Ameliorating effect of N-acetylcysteine and curcumin on pesticide-induced oxidative DNA damage in human peripheral blood mononuclear cells

Endosulfan, malathion, and phosphamidon are widely used pesticides. Subchronic exposure to these contaminants commonly affects the central nervous system, immune, gastrointestinal, renal, and reproductive system. There effects have been attributed to increased oxidative stress. This study was conducted to examine the role of oxidative stress in genotoxicity following pesticide exposure using peripheral blood mononuclear cells (PBMC) in vitro. Further possible attenuation of genotoxicity was studied using N-acetylcysteine (NAC) and curcumin as known modulators of oxidative stress. Cultured mononuclear cells was isolated from peripheral blood of healthy volunteers, and exposed to varying concentrations of different pesticides: endosulfan, malathion, and phosphamidon for 6, 12, and 24 h. Lipid peroxidation was assessed by cellular malondialdehyde (MDA) level and DNA damage was quantified by measuring 8-hydroxy-2'-deoxyguanosine (8-OH-dG) using ELISA. Both MDA and 8-OH-dG were significantly increased in a dose-dependent manner following treatment with these pesticides. There was a significant decrease in MDA and 8-OH-dG levels in PBMC when co-treated with NAC or/and curcumin as compared to pesticide alone. These results indicate that pesticide-induced oxidative stress is probably responsible for the DNA damage, and NAC or curcumin attenuate this effect by counteracting the oxidative stress.     

Current perspective on wastewater treatment using photobioreactor for Tetraselmis sp.: an emerging and foreseeable sustainable approach

Environmental Science and Pollution Research - Urbanization is a revolutionary and necessary step for the development of nations. However, with development emanates its drawback i.e., generation of...     

Phytoremediation potential of Petunia grandiflora Juss., an ornamental plant to degrade a disperse, disulfonated triphenylmethane textile dye Brilliant Blue G

Phytoremediation provides an ecofriendly alternative for the treatment of pollutants like textile dyes. The purpose of this study was to explore phytoremediation potential of Petunia grandiflora Juss. by using its wild as well as tissue-cultured plantlets to decolorize Brilliant Blue G (BBG) dye, a sample of dye mixture and a real textile effluent. In vitro cultures of P. grandiflora were obtained by seed culture method. The decolorization experiments were carried out using wild as well as tissue-cultured plants independently. The enzymatic analysis of the plant roots was performed before and after decolorization of BBG. Metabolites formed after dye degradation were analyzed using UV–vis spectroscopy, high-performance liquid chromatography, Fourier transform infrared spectroscopy, and gas chromatography–mass spectrometry. Phytotoxicity studies were performed. Characterization of dye mixture and textile effluent was also studied. The wild and tissue-cultured plants of P. grandiflora showed the decolorized BBG up to 86 %. Significant increase in the activities of lignin peroxidase, laccase, NADH-2,6-dichlorophenol-indophenol reductase, and tyrosinase was found in the roots of the plants. Three metabolites of BBG were identified as 3-{[ethyl(phenyl)amino]methyl}benzenesulfonic acid, 3-{[methyl (phenyl)amino]methyl}benzenesulfonic amino acid, and sodium-3-[(cyclohexa-2,5-dien-1-ylideneamino)methyl]benzenesulfonate. Textile effluent sample and a synthetic mixture of dyes were also decolorized by P. grandiflora. Phytotoxicity test revealed the nontoxic nature of metabolites. P. grandiflora showed the potential to decolorize and degrade BBG to nontoxic metabolites. The plant has efficiently treated a sample of dye mixture and textile effluent.     

Design and off-design analyses of a pre-combustion CO2 capture process in a natural gas combined cycle power plant

In this study, a cycle designed for capturing the greenhouse gas CO₂ in a natural gas combined cycle power plant has been analyzed. The process is a pre-combustion CO₂ capture cycle utilizing reforming of natural gas and removal of the carbon in the fuel prior to combustion in the gas turbine. The power cycle consists of a H₂-fired gas turbine and a triple pressure steam cycle. Nitrogen is used as fuel diluent and steam is injected into the flame for additional NO_x control. The heat recovery steam generator includes pre-heating for the various process streams. The pre-combustion cycle consists of an air-blown auto-thermal reformer, water–gas shift reactors, an amine absorption system to separate out the CO₂, as well as a CO₂ compression block. Included in the thermodynamic analysis are design calculations, as well as steady-state off-design calculations. Even though the aim is to operate a plant, as the one in this study, at full load there is also a need to be able to operate at part load, meaning off-design analysis is important. A reference case which excludes the pre-combustion cycle and only consists of the power cycle without CO₂ capture was analyzed at both design and off-design conditions for comparison. A high degree of process integration is present in the cycle studied. This can be advantageous from an efficiency stand-point but the complexity of the plant increases. The part load calculations is one way of investigating how flexible the plant is to off-design conditions. In the analysis performed, part load behavior is rather good with efficiency reductions from base load operation comparable to the reference combined cycle plant.     

Impact of urbanization on the groundwater regime in a fast growing city in central India

This paper describes the impact of urbanization on the groundwater regime in a fast growing city, Solapur, in central India, giving special emphasis on the management of the present and ultimate demand of water in 2,020 AD. The objective is to apprise the city planners and administrators of the effects of urbanization on the groundwater regime in a fast growing medium-sized city in a developing country where the infrastructure developments are not in conformity with the rapid growth in population. Solapur city with an area of 178.57 km2 receives a recharge of about 24 million m3 of groundwater from various sources annually. Reduction in recharge, as conventionally assumed due to the impact of urbanization, could not, however, be well established. Instead, there was a rise in recharge as water use in the city grew from time to time and more and more water was supplied to satisfy the human needs. Compared to mid-1970s, groundwater levels have increased within the main city area due to increased recharge and decreased groundwater abstraction. However, outside the main city area, there is a general decline in groundwater levels due to increased groundwater utilization for irrigation purposes. Groundwater quality deterioration has been highly localized. Water quality has deteriorated during the last 10 years, especially in dugwells, mainly due to misuse and disuse of these structures and poor circulation of groundwater. However, in case of borewells, comparison of the present water quality with that in mid-1970s and early 1980s does not show any perceptible change. Deeper groundwater tapped by borewells can still be used for drinking purposes with caution.     

Monitoring of organochlorine pesticides in and around Keoladeo National Park, Bharatpur, Rajasthan, India

Keoladeo National Park (KNP) is an important wintering ground for thousands of birds that undertake a perilous journey over the Himalaya to make a seasonal home in a wetland ecosystem. However, this wetland is now getting polluted by various types of contaminants such as pesticides because of the agricultural practices in the catchment area from where the park receives water. Keeping this in mind, the present study has been undertaken to assess the organochlorine pesticide (OCP) residues in the sediments inside and around KNP. Samples were collected from the different blocks of the park. The concentrations of α-HCH, β-HCH, γ-HCH, δ-HCH, S-HCH, aldrin, dieldrin, heptachlor, hept.epoxide, endosulfan-I, endosulfan-II, endo.sulfate, S-endosulfan, endrin, 4,4'-DDE, 4,4'-DDD, and DDT were quantified using gas chromatography with electron capture detection. Analysis showed that the samples were contaminated with the above mentioned pesticides and that the concentration of total OCPs in the sediments varied from 0.1173 (dieldrin) to 5.558 ppm (γ HCH) in the samples collected from inside the park, whereas a range of pesticides varying in concentration from 0.1245 (4,4'-DDD) to 7.54 ppm (γ HCH) was found in samples from outside the park. Residues of S-HCH and S-endosulfan were not detected in any of the sediment samples. The occurrence of pesticides inside the park is a major threat to the park's biodiversity. Eco-friendly agriculture practices with minimal use of inorganic chemicals are suggested to minimize the pesticide residue levels in the park.     

Dynamics of toxic heavy metals in different compartments of a highly urbanized closed aquatic system

This paper deals with the dynamics of chromium, nickel, copper and lead among the different components namely water, surface sediments, submerged and free floating macrophytes and fish of the twin manmade lakes, Upper and Lower lakes, of Bhopal (M.P., India). Some basic parameters of water and sediment have also been studied. The basin of the lake system is densely populated and the water is used for various purposes including drinking. Ni and Pb along with nitrate in both lakes are significantly higher than the drinking water quality criteria of USEPA. The concentration of the metals in the sediments is noticeably higher than that present in the adjoining rock, particularly Ni and Pb. There is a significant uptake of metals by the macrophytes (Eichhornia crassipes and Hydrilla verticillata) and fish (Labeo rohita and Oreochromis niloticus) mainly in summer. The fish of Lower lake (O. niloticus) is unfit for human consumption. The data have been statistically treated. Principle component analysis and cluster analysis were performed to define the origin of metals and to assess the relationship among the sites. Overall the Lower lake is more polluted than the Upper lake. In aggregate, the lake system is under an environmental stress due to certain practices.     

Isolation and identification of Aeromonas caviae strain KS-1 as TBTC- and lead-resistant estuarine bacteria

Tributyltin chloride (TBTC)- and lead-resistant estuarine bacterium from Mandovi estuary, Goa, India was isolated and identified as Aeromonas caviae strain KS-1 based on biochemical characteristics and FAME analysis. It tolerates TBTC and lead up to 1.0 and 1.4 mM, respectively, in the minimal salt medium (MSM) supplemented with 0.4 % glucose. Scanning electron microscopy clearly revealed a unique morphological pattern in the form of long inter-connected chains of bacterial cells on exposure to 1 mM TBTC, whereas cells remained unaltered in presence of 1.4 mM Pb(NO₃)₂ but significant biosorption of lead (8 %) on the cell surface of this isolate was clearly revealed by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. SDS-PAGE analysis of whole-cell proteins of this lead-resistant isolate interestingly demonstrated three lead-induced proteins with molecular mass of 15.7, 16.9 and 32.4 kDa, respectively, when bacterial cells were grown under the stress of 1.4 mM Pb (NO₃)₂. This clearly demonstrated their possible involvement exclusively in lead resistance. A. caviae strain KS-1 also showed tolerance to several other heavy metals, viz. zinc, cadmium, copper and mercury. Therefore, we can employ this TBTC and lead-resistant bacterial isolate for lead bioremediation and also for biomonitoring TBTC from lead and TBTC contaminated environment.     

Abiotic Oxidation Studies of Oxo-biodegradable Polyethylene

The best approach to induce oxo-biodegradation in polyethylene is the use of special additives known as pro-oxidants. Pro-oxidants accelerate abiotic oxidation and subsequent polymer chain cleavage rendering the product apparently more susceptible to biodegradation. In this work, the abiotic oxidation is studied to understand how the addition of nanoclay affects the oxidation rate and the degradation mechanism of oxo-biodegradable polyethylene. In order to achieve this, the following materials were used in this study: (1) polyethylene (PE), (2) oxo-biodegradable polyethylene (OPE), (3) polyethylene nanocomposite (PENac), and (4) oxo-biodegradable polyethylene nanocomposite (OPENac). Wide-Angle X-ray scattering (WAXS) and Transmission Electron Microscopy (TEM) studies reveal that grafting in the preparation of composites helps to achieve mixed intercalated/exfoliated morphology in PENac and OPENac. Abiotic oxidation was carried out in an oven for a period of 14 days at 70 °C with air supply. The effect of abiotic oxidation was evaluated by measuring the changes in tensile strength, elongation at break, carbonyl index and molecular weight. Results show that OPE and OPENac are more susceptible to oxidation than PENac. The molecular weight distribution data obtained from GPC reveal that the addition of nanoclay does not alter the oxidation mechanism in OPE significantly.     

IoT technologies in smart environment: security issues and future enhancements

Environmental Science and Pollution Research - IoT plays an important role in the overall development and advancement of the country as it is the key ingredient for the development of the smart...