Evaluation of fresh and stored rainwater quality in fluoride and arsenic endemic area of Thar Desert, Pakistan

Determination of toxic elemental levels in whey milk of different cattle and human using an innovative digestion method: risk assessment for children < 6.0 months to 5 years

In present study, the toxic elements, arsenic (As), cadmium (Cd), and lead (Pb), were determined in whey milk samples obtained from various cattle (cow, goat, buffalo, sheep, camel) and human subjects of different areas of Sindh, Pakistan, based on consuming drinking water (exposed area) and surface water (control/non-exposed area). The whey milk was separated from casein by lowering the pH, and heating in an ultrasonic bath at 60 °C for 5 min and centrifuged. The whey milk samples were treated with deep eutectic solvent, prepared from choline chloride-oxalic acid (ChCl-Ox) at different mole ratio. Effects of different parameters on digestion efficiency of whey milk samples, including time and temperature of electric hot plate, mole ratio, and volumes of deep eutectic solvent were examined. The total levels of all selected toxic elements were also detected in whole milk samples of all exposed and nonexposed cattle and human, after acid digestion method. The validity of the proposed method was established by a conventional acid digestion method of selected whey milk samples and spiked certified standards in replicate real whey milk samples. The resulted elements obtained after proposed and conventional heating system were determined by inductively coupled plasma-optical emission spectrometry. The % of all three toxic elements found in whey milk samples were 24 to 50% of their total content in milk samples of different cattle and human. The As, Cd, and Pb contents in cattle and human milk consumed contaminated groundwater was significantly higher (2- to 3-fold) than those values observed for milk samples of cattle, who receive drinking water from fresh canal water (p < 0.01). Estimating the daily intake, hazard quotient and carcinogenic risk for <6 month to 5 years old children, based on the concentrations of toxic elements in milk samples of different cattle and human..

Hydrogeochemistry and groundwater quality assessment in Ambagarh Chowki, Chhattisgarh, India

The current study was focused on hydrogeochemistry of Ambagarh chowki groundwater. The main aim of the study was to evaluate the water quality for drinking and irrigation uses, hydrogeochemistry of groundwater. For this purpose, various physicochemical parameters like pH, electrical conductivity (EC), total hardness (TH), chloride (Cl^-), fluoride (F^-), calcium (Ca²⁺), magnesium (Mg²⁺), sodium (Na⁺), potassium (K⁺), bicarbonate (HCO₃^-), and sulfate (SO₄^2-) were analyzed. The major dominating ions in groundwater was found as cation Ca²⁺  > Mg²⁺  > Na⁺  > K⁺ and as anions in order of HCO₃^-  > Cl^-  > SO₄^2-  > F^-. The pH of sampled groundwater was ranged from neutral to alkaline in nature (7.0-8.8). Among, all-analyzed parameters in groundwater were safe for drinking purpose except few ions and bicarbonate content was also exceeding the permissible limit which was not suitable for drinking purpose. The potential health hazard element fluoride was varied from 0.1 to 2.2 mg/l and positively associated with the pH, Na⁺, and HCO₃^- content in groundwater. The drinking water quality index (WQI) was fluctuated between 12.22 and 185.56 and reported that most of the groundwater was suitable for drinking purpose except only one sample was unsuitable for drinking. Irrigation water quality assessment of the area was performed by evaluating as sodium adsorption ratio (SAR), permeability index (PI), Kelly ratio (KR), magnesium hazard ratio (MHR), percent sodium (%Na), potential salinity (PS), and residual sodium carbonate (RSC). Whereas most of the groundwater were good and suitable for irrigation use excluding PI (3.70%), MHR (40.74%), RSC (22.22%) and PS (7.41%) were unsuitable for continuous irrigation. Hydrogeochemistry of groundwater evaluated with correlation, Piper, Gibbs, and other geochemical analysis. The Piper trilinear diagram reflects the Ca (Mg)-HCO₃^- type water was mainly contributed approximately 90% of entire sampled groundwater. The different ions in groundwater were originated from the rock water interaction through silicate and carbonate weathering of minerals.

Bioaccumulation of arsenic and fluoride in vegetables from growing media: health risk assessment among different age groups

The current study was conducted to evaluate the arsenic (As) and fluoride (F^-) concentrations in growing media (stored rainwater and soil), of district Tharparkar, Pakistan. The bioaccumulation/transportation of As and F from growing media to different types of vegetables (wild cucumis, Indian squish and cluster bean) was evaluated. Total concentrations of As and F^- in stored rainwater samples were observed up to 585 μg/L and 32.4 mg/L, respectively, exceeding many folds higher than WHO provisional guideline values. The As and F^- contents in soil samples of nine agricultural sites were found in the range of 121-254 mg/kg and 115-478 mg/kg, respectively. The highest contents of As and F^- were observed in wild cucumis as compared to Indian squish and cluster bean (p < 0.05), grown in the same agricultural field. The bioaccumulation factors of As and F^- were to be > 4.00, indicating the high rate of transportation of As and F^- from growing media to vegetables. A significant positive correlation of As and F^- in vegetables with their concentrations in soil and water was observed (r > 0.60 with p < 0.05). The risk assessment elucidated that the population of different age group consuming local vegetables and drinking water contaminated with As and F^- may have adverse health effects.

Coordination degree of the exploitation of water resources and its spatial differences in China

Coordinated relationships between socioeconomic development and water utilization, as well as environmental protection measures, are crucial for achieving sustainable water resource exploitation (WRE) under changing environmental conditions. Moreover, a balanced condition of regional WRE is essential to guaranteeing the water security of the entire nation. In this study, an evaluation model of the coordination degree (CD) of WRE is built based on 10 selected indicators and is then applied to 31 provincial zones in China during the period 2004-2014. The cluster analysis method is introduced to classify the relative rank (RK) of the CD at the provincial scale in the pre- (2004-2010) and post- (2011-2014) phases; these phases are divided by the first year of the implementation of the "Three Red Lines Policy" in China (2011), and the spatial differences of the CD of the entire nation were decomposed. The results showed the following. 1) The CD of WRE increases significantly in 26 provincial zones after the implementation of the "Three Red Lines Policy", and the average CD of WRE for 28 provincial zones during the post-phase was greater than that during the pre-phase. 2) Provincial zones with the RK of coordinated development model (CDM) are mainly located in southern and southwestern China. Provincial zones with the RK of the uncoordinated development model (UDM) were mainly found in northern inland China. Eight provincial zones with dense populations and intensive water use, but with only scarce per capita water resources, have the RK of the severely uncoordinated development model (SUDM). 3) The spatial differences in CD diminished in the post-phase, and the differences in CD at the inter-regional scale accounted for a predominant proportion of the difference in CD at the national scale. In addition to improving the coordination status of WRE, the implementation of the "Three Red Lines Policy" also decreased the disparity among the CD of WRE, and this policy continued to be effectively implemented and followed to make a lasting difference. Cross-regional cooperation and coordinated relationships between socioeconomic development and water resource protection are needed to achieve a more coordinated and balanced WRE for long-term development. The results of this study have scientific and practical implications for sustainable WRE and water security in rapidly developing countries such as China.

Effects of high fluoride content in livestock drinking water on milk samples of different cattle in endemic area of Pakistan: risk assessment for children

Fluoride in trace quantity is beneficial for human beings, serving to strengthen the apatite matrix of skeletal tissues and teeth, whereas high intake causes adverse impacts. In the present study, the effect of fluoride-contaminated drinking water of livestock on the milk samples of different cattle, belonging to a fluoride-endemic area (Tharparkar, Pakistan), was studied. In milk samples of different cattle (cows, camels, sheep, and goats), free and bound fluoride forms and its total (free (F^-) + bound (F^-)) contents were measured by ion-selective electrode. The concentration of fluoride in drinking water of livestock was also analyzed, as found in the range of 11.8-33.5 mg/L. The concentration of total fluoride in the milk samples of sheep, goats, cows, and camels were observed in the range of 1.72-2.43, 1.40-2.03, 0.835-1.41, and 0.425-0.897 mg/L, respectively. The resulted data indicated that the concentration of fluoride was higher in the milk samples of smaller cattle (sheep and goat), as compared to cow and camel. The fluoride in milk samples of all cattle appeared dominantly in free form. The percentage values of bound fluoride in the milk samples of sheep, goats, and cows were found to be 6.76, 11.6, and 19.7% in total, respectively, while in camel milk, the percentage was below the detection limit. The estimated daily intake of fluoride contents on consuming different types of milk by children age ranged 1.0 to 3.0 years was evaluated. Graphical abstract ᅟ.

The effects of arsenic contaminated drinking water of livestock on its total levels in milk samples of different cattle: Risk assessment in children

This work was carried out to evaluate the arsenic (As) levels in milk samples of different milch animals, sheep, goats, cows, buffaloes and camels in Tharparkar, Pakistan. The concentration of As in the milk samples of cows, buffalos, sheep, goats and camels were observed in the range of 15.1-18.4, 2.6-7.7, 25.7-33.2, 10.5-37.3 and 6.6-13.7 μg/L, respectively. The levels of As in livestock drinking water of each farms/flocks was found in the range of 238-2000 μg L^-1. A positive correlation with Pearson correlation coefficients, ranged as, 0.926-0.974 (p = 0.001-0.011) was observed between the As concentration in milk samples of cattle and in corresponding drinking water of farms/flocks. The high bio-transfer factor of As was occurred in the milk samples of sheep. The content of As in scalp hair of children was observed to be elevated, who consumed milk of lower cattle (sheep and goat) than cow and camel. The As content in scalp hair directly proportional to the age of children. The hazardous quotient value of As due to consumption of milk was observed in decreasing order as, sheep > goats > camels > cows. The total hazardous quotient or noncarcinogenic risk values for children consuming the milk of sheep, goat, cow and camels were found >1 of reference dose for As, creates adverse effects on health in childhood stage. The children of all three age group have higher carcinogenic risk factor who are consuming milk of goat and sheep than larger cattle.

Arsenic Exposure in Children through Drinking Water in Different Districts of Sindh, Pakistan

A cross sectional study has been conducted during 2007-2010 for the assessment of arsenic (As) contamination in drinking water, and its impact on the health of local public belongs to five districts of Sindh, Pakistan. The toxic risk assessment of As in different areas of Sindh province based upon its concentration in drinking water and scalp hair of boys and girls of age group 5-10 and 11-15 years. The total and inorganic As species in drinking water samples of four districts Hyderabad, Sukkur, Naushehro Firoze, Nawab shah, and Dadu were determined by advance pre-concentration methodologies. The resulting data indicated that the dominant inorganic As species in municipal treated (Hyaderabad) and hand pumps (Sukkur, Naushehro Firoze, Nawab shah and Dadu) water samples were arsenate (As(V)) and arsenite (As(III)), respectively. The total As concentrations in hand pumps water samples of Dadu district were 6.0- to 35-fold higher than the World Health Organization permissible limit of (10 μg/L) for drinking water. Whereas, total As in hand pump water samples of Sukkur, Naushehro Firoze, and Nawab shah were found in the range of 26.0-98.2, 18.0-50.6, and 52.3-85.2 μg/L, respectively. However, municipal treated water samples of Hyderabad were within recommended level (As <10 μg/L). The content of total As in children of both genders and age group belonging to Sukkur, Naushehro Firoze, Nawab shah, and Dadu was found to be significantly high as compared to those children residing in Hyderabad district. The Pearson coefficient of correlation r values between As levels in hand pump water and scalp hair samples of children belonging to Sukkur, Naushehro Firoze, Nawab shah, and Dadu were observed in the range of 0.65-0.75, 0.75-0.82, 0.80-0.90, and 0.95-0.98, respectively. The results of As toxicity risk assessment based on hazard quotient indicated that Dadu district has high carcinogenic exposure risk for children. Moreover, it is concluded that the children consuming groundwater of Sukkur, Naushehro Firoze, Nawab shah, and Dadu districts of Sindh, Pakistan were at risk of chronic As toxicity in future.

Simultaneously removal of inorganic arsenic species from stored rainwater in arsenic endemic area by leaves of Tecomella undulata: a multivariate study

In the present study, an indigenous biosorbent (leaves of Tecomella undulata) was used for the simultaneous removal of inorganic arsenic species (As(III) and As(V)) from the stored rainwater in Tharparkar, Pakistan. The Plackett-Burman experimental design was used as a multivariate strategy for the evaluation of the effects of six factors/variables on the biosorption of inorganic arsenic species, simultaneously. Central composite design (CCD) was used to found the optimum values of significant factors for the removal of As(III) and As(V). Initial concentrations of both inorganic As species, pH, biosorbent dose, and contact time were selected as independent factors in CCD, while the adsorption capacity (q e) was considered as a response function. The separation of inorganic As species in water samples before and after biosorption was carried out by cloud point and solid-phase extraction methods. Theoretical values of pH, concentration of analytes, biosorbent dose, and contact time were calculated by quadratic equation for 100 % biosorption of both inorganic As species in aqueous media. Experimental data were modeled by Langmuir and Freundlich isotherms. Thermodynamic and kinetic study indicated that the biosorption of As(III) and As(V) was followed by pseudo second order. It was concluded that the indigenous biosorbent material efficiently and simultaneously removed both As species in the range of 70.8 to 98.5 % of total contents in studied ground water samples. Graphical abstract Optimizing the significant varable by central 2(3) + star orthogonal composite design.

Toxic Risk Assessment of Arsenic in Males Through Drinking Water in Tharparkar Region of Sindh, Pakistan

Humans are exposed to arsenic (As) through air, drinking water, and food. The arsenic (As) hazardous quotient was calculated on the basis of its concentration in drinking water of different origin and scalp hair of male subjects (n = 313), residents of different exposed and non-exposed areas of Sindh, Pakistan. The total As was determined in water and scalp hair samples, while As species were determined in water samples by advance extraction methodologies. The total As concentrations in drinking water of less-exposed (LE) and high-exposed (HE) areas was found to be 2.63 to 4.46 and 52 to 235, fold higher than the permissible limit, respectively, than recommended by World Health Organization (2004) for drinking water. While the levels of As in drinking water of non-exposed (NE) areas was within the permissible limit. The resulted data indicated that the dominant species was As(+5) in groundwater samples. The levels of As in scalp hair samples of male subjects of two age groups (18-30 and 31-50 years), belonging to NE, LE, and HE areas, ranged from 0.26 to 0.69, 0.58 to 1.34, and 15.6 to 60.9 μg/g, respectively. A significant correlation between As levels in drinking water and scalp hair was observed in HE area (r = 0.86-0.90, p < 0.001) as compared to those subjects belonging to LE area. A toxicity risk assessment was calculated as hazard quotient (HQ), which indicates that the study subjects of HE area have significantly higher values of HQ than LE. The population of As exposed areas is at high risk of non-carcinogenic and carcinogenesis effects.

Correlation of Arsenic Levels in Smokeless Tobacco Products and Biological Samples of Oral Cancer Patients and Control Consumers

It has been extensively reported that chewing of smokeless tobacco (SLT) can lead to cancers of oral cavity. In present study, the relationship between arsenic (As) exposure via chewing/inhaling different SLT products in oral cancer patients have or/not consumed SLT products was studied. The As in different types of SLT products (gutkha, mainpuri, and snuff) and biological (scalp hair and blood) samples of different types of oral cancer patients and controls were analyzed. Both controls and oral cancer patients have same age group (ranged 30-60 years), socio-economic status, localities, and dietary habits. The concentrations of As in SLT products and biological samples were measured by electrothermal atomic absorption spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked by certified reference materials. The resulted data of present study indicates that the concentration of As was significantly higher in scalp hair and blood samples of oral cancer patients than those of controls (p<0.001). It was also observed that the values of As were two- to threefolds higher in biological samples of controls subjects, consuming SLT products as compared to those have none of these habits (p>0.01). The intake of As via consuming different SLT may have synergistic effects, in addition to other risk factors associated with oral cancer.