Health Risks Of Nitrate Research Articles

Contamination levels of water sources and the associated nitrate health risks to six age groups

Advancements in health risk assessment are vital for protecting public health. This study’s objectives were to analyze the degree of nitrate contamination, the multi-route health risks to six age groups, and the potential sources of water contaminants in a Nigerian suburban area. Nitrate pollution index (NPI) results were between −1.00 and 0.06, indicating low human impact. According to the nitrate health risk analysis, infants between the ages of 6 and 12 months were more vulnerable, whereas humans between the ages of 20 and > 60 have lower risks. This may be due to the fact that infants have bodily tissues that are more vulnerable to potentially toxic contaminants. For all six age categories, the risk associated with ingestion was greater than the risk associated with dermal contact. Varimax-rotated factor analysis with five principal component extractions revealed that the sources of the water contaminants varied from geogenic processes to human-initiated activities.

Assessing groundwater suitability and nitrate health risk in Edea, Cameroon: implications for drinking and irrigation purposes

Assessing groundwater suitability and nitrate health risk in Edea, Cameroon: implications for drinking and irrigation purposes

Hydrochemical characterization and health risk assessment of different types of water bodies in Fenghuang Mountain Area, Northeast China.

Groundwater, as an essential resource, holds significant importance for human production and livelihoods. With the deterioration of the water environment, the issue of groundwater quality has become an urgent international concern. This study focused on the Fenghuang Mountain Area (FMA) and collected a total of 41 sets of samples including pore groundwater (PGW), fissure groundwater (FGW), karst groundwater(KGW), and river water(RW). Hydrochemical analysis methods were employed to identify the hydrochemical characteristics and controlling factors. The entropy-weighted water quality index (EWQI) and health risk assessment model were utilized to assess the groundwater quality and nitrate health risk, respectively. The results indicated that the dominant anion and cation in both groundwater and surface water in the FMA were HCO3- and Ca2+, respectively, with the main hydrochemical type being HCO3-Ca. Groundwater and surface water in the FMA were primarily controlled by rock weathering process, with ion concentrations influenced mainly by the dissolution of halite, sylvite, carbonates (calcite and dolomite), silicates, and gypsum, as well as by reverse anion exchange process. PGW was significantly affected by agricultural activities, with NO3- concentration closely related to human activities. The water quality of FGW was relatively good, with Class I and Class II water accounting for the highest proportion, reaching 84.62%. The high-value area of EWQI in PGW was influenced by human activities. The impact of nitrate health risk on children was significantly greater than on adults, with FGW having the lowest health risk and PGW having the highest health risk. The research results can provide important guarantees for the rational development and utilization of water resources in the FMA and the sustainable development of the economy in Northeast China.

Hydrochemical characterization and comprehensive water quality assessment of groundwater within the main stream area of Yishu River.

To gain a comprehensive understanding of the hydrochemical characteristics, controlling factors, and water quality of groundwater in the main stream area of Yishu River (MSYR), a study was conducted using water quality data collected during both the dry and wet seasons. Through statistical analysis, hydrochemical methods, fuzzy comprehensive evaluation, and health risk evaluation modeling, the water chemical characteristics of the main stream area of Yishu River were studied, and the water quality of the area was comprehensively evaluated. The findings indicate that HCO3- and Ca2+ are the predominant anions and cations in the MSYR during the dry and wet seasons, respectively. Moreover, anion concentration in groundwater follows HCO3- > SO42- > NO3- > Cl-, while cations are ranked as Ca2+ > Na+ > Mg2+ > K+. Overall, the groundwater manifests as weakly alkaline and is predominantly classified as hard-fresh water. During the wet season, there is greater groundwater leaching and filtration, with rock and soil materials more readily transferred to groundwater, and the concentrations of main chemical components in groundwater are higher than those during the dry season, and the hydrochemical types are primarily characterized as HCO3-Ca·Mg and SO4·Cl-Ca·Mg types. These results also suggest that the chemical composition of the groundwater in the MSYR is influenced mainly by water-rock interaction. The primary ions originate from the dissolution of silicate rock and carbonate rock minerals, while cation exchange plays a critical role in the hydrogeochemical process. Groundwater in the MSYR is classified mostly as class II water, indicating that it is generally of good quality. However, areas with high levels of class IV and V water are present locally, and NO3- concentration is a crucial factor affecting groundwater quality. In the wet season, more groundwater and stronger mobility lead to greater mobility of NO3- and wider diffusion. Therefore, the risk evaluation model shows that nitrate health risk index is higher in the wet season than it is in the dry season, with children being more vulnerable to health risks than adults. To study groundwater in this area, its hydrochemical characteristics, water quality, and health risk assessment are of great practical significance for ensuring water safety for residents and stable development of social economy.

Hydrogeochemical characterization, quality assessment, and potential nitrate health risk of shallow groundwater in Dongwen River Basin, North China.

Assessing groundwater geochemical formation processes and pollution circumstances is significant for sustainable watershed management. In the present study, 58 shallow groundwater samples were taken from the Dongwen River Basin (DRB) to comprehensively assess the hydrochemical sources, groundwater quality status, and potential risks of NO3- to human health. Based on the Box and Whisker plot, the cation's concentration followed the order of Ca2+ > Mg2+ > Na+ > K+, while anions' mean levels were HCO3- > SO42- > NO3- > Cl-. The NO3- level in groundwater samples fluctuated between 4.2 and 301.3mg/L, with 67.2% of samples beyond the World Health Organization (WHO) criteria (50mg/L) for drinking. The Piper diagram indicated the hydrochemical type of groundwater and surface water were characterized as Ca·Mg-HCO3 type. Combining ionic ratio analysis with principal component analysis (PCA) results, agricultural activities contributed a significant effect on groundwater NO3-, with soil nitrogen input and manure/sewage inputs also potential sources. However, geogenic processes (e.g., carbonates and evaporite dissolution/precipitation) controlled other ion compositions in the study area. The groundwater samples with higher NO3- values were mainly found in river valley regions with intense anthropogenic activities. The entropy weight water quality index (EWQI) model identified that the groundwater quality rank ranged from excellent (70.7%) and good (25.9%) to medium (3.4%). However, the hazard quotient (HQ) used in the human health risk assessment (HHRA) model showed that above 91.38% of groundwater samples have a NO3- non-carcinogenic health risk for infants, 84.48% for children, 82.76% for females, and 72.41% for males. The findings of this study could provide a scientific basis for the rational development and usage of groundwater resources as well as for the preservation of the inhabitants' health in DRB.

Potential health risk assessment of nitrate in groundwater of Tonk district in Rajasthan, north western India

ABSTRACT Anthropogenic activities like adding synthetic nitrogenous fertilisers in agriculture fields, animal and human waste are the main factors responsible for the increase in nitrate concentration in groundwater of any area. Groundwater is the main source of not only irrigation but also dependency for drinking which has increased on it with decreasing surface sources. Today, increase in such anthropogenic activities has resulted in upsurge of the natural nitrate concentration to the extent of crossing its acceptable limit in drinking water. The Bureau of Indian Standard (BIS, 2012) 1 has prescribed the limit of 45 mg/L, whereas for WHO (2011) 2 the limit of nitrate is 50 mg/L. The goal of this present study is to assess the natural and anthropogenic NO3 concentrations in groundwater in a semi arid area of Rajasthan in Tonk District and its related risks to human health in the different groups of ages, such as children, males, and females. Being immune adults has little less effect on its continuous exposure than children. Even though these risks are non-carcinogenic, incessant exposure can create several health issues. In juveniles, it is known to cause methemoglobinemia, in adults it causes gastric and other stomach issues on prolonged consumption as well as dermal contact. The results show that the oral exposure of nitrate was very high compared to dermal contact. On the basis of non-carcinogenic health risk, the total Hazard Index (HITotal) values of groundwater nitrate were an average of 1.16 for males, 1.37 for females, and 1.58 for children. The nitrate health risk assessment shows that about 39%, 44%, and 51% of the samples constitute the non-carcinogenic health risk to males, females, and children, respectively.

Origin and health risks of nitrate in groundwater from a riverine reservoir basin in an agricultural region of Sichuan Basin

Origin and health risks of nitrate in groundwater from a riverine reservoir basin in an agricultural region of Sichuan Basin

Health risk assessment of drinking groundwater in rural areas of Ru village and surrounding areas in Wutai County, China.

Nitrate pollution in groundwater is a global environmental problem that poses risks to human health. We investigate the health risks of nitrate in rural drinking groundwater in Rucun Township and surrounding areas of Wutai County, and provide a basis for healthy drinking water. By using statistical analysis software (SPSS19) and hydrogeochemical analysis software (AqQA), a qualitative and quantitative evaluation of nitrate health risks was conducted among populations of different ages and genders through water sample collection, chemical analysis, and construction of a human health risk model (HHRA). Through research, it was found that the average concentration of nitrate in the study area is 43.99 mg/L. Groundwater is severely polluted by NO3-, and nitrate pollution areas are mainly concentrated in the main human activity areas, especially in the main agricultural production areas. The Quaternary loess layer, as a permeable layer, cannot prevent groundwater from being polluted by NO3-. Through evaluation, it is believed that there is a health risk of nitrate pollution in rural drinking groundwater in Rucun Township and surrounding areas. Health risk level: infants>children>adult females>adult males. The discovery and evaluation results can provide a basis for the prevention and control of nitrate pollution in groundwater.

Hydrochemical Appraisal and Driving Forces of Groundwater Quality and Potential Health Risks of Nitrate in Typical Agricultural Area of Southwestern China

Elucidating the hydrogeochemical processes and quality assessment of groundwater holds significant importance for its sustainable development. In this paper, 53 groundwater samples were collected from a typical agricultural area in the northeastern Chongqing municipality in SW China. The integration of multivariate statistical analysis, ion ratio analysis, geomodelling analysis, the entropy water quality index, health risks assessment, and sensitivity analysis was carried out to explore the hydrochemical processes and quality assessment of groundwater in this study. The statistical results reveal that the cationic concentrations followed the order of Ca2+ > Mg2+ > Na+ > K+, while the anionic components were in the order of HCO3− > SO42− > NO3− > Cl−. Based on the Piper trilinear diagram, the hydrochemical types were shown as Ca-HCO3 and Ca-Mg-HCO3 types. Hierarchical cluster analysis indicated that the groundwater samples could be categorized into three groups. The hydrochemical compositions were primarily influenced by water–rock interactions (e.g., carbonate dissolution and silicate weathering). In terms of irrigation suitability, the sodium adsorption ratios (SARs) ranged from 0.05 to 1.82, and the electrical conductivity (EC) varied from 116 to 1094 μs/cm, indicating that most groundwater samples were suitable for irrigation. The entropy-weighted water quality index ranged from 15 to 94, suggesting that the groundwater samples were suitable for drinking purposes. Non-carcinogenic human health risks followed the order of children > adult females > adult males, within the average values of 0.30, 0.21, and 0.18, respectively. Sensitivity analysis showed that the parameters had the weight order of NO3 > body weight (BW) > ingestion rate (IR) > exposure frequency (EF). Hence, we recommend prioritizing the management of areas with high salinity levels, while avoiding the excessive use of nitrogen fertilizers, raising awareness among local residents about safe groundwater, and providing robust support for the sustainable development of groundwater in typical agricultural areas.

Deciphering spatio-seasonal patterns, driving forces, and human health risks of nitrate and fluoride enriched water bodies in the Inner Mongolia Reaches of the Yellow River Basin, China.

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.

Evaluation of the drinking water quality and potential health risks of nitrate and fluoride in Southwest Delhi, India

ABSTRACT The present study was attempted to evaluate the water quality index (WQI) and also performed potential human health risk assessment i.e. Hazards quotient (HQ), Total hazard index (THI) of nitrate (NO3 −) and fluoride (F−) through ingestion of groundwater in pre-monsoon and post-monsoon seasons. The WQI classification showed that 56%, and 34% of groundwater resources were unfit for consumption in pre-monsoon and post-monsoon seasons. The HQ and THI of the non-carcinogenic hazards were computed using the potential health risk assessment of NO3 − and F−enriched groundwater. The findings showed that in adults, 26% and 36% of the water samples had high risk quotients for HQ-NO3 − and HQ-F−, respectively, while in children, 40% and 54% of the samples had risk quotients for HQ-NO3 − and HQ-F− above the permissible level. This suggests that F− contributes more to the non-carcinogenic risk than NO3 − in pre-monsoon. However, NO3 − adds more to the non-carcinogenic risk than F− in post-monsoon, as shown by the HQ-NO3 − and HQ-F− in 42% and 2% of samples for adults, and in 58% and 14% of samples for children, respectively. Children in the study area were more vulnerable to the non-carcinogenic effects of NO3 − and F− according to the findings. Total hazards index (THI) for adults and children in for NO3 − and F− were ranged from 0.34 to 8.61 (Avg. 1.68) and 0 to 8.20 (Avg. 1.75) in pre-monsoon season. Similarly, NO3 − and F− were ranged from 0.37 to 2.85 (Avg. 1.86) and 0 to 2.86 (Avg. 0.85) in post-monsoon season, respectively. The results of this study can improve effective environmental management measures for enhancing the groundwater quality and public health of the study area.

Hydrochemical characteristics and potential health risks of nitrate, fluoride, and uranium in Kota district, Rajasthan, India.

This study examines the uranium, fluoride, and nitrate dispositions in groundwater as well as potential health risks in Kota district, Rajasthan, India. Total 198 groundwater samples were collected in both dry and wet periods and analyzed for physicochemical parameters along with U, F-, and NO3- using standard methods. Results indicate that the electrical conductivity, total dissolved solids, total hardness, alkalinity, Ca2+, Mg2+, HCO3-, Cl-, NO3-, and F- exceed the WHO standard limits of drinking water in both periods. Uranium concentration is at the broader of drinking water permissible limit (30μg/L) and found about 1.05 times more. Nitrate and fluoride concentrations ranged from 9.8 to 412.0mg/L and 0.1 to 4.0mg/L for the dry season, while in the wet period, they varied from 10.0 to 954.0mg/L and 0.1 to 3.5mg/L, respectively. Correlation studies show a significantly strong positive correlation between uranium and total alkalinity and carbonate. Natural background levels (NBLs) were explored to assess the source of groundwater pollution. It shows that the second inflection points of NBLs estimated for NO3-, F-, and U are about 168mg/L, 1.2mg/L, and 7.3μg/L, respectively, during the experimental period. The USEPA technique was used to evaluate the non-carcinogenic health risks associated with consuming the NO3- and F--contaminated groundwater. The health risks in Kota district show that children are more at risk than adults. The risk assessment of uranium reveals that the excess cancer risk (ECR) and hazard quotient (HQ) are found to be below the standard limits, but a high concentration of uranium (31.6μg/L) is observed at Amarpura village of Digod block. This study will provide a baseline of uranium, fluoride, and nitrate dispositions in groundwater for simulating mass transport model and safe use of drinking water.

Contamination and health risk assessment of groundwater along the Red Sea coast, Northwest Saudi Arabia

Coastal groundwater is the major source of freshwater in coastal areas, due to shortage of the water resource in coastal zones. Groundwater samples were collected from 48 sites along the Saudi Red Sea coast between Rabigh and Yanbu to document the hydrogeochemical characteristics, water quality, and the health risks of nitrate, fluoride, nickel, copper, and zinc on adults and children. Groundwater chemistry indicated neutral to slightly alkaline nature, and the total dissolved salts (TDS) concentrations mainly increase towards the coastal plain. Major cations, major anions, and heavy metals (HMs) were in the order of Cl− > Na+ > SO42− > Ca2+ > HCO3− > NO3− > Mg2+ > K+, F− > Zn > Cu > Ni. Na-Cl, mixed Ca-Mg-Cl and Na-K-HCO3, CaCl, and Mg-HCO3 were the principal hydrochemical water types. Results of heavy metal pollution index (HPI), and water quality index (WQI) showed moderate to heavy pollution and unsuitable groundwater for human consumption mostly in the western side along the coastal plain, which might be influenced by the groundwater salinization. Principal component analysis (PCA) generated four components, which indicated the various sources of contamination. Hazard index (HI) of nitrate and fluoride were above the safety limit of 1, suggesting increase non-cancer health risk issues in both children and adults.

Nitrate health risk and geochemical characteristics of water in a semi-urban: implications from graphical plots and statistical computing

ABSTRACT The aim of this study was to assess the nitrate health risks due to water consumption via oral and dermal contact routes and to evaluate the geochemical characteristics of waters in the Umunya area, Nigeria, as implied from ionic ratios, graphical plots, and multivariate statistics. This study is the first to assess the human health risks associated with nitrate contamination in the semi-urban. Standard methods were used to achieve the aim of the study. Water from commercial and household sources were sampled. Measured physicochemical properties showed that the water resources are slightly contaminated. Health hazard quotient (oral) ranged from 0–0.5072 for men, 0–0.5994 for women, and 0–0.6858 for children. On the other hand, the maximum hazard quotient (dermal) for men, women, and children were 0.0013, 0.0016, and 0.0042, respectively. The total hazard index for men, women, and children respectively varied from 0–0.509, 0–0.601 and 0–0.690. Overall, it was indicated that 46.67%, 53.33%, and 53.33% of the water samples expose men, women, and children to low chronic health risk of nitrate. However, the risk for water ingestion was higher than that for dermal absorption. Hydrogeochemical plots revealed that Ca2+-Mg2+-HCO3 − and Na+-HCO3 − water types, representing recharge and base ion exchange processes, respectively, are predominant. Principal component analysis and R-type hierarchical clustering revealed that the hydrogeochemical characteristics are mostly controlled by geogenic factors than human-related factors. The geology of the area and silicate weathering processes were implicated as the major influencers of the hydrogeochemistry. For sustainable development and improved water monitoring in the area, the insights provided in this paper are considered very beneficial.

Spatial and temporal assessment of health risks associated with exposure to nitrates from shallow well water in West Africa

This study focused on estimating the health risks of nitrate from shallow well water in Agboville's city, Côte d'Ivoire. 100 samples of 50 wells were collected to analyze nitrate presence during one year in two major seasons. Probabilistic methods of hazard quotient were used to assess the health risks due to nitrate within different zones delineated in relation to the demographic and topographic situation of the areas. The mean nitrate levels of each zone during dry season were below the World Health Organization (WHO, 2011) limit value (i.e., 50 mg L−1), whereas for those of the wet season, the values of some sites were higher, but their average remained below this WHO reference, excluding of the low-slope area (i.e., zone 2 with 75.40 ± 68.33 mg L−1). During dry season, all the hazard quotient (i.e., HQ50 and HQ95) values were below to 1, as were HQ50 values in wet season, except for children in the low-slope area (i.e., zone 2). All HQ95 values were nearly greater than 1 during the wet season. Only, Hazard quotient using acceptable daily intake (HQADI) value at the 5% highly-exposed group of the strongest slope area (zone 4) was less than 1 in the wet seasons. It noted that the elevated HQ95 values would indicate a high risk of nitrate during the rainy season. Otherwise, HQ50/50 values determined according to WHO 2003 values were higher than 1 in rainy season, thereby underscoring that the elevated risk of contracting some diseases such as methemoglobinemia. Finally, a sanitation improvement in the study area could be an alternative method to reduce nitrate levels in well water as well as a reduction of the HQ50/50 in rainy season

A multi-model study for understanding the contamination mechanisms, toxicity and health risks of hardness, sulfate, and nitrate in natural water resources.

Several water quality contaminants have attracted the attention of numerous researchers globally, in recent times. Although the toxicity and health risk assessments of sulfate and water hardness have not received obvious attention, nitrate contamination has gained peculiar research interest globally. In the present paper, multiple data-driven indexical, graphical, and soft computational models were integrated for a detailed assessment and predictive modeling of the contamination mechanisms, toxicity, and human health risks of natural waters in Southeast Nigeria. Majority of the tested physicochemical parameters were within their satisfactory limits for drinking and other purposes. However, total hardness (TH), SO4, and NO3 were above stipulated limits in some locations. A nitrate health risk assessment revealed that certain areas present a chronic health risk to children, females, and males due to water intake. However, the dermal absorption route was found to have negligible health risks. SO4 in some locations was above the 100mg/L Nigerian limit; thus, heightening the potentialhealth effects due to intake of the contaminatedwater resources. Most samples had low TH values, which exposes users to health defects. There are mixed contamination mechanisms in the area, according to graphical plots, R-mode hierarchical dendrogram, factor analysis, and stoichiometry. However, geogenic mechanisms predominate over human-related mechanisms. Based on the results, a composite diagrammatic model was developed. Furthermore, predictive radial basis function (RBF) and multiple linear regression (MLR) models accurately predicted the TH, SO4, and NO3, with the RBF outperforming the MLR models. Insights from the RBF and MLR models were useful in validating the results of the hierarchical dendrogram, factor, stoichiometric, and graphical analyses.

Assessment of groundwater quality and human health risks of nitrate and fluoride contamination in a rapidly urbanizing region of India

Groundwater contamination studies are important to understand the risks to public health. In this study, groundwater quality, major ion chemistry, sources of contaminants, and related health risks were evaluated for North-West Delhi, India, a region with a rapidly growing urban population. Groundwater samples collected from the study area were analysed for physicochemical parameters - pH, electrical conductivity, total dissolved solids, total hardness, total alkalinity, carbonate, bicarbonate, chloride, nitrate, sulphate, fluoride, phosphate, calcium, magnesium, sodium and potassium. Investigation of hydrochemical facies revealed that bicarbonate was the dominant anion while magnesium was the dominant cation. Multivariate analysis using principal component analysis and Pearson correlation matrix indicated that major ion chemistry in the aquifer under study is primarily due to mineral dissolution, rock-water interactions and anthropogenic factors. Water quality index values showed that only 20% of the samples were acceptable for drinking. Due to high salinity, 54% of the samples were unfit for irrigation purposes. Nitrate and fluoride concentrations ranged from 0.24 to 380.19 mg/land 0.05 to 7.90mg/l, respectively due to fertilizer use, wastewater infiltration and geogenic processes. The health risks from high levels of nitrate and fluoride were calculated for males, females, and children. It was found that health risk from nitrate is more than fluoride in the study region. However, the spatial extent of risk from fluoride is more indicating that more people suffer from fluoride pollution in the study area. The total hazard index for children was found to be more than adults. Continuous monitoring of groundwater and application of remedial measures are recommended to improve the water quality and public health in the region.

Spatiotemporal Analysis and Health Risk Assessment of Nitrate in Kan River Basin, Tehran: Application of IRWQI and Monte Carlo Simulation

Introduction: Monitoring and controlling water resources and using health risk assessment approaches for water pollutants are essential for health promotion programs. This study aims to determine the water quality status and its spatiotemporal variation across the Kan River Basin, explore the interrelationship between surface and groundwater quality indices, and assess the nitrate health risk in drinking water.
 Materials and Methods: The water quality index (WQI) was calculated based on the guideline of the Iran Environmental Protection Organization, and spatiotemporal distribution maps were prepared using ArcGIS in 2020. To determine the correlation between IRWQISC and IRWQIGC indices, Spearman's non-parametric test was applied. Furthermore, Hazard Quotient (HQ), Excess Lifetime Cancer Risk (ELCR), and Monte-Carlo Simulation techniques were used to determine the carcinogenic and non-carcinogenic risks of nitrate in three age groups.
 Results: The water resources were classified into three groups of medium quality, relatively good, and good during the study period. All parameters complied with the Iranian water quality standards. Furthermore, the statistical analysis revealed no significant relationship between the surface and groundwater quality indices. The calculated HQ values for infants, children, and adults were 0.661, 0.620, and 0.236, respectively. The ELCR values for infants, children, and adults were 1.06 × 10-4, 0.99 × 10-4, and 0.38 × 10-4, respectively, which, for the infants' group, was higher than the guideline limit of the United States Environmental Protection Agency (USEPA) (10-4).
 Conclusion: The water resources are suitable for drinking purposes. However, more attention is needed to prevent water contamination in the coming years.

Groundwater evaluation of northern Jazmourian (south Iran) for drinking, agriculture, and associated health risks of nitrate and fluoride contamination

To investigate groundwater quality in the north of Jazmourian (Roudbar plain), 30 samples were collected and analyzed for evaluating drinking and irrigation status and associated health risks. In addition to major anions and cations, the fluoride and nitrate content of samples were analyzed using standard procedures. Nitrate levels range between 6.6 and 131 mg/L and exceed the WHO permissible limit in more than 23% and 80% of samples for adults and children, respectively. Fluoride amounts ranged from 0.4 to 4.8 mg/L in samples. The F- level exceeded the WHO standard limit in 10% of samples. The EC level increases in fine-grained deltaic deposits toward the south. The concentrations of major ions (HCO3, Cl, SO4, Mg, Na, K) increase southwards, following the flow direction. There are, however, lateral (east-west) differences in water quality due to the influence of such factors as the rate of recharge and the type of bedrock. Wherever the redbeds comprise the bedrock and the recharge rate is weaker, the dissolved salts are higher in amount. The water quality index (IWQ) indicated that 13, 13, and 4 samples are in “good,” “poor,” and “very poor” quality classes, respectively. By using the irrigation water quality index (IWQI), eight samples were at “low restriction,” nine samples at “moderate restriction,” twelve samples at “high restriction,” and one sample at “severe restriction” classes. The acquired findings revealed that the mean oral hazard quotient of nitrate was 1.14, 1.0, and 0.84, and for fluoride, it was 0.82, 0.72, and 0.61 for children, females, and males, respectively. The total hazard index for cumulative NO3 - and F- toxicity exceeded the acceptable level in 76.67%, 66.67%, and 56.67% of samples for children, females, and males, respectively.

Identifying the spatial pattern, driving factors and potential human health risks of nitrate and fluoride enriched groundwater of Ordos Basin, Northwest China

While the identification of the spatial patterns of fluoride (F−) and nitrate (NO3−) is important for groundwater management, these patterns remain poorly understood in the Ordos Basin. A total of 107 groundwater samples collected from phreatic aquifers were divided into three clusters using the self-organizing map (SOM). Cluster I, Cluster II and Cluster III represented the contaminated groundwater with different type and degree of pollution. On this basis, factor analysis (FA), together with classical hydrochemical diagrams reflected the major factors regulating the spatial characteristics of groundwater F− and NO3−. Firstly, water-rock interaction (carbonate precipitation, fluorite dissolution, and cation exchange) and evaporation were responsible for high groundwater NO3−, F−, hardness, and salinity. Secondly, anthropogenic inputs (agricultural activities and sewage) also contributed to high groundwater NO3− and F−. Finally, the universal alkaline environment could regulate groundwater NO3− and F−. Additionally, 68.22%, 37.38%, and 33.64% of samples showed higher total non-carcinogenic risk (HITotal > 1) for children, adult females, and adult males, respectively. Overall, the worst NO3− and F− contamination and health risks were evident in the western part of the Ordos Basin. The results of this study can contribute to the sustainable development of groundwater and to the protection of public health in the Ordos Basin.