Speciation of Ions in Groundwater and its Applications

Speciation of ions in groundwater is very important to understand its hydrogeochemical evolutions from its origin to its present status. The speciation will help to understand the geochemical process which controls their evolution and their present day environmental conditions which will ultimately lead us to utilize them directly or after the required treatment process to make them safe and useable. Some of the ions and their speciation were discussed in this line in this chapter

Hydrogeochemical Modeling of Groundwater in the Gadilam River Basin, South India

Hydrogeochemistry of a region is a reflection of hydrodynamic process, composition of lithology and physical constraints. The water chemistry is the resultant of all biogeochemical processes and reactions, which have acted on water from the moment it has condensed in atmosphere till the time it's discharged. A case study has been carried out in a varied lithological terrain with Archaean, Alluvium and Tertiary rocks to unravel the hydrogeochemical process. The dominant facies in the entire litho units is sodium - chloride type indicating saline nature in the groundwater. The speciation of bicarbonate, sulphate and phosphate in the groundwater samples in different litho units was determined using the computer program WATQ4F. This study reveals that higher speciation with increasing concentration of bicarbonate in summer and south west monsoon indicates static environment, whereas lesser speciation in north east monsoon and post monsoon indicates flushing environment in the basin. Higher speciation with lesser contribution of sulphate in summer and south west monsoon and an increasing trend of speciation in north east monsoon and post monsoon was observed

Association of depression with complications of type 2 diabetes - the Chennai Urban Rural Epidemiology Study (CURES - 102)

Objective: The aim of the study was to assess the relationship between depression and diabetic complications among urban south Indian type 2 diabetic subjects [T2DM]. Methods: T2DM subjects [n= 847] were recruited from the Chennai Urban Rural Epidemiology Study [CURES], a population based study in Chennai (formerly Madras) in South India. A previously validated depression questionnaire [PHQ-12 item] was administered. Four field stereo retinal colour photography was done and diabetic retinopathy [DR] was classified according to the Early Treatment Diabetic Retinopathy Study grading system. Neuropathy was diagnosed if the vibratory perception threshold of the right great toe, measured by biothesiometry, was ≥20. Nephropathy was diagnosed if urinary albumin excretion was ≥300 μg/mg creatinine. Peripheral vascular disease [PVD] was diagnosed if an ankle-brachial index was <0.9. Coronary artery disease [CAD] was diagnosed based on a past history of documented myocardial infarction and/or electrocardiographic evidence of Q wave and/or ST segment changes. Results: Of the 847 T2DM studied, 198 (23.4%) were found have depression. The prevalence of depression was significantly higher among diabetic subjects with DR (35.0% vs 21.1%,p<0.001), neuropathy (28.4% vs15.9%,p=0.023), nephropathy (35.6% vs 24.5%,p=0.04) and PVD (48.0% vs 27.4%,p<0.001) as compared to subjects without these complications. DR, neuropathy, nephropathy, and PVD were associated with depression even after adjusting for age, gender, duration of diabetes and glycated haemoglobin. DR (Odds ratio [OR] =2.19, Confidence interval [CI]:1.45-3.51,p<0.001) was associated with depression even after adjusting for neuropathy and nephropathy. There was also a significant association between depression and neuropathy, after adjusting for retinopathy and nephropathy (OR=2.07,CI:1.41-3.04,p<0.001). There was a significant association of depression with nephropathy but this was lost (OR=1.71, CI: 0.87-3.35,p=0.119) after adjustment for retinopathy. PVD (OR=3.52,CI:1.94- 6.40,p<0.001) remained significantly associated with depression even after adjusting for CAD. However, there was no significant association of depression with CAD (OR=0.73, CI:0.42 -1.27, p=0.264). Conclusion: Among Asian Indians, the prevalence of depression is higher in T2DM subjects with retinopathy, neuropathy, nephropathy and PVD compared to those without the respective complications

Studies on maturity onset diabetes of the young (MODY) from S. India

We examined the following aspects of Maturity Onset Diabetes of the Young (MODY): prevalence, vascular complications, insulin secretion in offspring of MODY subjects, insulin resistance and whether MODY can be considered a distinct disease. We report a higher prevalence of MODY among Asian Indian patients. The prevalence rates of microvascular complications in MODY were found to be the same as in classical NIDDM patients. Glucose stimulated insulin and C-peptide responses were compared with non-diabetic controls. In MODY subjects, C-peptide responses were lower, whereas insulin responses were varied. Insulin secretion in offspring of MODY subjects was similarly evaluated, and abnormalities discovered even in these prediabetic subjects. Using the euglycaemic clamp technique, MODY patients were found to be more insulin resistant than classical NIDDM patients. Further lines of evidence are needed to resolve whether MODY can be considered a distinct disease

A Novel Approach for Groundwater Budgeting Using GIS in a Part of Pondicherry Region, India

The over extraction of groundwater from the coastal aquifers, result in reduction of groundwater resource and lowering of water level. In general, the depletion of groundwater level enhances the landward migration of saltwater wedge. Pondicherry is one such region with recent alluvium as the major formation. Since the study area forms a part of the coastal aquifer system this behaves as a fragile ecosystem. The present study has been attempted to calculate the extraction of water and to estimate the amount of recharge into this allu-vial aquifer by using groundwater level variations. The monthly water level fluctuation was observed during the study period (2000-2002) in eighteen locations. The maximum rise in groundwater level observed during 2000 was considered as the initial water level for the study and the subsequent decline in water level (draw down) was monitored monthly until the rising trend was noted. This indicates the fall in water level due to extraction.Later keeping the deepest draw down as the initial value increasing water level trend was studied until there was a notice of decline in groundwater level. This indicates as the rise in water level due to re-charge. This method of observation carried out at a single location was adopted for all eighteen locations. The spatial representation of these data for eighteen locations were carried out by using GIS and the area occupied by different groundwater level contours were calculated and the amount of water withdrawn/re- charged was estimated. The maximum recharge was noted in the central and the northern part of the study area when compared to the other regions. Similarly, the maximum discharge was noted in the northern and the southern part of the study area during the study period

Evidence for Mechanistic Alterations of Ca2+ Homeostasis in Type 2 Diabetes Mellitus

Altered cytosolic Ca2+ is implicated in the aetiology of many diseases including diabetes but there are few studies on the mechanism(s) of the altered Ca2+ regulation. Using human lymphocytes, we studied cytosolic calcium (Cai) and various Ca2+ transport mechanisms in subjects with Type 2 diabetes mellitus and control subjects. Ca2+-specific fluorescent probes (Fura-2 and Fluo-3) were used to monitor the Ca2+ signals. Thapsigargin, a potent and specific inhibitor of the sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA), was used to study Ca2+- store dependent Ca2+ fluxes. Significant (P < 0.05) elevation of basal Cai levels was observed in lymphocytes from diabetic subjects. Cai levels were positively correlated with fasting, plasma glucose and HbAlc. There was also a significant (P < 0.05) reduction in plasma membrane calcium (PMCA) ATPase activity in diabetic subjects compared to controls. Cells from Type 2 diabetics exhibited an increased Ca2+ influx (as measured both by Fluo-3 fliorescence and C45a assays) as a consequence of of thapsigargin-mediated Ca2+ store depletion. Upon addition of Mn2+ (a surrogate of Ca2+), the fura-2 fluorescence decayed in an exponential fashion and the rate and extent of this decline was steeper and greater in cells from type 2 diabetic patients. There was also a significant (P < 0.05) difference in the Na+/Ca2+ exchange activity in Type 2 diabetic patients, both under resting conditions and after challenging the cells with thapsigargin, when the internal store Ca2+ sequestration was circumvented. Pharmacological activation of protein kinase C (PKC) in cells from patients resulted in only partial inhibition of Ca2+ entry. We conclude that cellular Ca2+ accumulation in cells from Type 2 diabetes results from (a) reduction in PMCA ATPase activity, (b) modulation of Na+/Ca2+ exchange and (3) increased Ca2+ influx across the plasma membrane

Epiphreatic caves in Niah karst tower (NW Borneo): occurrence, morphology and hydrogeochemistry

Epiphreatic caves develop close to the water table at the boundary between vadose and phreatic karst zones. The recognition of their former existence and position in uplifted limestone regions can inform on phases of uplift, base level lowering and rate of vertical deepening of the karst. Hence, epiphreatic caves and the karst processes that form them are of specific interest. Although the large and spectacular caves of Niah have been subject of much research and interest, the existence of small epiphreatic caves at the foot of the karst towers has not previously been documented in this region of NW Borneo. The study documents and reports an epiphreatic cave passage at water table elevation in the Painted Cave karst tower where several large caves are also known. The semi-flooded passage is over 480 m long and traverses the tower from east to west, intersecting other much larger vadose caves. The epiphreatic flow path is characterized by a number of sinking streams and resurgences as well as several sharp bends in the passage indicating joint control. As an initial attempt this study was undertaken to correlate the water chemistry along the cave path to understand the geomorphological controls. A preliminary campaign of water sampling was carried out with samples collected at ten locations along the path of the cave stream and analyzed for pH, EC, TDS, DO, Eh, major ions, nutrients and trace metals. The results show that dissolution of host rock and leaching of organic matter are the dominant controlling factors for the geochemistry of surface water along the cave stream passage. During dry conditions the water was under-saturated for carbonate minerals but not aggressive suggesting that most dissolution and erosion occurs during flood conditions. This is supported by the morphology of the passages and features of the rock wall both inside the caves and at the foot of the karst tower. Key words: Karst, Niah cave, Epiphreatic, Hydrogeochemistry, water table.Jame epifreatične cone v kraškem stolpu Niah (severozahodni Borneo): pojavnost, morfologija in hidrogeokemija Epifratične jame nastajajo na meji med vadozno in freatično cono. Prepoznavanje epifreatičnih elementov v bloku dvignjenega masiva nam omogoča razbrati faze dvigovanja masiva oz. spuščanja erozijske baze, zato so epifreatične jame in procesi še posebno zanimivi. Čeprav so o jamah stolpa Niah opravili številne študije, nobena od teh ne obravnava epifreatičnih jam ob vznožju kraškega stolpa. Ta študija obravnava epifreatične rove na ravni vodne gladine v stolpu Painted Cave v severozahodnem Borneu, kjer sicer poznamo več velikih jam. Delno potopljen rov je dolg več kot 480 m in preči stolp od vzhoda proti zahodu ter pri tem seka še več drugih, veliko večjih vadoznih jam. Epifreatični tok je povezan z več ponikalnicami in izviri, zanj so značilne nagle spremembe smeri, ki sledi vodilnim razpokam. Namen študije je povezati kemijo vode vzdolž toka in aktivne geomorfološke dejavnike. Vzorčenje in analize vode na desetih lokacijah so dali podatke o pH, električni prevodnosti, skupni raztopljeni snovi (TDS), raztopljenem kisiku, Eh ter o koncentraciji glavnih ionov, hranil in kovin v sledeh. Rezultati so pokazali, da sta raztapljanje matične kamnine in izpiranje organskih snovi prevladujoča dejavnika geokemije vode v kanalu. V sušnem obdobju je voda rahlo nenasičena na kalcit, a je agresivnost majhna, kar kaže na to, da glavna faza razvoja poteka v poplavnih obdobjih. To potrjujejo tudi morfologija rova in jamske skalne oblike v jami in ob vznožju kraškega stolpa.Ključne besede: kras, jama Niah, epifreatična cona, hidrogeokemija, vodna površina.