Evaluating health risks from the release of trace elements to groundwater by rock-water interaction in a weathered gneissic aquifer.

High concentration of trace elements in groundwater poses more health risks to humans by drinking groundwater and dermal contact. This work aimed to assess the trace element concentration in groundwater, water quality for drinking purposes, and its effect on human health upon prolonged consumption. The study was carried out in the gneissic terrain of Perambalur District, Tamil Nadu, India, where groundwater is used mainly for drinking, agricultural, and domestic purposes.

Fuzzy logic-based health risk assessment of fluoride in groundwater used as drinking source in Sira region, Tumkur, India.

Fluoride contamination in drinking water is a serious public health concern across the world, and more than 90 million people in India are affected by health risks associated with fluoride. Though the fatality due to fluoride chronic toxicity is uncommon, the exposure to fluoride at different concentration levels shows various adverse health effects such as dental and skeletal fluorosis, multiorgan failure, cognitive and behavioural effects. Hence, the objectives of the present study are to understand the hydrogeochemistry and drinking water suitability of groundwater of the Sira region, Karnataka, India, and to understand the occurrence of fluoride and its health risks using the United State Environmental Protection Agency (US EPA) method and fuzzy logic concepts.

Impacts of regional climate model projected rainfall, sea level rise, and urbanization on a coastal aquifer.

The objective of this study is to assess the impact of climate change induced rainfall, sea level rise, and urbanization on a fragile coastal aquifer. This study was carried out in one such an aquifer located in Southeast India. Downscaled climate projection was carried out using the regional climate model (RCM) with seven ensembles and the best matching ensemble for the study area has been taken to quantify the rainfall in future.

Seasonal changes in dissolved trace elements and human health risk in the upper and middle reaches of the Bhavani River, southern India.

The surface water is a significant feature in the hydrological system and is a vital compound for life growth. Assessment of trace elements in the water bodies is essential since it poses huge threats to aquatic organisms and humans if present in high concentrations. This study was carried out to assess the seasonal changes in the dissolved trace elements concentration in Bhavani river, which is one of the major rivers of Tamil Nadu, southern India and also to assess the human health risk due to its consumption.

Finite element modelling to assess the submarine groundwater discharge in an over exploited multilayered coastal aquifer.

A three-dimensional variable-density finite element model was developed to quantify the impact of groundwater over use on submarine groundwater discharge (SGD). The model was applied to the Arani-Korttalaiyar river basin, north of Chennai, India. This region has an upper unconfined and lower semi-confined aquifer extending up to 30 km inland from the coast and beyond this distance; the two aquifers merge and become a single unconfined aquifer.

Atmospheric CO consumption by rock weathering over a five year period in a large non-perennial tropical river basin of southern India.

Rivers engage in carbon cycle by transporting the dissolved products of weathering of rocks to the oceans, and this process is sensitive to the global climatic changes. The present study was carried out with an objective of estimating the spatial and temporal variation in carbon consumption due to rock weathering in Cauvery, which is a major non-perennial tropical river in the peninsular India. The samples of all the rock types of this river basin were collected and subjected to mineralogical analysis.

Long-term exposure to chromium contaminated waters and the associated human health risk in a highly contaminated industrialised region.

Disposal of industrial waste is of great concern because it releases toxic metals resulting into the degradation of environments and consequently causes health effects on humans. The present study was carried out with the objectives of identifying the possible source and migration of contaminants in the surface water and groundwater and the associated health risks in the industrial region of Ranipet, Tamil Nadu, India. A total of 22 water samples were collected and analysed for the concentration of major ions and trace elements.

Determination of distribution coefficient of uranium from physical and chemical properties of soil.

Uranium is a long lived radioactive element which is naturally present in minute concentrations in igneous, sedimentary and metamorphic rocks. These rocks when subjected to weathering results in the formation of soil which also has traces of uranium. Distribution coefficient (K) is a crucial parameter in environmental assessment which is used to predict the interaction and transport of uranium in groundwater.

Organic micropollutants in groundwater of India-A review.

Groundwater pollution due to organic micropollutants is a major cause of concern, especially in parts of the world where available water resources are on the decline. India is the largest user of groundwater where the presence of micropollutants in the subsurface environment has been the focus of many researchers. The objective of this study was to provide a detailed review of studies on micropollutants in Indian groundwater and to provide strategies for further work.

Seawater intrusion and submarine groundwater discharge along the Indian coast.

Intrusion of seawater into the coastal aquifers is a major concern as it affects the quality of groundwater. The objective of this study is to delineate the extent of seawater intrusion in the Indian coast based on previous studies and estimate the area as well as locations of seawater intrusion and submarine groundwater discharge based on the groundwater level of the years 2007 and 2017. Several researchers have reported seawater intrusion in the coastal regions of India by different methods of investigation.

Chromium and fluoride contamination in groundwater around leather tanning industries in southern India: Implications from stable isotopic ratio δCr/δCr, geochemical and geostatistical modelling.

This study investigates the contamination of groundwater by chromium and fluoride around leather tanning industries. Major ions, chromium, δCr/δCr and fluoride were analyzed by advanced analytical methods. High degree of variation was observed in the concentration of chloride in groundwater, which ranged between 205 and 3310 mg/L, around 56% of the samples were recorded above the acceptable limit indicating the quality of groundwater is fresh to saline and it could be due to mixing of tannery effluents with freshwater aquifers.

Impact of sea level rise and tidal effects on flux-controlled and partially isolated shallow aquifer on the southeast coast of India.

A rise in sea level is the most important threat to the coastal aquifers in which the intensity of threat also depends on the local hydrogeological settings. The present study seeks to identify the impacts of sea level rise and tidal effects on the shallow and complex aquifer located south of Chennai, India. The aquifer geometry is isolated dune surfaces due to the presence of enclosing saline surface water.

FIMAR: A new Fluoride Index to mitigate geogenic contamination by Managed Aquifer Recharge.

The objective of this study is to develop a Fluoride Index for mitigation of geogenic contamination by Managed Aquifer Recharge (FIMAR). This index was tested by applying to the Pambar river basin in southern India. About 40% of the study area had fluoride >1.

Hydrogeochemical processes and influence of seawater intrusion in coastal aquifers south of Chennai, Tamil Nadu, India.

Seawater intrusion promotes the salinity of groundwater, and it poses a great environmental impact on a global scale. The present study was carried out to determine the hydrogeochemical processes and influence of seawater intrusion in the coastal aquifers using geophysical, geochemical, and stable isotope techniques. The true resistivity value ranges from 0.

Chemical, microbial and antibiotic susceptibility analyses of groundwater after a major flood event in Chennai.

During floods, human exposure to pathogens through contaminated water leads to the outbreak of epidemic diseases. This research presents the first extensive assessment of surface and groundwater samples collected immediately after a flood (December 2015) and post-flood (April 2016) from the Adyar River of Chennai, a major city in India, for major ions, trace metals, bacterial population, and pathogens. Severe rains in a short period of time resulted in flooding which inundated the wells, allowing the entry of sewage contaminated river water into the groundwater zone.

Trace element concentrations in the groundwater of the Tamiraparani river basin, South India: Insights from human health risk and multivariate statistical techniques.

This study investigates the concentration of trace elements in the groundwater of Tamiraparani river basin, South India. 124 groundwater samples were collected representing diverse landuse condition over the study area. The results reveal that the mean concentrations of Fe, Mn, Cu, Cr, Pb, Zn and Ni were 0.

Regional and temporal variation in minor ions in groundwater of a part of a large river delta, southern India.

Impact of agricultural activities on groundwater can be determined from the concentration of nutrients present in groundwater. This study was carried out with the aim to assess the minor ions content of groundwater and to identify its sources, spatial, and seasonal variations in a part of the Cauvery River basin, southern India. Groundwater samples were collected from July 2007 to September 2009 and were analyzed for minor ions.

Managed aquifer recharge by a check dam to improve the quality of fluoride-rich groundwater: a case study from southern India.

In many regions around the globe, including India, degradation in the quality of groundwater is of great concern. The objective of this investigation is to determine the effect of recharge from a check dam on quality of groundwater in a region of Krishnagiri District of Tamil Nadu State, India. For this study, water samples from 15 wells were periodically obtained and analysed for major ions and fluoride concentrations.

Hydrogeochemical processes and impact of tanning industries on groundwater quality in Ambur, Vellore district, Tamil Nadu, India.

The present study was carried out to determine the hydrogeochemical processes and the impact of tanning industries on groundwater in Ambur, Vellore district, Tamil Nadu, India. Thirty groundwater samples were collected during pre monsoon (July 2015) and post monsoon (January 2016) from the open and shallow wells around this region and were analyzed for major ions and chromium. The major ion concentration follows the order of Na > Ca > Mg > K (cations) and Cl > HCO > SO > NO (anions) for both seasons.

Fluoride in weathered rock aquifers of southern India: Managed Aquifer Recharge for mitigation.

Climatic condition, geology, and geochemical processes in an area play a major role on groundwater quality. Impact of these on the fluoride content of groundwater was studied in three regions-part of Nalgonda district in Telangana, Pambar River basin, and Vaniyar River basin in Tamil Nadu, southern India, which experience semi-arid climate and are predominantly made of Precambrian rocks. High concentration of fluoride in groundwater above 4 mg/l was recorded.

Characterization of mechanisms and processes of groundwater salinization in irrigated coastal area using statistics, GIS, and hydrogeochemical investigations.

Coastal aquifers are at threat of salinization in most parts of the world. This study was carried out in coastal shallow aquifers of Aousja-Ghar El Melh and Kalâat el Andalous, northeastern of Tunisia with an objective to identify sources and processes of groundwater salinization. Groundwater samples were collected from 42 shallow dug wells during July and September 2007.

Assessment of Surface Water Quality Using Multivariate Statistical Techniques in a Part of River Cauvery, Tamil Nadu, India.

The study explains water quality of the Cauvery River in the southern region of Peninsular India. Thirteen parameters including trace elements (Cd, As, Cu, Cr, Zn and Pb) have been monitored on 50 sampling points from a hydro-geochemical survey, conducted in the river stretch under study. Several water quality parameters showed considerable changes due to increased runoff from the catchments and other seasonal factors.

Computation of groundwater resources and recharge in Chithar River Basin, South India.

Groundwater recharge and available groundwater resources in Chithar River basin, Tamil Nadu, India spread over an area of 1,722 km(2) have been estimated by considering various hydrological, geological, and hydrogeological parameters, such as rainfall infiltration, drainage, geomorphic units, land use, rock types, depth of weathered and fractured zones, nature of soil, water level fluctuation, saturated thickness of aquifer, and groundwater abstraction. The digital ground elevation models indicate that the regional slope of the basin is towards east. The Proterozoic (Post-Archaean) basement of the study area consists of quartzite, calc-granulite, crystalline limestone, charnockite, and biotite gneiss with or without garnet.

Nitrate pollution in groundwater in some rural areas of Nalgonda district, Andhra Pradesh, India.

Intake of water with high concentration of nitrate is a major problem in many countries as it affects health of humans. The present study was carried out with the objective of determining the causes for higher nitrate concentration in groundwater in parts of Nalgonda district, Andhra Pradesh, India. The study area is located at a distance of about 135 km towards ESE direction from Hyderabad.

Groundwater quality and its suitability for domestic and agricultural use in Tondiar river basin, Tamil Nadu, India.

Assessment of suitability of groundwater for domestic and agricultural purposes was carried out in Tondiar river basin, Tamil Nadu, India. The study area covers an area of 315 km(2) and lies in a semiarid region. Groundwater is the major source for domestic and agricultural activity in this area.