Potential toxic element contamination and non-carcinogenic risk assessment of groundwater from rapidly growing urban areas in Telangana, India.

Groundwater is a critical resource for drinking purposes that is under pressure and polluted with multiple inorganic contaminants. Among various contaminants, potentially toxic element contamination in groundwater has significant public health concerns due to their toxicity at a low level of exposure. This investigation aimed to assess the toxic element contamination and associated non-carcinogenic human health risk at rapidly growing urban centers in Telangana to ensure potable water and to generate baseline data in the study province. Thirteen potential toxic trace elements (Al, As, B, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn) were determined in 35 groundwater samples collected from the Karimnagar and Siddipet smart cities in lower Manair River basin using inductively coupled plasma mass spectrometry (ICP-MS). The trace element concentration is found in the range for Al (1-112 µg/L), As (2-8 µg/L), B (34-438 µg/L), Cd (bdl-2 µg/L), Co (bdl-17 µg/L), Cr (bdl-4 µg/L), Cu (bdl-216 µg/L), Fe (4-420 µg/L), Mn (bdl-3311 µg/L), Ni (5-31 µg/L), Pb (bdl-62 µg/L), Se (1-18 µg/L), and Zn (3-1858 µg/L). Analytical data of groundwater revealed the occurrence of toxic elements observed as above the acceptable limits of Bureau of Indian Standards for drinking purposes found in the order of Al > Ni ≥ Mn > Se ≥ Cu ≥ Pb > Fe with 26% > 14% ≥ 14% > 9% ≥ 9% ≥ 9% > 6% of samples, respectively. The non-carcinogenic health risk to humans upon groundwater ingestion has been evaluated and found to be non-hazardous for all the individual elements studied except for aresenic. However, cumulative hazard quotient observed as > 1 in the category of infants and children might be a major potential health concern. This study provided baseline data and suggested implementing preventive measures to protect human health around the urban areas of lower Manair river basin, Telangana, India.

Organochlorine pesticide residues in plants and their possible ecotoxicological and agri food impacts.

Scientific investigations on levels of Organochlorine Pesticide (OCP) residues in plants largely consider the edible parts (crops, vegetables, and fruit plants). Though the non-edible parts of plants are not eaten by human beings directly, these parts are consumed by livestock and other animals, thereby facilitating the flow of chemical residues through the food chain. The objective of the present investigation was to evaluate the concentration of OCP residues in non-edible plant parts to provide insights on their potential ecotoxicological impacts. Eighteen OCP residues were extracted in nine different plant species (banana Musa acuminate, brinjal Solanum melongena, Casuarina equisetifolia, Eucalyptus globulus, lotus Nelumbo nucifera, paddy Oryza sativa, sugarcane Saccharum officinarum, tapioca Manihot esculenta, tomato Lycopersicon esculentum) following QuEChERS method. The concentrations of OCP residues in plant extracts were determined using Gas Chromatography coupled with Mass Spectrometry (GC-MS). The OCP residues, namely: γ-HCH (lindane), heptachlor epoxide isomer, dieldrin, endrin, endrin aldehyde and endrin ketone were found predominantly in seven plant species. Residues of γ-HCH (lindane) were reported in different parts of plant species such as stem (581.14 ng/g in paddy and 585.82 ng/g in tapioca) and leaf (583.3 ng/g in tomato). Seven samples contained residues of heptachlor epoxide isomer (512.53 to 1173.8 ng/g). Dieldrin was found in paddy stem (489.97 ng/g), tapioca stem (490.21 ng/g) and tapioca leaf (490.32 ng/g). The detected OCPs in the present study were 10-50 times higher than the Maximum Residue Limits (MRL, 0.01-0.1 mg/Kg) as prescribed in the Codex Alimentarius of the FAO/WHO. Their elevated concentrations in the plant parts therefore pose risk of contamination to the consumers in the food chain, including human beings those are dependent on the animals as source of protein. The findings of this study are the first report on residue levels of OCPs in non-edible plant parts in the agricultural landscape of Puducherry region, India. Since, this study assumes significance for the strategic location of Oussudu Lake, an interstate lake spread over Puducherry and Tamil Nadu states, regular monitoring of OCP residues in different environmental segments in strategic locations in both the states is suggested, which will help the authorities in devising a comprehensive environmental management plan aiming at the ecosystem at large.

Hydrochemical characteristics and nitrate health risk assessment of groundwater through seasonal variations from an intensive agricultural region of upper Krishna River basin, Telangana, India.

Seasonal variations in hydrogeochemical characteristics of groundwater were assessed from an intensive agricultural region to identify contaminants of concern that are a potential risk to human health. A total of 116 groundwater samples were collected grid-wise from an intensive agricultural region of confined Wanaparthy watershed to evaluate seasonal variations in hydrogeochemical processes of dissolved ions, nitrate health risk assessment and water quality during pre-monsoon (PRM) and post-monsoon (POM) seasons. The major ions concentration found in ascending order as PRM: F- < NO3-< SO42-< HCO3-< Cl- and K+< Mg+2< Ca+2< Na+ while POM: F- < NO3-< SO42-< Cl-< HCO3- and K+< Ca+2< Mg+2< Na+ respectively. Piper diagram for water-types shows PRM; Na-Cl type (70.68%) while POM; Ca-Mg-Cl type (39.66%) and Ca-HCO3 type (31.03%). Gibbs diagram explained the favorable environmental conditions as rock and evaporation dominance in both seasons. Spatial distribution map shows samples with higher and above permissible limits are found at/near to adjoining to higher-order streams and streams origin. As per the water quality index (WQI), 36.21% (PRM) and 60.34% (POM) fall in poor to unfit for drinking class. Hazard quotient (HQ) values of nitrate reach as high as for infants 1.31E + 01, children 1.23E + 01 and adults 4.68E + 00 respectively. Subsequently, HQ>1 with 68.97% of infants and 72.41% of children are in danger for non-carcinogenic ingestion of nitrate contaminated groundwater than in adults.

Export of particulate organic carbon by the mountainous tropical rivers of Western Ghats, India: Variations and controls.

Transport of organic carbon by small mountainous rivers is essential, but the poorly constrained component of the global carbon cycle. In the current research, we sampled and analyzed particulate organic carbon (POC) contents from 70 sizeable tropical coastal rivers, draining the Western Ghats (WG) of India. This study aimed to investigate the spatiotemporal variability in POC contents, to estimate flux and to identify environmental controls on POC sources and transport characteristics across the region. The averaged value of organic carbon (OC) in the particulate samples is 3.24%, and the mean POC concentration is 2.86 mg l-1. We classified the samples based on total suspended matter (TSM) classes for source appropriation. Litter/riparian (42.5%) pools are the largest source of organic matter, followed by autochthonous (36%) and soil (21.5%) for the WG region. However, locally autochthonous sources contribute exceptionally to POC pools, indicating a favorable environmental condition for the growth of algae and phytoplankton. Land-use & land-cover, climate, topography, and sediment erosion seems to be determining the local variability in sources to POC pools and fluxes. The POC export rates suggest that within the region, the POC yields of the Deccan Trap (DT) and the Western Dharwar Craton (WDC) blocks are about two times higher than that of the Southern Granulite Terrain (SGT) region. With POC yield of 7.0 g m-2 yr-1, this region exports 0.79 Tg C (~ 0.5% of the global POC) to the Arabian Sea annually. The POC flux of the WG region (covering 0.25% of Asia's land area) is approximately 1.0% of Asia's riverine POC flux to the ocean.

Data on fluoride concentration profile in groundwater of rural habitats in Mahabubnagar district, Telangana, India.

Fluoride is an undesirable chemical in drinking water that can have dreadful concerns on health. The objective of this study is to establish the concentration profile of fluoride in groundwater used as drinking water in 31 rural habitats in Mahabubnagar district, Telangana State, India. Drinking water samples from bore wells/hand pumps were collected from different locations in the study area and analyzed for fluoride levels using a spectrophotometer. The fluoride levels range from 0.6 to 1.8 mg/L, with an average value of 1.31 mg/L. Overall, 32% of groundwater samples found to be exceeded the prescribed limits of fluoride in the study area, as prescribed by the World Health Organization (WHO). Besides, the optimal amounts of fluoride in drinking water have to meet in the range of 0.5 mg/L and 1.5 mg/L, as this range is the permissible limit for drinking. Fluoride is an essential micronutrient for normal mineralization of teeth and bones as well as for the formation of dental enamel in the human body. This study suggested that prolonged intake of drinking water with fluoride concentrations higher than acceptable limits can trigger dental and skeletal fluorosis in the general community of the study region. The fluoride data compared with the permissible levels recommended for drinking purposes by various regulatory agencies across the world.

Water quality index and GIS-based technique for assessment of groundwater quality in Wanaparthy watershed, Telangana, India.

A comprehensive study of 58 groundwater samples collected in the virgin area of Wanaparthy watershed (1600 km2), Telangana, India, to assess the hydrochemistry, quality, water types and potability using hydrogeochemical characterization, WQI and GIS technique. Major ions concentration of Na+, K+, Ca2+, Mg2+, Cl-, F-, NO3- and SO42- in groundwater were analysed using ion chromatography (IC). Physicochemical values of the potential of hydrogen (pH), total dissolved solids (TDS) and electrical conductivity (EC) were determined using Hanna portable meters, while total hardness (TH), alkalinity and bicarbonates are estimated by titrimetric methods. Results obtained enlighten the major anions and cations, which are found in order of Cl- > HCO3- > SO42- > NO3- > F- and Na+ > Ca+2 > Mg+2 > K+ respectively. Among various ions measured, fluoride (18.97%), chloride (3.44%), nitrate (8.62%), sulphate (5.17%), sodium (34.48%) and calcium (1.72%) were found to above acceptable limit values of Bureau of Indian Standards (BIS) for drinking purposes. According to Piper trilinear diagram, two dominant hydrochemical facies, Na-Cl-SO4 and Ca-Na-HCO3 types, were identified. Gibbs diagram imparted the dominancy of samples in the territory are rock-water reaction and evaporation dominance. WQI shows 67.79% of samples pertain to the excellent to good water types reveal fit for drinking. Drainage pattern enumerated the concentration of the parameters measured are exceeding towards the downstream region, which might be due to the chemical reaction of rock-water interaction (infiltration and recharge). As the groundwater is the major source of drinking in the study area, a proper management plan has to implement before its quality deteriorated.

Chitosan film loaded with silver nanoparticles-sorbent for solid phase extraction of Al(III), Cd(II), Cu(II), Co(II), Fe(III), Ni(II), Pb(II) and Zn(II).

The present study describes the ecofriendly method for the preparation of chitosan film loaded with silver nanoparticles (CS-AgNPs) and application of this film as efficient sorbent for separation and enrichment of Al(III), Cd(II), Cu(II), Co(II), Fe(III), Ni(II), Pb(II) and Zn(II). The stable CS-AgNPs colloid was prepared by dispersing the AgNPs sol in chitosan solution at appropriate ratio and further used to obtain a cast film with very good stability under storage and good mechanical strength for easy handling in aqueous medium. The incorporation of AgNPs in the structure of CS film and interaction between the polymer matrix and nanoparticles were confirmed by UV-vis and FTIR spectroscopy. The homogeneously embedded AgNPs (average diameter 29nm, TEM analysis) were clearly observed throughout the film by SEM. The CS-AgNPs nanocomposite film shows high sorption activity toward trace metals under optimized chemical conditions. The results suggest that the CS-AgNPs nanocomposite film can be feasibly used as a novel sorbent material for solid-phase extraction of metal pollutants from surface waters.

A rapid spectrophotometric determination of persulfate anion in ISCO.

Due to a gradual increase in the use of persulfate as an in situ chemical oxidation (ISCO) oxidant, a simple measurement of persulfate concentration is desirable to analyze persulfate distribution at designated time intervals on/off a site. Such a distribution helps evaluate efficacy of ISCO treatment at a site. This work proposes a spectrophotometric determination of persulfate based on modification of the iodometric titration method. The analysis of absorption spectra of a yellow color solution resulting from the reaction of persulfate and iodide in the presence of sodium bicarbonate reveals an absorbance at 352 nm, without significant interferences from the reagent matrix. The calibration graph was linear in the range of persulfate solution concentration of 0-70 mM at 352 nm. The proposed method is validated by the iodometric titration method. The solution pH was at near neutral and the presence of iron activator does not interfere with the absorption measurement. Also, analysis of persulfate in a groundwater sample using the proposed method indicates a good agreement with measurements by the titration method. This proposed spectrophotometric quantification of persulfate provides a simple and rapid method for evaluation of ISCO effectiveness at a remediation site.