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Milk is a complex of biomolecules and is a good source of proteins, fats, sugars, vitamins and minerals. Various types of milk available in the market are solid and liquid milk. Solid milk is available in the form of formula milk and liquid milk is raw and packed milk (branded milk) like GM1, OL2, Dp3, T4, H5, Mp6, DO7 and N8. Milk having different additive components like “micronutrients, vitamin and minerals” play a vital role in our daily life therefore it is by kids, adults and elders all over the world. The chemical composition of raw milk not only focuses on its components, but also the treatment, in the case of quality of the raw materials, packing, storage and conditions are very important. Cow milk is one of the major resources contaminated with different heavy metal atoms. Different samples of milk (raw and packed) were collected from diverse zone of Islamabad. The packed milk like GM1, OL2, Dp3, T4, H5, Mp6, DO7 and N8 were collected from different shops of Rawalpindi and Islamabad. Result showed the presence of different types of heavy metals in milk samples. The level of zinc in the raw milk samples was high in the Islamabad city as compared to Rawalpindi. The sequence of heavy metals present in fresh milk were detected as Zn> Cu> Cr> Pb and Cu. In packed milk, level of Chromium was different across the world.

To assess the loading profiles of groundwater nitrate (NO3−) and fluoride (F−), their spatial distributions, geochemistry and associated health risks were determined for 131 groundwater samples from eastern (ESR), central (CSR) and Trans-Indus Salt Ranges (TSR) in Pakistan. Groundwater NO3− concentrations were 0.2–308 mg/L (mean 59 mg/L) in ESR, 2.7–203 mg/L (mean 73 mg/L) in CSR and 1.1–259 mg/L (mean 69 mg/L) in the TSR. Forty-one %, 57% and 36% of the ESR, CSR and TSR samples, respectively, exceeded the WHO and Pak-NEQs permissible limit of 50 mg/L NO3−. Likewise, groundwater F− concentrations ranged from 0.1–1.8 mg/L (mean 0.6 mg/L), 0.1–2.7 mg/L (mean 0.9 mg/L) and 0.3–2.5 mg/L (mean 1.6 mg/L) mg/L in the ESR, CSR and TSR sites, respectively. In this case, 3%, 17% and 27% of the ESR, CSR and TSR samples, respectively, exceeded the WHO and Pak-NEQs permissible limit of 1.5 mg/L F. Oxidation of coal and coal waste resulted in the release of NO3− to groundwater. By contrast, enrichment of F− in groundwater was due to dissolution and cation exchange processes. Elevated values of the Higher Pollution Index (PI) and Health Risk Index (HRI) reflect a non-acceptable carcinogenic risk for drinking water NO3− and F− which should be addressed on a priority basis to protect human health.

This study was undertaken in order to determine heavy metal content in fifty-two (n = 52) cosmetic products both imported, locally manufactured and marketed at Quetta, Balochistan. An analytical te...

Geogenic contamination of Arsenic (As) poses major health threat to people living in Indus Plain of Pakistan particularly in Punjab. In this paper, we described in detail the hydrogeochemistry of As contaminated groundwaters in selected sites from Lahore, Kasur and Okara districts and its associated potential health risks. Sampling was done in 2019 and 141 groundwater samples were collected. High variability in As concentrations was observed varying between below detection level (3− and Fe-reduction in groundwaters was also seen. Furthermore, higher potential health risks were found to be associated with elevated As levels in terms of estimated average daily dosage (EDI), hazard quotient (HQ) and carcinogenic risk assessment (CR). The average values for HQ for adults, teenagers and children were found to be 9.06, 13.6 and 13.07, respectively. Meanwhile average CR values were found to be 0.004, 0.01, 0.006 mg/Kg/day in adults, teenagers and children respectively. These results suggest an increased risk of adverse health impacts in current study sites and require effective remedial measures at urgent basis.

Biochar, due to its heterogeneity, may not be equally effective for cationic and anionic metals/metalloid immobilization in soil. Biochar modification could facilitate the immobilization of specific metals/metalloids in soil. This study explored the potential of unmodified and modified (with KMnO4) biochars derived from sawdust and rice husk at two different temperatures (300 and 700 °C) on the mobility of arsenic (As) in contaminated soil. Soil column leaching experiments were performed with two application rates (2% and 5%; w/w) of different biochars, and the pore waters at different time intervals were analyzed for As and other cations and anion concentrations. In general, all the biochars increased As mobility in soil. The biochars produced at 300 °C significantly and highly increased As concentrations (up to 341%) in pore waters, as compared with the unamended soil. However, the modified biochars showed As immobilization in soil as compared with their unmodified counterparts. The mechanisms of biochar interaction with As in soil were investigated by developing correlations of As with various chemical constituents. It was inferred that As mobilization was increased due to competition between As and PO43−. Contrarily, immobilization of As in soil by modified biochars was related to sorption onto Fe- and Mn-oxides. Pristine biochar may not be an efficient remediation measure for As-contaminated soil. There could be a risk of As leaching into groundwater from soils amended with biochar. However, it is recommended that modification of biochar may assist the immobilization of As in soil.

Irrigating rice with groundwater can lead to As accumulation in soil and rice grains. Matched sets of irrigation water, paddy soil, and rice grains were collected to assess the scale of the problem in the Punjab plains of Pakistan. From a total of 60 sites, irrigation water and rice grains as well as 103 soil samples were collected and analyzed in the laboratory. Irrigation water and 660 soil samples were also analyzed in the field using a field kit. Concentrations of As in irrigation water (65 + 32 μg/L) are higher in the floodplain of the Ravi River compared to the Chenab (13 + 9 μg/L) and Jhelum (4 + 5 μg/L) rivers, as well as the intervening Rechna (6 + 6 μg/L) and Chaj doabs (0.8 + 0.2 μg/L). Area-weighted mean soil As concentrations are 12 + 3 mg/kg along the Ravi, 8.9 + 2 and 8.1 + 2 mg/kg along the Chenab and Jhelum, respectively, and 6.2 + 0.2 mg/kg and 6.1 + 0.1 mg/kg, respectively, within the Rechana and Chaj doabs. The As content of polished grains export-quality basmati rice of 0.09 + 0.05 mg/kg, however, is low across the entire area. Groundwater irrigation leads to elevated As concentrations in paddy soil of some rice-growing regions of Punjab but does not result in increased uptake of As in basmati rice grains.

Litho-geochemical characteristics of low and high fluoride (F−) groundwater along with hydrological processes were investigated to delineate its genesis and enrichment mechanism in a watershed sedimentary basin. In this study, groundwater F− concentration ranged from 0 to 20 mg/L with a mean and standard deviation of 2.8 and ± 3.7 mg/L, respectively. Out of N = 87, 63% of samples exceeded the World Health Organization (WHO) limit of 1.5 mg/L. The order of cationic and anionic dominance in groundwater samples with mean was found in decreasing order as Na+ > Mg2+ > Ca2+ > K+ and HCO3− > SO42− > Cl− > PO43− > NO3− measured in milligrams per liter. Groundwater chemistry changed from Ca-HCO3 to Na-HCO3 type and low to high fluoride as we moved from mountain foot towards the synclinal basin. Low fluoride groundwater reflected weathering, recharge, and reverse ion exchange processes with Ca–HCO3– and Ca–Mg–Cl–type water while high fluoride groundwater revealed base ion exchange, mixing, and desorption as dominant hydrological processes with Na-HCO3 and Na-Cl types of water. Gibb’s diagram showed rock weathering and mineral dissolution as the major geochemical processes controlling water chemistry with an insignificant role of evaporation in the semi-arid area. Fluoride was undersaturated with mineral fluorite, indicating fluoride in groundwater is released by secondary minerals. However, due to complex geological features, groundwater fluoride enrichment was affected by a broad-scale process across a wide area such as depth, residence time, and most important geomorphological units hosting the aquifer.

Hydrogeochemical methods were integrated to delineate the geochemical factors controlling fluoride (F-) contamination in groundwater at four sites in the districts of Lahore (Samada) and Kasur (Sari Chimba, Kot Maiga, and Chah Fatehwala) in Panjab province of Pakistan. Hydrochemical data and stoichiometric ratios indicate Na-Cl and Na-HCO3 as the dominant water types with silicate weathering influencing overall hydrogeochemistry of the study area. The groundwater F- concentrations ranged between 0.54 mg/L and 17.5 mg/L, with more than 70% samples having F- concentrations above the World Health Organization (WHO) provisional drinking water guideline (1.5 mg/L). Saturation indices determined that 100% samples were saturated with respect to calcite and 96% samples were undersaturated with respect to fluorite, indicating the influence of calcite precipitation on fluoride enrichment. A positive correlation was observed between fluoride with pH, Na+, and HCO3-, confirming that high fluoride concentrations were the result of weathering of silicate minerals and the exchange of OH- on clay surface under the alkaline pH conditions. The isotopic values of δ18O and δ2H in groundwater ranged from 9.14 to - 5.51‰ and 56.57 to - 39.5‰, respectively. The stable isotope data indicated the meteoric origin of groundwater with some evaporative effect, which is partly influencing groundwater quality such as high pH and salinity, as a result facilitating anion exchange (OH- for F-) on clays surface. The research indicates that the groundwater quality of the study area is not recommendable for drinking due to its high total dissolved solids (TDS) and elevated fluoride concentrations.

Fish and other aquatic biota are hampered by mixtures of pesticides which pollute natural water through agricultural runoff and other sources. Toxicity of combined exposures of endosulfan and imidacloprid on zebrafish in terms of oxidative stress and deoxyribonucleic acid (DNA) damage in liver and histological alterations in gills and muscles was investigated. Zebrafish were exposed to three different sub-lethal concentrations of endosulfan and imidacloprid along with control selected for each treatment for 21 days: control treatment (CT), treatment 1 (T1), treatment 2 (T2) and treatment 3 (T3). T1, T2 and T3 groups were exposed to 0.1, 0.5 and 1 μg/L of endosulfan, respectively, while imidacloprid concentration was maintained at 1 ppm in all three treatments. Oxidative stress was evaluated by measuring levels of catalase (CAT), superoxide dismutase (SOD) and malondialdehyde (MDA). Comet assay was applied to measure degree of DNA damage. Dose- and time-dependent decrease in SOD and CAT activity was observed after 21 days of exposure while low concentrations of pesticides induced SOD and CAT activities after early exposure to reduce the oxidative stress. MDA content was found to be increased in T3 having high concentrations of pesticides. Substantial increase in DNA damage was noticed after 21 days' exposure to pesticides. Significant morphological changes were observed in gills relative to muscles.

Chronic exposure from drinking well-water with naturally high concentrations of fluoride (F−) has serious health consequences in several regions across the world including South Asia, where the rural population is particularly dependent on untreated groundwater pumped from private wells. An extensive campaign to test 28,648 wells was conducted across the Punjab plains of Pakistan and India by relying primarily on field kits to document the scale of the problem and shed light on the underlying mechanisms. Groundwater samples were collected from a subset of 712 wells for laboratory analysis of F− and other constituents. A handful of sites showing contrasting levels of F− in groundwater were also drilled to determine if the composition of aquifer sediment differed between these sites. The laboratory data show that the field kits correctly classified 91% of the samples relative to the World Health Organization guideline for drinking water of 1.5 mg/L F−. The kit data indicate that 9% of wells across a region extending from the Indus to the Sutlej rivers were elevated in F− relative to this guideline. Field data indicate an association between the proportion of well-water samples with F− > 1.5 mg/L and electric conductivity (EC) > 1.5 mS/cm across six floodplains and six intervening doabs. Low Ca2+ concentrations and elevated bicarbonate (HCO3− > 500 mg/L) and sodium (Na+ > 200 mg/L) in high F− groundwater suggest regulation by fluorite. This could be through either the lack of precipitation or the dissolution of fluorite regulated by the loss of Ca2+ from groundwater due to precipitation of calcite and/or ion exchange with clay minerals. Widespread salinization of Punjab aquifers attributed to irrigation may have contributed to higher F− levels in groundwater of the region. Historical conductivity data suggest salinization has yet to be reversed in spite of changes in water resources management.

Arsenic (As), and fluoride (F−) are potent contaminants with established carcinogenic and non-carcinogenic impacts on the exposed populations globally. Despite elevated groundwater As and F− levels being reported from various regions of Pakistan no biomonitoring study has been reported yet to address the co-exposure impact of As and F− among school children. We aimed to investigate the effects of these two contaminants on dental fluorosis and intelligence quotient (IQ) along with the induction of oxidative stress in rural children under co-exposed conditions. A total of 148 children (5 to 16 years old) from the exposed and control group were recruited in the current study from endemic rural areas of Lahore and Kasur districts, Pakistan having elevated As and F− levels in drinking water than permissible limits. We monitored malondialdehyde and its probable association with antioxidants activity (SOD, CAT, and GR) as a biomarker of oxidative stress. GSTM1/T1 polymorphisms were measured to find the impact of As on health parameters. Mean urinary concentrations of As (2.70 vs. 0.016 µg/L, P

We analyse an ensemble of statistically downscaled Global Climate Models (GCMs) to investigate future water availability in the Upper Indus Basin (UIB) of Pakistan for the time horizons when the global and/or regional warming levels cross Paris Agreement (PA) targets. The GCMs data is obtained from the 5th Phase of Coupled Model Inter-Comparison Project under two Representative Concentration Pathways (RCP4.5 and RCP8.5). Based on the five best performing GCMs, we note that global 1.5 °C and 2.0 °C warming thresholds are projected in 2026 and 2047 under RCP4.5 and 2022 and 3036 under RCP8.5 respectively while these thresholds are reached much earlier over Pakistan i.e. 2016 and 2030 under RCP4.5 and 2012 and 2025 under RCP8.5 respectively. Interestingly, the GCMs with the earliest emergence at the global scale are not necessarily the ones with the earliest emergence over Pakistan, highlighting spatial non-linearity in GCMs response. The emergence of 2.0 °C warming at global scale across 5 GCMs ranges from 2031 (CCSM4) to 2049 (NorESM) under RCP8.5. Precipitation generally exhibits a progressive increasing trend with stronger changes at higher warming or radiative forcing levels. Hydrological simulations representing the historical, 1.5 °C and 2.0 °C global and region warming time horizons indicate a robust but seasonally varying increase in the inflows. The highest inflows in the baseline and future are witnessed in July. However, the highest future increase in inflows is projected in October under RCP4.5 (37.99% and 65.11% at 1.5 °C and 2.0 °C) and in April under RCP8.5 (37% and 62.05% at 1.5 °C and 2.0 °C). These hydrological changes are driven by increases in the snow and glacial melt contribution, which are more pronounced at 2.0 °C warming level. These findings should help for effective water management in Pakistan over the coming decades.

Groundwater is a major freshwater resource in Pakistan. However, overextraction and other anthropogenic pressures have led to contamination of this valuable resource. Numerous studies have reported four major tribulations of groundwater contamination in Pakistan: bacteriological, arsenic, nitrate, and fluoride. Bacteriological contamination is mainly due to leaching of municipal wastewater. It is the leading cause of gastrointestinal disorders and child mortality in Pakistan. Arsenic is classified as Group 1 human carcinogen. Pakistan ranks fourth globally among the arsenic-affected countries globally. Rural Sindh and Punjab are worst affected areas with arsenic pollution. Fluoride is responsible for skeletal and dental fluorosis. Districts Quetta, Lahore, Kasur, Gujrat, Swabi, Nagarparkar, and Umerkot have been reported with excess fluoride in their groundwater. Presence of nitrate can be attributed to agriculture activities and leaching of sewage water. Punjab and Balochistan provinces have highest reported nitrate concentrations. Metals such as zinc, lead, nickel, and iron have also been reported in various parts of the country, which are briefly discussed in the chapter along with the major anions.

The present study aimed at exploring the sources of salinity and the link it shares with the enrichment of As (arsenic) and F- (fluoride) in the groundwater of Rachna Doab. Total Dissolved Solids (TDS) were used as the measure of salinity to classify samples into three groups: TDS1000 mg/L (freshwater), 1000-3000 mg/L (slightly saline) and 3000-10,000 mg/L (moderately saline). The stable isotope analysis (δ

In this study, we tested 123 groundwater wells from five different areas of Punjab, Pakistan for arsenic (As) contamination level and species, as well as delineated hydrogeochemical behaviour of As in aquifers. Results revealed that 75% and 41% of the groundwater wells exceeded the safe As limit of World Health Organisation (WHO, 10 μg L−1) and Pakistan-EPA (50 μg L−1), respectively. Arsenite (As(III)) and arsenate (As(V)) spanned 0–80% and 20–100% of total As (1.2–206 μg L−1), respectively. The mean As content (5.2 μg L−1) of shallow wells at 9–40 m depth did not exceed the WHO safe limit, representing a safe aquifer zone for pumping of groundwater compared to deeper wells at 41–90 m (51 μg L−1) and >90 m (23 μg L−1) depths. Piper-plot elucidated that the aqueous chemistry was dominated with Na-SO4, Na-Ca-SO4, Na-Mg-SO4 type saline water. Principal component analysis grouped As concentration with well depth, pH, salinity, Fe and CO3, exhibiting that these hydrogeochemical factors could have potential role in controlling As release/sequestration into the aquifers of study area. Geochemical modeling showed positive saturation indices only for iron (Fe) oxide-phases, indicating Fe oxides as the major carriers of As. Overall, this study provides insights to tackle emerging As threat to the communities in Punjab, Pakistan, as well as help develop suitable management/mitigation strategies – based on the baseline knowledge of As levels/species and factors governing As contamination in the study area.

In the present study, the tubewell water quality, emphasizing on As contamination, were investigated in the Punjab plains of Pakistan. The Na-Cl water type is dominated in Doabs (Rechna and Chaj) whereas Ca-HCO3 water type is dominated in Ravi flood plain. Concentrations of As in well water (65 ± 32 μ g/L) are higher in the floodplains of the Ravi River compared to the Chenab (13 ± 9 μ g/L) and Jhelum (4 ± 5 μ g/L) rivers, as well as in the intervening Rechna (6 ± 6 μ g/L) and Chaj doabs (0.8 ± 0.2 μ g/L). The average Hazard quotients (HQ) is 9.09E+00 and Potential Cancer Risk (CR) is 4.09E−03 in Ravi flood plain which indicates the potential health risk to the consumers of well water for drinking purposes and also long term irrigation with this water will result As accumulation in paddy soil. Based on average values, the Sodium Adsorption Ratio (SAR), Magnesium Hazard (MH), %Sodium (%Na) and Kelly Ratio (KR) follows the sequence Rechna Doab>Chaj Doab>Chenab floodplain>Jhelum floodplain>Ravi floodplain in 5 geographic units, suggesting low salinity water in floodplains and saline water in Doabs.

Release of arsenic (As) and fluoride (F−) species into groundwater is a serious health concern around the world. The present study was the first systematic baseline study conducted in Rahim Yar Khan district, Punjab, focusing on As and F− contamination in groundwater. A total of 51 representative groundwater samples comprising of 44 samples from agricultural suburbs and 7 from an industrial base were analysed. Statistical parameters, principal component analysis-multiple linear regression (PCA-MLR) and health risk assessment model were used to investigate the hydro geochemistry, spatial patterns, interrelation, source contribution and associated health risks of high As and F− in groundwater of the study area. Results showed high risk of F− exposure to people of the study area, with all samples exceeding the WHO standard of 1.5 mg/L, and for As, 32.5% of the studied groundwater samples exceeded the WHO standard (10 µg/L). The maximum As (107.23 µg/L) and F− (26.4 mg/L) levels were observed in samples close to the agricultural and smelting areas, implicating the frequent use of fertilizers and influence of industrial effluents in the study area. The PCA-MLR receptor model quantitatively illustrates that the majority of As and F− comes from natural sources, while, among anthropogenic sources, industrial and agricultural activities contributed the most. Health risk assessment revealed a high risk of As and F− contamination to the exposed population; therefore, detailed control strategies and policies are required in order to mitigate the health risks.

Biogeochemical mobilization of arsenic in groundwater depends on the presence of dissolved organic matter (DOM) that likely promotes the As release, i.e., reductive dissolution, complexation, competition, and electron shuttling. We investigated the role of DOM in As release, along with its complete characterization, in the Indus plain of Pakistan, one of the worst arsenic impacted zones in the South Asian region. In total, 60 groundwater and 15 soil samples, collected at six sites from north to south within the flood plain of the Ravi River, Lahore, Pakistan were investigated. Arsenic concentration ranged from 9.61 μg/L to 386 μg/L in the groundwater samples (high As observed in areas close to the river). Dissolved organic carbon (DOC) in 29 groundwater samples ranged between 0 and 10.1 mg-C/L. A moderately positive correlation of As with DOC and Fe in the northern part of the study area suggest the reductive dissolution of FeOOH associated with dissolved organic matter (DOM). The reductive dissolution plays an essential role for As enrichment in the area evidenced by the lower concentrations of SO42−, NO3−, and PO34−and a non-correlative pattern with As. In contrast, a positive correlation of As with PO34−, DOC, and HCO3− in the southern part indicate competitive desorption behind the As release. Fluorescence excitation-emission matrix intensity data of DOM indicate the maximum presence of humic-like substances in the northern part that gradually shifts to aromatic, fulvic and protein type towards the southern part. Specific ultraviolet absorbance and fluorescence index display aromatic and terrestrial (allochthonous) sources of DOM near the riverbank and mixed (both allochthonous and autochthonous) source away from the river. The positive correlations of As with DOC and fluorescence intensity also attest that DOM played a vital role in the As mobilization in groundwater of the study area.

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.

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In this review article, we have compiled and reviewed the previously published available literature on environmental distribution, behaviour, fate and regional trends of legacy and emerging flame retardants (FRs) including brominated (BFRs), organo-phosphate (OPFRs), novel brominated flame retardants (NBFRs) and dechlorane plus (DP) in the freshwater ecosystem. Transport and fate is discussed briefly with the evidences of de-bromination, sedimentation and accumulation in biota. De-bromination of BDE-209 is considered of concern because the lower brominated congeners are more toxic and mobile thus posing increased risk to the freshwater ecosystem. The available data on temporal and spatial trends as yet, is too few to show any consistent trends, enabling only general conclusions to be drawn. There is a lack of temporal studies in Asia, while, overall the trends are mixed, with both increasing and decreasing concentrations of BFRs and OPFRs. OPFRs and NBFRs have replaced classical BFRs (polybrominated diphenyl ethers (PBDEs)) in some countries but the amount of PBDEs in the environment is still considerable. Knowledge gaps and recommendations for future research are discussed emphasizing on further monitoring, advanced analytical methodologies, and risk assessment studies to completely understand the science of flame retardants in the freshwater ecosystem.

Groundwater contamination with arsenic and fluoride has affected over 300 million people worldwide. Ingestion of arsenic and fluoride for extended period of time or at high concentration causes severe health effects. Arsenic can cause thickening and discoloration of the skin, cardiovascular disorders, cancer and skin lesions. Excessive intake of fluoride leads to dental and skeletal fluorosis and bone deformities. This report reviews the distribution of arsenic and fluoride contamination, their sources, mobilization and associated health risks. Remediation technologies to remove arsenic and fluoride are presented.

Trace metal contamination in drinking water poses severe threat to human health through long-term exposure. The present study highlighted the elevated arsenic (As) and trace metal concentrations in drinking water and associated potential health risk to local residents of Tehsil Mailsi (Punjab), Pakistan. Our results showed that concentrations of As, Cd, Fe, Cr and Pb exceeded the WHO limits in drinking water, whereas Cu, Mn, Co, Ni and Zn concentrations were below the safe limits. The calculated estimated daily intake (EDI) of metals from local drinking water had the order of Zn > As > Cu > Pb > Cd > Ni > Mn > Cr, and the consequent target hazard quotient (THQ) above 1 was observed for As and Cd, which employed high potential health risk to local residents. Spatial distribution of As and trace metals in drinking water were related to the local anthropogenic sources, due to intensive application of agrochemicals. The study area presents high potential health risk associated with As and trace metals pollution in drinking water. The local wells have never been tested for metal concentrations prior to use, and necessary processes should be taken to test the wells with respect to As and trace metals contamination.

The present study for the first time highlighted the arsenic and heavy metals (HM) concentrations as well as their source of contamination in tube-well water and associated potential health risk to local residents of Tehsil Mailsi (Punjab), Pakistan. 44 samples were collected from Jala Jeem and Dunia Pur. Results revealed average concentrations of anion and heavy metals such as Iron (Fe), (Cadmium) Cd, (Lead) Pb, (Sodium) Na+, (Bicarbonate) HCO3−, (Sulfate) SO42− and Arsenic (As) exceeded the WHO limits in the tube well water. The calculated target hazard quotient (THQ) of metals from local tube well water above 1 was observed for As (36.5) and Cd (6.2), which employed highly potential health risk to local residents. The suitability of water for irrigation is evaluated based on residual sodium carbonate (RSC), sodium adsorption ratio (SAR), Kelly’s index (KI), Sodium percent (%Na) and Magnesium absorption ratio (MAR). Dominant ions in the study area are HCO3−, Ca2+ and Mg2+ and water chemistry of the area is Ca2+-Mg2+-HCO3− type. However, different statistical tools, including principal component analysis (PCA), hierarchical cluster analysis (CA) and correlation matrices revealed the contribution of both natural as well as anthropogenic activities towards the high level of arsenic and heavy metals contamination in the local tube well water. The results show that consumption of heavy metals contaminated groundwater poses an emerging health threat to the populations in the study area, and hence needs urgent remedial and management measures. Continued monitoring of heavy metals levels is recommended for future management strategies.

In the present study, the tube well water quality and the associated health risks, emphasizing on arsenic contamination, were investigated in rural and urban samples from Tehsil Mailsi located in Punjab, Pakistan. Arsenic concentrations (μg/L) were ranged from 12 to 448.5 and which exceeded the WHO recommended limit (10 μg/L) in all cases. The calculated average daily dose (3.3 × 10−0.4 to 1.2 × 10−0.2 mg/kg day) and hazard quotient (1.1–40) reflected the potential health risk to local population due to tube well water consumption as drinking purpose. Sodium percent (Na%), sodium absorption ratio, residual sodium carbonate, Kelly’s index and magnesium absorption ratio were also determined to assess the suitability of tube well water for irrigation purpose. The resulting piper plot revealed the Na–Ca–HCO3 type water chemistry of the area and generally alkaline environment. The spatial distribution of arsenic in the tube well waters pinpoints the significant contribution of anthropogenic activities to arsenic pollution. Nevertheless, different statistical tools, including principal component analysis, hierarchical cluster analysis and correlation matrices, revealed the contribution of both natural and anthropogenic activities and alkaline type of aquifers toward the high level of arsenic contamination.

The present study aimed at exploring the sources of salinity and the link it shares with the enrichment of As (arsenic) and F- (fluoride) in the groundwater of Rachna Doab. Total Dissolved Solids (TDS) were used as the measure of salinity to classify samples into three groups: TDS

Present study aimed to provide a baseline data on arsenic (As) and other potentially toxic element (PTEs; Cd, Cr, Cu, Ni, and Pb) contamination in groundwater and soils (surface and sub-surface) from an industrial area of district Gujrat, Pakistan. Statistical parameters, principal component analysis-multiple linear regression (PCA-MLR), and health risk assessment model were used to elaborate the interrelations, source contributor, and associated health risks. This study revealed that the concentrations of Cd, Cr, Cu, and Pb in drinking water were within the permissible limits of the World Health Organization (WHO). However, As and Ni concentrations exceeded the WHO limits of 10 μg/L for As and 0.07 mg/L for Ni. In soils, the concentration of Cr was within permissible limits, whereas As, Cd, Cu, Ni, and Pb exceeded the prescribed values. Solid waste and industrial effluents from the area also contained high levels of As, Cd, Cr, Cu, Ni, and Pb. Calculated health index of As and other PTEs for industrial site and control area was less than 1 which indicated that the groundwater was assumed to be safe for drinking. High contamination of As (15 mg/kg) and other PTEs (Pb was 978, Cr 51, Cu 111, Cd 68, and Ni was 90 mg/kg, respectively) in upper soil could be due to the discharge of industrial effluent prior to the treatment, which signifies the industrial contribution towards As and heavy metal contamination. It can be concluded that critical examination of soil profile affinity to the respective, industrial waste pollutants can reduce the health risks to the local community. This trend not only reveals the geochemistry of the area but also useful for developing a link to access health risk and associated remediation processes.

Most of the rural population of 90 million in Punjab province in Pakistan and Punjab state in India drinks, and cooks with, untreated water drawn from shallow wells. Limited laboratory testing has shown that groundwater in the region can contain toxic levels of arsenic. To refine this assessment, a total of 30,567 wells from 383 villages were tested with a field kit in northern Punjab province of Pakistan and western Punjab state of India. A subset of 431 samples also tested in the laboratory show that 85% of wells were correctly classified by the kit relative to the World Health Organization guideline of 10 μg/L for arsenic in drinking water. The kit data show that 23% of the tested wells did not meet the WHO guideline for arsenic but also that 87% of households with a well high in arsenic live within 100 m of a well that meets the WHO guideline. The implication is that many households could rapidly lower their exposure if the subset of safe wells could be shared. In a follow-up conducted one year later in five villages where 59% of wells were elevated in arsenic, two-thirds of households indicated that they had switched to a neighboring well in response to the testing. The blanket testing of millions of wells for arsenic in the region should therefore be prioritized over much costlier water treatment and piped water supply projects that will take much longer to have a comparable impact.

Stable isotopes ratios (‰) of Hydrogen (δ2H) and Oxygen (δ1⁸O) were used to trace the groundwater recharge mechanism and geochemistry of arsenic (As) contamination in groundwater from four selected sites (Larkana, Naudero, Ghari Khuda Buksh and Dokri) of Larkana district. The stable isotope values of δ2H and δ1⁸O range from 70.78‰ to −56.01‰ and from −10.92‰ to −7.35‰, relative to Vienna Standard for Mean Ocean Water (VSMOW) respectively, in all groundwater samples, thus indicating the recharge source of groundwater from high-salinity older water. The concentrations of As in all groundwater samples were ranged from 2 μg/L to 318 μg/L, with 67% of samples exhibited As levels exceeding than that of World Health Organization (WHO) permissible limit 10 μg/L and 42% of samples expressed the As level exceeding than that of the National Environmental Quality Standard (NEQS) 50 μg/L. The leaching and vertical mixing with return irrigation water are probably the main processes controlling the enrichment of As in groundwater of Larkana, Naudero, Ghari Khuda Buksh and Dokri. The weathering of minerals mostly controlled the overall groundwater chemistry; rock-water interactions and silicate weathering generated yielded solutions that were saturated in calcite and dolomite in two areas while halite dissolution is prominent with high As area.

The study was done to assess the effect of the river Sutlej on arsenic (As) contamination. Sampling was done from the alluvial plain with increasing distance from the river Sutlej in district Vehari and compared with the study done in the proximity of River Sutlej. Sixty (60) groundwater samples mostly from shallow depths were collected and analyzed for As concentrations. Multivariate statistical tools (PCA and CA), saturation index, piper plots and Gibbs diagrams were used to detect evidence about the interrelationship and sources of As and other water quality variables responsible for groundwater contamination. Results revealed that As concentration ranged from below detection limit to 156 µg/L indicating that 50% samples exceeding the WHO guidelines (10 µg/L) and 17% exceeding the Pakistan National Environmental Quality Standards (NEQS) limits (50 µg/L) Sutlej. The piper plot revealed that water chemistry of the study area was Ca–HCO3−, Ca–Mg–Cl, type. Correlations between As and HCO3− (r2 = 0.433) was positive, while negative correlations were observed between As–Mn2+ and As–Fe2+ (r2 = − 0.102), (r2 = 0.107) respectively. Geochemical signatures of the groundwater in the study area showed that the As could be released by oxidative dissolution to some extent and elevated evaporation in the arid environment of the study area under the stimulus of alkaline water and high pH (range 7.1–8.4). Although the concentrations are exceeding the WHO limit in 50% of the water samples but, are less than the previous study done in Mailsi near River Sutlej. Further, the concentrations decreased as the distance from the River increased which shows the probable role of sediments deposited by the River Sutlej.

Biosorption efficiency of natural orange peel (NOP) and charred orange peel (COP) was examined for the immobilization of arsenate (As(V)) in aqueous environments using batch sorption experiments. Sorption experiments were carried out as a function of pH, time, initial As(V) concentration and biosorbent dose, using NOP and COP (pretreated with sulfuric acid). Arsenate sorption was found to be maximum at pH 6.5, with higher As(V) removal percentage (98%) by COP than NOP (68%) at 4 g L−1 optimum biosorbent dose. Sorption isotherm data exhibited a higher As(V) sorption (60.9 mg g−1) for COP than NOP (32.7 mg g−1). Langmuir model provided the best fit to describe As(V) sorption. Fourier transform infrared spectroscopy and scanning electron microscopy combined with energy dispersive X-ray spectroscopy analyses revealed that the –OH, –COOH, and –N-H surface functional groups were involved in As(V) biosorption and the meso- to micro-porous structure of COP sequestered significantly (2-times) higher As(V) than NOP, respectively. Arsenate desorption from COP was found to be lower (10%) than NOP (26%) up to the third regeneration cycle. The results highlight that this method has a great potential to produce unique ‘charred’ materials from the widely available biowastes, with enhanced As(V) sorption properties.