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The unplanned Bhalswa landfill is located in one of the most urbanized area of Delhi, and its influence on the huge population are inevitable in the capital city of India lying in flood plain of the Yamuna River, and its alluvial lithology makes it more susceptible to contamination by leaching of pollutants. The present study highlights to assess the impact of non-engineered Bhalswa landfill site on the groundwater quality and associated potential health risk by its consumption to local residents of New Delhi, by collecting four leachate and sixty groundwater samples for pre- and post-monsoon seasons in the year 2013. The contamination potential of the leachate samples and the groundwater quality were evaluated with the help of leachate pollution index (LPI) and water quality index (WQI), respectively. The value of LPI is high in both the seasons but more in pre-monsoon (31.51) as compared to post-monsoon (29.36). The Obtained results of groundwater samples showed elevated level of Electrical conductivity (EC), major cations and anions. The EC of groundwater samples display concentration as follows: (pre-monsoon, 456–10870, average 3772; post-monsoon, 465–10450, average 3747). The groundwater samples close to the Bhalswa landfill shows very high value of EC and other chemical parameters. WQI calculated (using 17 physico-chemical parameters and WHO standards) to distinguish the areas of excellent and unsuitable for drinking purposes which will be helpful for the management of water resources. Our results showed that the concentration of majority of heavy metals exceed the WHO permissible limit except Cr and Cu which may be due to redox conditions that control the mobility of these ions in aqueous solutions. The average target hazard quotient (THQ) value of heavy metals were found in the order of Cd > Mn > Pb > Cu > Ni > Fe > Zn > Cr in both the seasons. The tube wells with more than one THQ value for Cd (100%), Mn (63%) and Pb (37%) will have potential human health risks. Hazard index (HI) shows greater than one value for all the samples and the average HI values are 10.241 for pre- and 10.402 for post-monsoon season. THQ and HI values suggest that the residents are highly susceptible to ingestion pathway. A conceptual model is used to describe the dispersal of leachate pollutants with reference to various kinds of geo-environmental features which degrades the groundwater quality. The health risk associated with metals in near future can be a serious threat for this region if this groundwater is being used for long run without proper remedial measures. [ABSTRACT FROM AUTHOR]

Fluorosis is becoming a global environmental toxicological problem and is most commonly found in water-stressed regions. In order to evaluate the geochemical mechanism of fluoride enrichment in groundwater and health implications in the Padwakodari environs of eastern part of India, a total of twenty two samples were collected and analysed for physico-chemical parameters spreading across the study area. Geologically, the area mainly comprises of phyllites, granite gneiss, mica schist and sandstone. High fluoride concentrations found mainly in the granite gneisses which are situated central to northwestern parts of the study area. The concentration of fluoride in the groundwater samples ranges from 0.3 to 11 mg/l with an average of 2 mg/l. 64% of the groundwater samples containing fluoride concentration that exceed the WHO drinking water guidelines value of 1.5 mg/l. Chronic ingestion of high doses has been linked to the development of dental fluorosis, and in extreme cases, skeletal fluorosis. The dominant geochemical facies present in water are Na–Ca–Mg–HCO 3 (11 samples), Na–Mg–Ca–HCO 3 (5 samples), Ca–Na–Mg–HCO 3 (5 samples) and Ca–Mg–Na–HCO 3 (1 sample). Sodium and bicarbonate ions being major component in majority of the water types (located mostly in the granite gneiss formation) has a tendency to increase fluoride concentration in groundwater by dissolving the fluoride from fluoride bearing minerals. The oversaturation of half of the samples with respect to calcite and majority of samples undersaturation with respect to fluorite makes it feasible for fluoride to get released in to the groundwater. Decreasing Ca activity downgradient (recharge to discharge) leads to a dominance of fluorite-unsaturated conditions and consequently to mobilization of fluoride in groundwater. The results indicate that the fluoride concentration in groundwater is mainly governed by high weathering of fluoride bearing minerals (i.e. apatite and biotite) in granite gneiss contains abundant fluoride, alkaline hydrogeological environment, high temperature, low rainfall, evapotranspiration and ion exchange. [ABSTRACT FROM AUTHOR]

Fluoride (F¯) concentration over and above the permissible limits (1.5 mg/l) in drinking water leads to human health hazards, such as dental and skeletal fluorosis affecting millions of people in many parts of India. Preliminary investigations indicate that severe health disorders have been identified in parts of the Kachnarwa region, which is in the upper Panda river basin, Sonbhadra District, Uttar Pradesh, due to excess intake of fluoride through drinking water. The lithological units of the study area mainly consist of granite and gneissic complex rocks of the Chota-Nagpur Plateau. In order to understand the probable source of fluoride and its concentration, 17 groundwater samples mostly from granite and phyllite regions were collected for fluoride estimation during May 2006. The concentration of fluoride in the groundwater of the study area varies from 0.483 to 6.7 mg/l. Among the 17 samples analysed, 8 exceeded the maximum permissible limits of fluoride in the study area. The source of fluoride in the groundwater of the study area is mainly from geological occurrence (i.e. fluoridebearing minerals, viz. apatite and biotitic mica). Microscopic analysis of the rock samples showed 5-10% apatite and 20-25% biotite, but other fluoride-bearing minerals like fluorite and hornblende were characteristically absent. X-ray diffraction studies showed that apatite mineral peak profile of the rock samples corroborated with the fluorapatite of the standard set by the JCPDS. The worst fluoride-affected villages are Rohiniyadamar, Madhuri, Neruiyadamar, Gobardaha and Kunrwa. Most people in these villages suffer from dental and skeletal fluorosis such as mottling of teeth, deformation of ligaments, bending of spinal column and ageing problem. An urgent need is to educate the people on the causes of fluorosis, encouraging rainwater harvesting and providing fluoride-free drinking water in the study area. [ABSTRACT FROM AUTHOR]

In order to establish season-wise relationship between total dissolved solids (TDS), electrical conductance (EC) and silica (SiO2) in upper Gunjaneru River basin, Kadapa district, Andhra Pradesh, a study has been made by collecting 51 and 46 groundwater samples during post-monsoon and pre-monsoon season, respectively. TDS, EC and silica are some of the groundwater quality parameters measured in a laboratory generally. EC and silica measurements are made quickly and are less costly than TDS measurement. The results indicate that 99.7% and 99.8% of the variability in TDS could be ascribed to the variable EC and SiO2 concentrations and the rest by some other unaccounted variables in the post-monsoon and pre-monsoon season, respectively. Inclusion of SiO2 concentration in the regression models produces, for individual samples, a lower per cent difference between measured and estimated TDS for both seasons. However, on the average the inclusion of SiO2 in regression models reduced the mean difference 0.09% for the post-monsoon season and 0.11% for the pre-monsoon. From regression analysis it is found that the multiple regression model did not improve the predictability of TDS values over the linear regression model for both post-monsoon and pre-monsoon seasons. TDS can be estimated from either EC or EC and SiO2 by these regression models within the acceptable limit of error. This is due to the low content of SiO2 in the groundwater samples in shale aquifers of the study area. [ABSTRACT FROM AUTHOR]