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Unexpected mistreatment of groundwater from coastal aquifers may possibly cause salt water intrusion in coastal aquifers. Coastal areas are mostly overpopulated with productive agricultural lands and expanded irrigated farming actions. Field and modeling studies were started to consider the special effects of possible seawater intrusion into the coastal aquifers. Groundwater levels were measured at 61 locations in Nagapattinam and Karaikal coastal region, identified flow direction pointing toward the coast with no major change in groundwater table. Groundwater samples were collected and analyzed for major ionic parameters, represented higher concentration of conductivity, total dissolved solids, sodium and chloride along the coastal parts of the study area. A computer package for the simulation of dimensional variable density groundwater flow, SEAWAT, has been used to model the seawater intrusion in the coastal aquifers of the study area. The model was stimulated to predict the amount of seawater incursion in the study area for a period of 50 years. The simulation results signify saline water intrusion mainly due to up coning of saline water owing to over drafting of groundwater.

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Background/Aim: Fever can be caused by different reasons such as environmental conditions, acute rejection after kidney transplantation and bacterial diseases including kidney and urinary tract infections. The present study represents a novel idea of investigating the direct effect of body temperature elevation on kidney function to determine whether hyperthermia alters the kidney function transiently leading to inaccurate findings and possible misinterpretation of the radionuclide (^99mTc-MAG-3) renography studies. Methods: Renography studies were performed on New Zealand White rabbits weighing approximately 3–3.5 kg. Each rabbit was inject with 48.1 MBq (1.3 mCi) technetium-99m-mercaptoacetyltriglycine (^99mTc-MAG-3). Studies were acquired using a gamma camera equipped with a low-energy, high-resolution collimator interfaced with a computer. Dynamic images were acquired as 2-s frames for the first 1 min and every 30 s for the next 30 min on a matrix of 64 × 64. Regions of interest were drawn over the whole kidneys. Radioactivity time curves were generated from the regions of interest. Time to peak activity (T_max), time from peak to 50% activity (T_½), and the uptake slope of each kidney were calculated from the renograms. Three days later the same protocol was repeated for the same rabbit but with a higher body temperature by 2°C. Then it was repeated with a higher body temperature by 3°C, then 4°C with the same interval period. Blood pressure was measured using a catheter inserted into the femoral artery connected to a Lectromid recorder at normal temperature and during increasing the temperature by 2, 3 and 4°C. Renal blood flow was also measured via the renal artery using an electromagnetic blood flow sensor connected to a flowmeter. Creatinine and blood urea nitrogen (BUN) in blood were measured in control and hyperthermic rabbits. Results: During hyperthermia the experimental curves shifted to the right of the control curves indicating that there was a delayed renal uptake of ^99mTc-MAG-3 and clearance of radioactivity. This delay was proportional to body temperature. Calculated averages were: T_max 1.6 ± 0.1, 2.8 ± 0.3, 8.8 ± 1, 15 ± 4 min; T_½ 2.77 ± 0.2, 3 ± 0.4, 8.9 ± 1.1, 20 ± 3.4 min, and perfusion index 190 ± 5, 201 ± 4, 218 ± 7, 224 ± 9 of control and hyperthermic (elevation of temperature 2, 3, and 4°C) rabbits, respectively (n = 6; p < 0.05). Mean arterial pressure and renal blood flow did not significantly change during hyperthermia. Creatinine and BUN were proportionally elevated to high temperature. Conclusions: Our results indicate that hyperthermia causes a transient alteration in the function of the kidney and scintigraphic pattern on radionuclide renography. Radionuclide renography studies may be performed at normothermic temperature since interpretation at higher body temperature could lead to misleading results, and temperature should be checked and recorded for single and follow-up radionuclide renography studies.

ABSTACTThe absence of perennial river, semi arid climatic condition and growing neediness of water increased the usage of groundwater. In the area proposed for the study, all the water necessities are fulfilled with groundwater. Hydrochemistry of groundwater is influenced by geogenic and anthropogenic sources. Hence to assess the chemical characteristics of groundwater in the study area, a total of 74 groundwater samples were collected and analyzed for physical parameters such as pH, conductivity and Total Dissolved Solids along with major cations and anions using standard procedures. The dominant cations and anions were, Na ˃ Ca ˃ Mg ˃ K and HCO ˃Cl> NO3 ˃ F ˃ PO4 ˃SO4 respectively. Hydro chemical facies demarcated were NaCl , CaNaHCO3 , CaHCO3 and CaMgCl. The facies suggests ionic exchange, dissolution, silicate weathering and anthropogenic sources are responsible for the variation in groundwater chemistry of the study area. The silicate group minerals show over equilibrium conditions sulphate and halide group minerals indicate under saturation condition. The saturation values trend increases along the flow path. Identified hydro geochemical process were verified and quantified using hydro geochemical inverse mass-balance modeling (net geochemical reactions along a flow path,PHREEQC,WATQ4F).