Study of indiscriminate distribution of restrained antimicrobial resistome of different environmental niches

Environmental Science and Pollution Research - Prophylactic usage and high persistent nature of several antibiotics have put selective pressure on the native microbial population that led to the...     

Climate vulnerability index - measure of climate change vulnerability to communities: a case of rural Lower Himalaya,India

Climate Vulnerability Index (CVI) is being proposed to assess climate change vulnerability of communities with a case study. The index consists of household parameters of all the three dimensions of vulnerability such as Exposure, Sensitivity and Adaptive Capability. Exposure is defined by ‘Natural disaster and Climate variability’, however Sensitivity by ‘Health’, Food’, and ‘Water’ and Adaptive Capability by ‘Socio-demographic profile’, ‘Livelihood strategies’, and ‘Social networks’. Respective parameters were based on the peers and literature. The CVI vulnerable status ranges from high (0) to low (1). Household questionnaire survey was undertaken from two regions namely, near to district (NDH) and away to district (ADH), in Srinagar, Uttrakhand, India. Data for desired parameters for CVI was collected from 50 randomly selected households. Data were aggregated using a composite index and differential vulnerabilities were compared. High vulnerability was observed for livelihood strategies, food and natural disaster for ADH households, and health and water for NDH households. It was found that the adaptive capability and sensitivity of ADH households was higher than NDH, however, exposure realization was similar in both the regions. The CVI was 0.69 and 0.64 for NDH and ADH, respectively, suggests high vulnerability to NDH households. This pragmatic CVI approach may be used to assess and monitor vulnerability under various stress condition, and/or evaluate potential program/ policy effectiveness in various data-scarce regions by comparing various anticipated scenarios with baseline. Further, the result obtained by index may have implications for developing adaptation or coping strategies to the region.     

Potential fluoride contamination in the drinking water of Marks Nagar,Unnao district,Uttar Pradesh,India

This study was conducted in the summer season (May, 2007). The fluoride concentration along with other physico-chemical parameters in ground water samples was determined in Marks Nagar of Unnao district, Uttar Pradesh (India), since it is the only source of drinking water for the villagers. The fluoride concentration in the water varied from 0.8 to 13.9 mgl⁻¹ with a mean of 4.02 mgl⁻¹. The correlation analysis revealed that fluoride had a positive correlation with pH, CO₃, HCO₃, and sodium adsorption ratio (SAR), whereas a negative correlation with Ca and Mg was found. A soil profile was also dug in the area to assess depth-wise fluoride content in the soil. The soil samples and underneath calcium carbonate (CaCO₃) concretion were analyzed for fluoride content. The percent of soluble fluoride to total fluoride in the soil varied from 25.15 to 4.76% down the soil profile. The soluble fluoride was found to decrease with the increase in the clay content in the soil. The total leachable fluoride in CaCO₃ concretions was found to be 6.08%. It was inferred from this study that the soil and underneath layer of CaCO₃ concretions may be the potential source of fluoride contamination in the shallow drinking water sources of the area.     

Radiological assessment of surface water quality around proposed uranium mining site in India

The gross alpha and gross beta activities were estimated for radiological assessment of surface water quality around the proposed uranium mining site Kylleng Pyndengsohiong Mawthabah (Domiasiat), West Khasi Hills District, Meghalaya situated in a high rainfall area (12,000 mm) in India. 189 Surface water samples were collected over different seasons of the year from nine different locations covering around 100 km². Gross beta activities were found to vary from 144 to 361 mBq/L which is much below the prescribed WHO limit of 1000 mBq/L for drinking water. Gross alpha activities varied from 61 to 127 mBq/L. These values are much below the reported gross alpha values by other countries. In about 7% of the samples the alpha activities remain exceeded the WHO guideline limit of 100 mBq/L. Surface water samples collected during the summer season of the year show higher activity whereas low activity was found from samples collected during monsoon season. Results show that all water sources are acceptable as drinking water for human consumption from the radiological point of view, the higher gross alpha concentrations in a few locations remains so only for short duration during the summer season.     

Heavy metal concentration and distribution in a dated sediment core of Nainital Lake in the Himalayan region

The concentrations and distribution of the elements, including heavy metals such as As, Ba, Br, Co, Cr, Cs, Fe, Ga, K, Mn, Na, Rb, Sc, Sr, Th and Zn, were investigated in dated sediment cores of Nainital Lake located in the Himalayan region, in Uttar Pradesh state of India, which is considered as a remote background area. The concentrations of the elements were measured by instrumental neutron activation analysis using the k0 method. The International Atomic Energy Agency certified reference material SL-3 was used to evaluate the accuracy of the method. The normalized data for a series of elements were used to understand the source of loading. Elements like Br, Co, Cr, Fe, K, Mn and Zn show a negative correlation with increasing depth whereas elements like As, Ba, Cs, Na and Rb show a positive correlation with increasing depth. By considering the concentration for the bottom segments of the core as close to the baseline concentration, recent flux values for different elements were calculated. An increase in the flux value was observed for Br, Cr, Fe, K, Mn and Zn, which can be attributed to anthropogenic contribution in recent years.     

CLIMATE CHHANGE SENSITIVITY ASSESSMENT ON UPPER MISSISSIPPI RIVER BASIN STREAMFLOWS USING SWAT1

ABSTRACT: The Soil and Water Assessment Tool (SWAT) model was used to assess the effects of potential future climate change on the hydrology of the Upper Mississippi River Basin (UMRB). Calibration and validation of SWAT were performed using monthly stream flows for 1968–1987 and 1988–1997, respectively. The R² and Nash‐Sutcliffe simulation efficiency values computed for the monthly comparisons were 0.74 and 0.69 for the calibration period and 0.82 and 0.81 for the validation period. The effects of nine 30‐year (1968 to 1997) sensitivity runs and six climate change scenarios were then analyzed, relative to a scenario baseline. A doubling of atmospheric CO₂ to 660 ppmv (while holding other climate variables constant) resulted in a 36 percent increase in average annual streamflow while average annual flow changes of ?49, ?26, 28, and 58 percent were predicted for precipitation change scenarios of ?20, ?10, 10, and 20 percent, respectively. Mean annual streamflow changes of 51,10, 2, ?6, 38, and 27 percent were predicted by SWAT in response to climate change projections generated from the CISRO‐RegCM2, CCC, CCSR, CISRO‐Mk2, GFDL, and HadCMS general circulation model scenarios. High seasonal variability was also predicted within individual climate change scenarios and large variability was indicated between scenarios within specific months. Overall, the climate change scenarios reveal a large degree of uncertainty in current climate change forecasts for the region. The results also indicate that the simulated UMRB hydrology is very sensitive to current forecasted future climate changes.     

Household-specific variables and forest dependency in an Indian hotspot of biodiversity: challenges for sustainable livelihoods

Deforestation studies have attracted considerable attention over the past two decades. Analyses of local deforestation examine the significance of numerous explanatory variables for the extraction of forest products. This study distinguishes among the explanatory variables as household-specific and site-specific, and argues for in-depth analysis of household-specific variables. It examines the role of household size, income, and education on firewood extraction and beedi-making in the Western Ghats of India, a hotspot of biodiversity. The study documents the incidence of these livelihoods, investigates the interaction among the three variables, and uses logistic regression models to determine the exact probability for the livelihoods. Two novel features of the study include analysis of wood and non-wood extraction through a single dataset and determination of model by the data. The results show high dependency of households on forest-based livelihoods, situations when the probability of livelihoods changes substantially, and non-parallel trends for household dependency. The study suggests the role of household-specific variables as the agents of motivation and persistence for forest-based livelihoods and presents a hypothesis about the critical size of household in forest dependency. The study recommends four measures—harvest of ecosystem services, rise in income, migration and mobility, and environmental education—to promote sustainable livelihoods.     

Monitoring of organochlorine pesticide residues in the Indian marine environment.

Organochlorine pesticide residues in sediment and fish samples collected from the east and west coasts of India are presented. HCH isomers and DDT and its metabolites are the predominantly identified compounds in most of the samples. Despite the higher quantity of consumption, HCH and DDT levels in fish in India were lower than those in temperate countries suggesting a lower accumulation in tropical fish, which could be due to rapid volatilization and degradation of these insecticides in the tropical environment. The predominance of alpha- and beta-HCH reflect the use of technical grade HCH in India. The high temperature in the tropics also enhances the elimination rate of chemicals in fish, as the biological half-lives of semivolatile compounds such as DDT are short at high temperature.