An investigation of water quality index and health risks of fluoride and nitrate in the arid groundwater (India)

Groundwater is widely recognized as an essential source of water for drinking and irrigation uses in the South India. It is essential to evaluate the characterization of groundwater for drinking and irrigation uses. A total of 67 samples were collected in different locations of study area from tube wells for physio-chemical analysis. Water quality index (WQI), nitrate pollution index (NPI), human health risk assessment (HHRA), and irrigation water quality index (IWQI) efficient tools have been used to evaluate the quality of groundwater in the present study. The Piper and Gibbs diagram revealed that weathering of parent rocks, evaporation, rock water interaction, and ion exchange process are influencing the nature of groundwater. The result of WQI showed that, 20.89% and 7.46% of the sample locations are moderate and poor quality of water for drinking purpose. In order to evaluate the nitrate contamination, NPI divulged that seven sample locations are significant very significant type of pollution. Based on HHRA, the children are at high risk compared to male and female in the study region. The higher percentage of the sample locations are suitable for irrigation uses. The study helps to identify the contaminated zones and also to follow emerging remedial measures to control the source of contamination in the region.

Evaluation of groundwater chemistry and its related health hazard risk for humans is a prerequisite remedial measure. The semi-urban region in southern India was selected to measure the groundwater quality to know the human health risk valuation for different age groups of adults and children through oral intake and skin contact with elevated concentrations of fluoride ([Formula: see text]) and nitrate ([Formula: see text]) groundwater. Groundwater samples were collected from the semi-urban region for pre- and post-rainfall periods and resolute its major ion chemistry. The pH values showed the water is alkaline to neutral in nature. Total dissolved solid (TDS) ranged from 201 to 3612mg/l and 154 to 3457mg/l. However, [Formula: see text] concentration ranges from 0.28 to 5.48mg/l and 0.21 to 4.43mg/l; and NO3- ranges from 0.09 to 897.28mg/l and 0.0 to 606.10mg/l elevating the drinking water standards of [Formula: see text] in 32% and 38% samples and for [Formula: see text] about 62% and 38% during pre- and post-rainfall seasons, respectively. The fluoride-bearing minerals are the main sources of elevated concentrations of [Formula: see text] and excessive use of chemical fertilizers as the chief source of NO3- concentration in the aquifer regime. Water quality index (WQI) ranged from 18.3 to 233 and 12.97 to 219.14; 20% and 22% showed poor water quality for pre- and post-rainfall seasons with WQI ≥ 200. Piper plot suggests that 46% and 51% of samples signify carbonate water type ([Formula: see text]), and 32% and 28% of groundwater samples show ([Formula: see text]) type water for pre- and post-rainfall seasons respectively. Gibbs' plot suggests the dominance of water-rock interaction in the aquifer system. Further, the principal component analysis (PCA) revealed three and four components which explain 74.85% and 79.30% of the variance in pre- and post-rainfall seasons with positive loading of EC, TDS, Ca2+, Na+, Mg2+, K+, [Formula: see text], Cl-, and [Formula: see text] due to mineral weathering and water-rock interactions altering the chemistry for an elevated concentration of [Formula: see text] and [Formula: see text] in groundwater. Cluster analyses of chemical variables observed four clusters with a linkage distance of 5 to 25 with a linkage between different variables displaying predominant ion exchange, weathering of silicate and fluoride-rich minerals, salinization of the water, and a high value of [Formula: see text] concentration, resulting from fertilizers. The hazard quotient (HQ) through ingestion (HQing) and dermal (HQder) pathways of F- and NO3- was observed higher than its acceptable limit of 1.0 for different age groups indicating the non-carcinogenic effect on human health. Effective strategic measures like defluoridation, denitrification, safe drinking water supply, sanitary facilities, and rainwater harvesting structures are to be implemented in the area for improvement of human health conditions and also bring awareness to the local community about the health hazard effects of using high concentrated [Formula: see text] and [Formula: see text] water for daily uses.

Purpose This study presents a comprehensive hydrogeochemical assessment of groundwater in the Midyan Basin, northwest Saudi Arabia, with the goal of evaluating its suitability for irrigation and drinking in a hyper-arid environment. Design/methodology/approach A total of 72 groundwater samples were collected from shallow wells and analyzed for major ions and trace metals using ion chromatography and ICP-MS. Hydrochemical facies were determined through Piper and Gibbs diagrams. Water quality indices, including Sodium Adsorption Ratio (SAR), Electrical Conductivity (EC), and Residual Sodium Carbonate (RSC), Sodium Percentage (Na%), Magnesium Ratio (MR)and Chloro-Alkaline Indices (CAI) were used to assess irrigation suitability. Findings Groundwater is dominated by Ca2+–SO42−–Cl− and Na+–SO42−–Cl− facies, reflecting evaporite dissolution, carbonate weathering and ion exchange. EC ranged from 1,106 to 14,290 µS/cm and TDS from 545 to 7,027 mg/L. About 29% of samples exceeded the WHO TDS limit, and 95% exceeded sodium limits (200 mg/L). Magnesium ranged from 18.8 to 899.3 mg/L, and calcium from 144.6 to 1869.0 mg/L, both often exceeding guideline values. Nitrate exceeded the 50 mg/L limit in 29% of samples, while fluoride concentrations ranged from 0.98 to 2.10 mg/L. Most trace metals were within safe limits, though slightly elevated levels of Mn, Cr, Zn, and As were detected in a few locations, likely due to anthropogenic inputs. Based on EC and SAR values, nearly 40% of samples are unsuitable for irrigation, though 91% fall within acceptable zones for salt-tolerant crops based on the Wilcox diagram. Originality/value This is the first systematic hydrogeochemical investigation of the Midyan Basin. It reveals significant geogenic and anthropogenic influences on groundwater quality and provides essential data to guide sustainable water management and agricultural planning in arid regions.

Long-term monitoring through the use of water quality indices is essential for identifying trends in water quality, detecting emerging issues, and evaluating the effectiveness of pollution control strategies. In this study, groundwater quality was evaluated for its suitability for drinking purposes, and the Water Quality Index (WQI) was introduced as a practical tool for monitoring water wells in the Zakho District of Duhok Governorate, located in the Kurdistan Region of Iraq. A total of 90 groundwater samples were collected from 15 wells in Zakho during August 2023. The water samples were tested for their major physicochemical properties, including pH, total dissolved salts (TDS), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), chloride (Cl−), nitrate (NO3 −), sulfate (SO4 2-), total alkalinity (TA), and total hardness (TH). A weighted arithmetic index was applied using Iraqi standards and other international and national standards to evaluate the overall quality of the water. The results revealed that most parameters were within acceptable limits, with the exception of calcium (Ca2+), which exceeded permissible levels in most cases, followed by magnesium (Mg2+) in several instances, and total hardness (TH), sulfate (SO₄2−), and TDS in a few cases. The calculated WQI values ranged from 40.65 to 70.48, indicating that 60% of the samples were classified as “good” quality, while 40% were categorized as “poor.” Hydro-chemical facies, identified using the Piper diagram, showed that the dominant water types were Ca2+ –Mg2+ –HCO₃− (80%) and Ca2+ –Mg2+ –SO₄2− (20%), suggesting that alkaline earth metals predominate over alkali metals. Based on these findings, it can be concluded that some groundwater sources in the study area are unsuitable or excessively hard for direct human consumption, and the implementation of water softening treatments is strongly recommended prior to use.

Nitrate contamination in groundwater and its evaluation of non-carcinogenic health hazards from Arjunanadi River basin, south India

Groundwater in the semi-arid region of Dharapuram, southern India, is increasingly affected by nitrate and other chemical contaminants due to both natural and anthropogenic activities. This study aims to assess nitrate contamination and its associated health risks in the region. Total dissolved solids, nitrate, and fluoride levels exceeded permissible limits in 11.76%, 32.35%, and 23.53% of samples, respectively. Gibbs and Piper diagrams indicated that rock-water interactions, evaporation, and mineral dissolution play key roles in groundwater composition. Principal Component Analysis identified geochemical processes, and agricultural runoff as major factors influencing groundwater quality. Dendrogram analysis showed distinct clustering, with ionic strength dominating groundwater chemistry, while pH and fluoride behaved independently. Correlations were observed between EC, chloride, sodium, and sulphate. The Entropy Water Quality Index classified 45.59% of samples as poor, 13.23% as very poor, and 2.94% as unfit for drinking. The Nitrate Pollution Index identified 10.29% and 17.64% of samples as significantly and very significantly polluted, respectively. Nitrate levels were especially high in shallow aquifers, with 16.18% of samples containing 45-100mg/L and 8.82% exceeding 100mg/L. Health Risk Assessment (HRA) resultsrevealed that the THI >1 forchildren(64%), Teen (44%), Women (35%) and Men (30%). Children are particularly vulnerable to nitrate exposure, with risk indices surpassing safe thresholdsin some groundwater samples. The study underscores the urgent need for targeted nitrate mitigation and sustainable groundwater management strategies.

This work was carried out for the determination of the water quality in the Talagang District of Pakistan, as water is essential for agriculture and drinking uses. This study aims to assess the water quality for irrigation, drinking, and health risks using the Water Quality Index (WQI) and Human Health Risk Assessment (HHRA) tools to identify regions with contaminated water, and to evaluate the associated risks. A total of 98 water samples were taken at various points from diverse sources such as hand pumps, streams, springs, dug wells, and tube wells for physio-chemical assessment. In the current study, the effectiveness of the irrigation water quality index (IWQI), human health risk assessment (HHRA), and water quality index (WQI) tools have been assessed. The characteristics of subterranean water are influenced by evaporation, ion exchange, rock-water interaction, and parent-rock weathering, as shown by the Piper and Gibbs diagram. According to the WQI results, the water quality is 20. 89% and 27.46% of the sample sites are moderate and poor, making them unfit for human intake. Based on HHRA, compared to adult males and females in the study area, children are deemed to be at a higher risk. A larger number of the sample localities are appropriate for irrigation purposes. The study assists in identifying contaminated regions and in monitoring newly implemented remediation actions to manage the source of contaminants in the study area.

This systematic study was carried out with objective to delineate the various sources responsible for $$\hbox {NO}_{3}^{-}$$ contamination and $$\hbox {F}^{-}$$ enrichment by utilizing statistical and graphical methods. Since Central Ground Water Board, India, indicated susceptibility of $$\hbox {NO}_{3}^{-}$$ contamination and $$\hbox {F}^{-}$$ enrichment, in most of the groundwater, $$\hbox {NO}_{3}^{-}$$ and $$\hbox {F}^{-}$$ concentration primarily observed $${>}45$$ and $${>}1.5~\hbox {mg/L}$$ , respectively, i.e., higher than the permissible limit for drinking water. Water Quality Index (WQI) indicates $${\sim }22.81\%$$ groundwater are good-water, $${\sim }71.14\%$$ groundwater poor-water, $${\sim }5.37\%$$ very poor-water and 0.67% unsuitable for drinking purpose. Piper diagram indicates $${\sim }59.73\%$$ groundwater hydrogeochemical facies are Ca–Mg– $$\hbox {HCO}_{3 }$$ water-types, $${\sim }28.19\%$$ Ca–Mg– $$\hbox {SO}_{4}$$ –Cl water-types, $${\sim }8.72\%$$ Na–K– $$\hbox {SO}_{4}$$ –Cl water-types and 3.36% Na–K– $$\hbox {HCO}_{3 }$$ water-types. This classification indicates dissolution and mixing are mainly controlling groundwater chemistry. Salinity diagram indicate $${\sim }44.30\%$$ groundwater under in low sodium and medium salinity hazard, $${\sim }49.66\%$$ groundwater fall under low sodium and high salinity hazard, $${\sim }3.36\%$$ groundwater fall under very-high salinity hazard. Sodium adsorption ratio indicates $${\sim }97\%$$ groundwater are in excellent condition for irrigation. The spatial distribution of $$\hbox {NO}_{3}^{-}$$ indicates significant contribution of fertilizer from agriculture lands. Fluoride enrichment occurs in groundwater through the dissolution of fluoride-rich minerals. By reducing the consumption of fertilizer and stress over groundwater, the water quality can be improved.

Assessment of Bangladesh groundwater for drinking and irrigation using weighted overlay analysis

Fifty groundwater samples were collected from Al-Hasa to analyze the pH, electrical conductivity (EC, dS m−1), total dissolved solids (TDS), major anions (HCO3−, CO32−, Cl−, SO42−, and NO3−), major cations (Ca2+, Mg2+, Na+, and K+), and total hardness. The analyzed data plotted in the Piper, Gibbs, and Durov diagrams, and water quality index (WQI) were calculated to evaluate the groundwater geochemistry and its water quality. The results reveal that most of the investigated samples are Ca2+, Mg2+, SO42−, Cl− and Na+, and HCO3− water types using the Piper diagram. Na+ > Ca2+ > Mg2+ are the dominant cations, while Cl− > HCO3− > SO42− > CO32− are the dominant anions. Sodium adsorption ratio (SAR) values varied from 0.79 to 10; however, the Kelly ratio (KR) ranged between 0.1 and 2.2. The permeability index (PI) showed that well water is suitable for irrigation purposes with 75% or more of maximum permeability. The US salinity diagram revealed that the water quality classes of studied waters were CIII-SI, CIII-SII, and CIV-SII, representing height hazards of salinity and medium- to low-sodium hazard. The water quality index (WQI) results indicated that total dissolved solids are out of the drinking water standard limits in Saudi Arabia. The WQI revealed that 38% of the studied wells were considered as poor water (class III), 52% are found as very poor water class (IV), and 10% are unsuitable water for drinking class (V).

Water containing high concentrations of nitrate is unfit for human consumption and, if discharging to freshwater or marine habitats, can contribute to algal blooms and eutrophication. The level of nitrate contamination in groundwater of two densely populated, agro-industrial areas of the Cameroon Volcanic Line (CVL) (Banana Plain and Mount Cameroon area) was evaluated. A total of 100 samples from boreholes, open wells and springs (67 from the Banana Plain; 33 from springs only, in the Mount Cameroon area) were collected in April 2009 and January 2010 and analyzed for chemical constituents, including nitrates. The average groundwater nitrate concentrations for the studied areas are: 17.28 mg/l for the Banana Plain and 2.90 mg/l for the Mount Cameroon area. Overall, groundwaters are relatively free from excessive nitrate contamination, with nitrate concentrations in only 6 % of groundwater resources in the Banana Plain exceeding the maximum admissible concentration for drinking water (50 mg/l). Sources of NO3− in groundwater of this region may be mainly anthropogenic (N-fertilizers, sewerage, animal waste, organic manure, pit latrines, etc.). Multivariate statistical analyses of the hydrochemical data revealed that three factors were responsible for the groundwater chemistry (especially, degree of nitrate contamination): (1) a geogenic factor; (2) nitrate contamination factor; (3) ionic enrichment factor. The impact of anthropogenic activities, especially groundwater nitrate contamination, is more accentuated in the Banana Plain than in the Mount Cameroon area. This study also demonstrates the usefulness of multivariate statistical analysis in groundwater study as a supplementary tool for interpretation of complex hydrochemical data sets.

The ecology and environment of the Yellow River Basin is threatened by fluoride and nitrate contamination induced by anthropogenic activity and geogenic factors. As a result, deciphering the spatio-temporal variability of fluoride and nitrate contamination in this area remains a challenge. Three hundred eighty-six samples of surface water and groundwater from the Inner Mongolia Reaches of the Yellow River Basin were taken for this investigation. According to the results of the multivariate statistical and geostatistical analyses, the fluoride pollution was primarily discovered in the middle and lower reaches of the study area and was determined to be more severe during the dry season. In contrast, nitrate contamination was found to be more severe during the wet season while being widely distributed in groundwater and concentrated in areas with intensive agricultural activities. The primary mechanisms governing the spatial-seasonal patterns of NO3- and F- pollution were shown by the principal component analysis, isotopic, and hydrochemical diagrams. The water-rock interaction or evaporation was crucial in the enrichment of F-. The human inputs (e.g., fertilizer or sewage) dominated fluoride and nitrate contamination. Additionally, the alkaline environment played a role in the generation of NO3- and F-. The health risk assessment concluded that the threat of fluoride contamination was greater than that of nitrate contamination. Children faced the greatest health risks, followed by females and males. These findings would serve as a guide for water management and pollution control in the Yellow River Basin.

Estimation of the groundwater quality index and investigation of the affecting factors their changes in Shiraz drinking groundwater, Iran

The study was carried out in the Khandbari Municipality, Sankhuwasabha District, Eastern Nepal to document the spring location and assess the water quality of the spring water for drinking and irrigation purposes. A total of 85 springs were mapped, which are located from 274 to 2176 m in altitude. Spring water samples were collected from 33 springs in the pre-monsoon (November, 2021) and 31 springs in the post-monsoon (March, 2022). Correlation matrices, t-test, principal component analysis (PCA), Piper diagram, Gibbs diagram, water quality index (WQI), United States Salinity Laboratory (USSL) diagram, and Wilcox diagram were applied for evaluating the spring water. All the physicochemical parameters were within the Nepalese National Drinking Water Quality Standard (NDWQS) and drinking water quality guidelines of the World Health Organization (WHO) except for pH in the pre-monsoon and iron in the post-monsoon season. The main contributors to the groundwater are Na+, Ca2+, Cl-, total dissolved solids (TDS), and total hardness, which exhibit significant correlations with electrical conductivity (EC) similar to TDS, suggesting their common source of origin. Based on the WQI, spring water is excellent in the post-monsoon and excellent and good in the pre-monsoon season. Furthermore, the spring water is excellent for irrigation purposes except for thepercent sodium in the post-monsoon and the magnesium ratio in the pre-monsoon season. Gibbs diagram illustrates that spring water is mainly governed by rock and precipitation dominance in some springs. The PCA indicates that anthropogenic activities (mixing of human waste and agricultural run-off in the spring water) are the main causes of contamination. Piper trilinear diagram demonstrates carbonate dissolution and silicate weathering as major processes for controlling the spring water chemistry. The study reveals that 62.5% of spring water was contaminated with microbes. For benthic macroinvertebrates, 18 springs were sampled, where nine orders and 17 families were recorded in the pre-monsoon and six orders and ten families in the post-monsoon season. The main influencing variables for macroinvertebrate assemblages are elevation, discharge, NO3-, and NH3.

This paper investigates the suitability of groundwater for domestic and agricultural use in the Rafsanjan plain, southwest part of the Daranjir–Saghand basin, Iran. Fifty-five groundwater samples were collected and analyzed by six methods including the water quality index (WQI), Schoeller diagram, irrigation water quality (IWQ) parameters, Piper diagram, US salinity diagram and Wilcox diagram. The spatial distribution maps of chemical parameters and groundwater quality indices were plotted using the IDW method in GIS. The results showed a low concentration of major ions in the southeastern part and a high concentration from the central part towards northwestern part of the plain. The concentration of major ions in groundwater was strongly affected by groundwater flow, geological setting and the existence of the evaporative layers in the studied area. Moreover, results revealed that most of samples exceeded the acceptable limits recommended by the WHO and ISIRI1053 standards for domestic and agricultural purposes. In most of the wells, groundwater was classified into saline and very hard categories. The analyses based on WQI values indicated that above 87% of water samples were unsuitable for drinking purposes. IWQ parameters expressed that 85%, 67%, 32%, 51%, 43% and 50% of samples had EC > 3000, Na% > 60%, MAR > 50%, KR > 1, SAR > 9 and Cl− > 350, respectively, which were unsuitable for irrigation use. The dominant hydrochemical facies of water was Na–Cl–SO4 type, and 63% and 22.8% of samples were categorized as C4S4 and C4S3 class, with very high-salinity–high-sodium hazards and very high-salinity–high-sodium hazards, respectively. It indicated that most irrigated lands in this study area were affected by different levels of salinity and sodicity hazards that caused decreases in plant growth and crop productivity. The results can assist decision-makers and planners in prioritizing groundwater resources management in the region.