residential areas of the Rajanpur District, Pakistan. Groundwater samples (n = 200) were collected from various sites in the study area and analyzed by in situ tests (pH, EC, TDS, temperature, and turbidity), and the concentration of 32 dissolved elements and ions was also analyzed. The results showed that higher concentrations of dissolved elements are the primary reason for poor drinking water quality. A few measured parameters (TDS~992 mg L−1 and EC~1921.15 µS/cm) exceeded the permissible limits of the World Health Organization (WHO, Geneva, Switzerland) in most of the samples. Elements that had higher values than the allowable limits in most of the samples were calcium (Ca), sodium (Na), bicarbonates (HCO3), sulfate (SO4), chlorides (Cl), manganese (Mn), and strontium (Sr), with average values of 113 mg L−1, 223 mg L−1, 282 mg L−1, 367 mg L−1, 175 mg L−1, 69 mg L−1, and 1291 mg L−1, respectively. The measured parameters that had no significant issues in terms of drinking water quality were aluminum (Al), nitrite (NO2), phosphate (PO4), pH, and turbidity. The levels of potentially toxic elements such as arsenic (As), lead (Pb), chromium (Cr), and copper (Cu) (average ~2.179 mg L−1, 1.659 mg L−1, 0.092 mg L−1, and 1.032 mg L−1, respectively) were found to be lower than the drinking water guideline values of the WHO. The statistical analysis revealed weak correlations possibly due to multiple sources and localized variations. The physicochemical analysis-based WQI values for all groundwater samples were much lower at the residential sampling locations and in industrial settings, indicating poor water quality. The elevation model indicated that as water moves in the aquifer in the general direction of west to southeast, it gets concentrated by mineral dissolution, with geogenic sources having a major impact on the hydrochemistry. Hence, regular monitoring of water quality is required through advanced technology to overcome groundwater deterioration issues. The quality of water is poor for drinking purposes and the health of the residents of the Rajanpur District may be at risk.

Trend Analysis on Water Quality Index Using the Least Squares Regression Models

River water pollution requires continuous water quality monitoring that promotes the improvement of water resources. Therefore, the trend analysis on water quality data using mathematical model is an important task to determine whether the measured data increase or decrease during the time period. This paper is intended to highlight the applicability of the least squares regression models to fit the WQI data of the Skudai River, Tebrau River and Segget River located in Johor, Malaysia. As per the 12 years of trend analysis, the data of WQI are collected from the Environmental Quality Reports 2009-2020. The least squares method is utilized to estimate the unknown constants of the linear, quadratic, cubic, polynomial of degree four and degree five regression models. The advantage of using proposed models is that it can be implemented easily even on relatively low computational power systems. The results show that the higher degree polynomial model fits the data reasonably well, in which the polynomials of degree 4 and 5 have lowest average error. Assessment of actual and predictable values of WQI shows that the trends in WQI for all study areas are downward year after year.

Quality Index of Borehole Water in Marmara and New Site Communities of Wukari, Nigeria

The fitness of groundwater has continued to deteriorate due to increasing population, commercialization, and urbanization, among others. Water quality can be assessed on physical, chemical and biological basis. This study evaluates the physicochemical properties and quality index of borehole water in Marmara and New site community of Wukari Local Government area using standard procedure. Result showed that the mean pH, Total Dissolved Solids (TDS), Total Suspended Solids (TSS), alkalinity, Biological Oxygen Demand (BOD) and nitrates were 6.6 and 6.9; 111.6 and 385 mg/L; 34.6 and 33.4 mg/L; 102.4 and 150 mg/L; 21.69 and 8.42 mg/L; 31.51 and 16.85 mg/L; 8.98 to 18.30 mg/L for Marmara and New site borehole water samples respectively and are within the permissible limit of the World Health Organization. Marmara recorded the highest pH, temperature, dissolved oxygen, TDS, alkalinity and nitrate while New site had higher total suspended solids, COD and BOD. WQI values of 86.03 and 80.22 were obtained in borehole water sourced from New site and Marmara respectively, rating the quality of borehole water in this study good and, on further purification, can serve for drinking and other domestic applications.

Groundwater quality assessment for drinking and clean water in Bagelen and its surrounding area

Bagelen and its surrounding area are parts of the Kulon Progo Hills which have less water potential. However, groundwater can still be obtained from dug wells or several springs in the hills. This study aims to determine the quality of groundwater in the study area as clean water and drinking water. Hydrogeological surveys have been conducted to see the quality of this groundwater. Groundwater samples were taken from six dug wells and two springs. Groundwater can be found in sandstone, limestone and andesite breccias aquifers, through intergrains and cracks porosities. Groundwater usually has Ca-bicarbonate facies. The need for good quality groundwater for drinking and clean water has been investigated based on the WQI value. The WQI value is determined based on several physical parameters, including turbidity and TDS and chemical parameters such as pH, Fe, hardness, Mn, nitrate, Zn, sulfate, chloride and sodium. Based on the Minister of Health Regulation standard No. 492/2010 for drinking water and No. 32/2017 for clean water, the groundwater showed good - excellent value for drinking water and excellent value for clean water.

Monitoring the Water Quality of Tigris River by Applied Overall Index of Pollution

The alteration in the hydrological regime in Iraq and the anthropogenic increasing effect on water quality of a lotic ecosystems needs to continuous monitoring. This work is done to assess the water quality of Tigris River within Baghdad City. Five sites were selected along the river and ten physicochemical parameters and Overall Index of Pollution (OIP) were applied to assess the water quality for the period between November 2020 and May 2021, the studied period were divided into dry and wet seasons. These parameters were water temperature, pH, dissolved oxygen (DO), biological oxygen demand (BOD), total hardness, alkalinity, turbidity, total phosphorus, total nitrogen, electrical conductivity (EC). Results showed that the values of parameter indicated slightly polluted in terms of values of DO, BOD and EC in both wet and dry seasons. The findings of the present study showed the OIP values in wet season less than recoded in dry season at all sites. The OIP values ranged between class 2 and class 3 (Acceptable – Slightly polluted ). While sites 2 and 3 were recorded OIP values less the 2 in wet season. However, the variation in OIP- WQI value in five different areas are attributed to impact of different pollutants.

Spatio-temporal characterization of nutrient and organic pollution along with nutrient-chlorophyll-a dynamics in the Geum River

River water pollution is one of the biggest environmental challenges in the world. Therefore, it is imperative to assess the spatial and temporal variability of surface water quality to manage water resources from pollution. This study aimed to identify spatio-temporal variations of Geum River surface water quality and the factors that influence it. Summer monsoon, land-use land-cover (LULC), and weirs are dominant factors determining the dynamics of river water quality. Empirical analysis showed that total phosphorus (TP), total nitrogen (TN), biological oxygen demand (BOD), and chemical oxygen demand (COD) had positive linear functional relations with the agricultural and built-up cover but negative linear relations with forest cover. The results showed that the total suspended solids (TSS), chlorophyll-a (CHL-a), TP, and COD levels were higher in the summer than in any other season. On the other hand, total nitrogen (TN) and electrical conductivity (EC) levels were lower during summer in the river due to the dilution effect. Pollutant-transport theory shows that TSS acts as a TP carrier (R2 = 0.83, p < 0.001). The empirical model suggested that TP (R2 = 0.76, p < 0.001) was the better predictor for CHL-a compared to TN (R2 = 0.13, p < 0.001) as well as showed strong P-limitation based on TN:TP ratios. The high average WQI values of the Geum River (except for S01 and S02) show a higher pollution level, indicating its unsuitability for drinking, irrigation, and industrial usage. Our results suggest that industrial and domestic sewage treatment and agricultural diffuse pollution control could improve the Geum river water quality.

Evaluation of Groundwater Quality by Water Quality Index During Successive Periodic Intervals in the Selected Villages of Gara Mandal of Srikakulam District in Andhra Pradesh

The quality of groundwater is assessed using the Water Quality Index method and it is pertinently helpful to transfer the complex data into usable data. In this research study the WQI values have been estimated for each water sample (in total, 66 samples have been collected) based on 9 water quality parameters at periodic intervals in May 2015, 2016 and 2017 in the villages of Gara Mandal of Srikakulam District in Andhra Pradesh. The overall results disclosed that 50-54% of the groundwater samples (WQI lies between 100-200) showed poor quality and 10-13% of water samples (WQI lies between 200-300) showed very poor quality in successive periodic intervals. An assessment of measured physicochemical parameters of 66 sample sites has shown that the majority of the groundwater samples have a high concentration of calcium, magnesium, sodium, chloride and sulfate ions beyond the desirable limits of BIS and WHO standards. Correlation matrix show a strong positive correlation existing between the calcium, magnesium, sodium, chloride and sulfate ions pointing out that groundwater in this region has been contaminated more by these components due to anthropogenic activities and over-exploitation. Hence, in the study region, suitable treatment of water is necessary before consumption, this is because maximum parts of the sampling points have a high WQI value.

Variations in the macrobenthic invertebrates in relation to physico-chemical characteristics and WQI in Lake Qarun, Egypt

The seasonal relationship between the physico-chemical characteristics and the macrobenthic fauna community was studied in Lake Qarun, Egypt. Lake Qarun receives a huge amount of agricultural drainage water from the neighboring cultivated land via El-Batts and El-Wadi drains. Generally, the obtained results have shown a decrease in dissolved oxygen, transparency and increase in COD, NO3– and NH3 at the stations in front of El-Batts and El-Wadi drains due to the continuous pollutants discharged into the Lake's water. The WQI revealed that the water quality of Lake Qarun is poor for aquatic life. The macrobenthic community consisted of sixteen species belonging to three phyla, Mollusca (7 species) that was dominated by Cerastoderma glaucum, Annelida (4 species) that was dominated by Limnodrillus spp. and Arthropoda (5 species) that was dominated by Balanus pallidus. The structure and abundance of macrobenthic species were affected by many factors especially pollution from the drainage water contaminated with sewages, which affected all living organisms in the Lake. The WQI values of Lake Qarun ranged from 32.30 to 38.40 (poor class) and the average value in the whole area was 35.89 ± 1.64 that is ranked as poor for the aquatic life utilization. To avoid this undesirable effect, the pollutants that flow into the Lake must be treated before being discharged.

Physicochemical properties of water in an intensive agricultural region in Bangladesh: a preliminary study for water quality and health risk assessment

ABSTRACT There are many reservoirs, ponds and Korotoa River in the capital of ancient Pundranagar, Bangladesh, which is an intensive agricultural region. Since different industries are operated for the preparation of different agricultural instruments and agrochemicals are extensively applied to the agricultural soils which mix with the river and pond water and these water bodies may be contaminated with trace elements. In this study, levels of nine trace elements (Cr, As, Cu, Ni, Zn, Cd, Fe, Mn and Pb) and physicochemical properties in surface water from one river and five ponds were measured and compared with water quality guidelines. In addition, health risks, pollution status and possible sources of trace elements were assessed. The mean concentrations of As, Cd, Pb, Cr, Ni, Cu, Fe, Mn and Zn in pond water were 0.059, 0.033, 0.067, 0.136, 0.133, 0.280, 0.733, 0.127 and 0.266 mg/L and river water were 0.055, 0.037, 0.054, 0.104, 0.120, 0.230, 0.702, 0.125 and 0.200 mg/L, respectively. Except Cu and Zn, the mean concentrations of trace elements were above the water quality permissible standards indicating water from these sources is not safe for human use. The WQI values suggested that the water quality is excellent to poor water quality class. Health risk indices indicated that As in water via ingestion exposure pathway may pose both non-carcinogenic and carcinogenic health risks to the residents where the non-carcinogenic risk to the residents is raised from ingestion of As, Cd, Cr and Pb from water.