In vivo studies on the effect of Ocimum sanctum L. leaf extract in modifying the genotoxicity induced by chromium and mercury in Allium root meristems

In vivo cytogenetic assay in Allium cepa root tip cells has been carried out to detect the modifying effect of Ocimum sanctum aqueous leaf extract against chromium (Cr) and mercury (Hg) induced genotoxicity. It was observed that the roots post-treated with the leaf extract showed highly significant (p < 0.001) recovery in mitotic index (MI) and chromosomal aberrations (CA) when compared to pre-treated (Cr/Hg) samples and the lower doses of the leaf extract were found to be more effective than higher doses. The present study reveals that the Ocimum sanctum leaf extract possesses the protective effect against Cr/Hg induced genetic damage.     

Need for adaptation strategy against global sea level rise: an example from Saudi coast of Arabian gulf

This paper reports sea level rise (SLR) scenarios causing land loss, environmental degradation and destruction of infrastructure in the Saudi coast of the Arabian Gulf. Human development structures such as, sea ports, desalination plants, industrial establishments, commercial buildings, fish farms etc. will be impacted, leading to great economic losses. A systematic analysis on the current environmental setting of east coast of Kingdom of Saudi Arabia (KSA) versus the existing infrastructure assets indicates that a 1?m sea level rise in Arabian Gulf affects approximately 650?km² land area, along the Saudi coastline of ~1,800?km in 1:50,000 scale. Three simulation scenarios were created with respect to 1?m, 2?m and 3?m rises from the present mean sea level and its impacts were assessed. Maps depicting major infrastructure assets, ecologically sensitive elements, historical locations, anthropogenic zones, and Environmental Sensitivity Indices (ESI) were used for overlaying the sea level change map, in a Geographic Information System (GIS) platform. In general, the Jubail Marine Park area will have serious impact due to SLR. The inundation of low?Clying lands will affect the mangroves species of Dawhat Ad Dafi, coral reefs, coastal salt marshes, groundwater aquifers, and fish stocks. The risk of inundation on the Abu Ali Island, given their status as marine sanctuary of international importance, is particularly high. As an adaptation strategy, it is proposed that the KSA should implement Integrated Coastal Zone Management Plan (ICZMP) for the Arabian Gulf coast without further delay for the protection of its vulnerable resources and for sustainable development.     

An environmental forensic investigation at a bio-medical waste treatment and disposal facility in Kerala,India

Indian statutes identify twelve different types of biomedical wastes and give the treatment and disposal options for each. Since it is not possible for every generator of biomedical waste to go for their own treatment and disposal facility, the small-scale generators take the service of centralized treatment and disposal facilities available to them on payment. In the state of Kerala in India, where the basic health indicators match those of many developed countries, the centralized biomedical waste treatment facility is run by Indian Medical Association (IMA), Kerala, under the banner IMAGE (IMA Goes Eco-Friendly) at a place called “Kanjikode” in the Palakkad District. The facility receives biomedical waste from around 4500 hospitals across the State and an equal number of medical laboratories. The plant incinerates the incinerable waste and the other kind of waste are disinfected and decontaminated. The residual ash and dried sludge are then moved to the landfill area. Recently, the facility was in the middle of a controversy due to the alleged health hazards it posed to the surrounding population. An environmental forensic investigation was carried out at the site to establish the merits of the allegation. The reported study is a part of the investigation where groundwater was analysed for the presence of heavy metals. As the biomedical waste contain heavy metals like Zn, Pb, Cd, Cr, and Hg, the presence of these were analysed to establish contamination of groundwater by the facility. The study area is bounded by Malampuzha dam and Korayar river. Groundwater contaminant transport modelling was done for a 3430 m × 3960 m area surrounding the waste treatment facility using Visual MODFLOW and MODPATH. Ground water flow direction and particle pathlines were computed to track the movement of contaminants. Groundwater samples were collected from the area shown to be polluted by the model, if metals were discharged by the facility, and also from outside this area. Water samples were collected conforming to the guidelines in the “Pollution Crime Forensic Investigation Manual” published by INTERPOL. The collected water samples were tested for heavy metal concentration using atomic absorption spectroscopy (AAS). The water sample analysis showed that the groundwater is not contaminated by heavy metal discharge from the biomedical treatment facility.     

Investigation on the Influence of EVA Content on the Mechanical and Thermal Characteristics of Poly(lactic acid) Blends

Poly(lactic acid) (PLA) has gained considerable attention nowadays as a biocompatible polymer owing to its advantage of being prepared from renewable resources. PLA exhibits excellent tensile strength, fabricability, thermal plasticity and biocompatibility properties comparable to many petroleum based plastics. However, low heat distortion temperature, brittleness and slow crystallization rate limit the practical applications of PLA. In order to address these limitations, an attempt has been made in the current work to prepare binary blends of PLA with ethylene vinyl acetate (EVA) at different compositions via melt mixing technique. Systematic investigation on the mechanical properties, thermal degradation and crystallization behavior for PLA-EVA blends was carried out. The impact strength of binary blends of PLA–EVA was found to increase significantly by 176% for 15 wt% of EVA compared to virgin PLA. This is due to the strong interfacial adhesion among PLA and EVA resulting in brittle to ductile transition. Scanning electron microscopy analysis for impact fractured surfaces of binary blends of PLA implied the toughening effect of PLA by EVA. Thermogravimetry analysis results revealed that the activation energy of PLA–EVA blends decreased with increase in EVA content in the PLA matrix. While, differential scanning calorimetry results obtained for PLA–EVA blends revealed the improvement in crystallinity when compared with neat PLA. The effect of EVA on non-isothermal melt crystallization kinetics of PLA was also examined via DSC at various heating rates. Decreasing trend in the t_1/2 values indicated the faster rate of crystallization mechanism after addition of EVA in the PLA matrix.     

Cadmium and copper toxicity in three marine macroalgae: evaluation of the biochemical responses and DNA damage

Marine macroalgae have evolved a different mechanism to maintain physiological concentrations of essential metal ions and non-essential metals. The objective of the present work was to evaluate the antioxidant response and DNA damage of copper and cadmium ions in three halophytes, namely, Acanthophora spicifera, Chaetomorpha antennina, and Ulva reticulata. Accumulation of copper was significantly higher (P?P?U. reticulata > A. spicifera > C. antennina. DNA damage index analysis supported that copper was significantly (P?相似文献   

Exploring potential of C band synthetic aperture radar imagery to investigate rice crop growth mechanism and productivity

Environmental Science and Pollution Research - Development of satellite technology over decades established unique approach to analyze rice crop phenological parameters and supervise growth and...     

Rapid synthesis of mono/bimetallic (Zn/Co/Zn–Co) zeolitic imidazolate frameworks at room temperature and evolution of their CO2 uptake capacity

Environmental Chemistry Letters - Carbon dioxide (CO2) emissions from fossil fuels cause air pollution and lead to adverse impact on environment. To achieve low-carbon economy, capturing CO2 in the...     

Assessment of the effects of municipal sewage,immersed idols and boating on the heavy metal and other elemental pollution of surface water of the eutrophic Hussainsagar Lake (Hyderabad,India)

The surface water qualities of Hussainsagar, an eutrophic urban lake in the midst of twin cities of Hyderabad and Secunderabad (India) receiving large quantities of external inputs—both untreated municipal sewage containing industrial effluents, and treated sewage, a large number of annually immersed idols of God and Goddess, and intense boating activities were assessed in relation to the concentration of elements including heavy metals of the water along the necklace road of the lake. Elemental analyses of water using ICP-MS revealed 26 elements including heavy metals—As, Cd, Cr, Ni, Pb, Cu, Fe, Mn, Se, Ba, Zn, Mo, V, Co, Ag, Sr, Rb, Mg, K, Ca, Al, Si, Sb, Na, Li, and B, in the surface water of the lake. Of these, the first 15 elements were found in elevated concentrations in the water at the outfall point of the untreated municipal sewage (site 3), which was the main dominating source of contamination of the lake water while Cu and Sb were recorded in higher concentrations at the outfall of treated effluent from Sewage Treatment Plant, and three elements (Ba, Si, and B) were in higher concentration at the sites of outfall of sewage flowing from an oxygenated pond (site 4), Ca, Zn, and Sr, at the site immersed with idols (site 1), and Pb, Ag, and Al at the center of the lake (site 5) with intense boating activities. Concentrations of most of these elements exceeded the maximum permissible limits of national (Indian Council Medical Research) standards for drinking water. The concentrations of most of the elemental contaminants showed significant positive correlations between them.     

Parametric study of MSW landfill settlement model

A newly developed and validated constitutive model that accounts for primary compression and time-dependent mechanical creep and biodegradation is used for parametric study to investigate the effects of model parameters on the predicted settlement of municipal solid waste (MSW) with time. The model enables the prediction of stress strain response and yield surfaces for three components of settlement: primary compression, mechanical creep, and biodegradation. The MSW parameters investigated include compression index, coefficient of earth pressure at-rest, overconsolidation ratio, and biodegradation parameters of MSW. A comparison of the predicted settlements for typical MSW landfill conditions showed significant differences in time-settlement response depending on the selected model input parameters. The effect of lift thickness of MSW on predicted settlement is also investigated. Overall, the study shows that the variation in the model parameters can lead to significantly different results; therefore, the model parameter values should be carefully selected to predict landfill settlements accurately. It is shown that the proposed model captures the time settlement response which is in general agreement with the results obtained from the other two reported models having similar features.     

Trajectory of an oil spill off Goa, eastern Arabian Sea: field observations and simulations

An oil spill occurred off Goa, west coast of India, on 23 March 2005 due to collision of two vessels. In general, fair weather with weak winds prevails along the west coast of India during March. In that case, the spill would have moved slowly and reached the coast. However, in 2005 when this event occurred, relatively stronger winds prevailed, and these winds forced the spill to move away from the coast. The spill trajectory was dominated by winds rather than currents. The MIKE21 Spill Analysis model was used to simulate the spill trajectory. The observed spill trajectory and the slick area were in agreement with the model simulations. The present study illustrates the importance of having pre-validated trajectories of spill scenarios for selecting eco-sensitive regions for preparedness and planning suitable response strategies whenever spill episodes occur.