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Spectrophotometer-based student education program on health hazard assessment due to Cr(VI) and Pb contamination in surface and groundwaters of Hyderabad City, India
2015
Das Sharma, Mala | Juyal, Archana | Karuna, Mantha | Das Sharma, Subrata
A student-centric research education program with the active participation of undergraduate students is initiated. The aim is to imbibe ―responsible citizenship behavior‖ in them so that each member becomes conscious and well trained to take up environmental-related issues and challenges for long-term sustainability of the ecosystem. In this work, we report spectrophotometer-based estimation of hexavalent chromium (57-268 gL-1) and lead (34–158 gL-1) concentrations in different surface waters and groundwater samples in and around the city of Hyderabad, India. Our results indicate that the studied surface water bodies and aquifers are contaminated to variable degrees and pose a serious threat to the ecosystem. In view of low geochemical baseline values for chromium and lead, the origin of heavy metal pollution is inferred to be anthropogenic, mainly originating from industrial effluents. The toxicological data are integrated with health data for risk assessment and impending health hazard. Finally, the novelty of this student-centric research program is highlighted.
Показать больше [+] Меньше [-]Impact of copper mines and smelter on groundwater quality (Case Study: Rajasthan State in India)
2015
Hussain, Ikbal | Hussain, Jakir | Arif, Mohammed | Vadiya, Vinod
Rajasthan is one of the main mineral potential state of India. During the last 30 years it has witnessed enormous expansion of mining industries, but mining of most of the minor minerals coupled with changing climate has posed serious problems to the environmental fabric in the state, apart from base metal beneficiation plants. Groundwater is also being polluted day-by-day by effluents generated from mineral wastes and beneficiation processes in the vicinity of mining sites such as Khetri. Pollutant concentrations were measured in groundwater at the vicinity of Khetri copper mining project, Rajasthan to investigate the influence of copper mining on environment. Pollutant concentrations in groundwater were investigated. Copper metal concentration in water samples were found above the maximum desirable limit in two sources: G4 and G5, due to washing away of mineral with water. Mining industry has deteriorated quality of groundwater resources in the state of Rajasthan, and these industries are becoming centers of pollution sources which need timely actions at government level so that natural resources such as groundwater can be protected.
Показать больше [+] Меньше [-]Occurrence and sources of selected organochlorine pesticides in the soil of seven major Indian cities: Assessment of air–soil exchange
2015
Chakraborty, Paromita | Zhang, Gan | Li, Jun | Sivakumar, A. | Jones, K. C. (Kevin C.)
India is an agricultural country and organochlorine pesticides (OCPs) accounts for nearly three fourth of the annual pesticide consumption. Selected OCPs were therefore quantified in 81 soil samples along urban–suburban–rural transect from New Delhi and Agra in the north, Kolkata in the east, Mumbai and Goa in the west and Chennai and Bangalore in the southern part of India. ΣOCPs ranges from 2 to 410 ng/g dry weight (Mean, 35) with dominance of endosulfan sulfate in the rural sites. Urban centers and suburbs reflects OCP usage for vector control. Lower winter temperature in New Delhi favored site-specific deposition of most OCPs in soil. Volatilization of OCPs from soil occurred in the Indian cities having higher ambient temperature. Due to the compounded impact of past and ongoing usage of selected OCPs like DDT, a sporadic cycle of emission and re-emission from Indian soil is expected to continue for many more years to come.
Показать больше [+] Меньше [-]Enterococcus species diversity and molecular characterization of biomarker genes in Enterococcus faecalis in Port Blair Bay, Andaman and Nicobar Islands, India
2015
Meena, Balakrishnan | Anburajan, Lawrance | Sathish, Thadikamala | Raghavan, Rangamaran Vijaya | Jha, Dilip Kumar | Venkateshwaran, Pitchiah | Das, Apurba Kumar | Dheenan, Palaiya Sukumaran | Vinithkumar, Nambali Valsalan | Dharani, Gopal | Kirubagaran, Ramalingam
This study was performed to evaluate the abundance and diversity of Enterococcus sp. and the distribution of biomarker genes in Enterococcus faecalis in Port Blair Bay, Andaman and Nicobar Islands. The Enterococcus sp. densities at the seven sampling stations were highly influenced by tidal fluctuations and season. The distributions and diversities of species varied in the inner and outer regions of Port Blair Bay. Among the 1816 total isolates, the occurrence of fecal Enterococcus was high (1.78×104CFU/100mL) in Phoenix Bay. Moreover, 67.76% of the isolates were identified as Enterococcus, and the most frequently identified species were E. hirae, E. avium and E. faecalis. Assessments of antibiotic resistance and biomarker genes revealed the maximum occurrence in the Aberdeen Bay isolates. The most prevalent biomarker genes observed in the E. faecalis isolates were gelE and asa1, whereas cyl was not found among the isolates. In silico sequence analysis of biomarker genes of E. faecalis also revealed that they are evolutionarily well conserved with those of earlier reports. Further, multivariate analysis distinguished the JB, PB and OS stations from the other stations according to distinctive microbial densities and compositions. In addition, the Shannon-Wiener diversity indices and box-whisker plots further facilitated and supported the multivariate results.
Показать больше [+] Меньше [-]Spatial and vertical distributions of heavy metals and their potential toxicity levels in various beach sediments from high-background-radiation area, Kerala, India
2015
Suresh, G. | Ramasamy, V. | Sundarrajan, M. | Paramasivam, K.
The spatial and vertical distribution of heavy metals and the sediment characteristics of beaches in Kerala, India (the upper surface sediments and the first, second and third one-foot-thick strata) were assessed in this study. The concentrations of most of the studied metals were highest at sampling site S1 (Cochin). The measured concentrations were compared with background and toxicological reference values. The results show that definite adverse biological effects are possible at most of the sampling sites due to the high Pb levels. Three different indexes were calculated to investigate the potential toxicity level. Most of the studied metals and all calculated indexes were highest in the third foot of sediment. Multivariate statistical analyses were performed and suggested that particular heavy metals, e.g., Pb, Cd, Cr and Ni, may represent contamination from a common source. The Cd and Pb concentrations and all the calculated index values show a relationship with the content of organic matter. The results of the present study suggest the recommendation that a systematic analysis is needed to monitor heavy metal levels in the studied area.
Показать больше [+] Меньше [-]Impact of silver nanoparticles on benthic prokaryotes in heavy metal-contaminated estuarine sediments in a tropical environment
2015
Antizar-Ladislao, B. | Bhattacharya, B.D. | Ray Chaudhuri, S. | Sarkar, S.K.
Little knowledge is available about the potential impact of commercial silver nanoparticles (Ag-NPs) on estuarine microbial communities. The Hugli river estuary, India, is susceptible to heavy metals pollution through boat traffic, and there is the potential for Ag-NP exposure via effluent discharged from ongoing municipal and industrial activities located in close proximity. This study investigated the effects of commercial Ag-NPs on native microbial communities in estuarine sediments collected from five stations, using terminal restriction fragment length polymorphism (T-RFLP) technique. An increase in the number of bacteria in consortium in sediments was observed following exposure to Ag-NPs. In general microbial communities may be resistant in estuarine systems to the antimicrobial effects of commercial Ag-NPs, but key microorganisms, such as Pelobacter propionicus, disappeared following exposure to Ag-NPs. In conclusion, the T-RFLP analysis indicated that Ag-NPs have the potential to shape estuarine sediment bacterial community structure.
Показать больше [+] Меньше [-]Environmental controls on the speciation and distribution of mercury in surface sediments of a tropical estuary, India
2015
Chakraborty, Parthasarathi | Babu, P.V Raghunadh
Distribution and speciation of mercury (Hg) in the sediments from a tropical estuary (Godavari estuary) was influenced by the changing physico-chemical parameters of the overlying water column. The sediments from the upstream and downstream of the estuary were uncontaminated but the sediments from the middle of the estuary were contaminated by Hg. The concentrations of Hg became considerably less during the monsoon and post monsoon period. Total Hg concentrations and its speciation (at the middle of the estuary) were dependent on the salinity of the overlying water column. However, salinity had little or no effect on Hg association with organic phases in the sediments at downstream. Increasing pH of the overlying water column corresponded with an increase in the total Hg content in the sediments. Total organic carbon in the sediments played an important role in controlling Hg partitioning in the system. Uncomplexed Hg binding ligands were available in the sediments.
Показать больше [+] Меньше [-]Arsenic Contamination in Soil and Sediment in India: Sources, Effects, and Remediation
2015
Shrivastava, Anamika | Ghosh, Devanita | Dash, Ayusman | Bose, Suatapa
Arsenic contamination is turning out to be a major problem these days with its area coverage and the number of people affected directly or indirectly. Now, the level of the contaminant has spread over the soil and sediments from groundwater and other natural sources. Arsenic poisoning in groundwater events is familiar to the world, but the consequences of soil contamination are still unrevealed to the community, specially the people of contaminated counties. Arsenic is a serious instantaneous concern for the people and other life forms regarding the poisoning through crops and vegetables. Many remediation technologies that mainly include physical, chemical, and a few biological methods have been evolved with time to check its effects. The physical and chemical methods for this purpose are often inefficient and/or very expensive, mainly limited to application in aqueous systems, and produce toxic sludge, which again becomes a matter of concern. But bioremediation relies on the fact that biological organisms have the ability to degrade, detoxify, and even accumulate harmful chemicals and offers attractive perspectives for biomonitoring (via biosensors), treatment of wastewater, and the recycling of polluted soils.
Показать больше [+] Меньше [-]Metal concentrations in the growth bands of Porites sp.: A baseline record on the history of marine pollution in the Gulf of Mannar, India
2015
Krishnakumar, S. | Ramasamy, S. | Magesh, N.S. | Chandrasekar, N. | Simon Peter, T.
The present study was carried out on the Porites coral growth bands (1979 to 2014) to measure the metal accumulation for assessing the environmental pollution status. The concentrations of studied metals are compared with similar global studies, which indicate that the metals are probably derived from natural sources. The identical peaks of Fe and Mn are perfectly matched with Cu, Cr and Ni concentrations. However, the metal profile trend is slightly depressed from a regular trend in Zn, Cd and Pb peaks. The metal accumulation affinity of the reef skeleton is ranked in the following order Cr>Cd>Pb>Fe>Mn>Cu>Ni>Zn. The distribution of metal constituents in coral growth bands is primarily controlled by Fe and Mn in the reef skeleton. Other reef associated metals such as Pb and Cd are derived from other sources like coastal developments and anthropogenic sources.
Показать больше [+] Меньше [-]Oil spill experiment using airborne DLR ESAR off the coast of Diu, India
2015
Sasamal, S.K. | Rao, M.V.
Oil spill experiment results in the coastal waters of Diu, India, with an airborne DLR ESAR sensor are discussed with reference to the SAR frequency, polarization and viewing angle. The SAR data acquired in the quad polarization of the L band and dual polarization of the C band over two spills are studied. A higher oil and water contrast is observed in the L-VV polarization than in the C-HH mode. Oil spill discrimination is possible over a wider view angle of the airborne SAR sensor data in L band than in C band. This study has also analyzed the spread and drift of oil in coastal waters.
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