Assessment of groundwater quality and health risk in drinking water basin using GIS

Assessment of hydrochemical characteristics, health risks and quality of groundwater for drinking and irrigation purposes in a mountainous region of Pakistan

Renowned for its agriculture, livestock, and mining, Zhob district, Pakistan, faces the urgent problem of declining groundwater quality due to natural and human-induced factors. This deterioration poses significant challenges for residents who rely on groundwater for drinking, domestic, and irrigation purposes. Therefore, this novel study aimed to carry out a comprehensive assessment of groundwater quality in Zhob district, considering various aspects such as hydrochemical characteristics, human health risks, and suitability for drinking and irrigation purposes. While previous studies may have focused on one or a few of these aspects, this study integrates multiple analyses to provide a holistic understanding of the groundwater quality situation in the region. Additionally, the study applies a range of common hydrochemical analysis methods (acid-base titration, flame atomic absorption spectrometry, and ion chromatography), drinking water quality index (WQI), irrigation indices, and health risk assessment models, using 19 water quality parameters. This multi-method approach enhances the robustness and accuracy of the assessment, providing valuable insights for decision-makers and stakeholders. The results revealed that means of the majority of water quality parameters, such as pH (7.64), electrical conductivity (830.13 μScm-1), total dissolved solids (562.83 mgL-1), as well as various anions, and cations, were in line with drinking water norms. However, the water quality index (WQI) predominantly indicated poor drinking water quality (range = 51-75) at 50% sites, followed by good quality (range = 26-50) at 37% of the sites, with 10% of the sites exhibiting very poor quality (range = 76-100). For irrigation purposes, indices such as sodium percent (mean = 31.37%), sodium adsorption ratio (mean = 0.98 meqL-1), residual sodium carbonate (- 3.15 meqL-1), Kelley's index (mean = 0.49), and permeability (mean = 49.11%) indicated suitability without immediate treatment. However, the magnesium hazard (mean = 46.11%) and potential salinity (mean = 3.93) demonstrated that prolonged application of groundwater for irrigation needs soil management to avoid soil compaction and salinity. Water samples exhibit characteristics of medium salinity and low alkalinity (C2S1) as well as high salinity and low alkalinity (C3S1) categories. The Gibbs diagram results revealed that rock weathering, including silicate weathering and cation exchange, is the primary factor governing the hydrochemistry of groundwater. The hydrochemical composition is dominated by mixed Ca-Mg-Cl, followed by Na-Cl and Mg-Cl types. Furthermore, the human health risk assessment highlighted that fluoride (F-) posed a higher risk compared with nitrate (NO3-). Additionally, ingestion was found to pose a higher risk to health compared to dermal contact, with children being particularly vulnerable. The average hazard index (HI) for children was 1.24, surpassing the allowable limit of 1, indicating detrimental health effects on this subpopulation. Conversely, average HI values for adult females (0.59) and adult males (0.44) were within safe levels, suggesting minimal concerns for these demographic groups. Overall, the study's interdisciplinary approach and depth of analysis make a significant contribution to understanding groundwater quality dynamics and associated risks in Zhob district, potentially informing future management and mitigation strategies.

Sources, distribution, associated health risks and remedial technologies for inorganic contamination in groundwater: A review in specific context of the state of Haryana, India

Haryana is one of the leading states in India in the agricultural and industrial production. With the expansion of these sectors, a continuous increase in water demand is leading to water crises arising from overexploitation and quality deterioration of the available water. Contamination of aquifer resources is a significant concern, because majority of population depends on the groundwater for various agricultural, industrial, and domestic needs. This review article provides an overview of groundwater contamination, associated health risks with different contaminants with regions severely affected by poor water quality, and delves in identifying the sources, by observing and recognising the types of industries dominant in the state with types of effluents discharge. It further suggests the possible mitigation measures such as advanced remedial technologies and proper management practices from the consequent contamination sources. It has been observed during the perusal of various studies and data that the degree of contamination was considerably higher in districts with heavy agro-industrial activities. The groundwater resources in three highly industrialized districts were found to be gravely contaminated with toxic heavy metals. Alongwith heavy metals, the salinity, hardness, nitrate, and fluoride are also posing significant problems in the aquifer resources of Haryana state. The article also discusses various technologies for remediation of different pollutants from groundwater so it can be made potable after treatment.

Assessment of heavy metal pollution and quality in lake water and sediment by various index methods and GIS: A case study in Beyşehir Lake, Turkey

Beyşehir Lake, Turkey's largest freshwater lake, is also a "Drinking Water Reserve". In the study, heavy metal (As, Cr, Cu, Ni, Zn, Pb, Cd, Hg, Fe, Al, Mn) concentrations of seasonal lake water and bottom sediment samples were determined to evaluate the heavy metal pollution. Several index methods were applied, and pollution assessments were made using the obtained analysis results of lake water and sediment samples. The average concentrations of the heavy metals in the lake waters are observed as Fe > Al > Mn > As>Zn > Ni > Pb > Cr > Cu > Hg > Cd. When the lake waters were compared with the TS 266 (2005) and WHO (2017) limit values, it was determined that lake waters are below the limit values in terms of the heavy metals. According to index results, all of the lake samples are suitable for use as drinking water in accordance with the heavy metal pollution index (HPI) value, all of the samples are in the "low pollution" class in accordance with the heavy metal evaluation index (HEI) and degree of contamination (Cd) values. In addition, the water average concentrations of the heavy metals in the lake sediments are observed as Fe > Al > Mn > Cr > Ni > Zn > Cu > As>Pb > Cd > Hg. The contamination factor (CF) and enrichment factor (EF) revealed that sediments were considerably and moderately polluted by As, Cr, Cu, Ni, Cd, Fe and Mn and low polluted and/or unpolluted by other metals. The calculated pollution load index (PLI) and Igeo values indicate that lake sediments do not carry a risk of heavy metal contamination.

Groundwater quality, heavy metal pollution, and health risk assessment using geospatial techniques and index methods in Eber wetland and surroundings (Afyonkarahisar/Turkey)

The continuous increase in the demand for water and the scarcity of water to be used as drinking water have made groundwater even more important. The study area, Eber wetland, is located in the Akarçay river basin, which is one of the most important river basins in Turkey. The groundwater quality and heavy metal pollution were investigated in the study using index methods. In addition, health risk assessments were performed. Ion enrichment was determined at locations E10, E11, and E21 related to water-rock interaction. In addition, nitrate pollution was observed in many samples due to agricultural activities and also fertilizer application in the areas. The water quality index (WOI) values of the groundwaters vary between 85.91 and 201.77. In general, groundwater samples located around the wetland were in the "poor water" class. According to the values for the heavy metal pollution index (HPI), all the groundwater samples are suitable for use as drinking water. They are also classified as "low pollution" according to the heavy metal evaluation index (HEI) and the value/degree of contamination (Cd). In addition, since the water is been used for drinking by the people in the area, a health risk assessment was performed to ascertain As and NO₃. It was determined that the R_cancer values calculated for As were considerably higher than the tolerable/acceptable values for both adults and children. The results obtained clearly show that the groundwater should not be used as drinking water.

The concentration of potentially toxic elements (PTEs) in drinking water from Shiraz, Iran: a health risk assessment of samples

The existence of potentially toxic elements (PTEs) in water bodies has posed a menace to human health. Thus, water resources should be protected from PTEs, and their effect on the exposed population should be investigated. In the present investigation, the concentrations of PTEs such as lead (Pb), mercury (Hg), manganese (Mn), and iron(Fe) in the drinking water of Shiraz, Iran, were determined for the first time. In addition, hazard quotient, hazard index, cancer risk, and sensitivity analysis were applied to estimate the noncarcinogenic and carcinogenic impacts of Pb, Hg, Mn, and Fe on exposed children and adults through ingestion. The mean concentrations (µg/L) of Pb, Hg, Mn, and Fe were 0.36, 0.32, 2.28, and 8.72, respectively, in winter and 0.50, 0.20, 0.55, and 10.36, respectively, in summer. The results displayed that Fe concentration was more than the other PTEs. PTE concentrations were lower than the standard values of the Environment Protection Agency and World Health Organization. Values of the degree of contamination and heavy metal pollution index for lead, mercury, manganese, and iron were significantly low (< 1) and excellent (< 50), respectively. Based on the Spearman rank correlation analysis, positive and negative relationships were observed in the present study. The observations of the health risk assessment demonstrated that mercury, lead, iron, and manganese had an acceptable level of noncarcinogenic harmful health risk in exposed children and adults (hazard quotients < 1 and hazard index < 1). The carcinogenic risk of lead was low (< E - 06), which can be neglected. Monte Carlo simulation showed that water intake rate and mercury concentration were the most critical parameters in the hazard index for children and adults. Lead concentration was also the most crucial factor in the cancer risk analysis. The results of the present study proved that the drinking water of Shiraz is safe and healthy and can be confidently consumed by people.

Water quality characterization and pollution source apportionment in the Himalayan river flowing through Jammu City, India, using multivariate statistical approach and geospatial techniques

The present study evaluates and characterizes the water quality of River Tawi in Jammu city of Union Territory of J&K, using water quality index, multivariate statistical methods, and geospatial techniques. Water quality parameters were measured at fourteen selected sites along a 12 km (approx.) stretch of river (passing through the city) over two seasons (pre-monsoon and post-monsoon) using standard methods. Water quality index (WQI) results demonstrated spatial and temporal variations and the pollution level of the river increased from upstream to downstream sites. Calculated WQI revealed 35.71% of the water samples in the unfit for drinking category, 28.57% in good and poor category each, and 7.14% samples in very poor drinking water category during the study period. Comparison of analysis results with the drinking water standards prescribed by the World Health Organization and Bureau of Indian standards recorded elevated ranges of parameters like turbidity, BOD, total alkalinity, nitrate, and faecal coliform beyond the permissible limits. Hierarchical cluster analysis has transformed the sites into two clusters during pre-monsoon and three clusters during post-monsoon season indicating more water quality variation during post-monsoon season. Principal component analysis resulted in two PCs for the water quality, explaining 80.827% and 73.672% of the variance for pre-monsoon and post-monsoon periods. The prepared WQI maps confirmed and depicted deterioration of river water quality towards the midstream and downstream sites of the river basin. Entry of major sewage drains from the city particularly at the midstream sites and dumping of solid waste and agricultural runoff towards the downstream sites of the river constituted the main anthropogenic sources that decreased the river water quality. The study establishes first step towards spatial zoning of River Tawi based on pollution level which would help in improving the river water quality through proper basin management. The study also recommends installation of sewage treatment plants particularly at the midstream and downstream sites.

Health Risk of the Shallow Groundwater and Its Suitability for Drinking Purpose in Tongchuan, China

Studying the quality and health risks of groundwater is of great significance for sustainable water resources utilization, especially in arid and semi-arid areas around the world. The current study is carried out to evaluate the quality and potential health risks of groundwater in the Tongchuan area on the Loess Plateau, northwest China. Water quality index (WQI) and hydrochemical correlation analysis were implemented to understand the status of groundwater quality. Daily average exposure dosages through the oral and dermal contact exposure pathways were taken into consideration to calculate the health risks to the human body. Additionally, graphical approaches such as Piper diagram, Durov diagram and GIS mapping were used to help better understand the results of this study. The WQI approach showed that 77.1% of the samples were of excellent quality. The most significant parameters affecting water quality were NO3−, F−, and Cr6+. The health risk assessment results showed that 27.1% and 54.2% of the samples lead to non-carcinogenic risks through oral intake for adults and children, respectively. In contrast, 12.5% of the groundwater samples would result in carcinogenic risks to the residents. This study showed that the WQI method needs to be supplemented by a health risk evaluation to obtain comprehensive results for groundwater quality protection and management in the Tongchuan area.

Water intake meets the Water from inside the human body – physiological, cultural, and health perspectives - Synthetic and Systematic literature review

Background. The average adult human body of 70 kilograms consists in about 67.85% water distributed evenly to an average of 70 % in all major organs of the body: skin, muscles, brain, spinal cord, liver, heart, lungs, spleen, kidneys, pancreas and gastro-intestinal tract. A smaller percentage is found in the bones (30%), teeth (5%) and fat tissue (50%). Objective. This review article attempts to present different perspectives on the physiological properties of water in the human body. We describe from the ancient Chinese medicine theory about water being one of the 5 elements of nature and its harmonious interrelation with the other elements in order to balance the human body, to the successful experiments of researchers which demonstrated waters’ capability to change its molecular structure based on feelings, intentions and energy it was exposed to. We briefly describe the role of water for the human body and what effects can the lack of it have, especially dehydration with all the phases of severity. Also, we present the health benefits of drinking water and which type of water is best to consume. We shorty review the different types of natural mineral waters in Romania and the importance of the Romanian researches for balneology and how the waters cand be administrated in crenotherapy for different types of pathologies. Methods. To elaborate our systematic review, we have searched for relevant open access articles and review articles in ISI Web of Science, published from January 2017 until August 2021. The terms used were water AND health in the title. Articles were excluded in the second phase if they did not reach the relevance citation criterion. The eligible articles were analyzed in detail regarding water importance for human health. Results. Our search identified, first, 548 articles. After applying a PEDro like selection filter and, we selected 93 articles with a minimum of 8 points on our PEDro like filtering scale (good, very good, and excellent articles with a minimum of 5 citations per year). Detailed analysis of the 93 selected articles has conducted us to the elimination of 33 of them as being on a different subject than that of our article. To the 60 full articles retained for this systematic and synthetic article, we have added 10 articles found through a separate Google search, as being considered of high relevance for our subject and necessary to be included. Conclusions. Water is essential for the entire planet and also indispensable for the survival of the human body. Keywords: water intake, water balance, body water, water molecular structure, dehydration, crenotherapy

Exposure and health risk assessment of nitrate contamination in groundwater in Coimbatore and Tirupur districts in Tamil Nadu, South India

Anthropogenic factors are contaminating crystalline aquifers more rapidly than natural sources and affecting human health in many states in India. Since a large population depends on untreated groundwater, identifying the sources of this contamination and assessing the related human health risk are essential to ensure a good-quality water supply. Nitrate is one of the most widespread means of groundwater contamination in many parts of India. Coimbatore and Tirupur districts are the most rapidly growing industrial urban areas in southern India. This paper deals with nitrate contamination and possible health risks for children and adults in the Coimbatore and Tirupur districts based on 93 groundwater samples. To achieve this goal, classical hydrochemical and deterministic hazard identification methods coupled with spatial mapping technologies were applied. A wide variation in nitrate concentration, between 1 and 415 mg/L, was observed, with 37% of the samples exceeding the WHO permissible limit of 50 mg/L. The distinct concentrations of nitrate and other ions observed spatially can be attributed to the diverse geochemical and land use settings in the study area. The bivariate plots of NO3 with other ions suggested that the principal origin of nitrate in this study is related to the excess application of fertilizers and sewages. The spatial variation of NO3, in comparison with the land use map, confirmed these results. The values of hazard quotient (HQ) via ingestion exceeded the critical value, one in 40% in males, 42% in females, and 45% in children. However, HQ values via oral pathways are within one and pose no exposure risk. Thus, the hazard index corresponds to HQingestion only. The health risk was in the increasing order of male>female>children, and shows that body weight is the most critical factor that is influencing the health impact to children as compared to adults. The spatial variation of hazard index values showed that groundwater quality is highly polluted with NO3 in the north and northeastern parts of the study area, mainly due to intensive agricultural practices, and poses critical health concerns. Considering the increasing population and higher dependencies on groundwater, immediate and sufficient measures are proposed.

Heavy metal pollution in surface water of the Upper Ganga River, India: human health risk assessment

To assess the risk on human health, heavy metal contamination was analysed from surface water in the Upper Ganga river, India. Spatial and seasonal distribution of Fe, Mn, Zn, Cr and Pb was evaluated at eight sites during pre-monsoon and post-monsoon season of 2017. Average concentration of heavy metals was high, often exceeding the limits prescribed for surface water by Bureau of Indian Standard (BIS) and the World Health Organization (WHO). Based on heavy metal pollution index (HPI), 87% of the river stretch was classified as medium to highly polluted. Simultaneous assessment of the health risk employing chronic daily intake (CDI) and hazard quotient (HQ) indicates that exposure through ingestion and dermal pathways currently poses no serious threat to human health (CDI < 1, HQ < 1). For the two population groups analysed, HQ_Ingestion values for Cr (adults 0.51, child 0.55) and Pb (adult 0.31, child 0.34) were significantly higher as compared with other heavy metals. HI_Ingestion varied from 0.85 to 1.64 for adult and 0.92 to 1.77 for child group, indicating health risk to both groups with child group being more risk prone from either of the exposure pathways. In addition, HI values revealed an increased risk to health for both groups during the post-monsoon season. Higher hazard index (HI) values (> 1) in the Upper Ganga river indicate an ever-increasing non-carcinogenic risk to the exposed population within the riverine landscape. The study highlights the impact of heavy metals in degrading the water quality of the Upper Ganga river and also advocates immediate attention towards reducing human health risk.

Integration of remote sensing data and in situ measurements to monitor the water quality of the Ismailia Canal, Nile Delta, Egypt

The Ismailia Canal is one of the most important tributaries of the River Nile in Egypt. It is threatened by extinction from several sources of pollution, in addition to the intersection and nearness of the canal path with the Bilbayes drain and the effluent from the two largest conventional wastewater treatment plants in Greater Cairo. In this study, the integration of remote sensing and geospatial information system techniques is carried out to enhance the contribution of satellite data in water quality management in the Ismailia Canal. A Landsat-8 operational land imager image dated 2018 was used to detect the land use and land cover changes in the area of study, in addition to retrieving various spectral band ratios. Statistical correlations were applied among the extracted band ratios and the measured in situ water quality parameters. The most appropriate spectral band ratios were extracted from the NIR band (near infrared/blue), which showed a significant correlation with eight water quality metrics (CO₃, BOD₅, COD, TSS, TDS, Cl, NH₄, and fecal coliform bacteria). A linear regression model was then established to predict information about these important water quality parameters along Ismailia Canal. The developed models, using linear regression equations for this study, give a set of powerful decision support frameworks with statistical tools to provide comprehensive, integrated views of surface water quality information under similar circumstances.

Geochemical modeling, source apportionment, health risk exposure and control of higher fluoride in groundwater of sub-district Dargai, Pakistan

The present study examined the hydrogeochemical profile of higher fluoride (F^─) in groundwater of mixed industrial and mining areas of Dargai, northern Pakistan. Groundwater samples (n = 75) were collected from three hydrogeochemical environments. The mean concentrations of pH, EC, TDS, Depth and Temperature were (7.6, 1081 μS/cm, 590 mg/L, 75 m, 28.03 °C), for chemical ions viz. NO₃, PO₄, SO₄, Cl, HCO₃, Na, K, Ca and Mg were (18.5, 2.7, 161, 107, 330, 150, 9.76, 33, 52) mg/L respectively. Whereas, the mean concentration of F^─ was 2.0 mg/L. Therefore, 51% groundwater samples exceeded the WHO guideline of F^─ 1.5 mg/L. Additionally, we measured the mean F^─ concentration in rocks, coal and wastewater, which were (670, 98) mg/Kg and 2.3 mg/L respectively. The principal component analysis multilinear regression (PCA─MLR) extracted five significant factors which shows natural, mixed and anthropogenic pollution. Thus, fluorite is the primary source of F^─ contamination in groundwater. While apatite, biotite and muscovite minerals are the secondary sources which occurs in association with quartzite, granite rocks. Under alkaline conditions, F^─ contamination is supported by higher Na⁺, HCO₃^─ and lower Ca⁺⁺ concentrations. The accuracy and reproducibility of the measurement of fluoride was assessed by adopting a standard method of water. The percentage recovery of F^─ was 97% and reproducibility was within ±5% error limit. Lastly, a health risk community fluorosis index (CFI) was calculated through Dean's formula which shows unsuitability of groundwater sources conceiving community fluorosis in the entire study area.

A biomimetic SiO2@chitosan composite as highly-efficient adsorbent for removing heavy metal ions in drinking water

Highly efficient adsorbents for drinking water purification are demanded since the contaminants are generally in a low concentration which makes it difficult for conventional adsorbents. Herein, we present a novel biomimetic SiO₂@chitosan composite as adsorbent with a high adsorption capability towards heavy metal ions including As(V) and Hg(II). The hollow leaf-like SiO₂ scaffold within the adsorbent has a stable chemical property; while on the surface SiO₂, the chitosan nanoparticle provide a large amount of active sites such as amino and hydroxyl groups for adsorbing heavy metal ions. The special SiO₂ structure also prevents the agglomeration and loss of chitosan, which enables the efficient contact between the functional groups of chitosan and heavy metal ions. The SiO₂@chitosan composite exhibits maximum adsorption capacities of 204.1 and 198.6 mg g^-1 towards Hg(II) and As(V), respectively. In addition, the removal efficiency reaches over 60% within 2 min. The adsorption performance enables the presented biomimetic adsorbent suitable for adsorbing low-concentration heavy metal ions, especially possessing a promising potential for drinking water purification.

Spatial analysis and health risk assessment of heavy metals concentration in drinking water resources

The heavy metals available in drinking water can be considered as a threat to human health. Oncogenic risk of such metals is proven in several studies. Present study aimed to investigate concentration of the heavy metals including As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn in 39 water supply wells and 5 water reservoirs within the cities Ardakan, Meibod, Abarkouh, Bafgh, and Bahabad. The spatial distribution of the concentration was carried out by the software ArcGIS. Such simulations as non-carcinogenic hazard and lifetime cancer risk were conducted for lead and nickel using Monte Carlo technique. The sensitivity analysis was carried out to find the most important and effective parameters on risk assessment. The results indicated that concentration of all metals in 39 wells (except iron in 3 cases) reached the levels mentioned in EPA, World Health Organization, and Pollution Control Department standards. Based on the spatial distribution results at all studied regions, the highest concentrations of metals were derived, respectively, for iron and zinc. Calculated HQ values for non-carcinogenic hazard indicated a reasonable risk. Average lifetime cancer risks for the lead in Ardakan and nickel in Meibod and Bahabad were shown to be 1.09 × 10^-3, 1.67 × 10^-1, and 2 × 10^-1, respectively, demonstrating high carcinogenic risk compared to similar standards and studies. The sensitivity analysis suggests high impact of concentration and BW in carcinogenic risk.