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1.
Anupgarh is the most fertile area of Rajasthan state where a variety of seasonal crops are grown. The availability of three manmade canals has enhanced the agricultural activities in this area. The farmers use huge amounts of pesticides to increase the crop productivity. Exposure of humans to these hazardous chemicals occurs directly in the fields and indirectly due to consumption of contaminated diet, or by inhalation or by dermal contact. The organochlorine pesticides are reported to be lipophilic and their presence in human milk and blood has been documented in different parts of the world. Blood and milk samples were collected from lactating women who were divided into four groups on the basis of different living standards viz residence area, dietary habits, working conditions and addiction to tobacco. The level of total organochlorine pesticides in blood ranged from 3.319mg/L—6.253mg/L while in milk samples it ranged from 3.209Mdash;4.608 mg/L. The results are in concurrence with the reports from other countries.  相似文献   
2.
Four efficient Cr(VI)-reducing bacterial strains were isolated from rhizospheric soil of plants irrigated with tannery effluent and investigated for in vitro Cr(VI) reduction. Based on 16S rRNA gene sequencing, the isolated strains SUCR44, SUCR140, SUCR186, and SUCR188 were identified as Bacillus sp. (JN674188), Microbacterium sp. (JN674183), Bacillus thuringiensis (JN674184), and Bacillus subtilis (JN674195), respectively. All four isolates could completely reduce Cr(VI) in culture media at 0.2 mM concentration within a period of 24–120 h; SUCR140 completely reduced Cr(VI) within 24 h. Assay with the permeabilized cells (treated with Triton X-100 and Tween 80) and cell-free assay demonstrated that the Cr(VI) reduction activity was mainly associated with the soluble fraction of cells. Considering the major amount of chromium being reduced within 24–48 h, these fractions could have been released extracellularly also during their growth. At the temperature optima of 28 °C and pH?7.0, the specific activity of Cr(VI) reduction was determined to be 0.32, 0.42, 0.34, and 0.28 μmol Cr(VI)?min?1?mg?1 protein for isolates SUCR44, SUCR140, SUCR186, and SUCR188, respectively. Addition of 0.1 mM NADH enhanced the Cr(VI) reduction in the cell-free extracts of all four strains. The Cr(VI) reduction activity in cell-free extracts of all the isolates was stable in presence of different metal ions tested except Hg2+. Beside this, urea and thiourea also reduced the activity of chromate reduction to significant levels.  相似文献   
3.
Pot culture experiments were conducted in a glasshouse to evaluate the effects of four efficient Cr(VI)-reducing bacterial strains (SUCR44, SUCR140, SUCR186, and SUCR188) isolated from rhizospheric soil, and four arbuscular mycorrhizal fungi (AMF—Glomus mosseae, G. aggregatum, G. fasciculatum, and G. intraradices) alone or in combination, on Zea mays in artificially Cr(VI)-amended soil. Presence of a strain of Microbacterium sp. SUCR140 reduced the chromate toxicity resulting in improved growth and yields of plants compared to control. The bioavailability of Cr(VI) in soil and its uptake by the plant reduced significantly in SUCR140-treated plants; the effects of AMF, however, either alone or in presence of SUCR140 were not significant. On the other hand, presence of AMF significantly restricted the transport of chromium from root to the aerial parts of plants. The populations of AMF chlamydospores in soil and its root colonization improved in presence of SUCR140. This study demonstrates the usefulness of an efficient Cr(VI)-reducing bacterial strain SUCR140 in improving yields probably through reducing toxicity to plants by lowering bioavailability and uptake of Cr(VI) and improving nutrient availability through increased mycorrhizal colonization which also restricted the transport of chromium to the aerial parts.  相似文献   
4.
Climate change is the main global challenge of this century; it is therefore imperative to identify its effects on agriculture in developing countries. This research makes spatial assessment of climate change effect on major plantation crops in Sri Lanka, with emphasis on crop suitability of tea, rubber, and coconut. Geo-referenced maps of spatial and temporal changes in crop suitability and production potentials are generated and compared. Data pertaining to six agro-ecological zones under the study area are analyzed for a period of 1980–2007. Crop suitability maps are generated amalgamating yield maps and climatic factors maps using AHP in multi-criteria analysis under two time frames of 1980–1992 and 1993–2007. Percent change in crop suitability and crop yield classes is calculated based on five crop suitability and five crop yield classes during two time frames. Dynamics of climatic parameters and crop yield are recognized using geo-referenced maps. The suitability maps of the two time frames are compared to identify the changes with each crop in conjunction with changes in the prevailing climate and yield. Geographic shift of suitability, yield, and climate classes are examined. Net gain or loss in crop production is quantified. Long-term annual rainfall significantly decreased in mid-country wet zone, whereas the mean temperature of the study area increased by 1.4°C. Results clearly showed that the climate and yield can be meaningfully related to the crop suitability and management.  相似文献   
5.
Various agricultural and kitchen waste residues were assessed for their ability to support the production of a complete cellulase system by Aspergillus niger NS-2 in solid state fermentation. Untreated as well as acid and base-pretreated substrates including corn cobs, carrot peelings, composite, grass, leaves, orange peelings, pineapple peelings, potato peelings, rice husk, sugarcane bagasse, saw dust, wheat bran, wheat straw, simply moistened with water, were found to be well suited for the organism's growth, producing good amounts of cellulases after 96 h without the supplementation of additional nutritional sources. Yields of cellulases were higher in alkali treated substrates as compared to acid treated and untreated substrates except in wheat bran. Of all the substrates tested, wheat bran appeared to be the best suited substrate producing appreciable yields of CMCase, FPase and β-glucosidase at the levels of 310, 17 and 33 U/g dry substrate respectively. An evaluation of various environmental parameters demonstrated that appreciable levels of cellulases could be produced over a wide range of temperatures (20-50 °C) and pH levels (3.0-8.0) with a 1:1.5 to 1:1.75 substrate to moisture ratio.  相似文献   
6.
Inhalation effects of trichloroethylene, at levels of 0, 200 and 600 ppm for a period of 4 and 12 weeks, on the contents of hepatic microsomal protein, cytochrome P450, cytochrome b5, and on the activities of NADPH cytochrome C reductase, aminopyrine N‐demethylase and aniline hydroxylase were investigated. Body weight remained unaltered at 200 ppm level, whereas at 600 ppm level a significant decrease in body weight was observed. Liver weight showed increases at an exposure level of 200 ppm by the end of 4 and 12 weeks. Relative liver weight (% body weight) showed an increase at 200 and 600 ppm level by the end of week 4, whereas, after 12 weeks increase was observed only in animals exposed to the 600 ppm level. Hepatic microsomal protein was decreased by the end of 4 weeks at both the exposure levels. Cytochrome P450 and cytochrome b, contents were increased at the 200ppm level after 4 and 12 weeks. NADPH cytochrome C reductase activity showed a marked increase at both the 200 and 600 ppm levels after 4 and 12 weeks. Aminopyrine N‐demethylase activity was increased at the 200 ppm level and decreased at the 600 ppm level by the end of 4 weeks, whereas, at the end of 12 weeks the aminopyrine N‐demethylase activity was near control values. Aniline hydroxylase activity was increased at the 200 ppm level after 4 and 12 weeks. Similarly, at the 600 ppm level aniline hydroxylase activity was increased after 12 weeks.  相似文献   
7.
In this study, we systematically document the link between dust episodes and local scale regional aerosol optical properties over Jaipur located in the vicinity of Thar Desert in the northwestern state of Rajasthan. The seasonal variation of AOT500 nm (aerosol optical thickness) shows high values (0.51?±?0.18) during pre-monsoon (dust dominant) season while low values (0.36?±?0.14) are exhibited during winter. The Ångström wavelength exponent has been found to exhibit low value (<0.25) indicating relative dominance of coarse-mode particles during pre-monsoon season. The AOT increased from 0.36 (Aprilmean) to 0.575 (May–Junemean). Consequently, volume concentration range increases from April through May–June followed by a sharp decline in July during the first active phase of the monsoon. Significantly high dust storms were observed over Jaipur as indicated by high values of single scattering albedo (SSA440 nm?=?0.89, SSA675 nm?=?0.95, SSA870 nm?=?0.97, SSA1,020 nm?=?0.976) than the previously reported values over IGP region sites. The larger SSA values (more scattering aerosol), especially at longer wavelengths, is due to the abundant dust loading, and is attributed to the measurement site’s proximity to the Thar Desert. The mean and standard deviation in SSA and asymmetry parameter during pre-monsoon season over Jaipur is 0.938?±?0.023 and 0.712?±?0.017 at 675 nm wavelength, respectively. Back-trajectory air mass simulations suggest Thar Desert in northwestern India as the primary source of high aerosols dust loading over Jaipur region as well as contribution by long-range transport from the Arabian Peninsula and Middle East gulf regions, during pre-monsoon season.  相似文献   
8.
The Kovaya Limestone Mine is situated on the Saurashtra coast of India. Though the mine is dependent on the desalination plant installed in the plant for its domestic and industrial water requirements, there is significant withdrawal of groundwater by the large number of bore wells and open wells, which are present in the agricultural fields lying in and around the leased area of the mine. The heavy withdrawal of groundwater has led to intrusion of seawater. The present work entails study of possible seawater intrusion by chemical analysis of major cations and anions in selected groundwater samples. Very high total dissolved solids in the range of >1,000 mg/l and high chloride in the range of 103 mg/l to 3,899 mg/l have been measured in the groundwater samples. 'Resistivity Imaging Survey' has also been carried out on selected profiles in the study area. The Electrical Resistivity Tomography images indicate very low resistivity zones (~0-3 Omega m) in the bottom portion of the resistivity depth section. These low resistivity zones can be interpreted to be due to seawater intrusion. The resistivity sections on the excavated Pits, where mining is going on, indicate possibilities of seawater intrusion. Hence, protection from seawater intrusion is recommended through restriction of mining up to the safe level.  相似文献   
9.
Earthworms are justifying the beliefs of Great Russian scientist Dr. Anatoly Igonin who said they are????disinfecting, detoxifying, neutralizing, protective and productive??. Studies indicate that some species of earthworms can ??bio-accumulate, biodegrade or bio-transform?? any toxic chemicals including ??heavy metals??, ??organochlorine pesticide??, ??herbicides??, and the lipophilic organic micro-pollutants like ??polycyclic aromatic hydrocarbons?? (PAHs). Worm vermicasts, due to the presence of ??hydrophilic?? groups in the ??lignin contents?? and ??humus??, also provide wonderful sites for ??adsorption?? of heavy metals and chemical pollutants in wastewater. Vermifiltration of wastewater using waste-eater earthworms is a newly conceived novel technology with several economic and environmental advantages. The earthworm??s body and the their ??vermicast?? work as a ??biofilter?? removing BOD5 by over 90?%, COD by 60?C80?%, TDSS by 90?C95?%, and toxic chemicals and pathogens from wastewater. This was a pioneering work done on an extremely ??toxic wastewater?? from the petroleum industry. It contained mixture of ??aliphatic?? and ??aromatic?? volatile petroleum hydrocarbons (C 10?CC 36) and ??organochlorines?? originating from the cooling liquids, waste engine and gear oil, waste transmission and brake fluid, grease, spilled petrol, and diesel oil. The aliphatic fraction contained cycloalkanes as well as a complex mixture of saturated toxic hydrocarbons. The aromatic fraction mainly consisted of PAHs, which are more toxic and persistent than the aliphatic part. The chemicals of concern were the total petroleum hydrocarbons (TPH), dichloromethane (DCM), dichloroethane (DCE), and t-butyl methyl ether (tBME). The tBME compound has raised global concern recently due to its high mobility and persistence in the environment and possible carcinogenicity. About 1,000 earthworms (species Eisenia fetida) were released in the soil of vermifilter bed. They not only tolerated and survived in the toxic petroleum environment but also bio-filtered and bio-remediated the dark-brown petroleum wastewater with a pungent smell into pale-yellow and odorless water indicating disappearance of all toxic hydrocarbons. The hydrocarbons C 10?CC 14 were reduced by 99.9?%, the C 15?CC 28 by 99.8?%, and the C 29?CC 36 by 99.7?% by earthworms.  相似文献   
10.
Environmental Science and Pollution Research - By 2040, India hopes to have completed its energy supply to fulfill the country’s rising energy demands. Renewable and conventional sources must...  相似文献   
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