Compositional and health risk assessment of drinking water from health facilities of District Vehari, Pakistan

Comparison of As removal efficiency and health risks from aqueous solution using as-synthesized Fe0 and Cu0: modelling, kinetics and reusability

Batch scale removal of arsenic (As) from aqueous media was explored using nano-zero valent iron (Fe0) and copper (Cu0) particles. The synthesized particles were characterized using a Brunauer-Emmett-Teller (BET) surface area analyzer, a scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR). The BET result showed that the surface area (31.5 m2/g) and pore volume (0.0415 cm3/g) of synthesized Fe0 were higher than the surface area (17.56 m2/g) and pore volume (0.0287 cm3/g) of Cu0. The SEM results showed that the morphology of the Fe0 and Cu0 was flowery microspheres and highly agglomerated with thin flakes. The FTIR spectra for Fe0 showed broad and intense peaks as compared to Cu0. The effects of the adsorbent dose (1-4 g/L), initial concentration of As (2 mg/L to 10 mg/L) and solution pH (2-12) were evaluated on the removal of As. Results revealed that effective removal of As was obtained at pH 4 with Fe0 (94.95%) and Cu0 (74.86%). When the dosage increased from 1 to 4 g L-1, the As removal increased from 70.59 to 93.02% with Fe0 and from 67 to 70.59% with Cu0. However, increasing the initial As concentration decreased the As removal significantly. Health risk indices, including estimated daily intake (EDI), hazard quotient (HQ), and cancer risk (CR) were employed and a significant decline (up to 99%) in risk indices was observed in As-treated water using Fe0/Cu0. Among the adsorption isotherm models, the values of R2 showed that isothermal As adsorption by Fe0 and Cu0 was well explained by the Freundlich adsorption isotherm model (R2 > 0.98) while the kinetic experimental data was well-fitted with the Pseudo second order model. The Fe0 showed excellent stability and reusability over five sorption cycles, and it was concluded that, compared to the Cu0, the Fe0 could be a promising technology for remediating As-contaminated groundwater.

A critical analysis of wastewater use in agriculture and associated health risks in Pakistan

Freshwater shortage and its contamination with various types of pollutants are becoming the most alarming issues worldwide due to impacts on socioeconomic values. Considering an increasing freshwater scarcity, it is imperative for the growers, particularly in semiarid and arid areas, to use wastewater for crop production. Wastewaters generally contain numerous essential inorganic and organic nutrients which are considered necessary for plant metabolism. Besides, this practice provokes various hygienic, ecological and health concerns due to the occurrence of toxic substances such as heavy metals. Pakistan nowadays faces a severe freshwater scarcity. Consequently, untreated wastewater is used routinely in the agriculture sector. In this review, we have highlighted the negative and positive affectivity of wastewater on the chemical characteristics of the soil. This review critically delineates toxic metal accumulation in soil and their possible soil-plant-human transfer. We have also estimated and deliberated possible health hazards linked with the utilization of untreated city waste effluents for the cultivation of food/vegetable crops. Moreover, we carried out a multivariate analysis of data (144 studies of wastewater crop irrigation in Pakistan) to trace out common trends in published data. We have also compared the limit values of toxic metals in irrigation water, soil and plants. Furthermore, some viable solutions and future viewpoints are anticipated taking into account the on-ground situation in Pakistan-such as planning and sanitary matters, remedial/management technologies, awareness among local habitants (especially farmers) and the role of the government, NGOs and pertinent stakeholders. The data are supported by 13 tables and 7 figures.

Spatial distribution, health risk assessment, and public perception of groundwater in Bahawalnagar, Punjab, Pakistan: a multivariate analysis

The current study investigated the hydrogeochemical behavior of groundwater quality attributes including arsenic (As) and their associated health risks in unexplored groundwater aquifers of Bahawalnagar, Punjab, Pakistan. The groundwater samples were collected from 40 colonies of Bahawalnagar city from electric/hand pumps, tube wells and turbines installed at varying depth (20 to > 100 m). The groundwater possessed the highest concentrations of PO₄ (0.5 mg/L), HCO₃ (425 mg/L), Cl (623 mg/L), NO₃ (136.68 mg/L) and SO₄ (749.7 mg/L) concentrations. There was no difference in concentration of As in shallow and deep aquifers. Interestingly, none of the water samples showed As concentration higher than the WHO limit of 10 µg/L for drinking water with groundwater As concentration spanning from 2.5 to 7.9 µg/L. The HQ values for As were less than 1 and there was no apparent non-carcinogenic risk from the long-term consumption of As contaminated water. The questionnaire survey indicated that 82% respondents believe that drinking water quality affects human health and 55% of respondents considered that groundwater in the area is not suitable for drinking. Survey results revealed that 29.11, 22.78, 17.08, 15.19, 7.59, 5.06 and 3.16% respondents/family members suffered from hepatitis, skin problems, diabetes, tuberculosis, kidney disorders, muscular weakness and gastro, respectively. However, the data cannot be correlated with As contamination and disease burden in the local community and it can be anticipated that the groundwater may contain other potentially toxic ions that are deteriorating the water quality and compromising human health. The hydrogeochemical analysis revealed Na-Cl/SO₄, K-SO₄ type of groundwater suggesting the potential role of sulfate containing minerals in releasing As in the groundwater aquifers.

Irrigation suitability, health risk assessment and source apportionment of heavy metals in surface water used for irrigation near marble industry in Malakand, Pakistan

Water is a vital, finite resource whose quantity and quality are deteriorating as the world population increases. The current study aims to investigate the concentration of heavy metals (HM) in surface water for irrigation purposes with associated human health risks and pollution sources near the marble industry in Malakand, Pakistan. Twenty-seven water samples were randomly collected and analyzed for HM concentration by inductively coupled plasma‒optical emission spectrometry (ICP‒OES). pH, electrical conductivity (EC), total dissolved solids (TDS), biological oxygen demand (BOD), and chemical oxygen demand (COD) were measured using standard methods of American Public Health Association (APHA). Irrigation suitability was assessed using specific water quality parameters. The associated health risks from ingestion and dermal exposure to heavy metals were calculated by USEPA health risk indices. Pollution sources and spatial distribution mapping were studied using compositional data analysis (CoDa) and the application of a geographic information system (GIS) to understand the changing behavior of heavy metals in surface waters. The concentrations of BOD (89%), COD (89%), Al (89%), Ca (89%), Cr (56%), Cu (78%), Fe (56%), K (34%) Mg (23%), Mn (56%), Na (89%), Ni (56%), P (89%), and Zn (11%) exceeded the safety limits of National Environmental Quality standards (NEQs) of Pakistan. The results of Kelly's ratio (KR) classified surface water as unsuitable for irrigation. The average daily doses (ADD, mg/kg/day) for Al, Cu, Cr, Fe, Mn, Ni, and Zn were higher in children than in adults. The hazard index (HI) for children and adults was above the threshold (HI > 1), indicating a significant risk of non-carcinogenic toxicity. The carcinogenic risk values for Cr and Ni were above the USEPA limit (1 × 10-6 to 1 × 10-4), suggesting a potential carcinogenic risk for the target population. Principal component analysis (PCA), biplot (CLR), and the CoDa-dendrogram allowed for the identification of elemental associations, and their potential source was anthropogenic rather than natural in origin. Regular monitoring and phytoremediation strategies are proposed to safeguard crops and human health.

Contamination and Human Health Risk Assessment of Toxic Trace Elements in Drinking Water of Gilgit-Baltistan, Pakistan

This study investigated the contamination level and risk associated with toxic trace elements in springs’ water from Gilgit-Baltistan, Pakistan. Toxic trace elements, including Hg, As, and Zn, were analyzed by metalyzer, HM 2000 serial no. MY-011-006, while elements such as Cr, Al, B, Ni, Cu, Mn, and Fe were analyzed using Metalometer HM 2000 serial no. MM005-007, the United Kingdom. The mean concentrations of TTEs in water samples from Skardu were ordered as, Mn < Cu < Fe < Zn < Al < Cr < As < Ni < Hg, in Gilgit, Mn < Cu < Zn < Ni < B < Cr < Fe < As < Hg, in Ghizer Cu < Mn < Zn < Ni < Cr < Fe < As < Hg, while in Nagar the concentration of TTEs in water samples were ordered as Cu < Mn < Fe < Ni < Al < Cr < Zn < As < Hg. Results obtained from this study showed that the concentrations of As, Hg, Ni, Cr, Al, and Mn in some water samples were higher than the limits recommended by WHO and Pak-NDWQS. However, the chronic daily intake indices (CDIs) and health risk index (HRI) in all samples were found below the US-EPA standards. The correlation analysis revealed a positive association among different elements, which revealed that the sources of TTES in water samples were mainly geological strata and anthropogenic activities.

Evolution Mechanism of Arsenic Enrichment in Groundwater and Associated Health Risks in Southern Punjab, Pakistan

Arsenic (As) contamination in groundwater is a worldwide concern for drinking water safety. Environmental changes and anthropogenic activities are making groundwater vulnerable in Pakistan, especially in Southern Punjab. This study explores the distribution, hydrogeochemical behavior, and pathways of As enrichment in groundwater and discusses the corresponding evolution mechanism, mobilization capability, and health risks. In total, 510 groundwater samples were collected from three tehsils in the Punjab province of Pakistan to analyze As and other physiochemical parameters. Arsenic concentration averaged 14.0 μg/L in Vehari, 11.0 μg/L in Burewala, and 13.0 μg/L in Mailsi. Piper-plots indicated the dominance of Na+, SO42-, Ca2+, and Mg2+ ions in the groundwater and the geochemical modeling showed negative saturation indices with calcium carbonate and salt minerals, including aragonite (CaCO3), calcite (CaCO3), dolomite (CaMg(CO3)2), and halite (NaCl). The dissolution process hinted at their potential roles in As mobilization in groundwater. These results were further validated with an inverse model of the dissolution of calcium-bearing mineral, and the exchange of cations between Ca2+ and Na+ in the studied area. Risk assessment suggested potential carcinogenic risks (CR > 10-4) for both children and adults, whereas children had a significant non-carcinogenic risk hazard quotient (HQ > 1). Accordingly, children had higher overall health risks than adults. Groundwater in Vehari and Mailsi was at higher risk than in Burewala. Our findings provide important and baseline information for groundwater As assessment at a provincial level, which is essential for initiating As health risk reduction. The current study also recommends efficient management strategies for As-contaminated groundwater.

Geochemical characterization and health risk assessment in two diversified environmental settings (Southern Italy)

An integrated approach using chemical and microbial indicators has been tested in two different sites of the Campania Plain (Southern Italy) with different land use covering and different hydrogeological features in order: (1) to define the water-rock interaction processes, (2) to differentiate sources of pollution in a detailed way (3) to evaluate the degree of water quality in the studied alluvial aquifer and (4) to identify the most worrying elements for human's health. Groundwater have showed a HCO₃-Ca signature for both investigated sites, and a progressive enrichment in alkali ions has been highlighted moving from the boundary of the plain toward the coastal areas, due to groundwater interaction with volcanic rocks along the flow path. The application of the Factor Analysis allowed to identify different sources of pollution, which were attributed to (a) leaks in the sewer system for the Agro-Aversano Area and also the spreading of manure as fertilizers in agricultural activities for the Caiazzo Plain. Furthermore, it has been highlighted that the use of major elements, trace elements and microbiological indicators, allows to accurately differentiate contamination processes in progress. In fact, from the results of the Factor Analysis applied in the Agro-Aversano area, no significant statistically relationships between major elements and microbiological indicators of fecal contamination were highlighted, unlike the Caiazzo plain where statistically significant correlations have been found between major and trace elements and microbiological indicators. The use of a Groundwater Quality Index has shown general poor water quality for the majority of analyzed samples due to the high amount of Nitrate and Fecal indicators. The use of a Health Risk Assessment highlighted that Nitrate coupled with Fluoride represent the most important concern for human health compared to the all investigated parameters in both sites.

Arsenic concentrations in soil, water, and rice grains of rice-growing areas of Punjab, Pakistan: multivariate statistical analysis

Arsenic (As), a class-A human carcinogen, is ubiquitously present in the earth's crust and soil and may enter the air, water, and surface environments through different natural and anthropogenic sources. In this experiment, soil, irrigation water, and rice grains were sampled from conventional rice-growing areas of Punjab, Pakistan. Soil samples were collected from 0 to 15 cm surface soil of rice growing fields, and rice grains were collected from the same field at crop maturity. Irrigation water samples were collected from the source used to irrigate the respective rice fields. Coordinates of sampling locations were noted using a global positioning system, and a locations map was made using ArcGIS. Soil samples were digested in a microwave digester using aqua regia, and plant samples were block digested using nitric acid. Arsenic concentration was determined using an inductively coupled plasma mass spectrometer coupled with an auto-sampler and integrated samples introduction system. The mean concentration of As in rice grains, soil, and water samples was found within the safe limit set by WHO except for a sample from Narowal (148.54 µg l^-1) that exceeded the irrigation water standard limit, i.e., 100 µg l^-1 for irrigation water. Principal component analysis was performed to reduce the multidimensional space of variables and samples. Through the calculations of estimated daily intake, it has been revealed that the As levels measured in this study would only contribute a small amount (less than 5%) of the total recommended daily intake allowance.

Multivariate analysis of accumulation and critical risk analysis of potentially hazardous elements in forage crops

Potentially hazardous element (PHE) contamination of aquifers is an issue of global concern, as this not only affects soil and plants but also exerts a negative impact on livestock. The current study assessed the extent of PHE (cadmium, copper, nickel, and lead) contamination of groundwater, soil, and forage crops in Shorkot, Punjab, Pakistan. Low concentrations of PHEs, particularly Cd and Cu, were found in drinking water which remained below detection limits. The concentrations of Ni and Pb in water samples were 0.1 and 0.06 mg L^-1, respectively. Calculated risk indices showed that there was a high carcinogenic and non-carcinogenic risk to livestock (sheep and cow/buffalo) from the ingestion of Ni- and Pb-contaminated water. Soil irrigation with contaminated water resulted in PHE accumulation (Cd: 0.4 mg kg^-1, Cu: 16.8 mg kg^-1, Ni: 17.6 mg kg^-1, Pb: 7.7 mg kg^-1) in soil and transfer to forage crops. The potential impact of PHE contamination of the groundwater on fodder plants was estimated for animal health by calculating the average daily dose (ADD), the hazard quotient (HQ), and the cancer risk (CR). While none of the PHEs in forage plants showed any carcinogenic or non-carcinogenic risk to livestock, a high exposure risk occurred from contaminated water (HQ: 12.9, CR: 0.02). This study provides baseline data for future research on the risks of PHE accumulation in livestock and their food products. Moreover, future research is warranted to fully understand the transfer of PHEs from livestock products to humans.

Hydrogeochemical and health risk investigation of potentially toxic elements in groundwater along River Sutlej floodplain in Punjab, Pakistan

Understanding groundwater quality and hydrogeochemical behavior is important because consumption of the potentially toxic elements (PTEs)-contaminated drinking water may induce several health problems for humans and animals. In the current study, we examined the potential groundwater contamination with various PTEs (arsenic, As; cadmium, Cd; copper, Cu; manganese; Mn) and the PTEs-induced health risk. Groundwater (n = 111) was characterized for total As, Cd, Cu, and Mn concentrations and other water quality attributes along the River Sutlej floodplain of Punjab, Pakistan. Results revealed that groundwater, which is used for drinking purpose, contained high concentrations of As and Cd (mean As: 33 µg/L, mean Cd: 3 µg/L), exceeding 100% and 32% than the World Health Organization's safe limits (10 and 3 µg/L, respectively) in drinking water. The other water quality attributes (i.e., EC, HCO₃, Cl and SO₄) were also found above their safe limits in most of the wells. Hydrogeochemical data showed that groundwater was dominated with Na-SO4, Na-Cl, Ca/Mg-CO₃ type saline water. The hazard quotient and cancer risk indices values calculated for As and Cd indicated potential threat (carcinogenic risk > 0.0001 and non-carcinogenic risk > 1.0) of drinking groundwater in the study area. This study shows that the groundwater along River Sutlej floodplain poses a health threat to the communities relying on it for drinking and irrigation due to high concentrations of As and Cd in water. Moreover, it is important to monitor groundwater quality in the adjacent areas along River Sutlej floodplain and initiate suitable mitigation and remediation programs for the safety of people's health in Punjab, Pakistan.

A holistic study on fluoride-contaminated groundwater models and its widespread effects in healthcare and irrigation

Groundwater is a key resource in the world. Its importance is often undermined, despite the various applications which include irrigation, drinking, sanitation, and industrial uses. One of the contaminants of groundwater is fluoride or the fluorine ion. Fluoride is a common pollutant of water, carrying potential benefits and costs to various sectors. Fluoride contamination of groundwater can impact humans, animals, healthcare, and the agricultural sector in direct or indirect ways. This paper aims to establish the definition of fluoride contamination of groundwater and simultaneously provide an outline of a few common sources that may cause fluoride contamination. Furthermore, this study will lay out the impacts of fluoride-contaminated groundwater on two sectors: healthcare and agriculture/irrigation. This study will also summarize various other research projects conducted across the world, which deliver promising evidence to support the points made throughout the paper. In addition to a detailed analysis of the impacts of fluoride on the healthcare and agricultural sector, this study also evaluates few other challenges which this issue poses and how to overcome them in the near future. A summation of deflouridation techniques is included, along with the future scope pertaining to the field of fluoride contamination. Another objective of the study is to spread awareness about the various health impacts that fluoride contamination poses and encourages consumption of fluoride in accordance with the set limit of 0.5-1.5 mg/L. The motivation behind writing this review is to compile and document various researches, along with an address on this prevalent issue to minimize the detrimental impacts and potential health risks on the society. The results of this study help to minimize risks in the future and encourage scientists to come up with mitigation strategies to ensure a safer environment.

Severity of zinc and iron malnutrition linked to low intake through a staple crop: a case study in east-central Pakistan

Micronutrients deficiency in soil-plant and human is well-addressed; however, little is known about their spatial distribution, magnitude of deficiency and biological nexus. Zinc deficiency (ZnD) and iron-deficiency anemia (FeD) are two serious nutritional concerns which are negatively affecting human health. Herein, a survey-based case study was conducted in major wheat-based cropping system of east-central Pakistan. Soil and grain samples were collected from 125 field-grown wheat from 25 distinct sites/villages and GPS coordinates were taken for mapping. The collected samples were tags according to the names of 25 sites, i.e., UCs (union councils; an administrative unit). The quantified amount of zinc (Zn) or iron (Fe) in soil-wheat grains was compared with their recommended concentrations (RCZn, RCFe) for human nutrition. Additionally, clinical features of ZnD and FeD were diagnosed among local farmers who used to consume these grains, throughout the year, cultivated on their farm, and quantified their deficiency prevalence (ZnDP, FeDP). Results revealed, the collected 64% (0.54 to 5.25 mg kg^-1) soils, and 96% (1.4 to 31 mg kg^-1) grain samples are Zn-deficient (RCZn) along with ZnDP recorded among 68% of population. Meanwhile, FeD is quantified in 76% (1.86 to 15 mg kg^-1) soil, 72% grain (2.1 to 134 mg kg^-1) samples, and FeDP is found among 84% of studied population. A strong and positive correlation is developed in the Zn-or FeDP with their deficiencies in soil and grain by plotting multivariate analysis. In line with spatial distribution pattern, the UCs, namely, 141, 151, 159 and 132 are quantified severe deficient in Zn and Fe, and others are marginal or approaching to deficient level. Our findings rationalize the biological nexus of Zn and Fe, and accordingly, draw attention in the biofortification of staple crop as a win-win approach to combat the rising malnutrition concerns.

Distribution and health risk assessment of trace elements in ground/surface water of Kot Addu, Punjab, Pakistan: a multivariate analysis

Water is a key component for living beings to sustain life and for socio-economic development. Anthropogenic activities contribute significantly to ground/surface water contamination particularly with trace elements. The present study was designed to evaluate distribution and health risk assessment of trace elements in ground/surface water of the previously unexplored area, Tehsil Kot Addu, Southern-Punjab, Pakistan. Ground/surface water samples (n = 120) were collected from rural and urban areas of Kot Addu. The samples were analyzed for physicochemical characteristics: total dissolved solids (TDS), pH, and EC (electrical conductivity), cations, anions, and trace elements particularly arsenic (As), lead (Pb), cadmium (Cd), and zinc (Zn). All of the water characteristics were evaluated based on the water quality standards set by World Health Organization (WHO). Results revealed the suitability of water for drinking purpose with respect to physicochemical attributes. However, the alarming levels of trace elements especially As, Cd, and Pb make it unfit for drinking purpose. Noticeably, 23, 96, and 98% of water samples showed As, Cd, and Pb concentrations higher than the permissible limits. Overall, the estimated carcinogenic and non-carcinogenic risk to the exposed community was higher than the safety level of USEPA, suggesting the probability of cancer and other diseases through long-term exposure via ingestion routes. Therefore, this study demonstrated an urgent need for water filtration/purification techniques, and some quality control measures are warranted to protect the health of the exposed community in Tehsil Kot Addu.

Determination and health risk assessment of trace elements in the tap water of two Sub-Cities of Addis Ababa, Ethiopia

Water is an essential component of all living things on earth and the contamination of water by heavy metals can cause detrimental health effects. This study aimed to determine the health risk posed by trace elements (Fe, Zn, Cu, Mn, Ni, Cr, Cd, Co, Pb, and As) present in the drinking water supplies of Gullele and Akaki-Kality Sub-Cities, upstream and downstream parts of Addis Ababa, respectively. The concentrations of the potentially toxic trace elements in the water samples were determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). The highest concentration of the heavy metals was observed for Iron. Cadmium and cobalt were not detected in any of the tap water samples. Samples from Gullele contained higher levels of Fe and Mn, 220.3 ± 0.17 and 19.78 ± 0.08 μg/L, respectively compared to Akaki-Kality, 38.87 ± 0.14 and 2.08 ± 0.01 μg/L, respectively. Conversely, tap water from Akaki-Kality contained significantly higher levels of As than that from Gullele. Additionally, Cr and Ni were detected only in samples from Akaki-Kality, which might be due to the various industries in the area. The highest incremental lifetime cancer risk was found for arsenic, with values for children and adults in Akaki-Kality 2.50 × 10-4 and 4.50 × 10-4, respectively. Likewise, in Gullele Sub-City, it was 5.00 × 10-5 and 1.00 × 10-4 for adults and children, respectively. The results indicate that carcinogenic risk occurrence is probable from As in both studied areas.

Effects of arsenite on physiological, biochemical and grain yield attributes of quinoa (Chenopodium quinoa Willd.): implications for phytoremediation and health risk assessment

The objectives of this study were to investigate the effects of arsenic (As) on physiological and biochemical attributes of quinoa, and human health risks associated with the consumption of As contaminated grains of quinoa. Quinoa genotype, Puno was grown on soil contaminated with various levels of arsenite; 0, 10, 20, 30, and 40 mg As kg^-1 soil. Results revealed that plant growth, photosynthetic pigments, stomatal conductance, and grain yield of As treated plants were significantly less as compared to control plants. Plants exposed to elevated levels of 30 and 40 mg As kg^-1 of soil could not survive until maturity. Plant roots retained higher concentration of As than shoot indicating As phytostabilizing behavior of quinoa. Arsenic toxicity caused oxidative stress in quinoa plants, which elevated the H₂O₂ and TBARS contents and decreased membrane stability. This oxidative stress was partly mitigated by the induction of antioxidant enzymes (SOD, CAT, POD, APX). Perhaps, our results regarding As availability might be an overestimate of the typical natural conditions, As accumulation in quinoa grains posed both carcinogenic and non-carcinogenic health risks to humans. It was concluded that quinoa is sensitive to As and the consumption of quinoa grains from plants grown on As concentration ≥20 mg kg^-1 of soil was not safe for humans. Novelty statement: The tolerance potential of quinoa (Chenopodium quinoa Willd.) against the trivalent form of arsenic (arsenite), and the health risks due to the consumption of arsenic-contaminated grains has not been explored yet. This is the first study in which we have explored the effects of arsenite on physiological, biochemical and phytoremedial attributes of quinoa. Moreover, human health risks associated with the consumption of As contaminated grains of quinoa has have been investigated. The findings of the present study would be helpful for farmers who intend to grow quinoa on arsenic-contaminated soils.

Risk assessment of heavy metal(loid)s via Spinacia oleracea ingestion after sewage water irrigation practices in Vehari District

The use of sewage water as an irrigation source can be beneficial in agricultural practices, however, it may result in human health risks due to the consumption of heavy metal(loid)-contaminated food. This study evaluated the suitability of using sewage water (SW), freshwater (FW), and groundwater (GW) for vegetable irrigation in District Vehari. Spinach (Spinacia oleracea) plants were grown in pots irrigated with FW, GW, and SW in different proportions and combinations. The results indicated the substantial lesser buildup of heavy metal(loid)s (As (- 0.8%), Cd (- 38%), Cr (- 6.2%), Cu (- 20%), Fe (- 9.2%), Mn (- 13%), Ni (- 16%), Pb (- 19%), and Zn (-15%)) in soil after S. oleracea cultivation compared to unirrigated soil possibly due to high metal(loid) uptake by S. oleracea. Irrigation with all types of waters resulted in metal(loid) accumulation in S. oleracea predominantly in roots. The combinations of FW, GW, and SW resulted in high metal(loid) accumulation (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in the edible S. oleracea leaves than their alone application. Owing to high metal(loid) buildup, plants showed a linear trend in physiological imbalance in terms of reduced pigment content, induction of peroxidation, and oxidation of lipids. The severe oxidative stress was observed in S. oleracea plants under FW and GW irrigation due to high metal(loid) accumulation. The risk indices showed possible carcinogenic risk (CR > 0.0001) and non-carcinogenic risk (HI > 1) from the consumption of metal(loid)-contaminated S. oleracea leaves. Results revealed unsuitability of all waters and their combinations for S. oleracea irrigation. Moreover, this study does not encourage the use of mixed water for vegetable irrigation in Vehari District. Therefore, it is of utmost importance to monitor the quality of irrigation waters to ensure food safety and prevent chronic health risks to the exposed population.

Hydrogeochemical investigation of arsenic in drinking water of schools and age dependent risk assessment in Vehari District, Punjab Pakistan: a multivariate analysis

Globally, a large number of school-aged children is suffering from water-borne diseases, particularly in low-income countries. Arsenic (As) is a hazardous and potentially carcinogenic metal(loid) in drinking water. Nowadays, alarming levels of As have been reported in the groundwater of Vehari District, Punjab Pakistan. In this study, drinking water supplies for high and higher secondary schools were examined in Vehari District. A total of 164 water samples were collected from schools and subjected to heavy metal(loid) analysis (As) and basic water physicochemical parameters. The results were analyzed with respect to sampling area, school type, school education level, sources of sample collection, and the depth of the source. The results revealed that As concentration of water samples in boys' and girls' schools was 12.8 μg/L and 9.2 μg/L, respectively. However, when the As concentration in drinking water was evaluated at the school education level, a notable higher concentration of As was observed in the higher secondary schools than the high schools with an average of 19.5 and 9.7 μg/L, respectively. The risk assessment indices were calculated based on education level and different age groups of the children (primary, elementary, high, and higher secondary). High carcinogenic (cancer risk = 0.001) and non-carcinogenic (hazard quotient = 2.0) risks were noted for the children in higher secondary school. The current findings anticipated that the drinking water of schools in Vehari District did not meet the requirement of the World Health Organization (WHO) drinking water quality guidelines. Safe drinking water is crucial for the development and growth of children. Therefore, it is important for educational authorities to take steps for provision of As free safe drinking water to students and local inhabitants.