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Экологическая и аналитическая токсикология

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Объем 5, Проблема 6 (2015)

исследовательская статья

Analysis of Occupational Hazards and Safety of Workers in Selected Working Environments within Enugu Metropolis

Emodi Edmund E

Workers in various occupations have been subjected to various enormous pains and sufferings. The workplace is supposed to be the second home of the workers, having put in a lot of hours in the workplace each week. Unfortunately, some of the hazards faced by workers are brought about by the ignorance of the workers, resulting in the workers not adhering to the guiding rules in the occupation. Besides, the employers themselves also contribute towards bring these hazards into place in the working environment. This paper, therefore examined the various hazards faced by workers in various occupations in Enugu Metropolis. Occupations in seven industries of agriculture, building, construction, Energy/ power, communications, Education and transport were studied. Questionnaires were used primarily to collect data. Descriptive statistics of frequency distribution and percentage were used in the analysis of data. The findings included that there was no policy guideline in each of the industries studied in the area. It was recommended among other things that employers should improve working conditions of workers in the industries and organize seminars, education programmes and ergonomic interventions so as to ensure that workers remain healthy.

исследовательская статья

Photocatalytic Degradation of Toxic Methyl Red Dye Using Silica Nanoparticles Synthesized from Rice Husk Ash

Vinoda BM, Vinuth M, Yadav D Bodke and Manjanna J

Herein we reported the preparation and potential application of SiO2 NPs (SiO2 NPs) for the photocatalytic degradation of methyl red dye in aqueous medium. These are synthesized from rice husk ash (RHA) which was collected from rice mill near Shankaraghatta (Shimoga, Karnataka). Silica was present in large quantity in RHA, hence it can be extracted by an alkaline precipitation method was developed to produce pure silica xerogel. From XRD and FTIR analysis revealed the amorphous nature of SiO2 NPs along with the presence of siloxane group. TEM image confirms the formation of SiO2 NPs at 10 to 20 nm range. Furthermore the stabilization and formation of SiO2 NPs was confirmed by SEM/EDAX and TEM analysis. The photo catalytic activity of prepared pure SiO2 NPs towards remediation of dyes like Methyl red (MR) dye has been tested.

исследовательская статья

Fe Absorption and Distribution of Imperata cylindrica (L.) P. Beauv. under Controlled Conditions

Alejandro Franco, Lourdes Rufo and Vicenta de la Fuente

Background and aims: Imperata cylindrica (L.) P. Beauv. is a grass whose capacity to hyperaccumulate Fe and biomineralize jarosite has been proved in its natural habitat. Here we carried out an experiment to reproduce the Fe hyperacummulation under laboratory controlled conditions and a study to locate and identify the Fe compounds formed in the process. Methods: The experiment was conducted with plants cultivated in a hydroponic culture in Hoagland solution enriched with 300 mg/kg of Fe at pH 3 for 60 days. Samples were analyzed with mass spectrometry (ICP-MS) for its elemental analysis; with electronic microscopy (SEM, TEM) and energy dispersive X-ray (EDX) analysis to analyze the different organs, tissues and cell content; and with X-ray diffraction (XRD) to identify the possible biomineral production. Results: I. cylindrica specimens reached 4805, 7976 and 53886 Fe mg/kg d.w. in leaves, rhizomes and roots respectively. Fe was visible as a plaque in the root and as deposits inside all the organs. Part of these accumulations corresponds to crystallized jarosite and iron oxides. Conclusions: We induced Fe hyperaccumulation and biomineralization in I. cylindrica under specific controlled conditions. Considering this we think this species could be an interesting candidate to phytoremediate soils.

исследовательская статья

Heavy Metal Concentrations in Plants and Soil along Heavy Traffic Roads in North Central Nigeria

Ogundele DT, Adio AA and Oludele OE

Plant and soil samples were analyzed to determine the heavy metals (Cd, Zn, Cu, Cr, Pb and Ni) along major roads in Kwara State, Nigeria. Control plant and soil samples were obtained from Kwara State University (KWASU). Eight soil and plant samples were collected. One sample each of soil and plant was collected from Kwara State University as the control sample. Three plant species (Kyllinga pumila michx, Kyllinga squamulata thanm ex vahl, Cenchrus biflorus roxb) on which animals feed were collected along major roadsides. The samples were digested using wet method and heavy metals were analyzed using Atomic Absorption Spectrophotometry Technique. Lead concentration of plants from the sites was found between 24-142 mg/kg and 24-157.667 mg/kg in soil samples. Copper was found between 28.55-115.2 mg/kg and 7.70-80.13 mg/kg in plant and soil samples respectively. Zinc ranges from 13.00-120.45 mg/kg and 30.8- 219.23 mg/kg in plants and soil respectively. Cadmium was between BDL-0.400 mg/kg and BDL-0.366 mg/kg in plants and soil. Chromium was detected between BDL-53.65 mg/kg and 10.57-77.10 mg/kg in plants and soil respectively. Nickel was between 1.65-11.85 mg/kg and 1.83-14.87 mg/kg in soil and plants samples. Heavy metals (Cd, Zn, Cu, Cr, Pb and Ni) in the control samples were found to be 0.35, 40.00, 88.55, 0.65, 238 and 0.65 mg/kg for Cadmium, Zinc, Copper, Chromium, Lead and Nickel in plants respectively. The soil samples were between 0.066, 9.50, 4.83, 55.63, 33.667, 4.33 mg/kg, Zinc, Copper, Chromium, Lead and Nickel respectively. Based on this study, plant and soil along road sides were found with high concentration of heavy metals.

исследовательская статья

Evaluation of Biofield Treatment on Physical and Thermal Characteristics of Selenium Powder

Mahendra Kumar Trivedi, Rama Mohan Tallapragada, Alice Branton1, Dahryn Trivedi, Gopal Nayak, Omprakash Latiyal and Snehasis Jana

Selenium (Se) is an essential trace element, and its deficiency in the humans leads to increase the risk of various diseases, such as cancer and heart diseases. The objective of this study was to investigate the influence of biofield energy treatment on the physical and thermal properties of the selenium powder. The selenium powder was divided into two parts denoted as control and treated. Control part was remained as untreated and treated part received Mr. Trivedi’s biofield energy treatment. Both control and treated selenium samples were characterized using x-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis - differential thermal analysis (TGA-DTA), and Fourier transform infrared spectroscopy (FT-IR). The XRD data showed that biofield energy treatment has slightly altered the lattice parameter (0.07%), unit cell volume (0.15%), density (-0.14%), atomic weight (0.15%), and nuclear charge per unit volume (-0.21%) in the treated selenium powder as compared to the control. The crystallite size of the treated selenium powder was reduced considerably from 106.98 nm (control) to 47.55 nm. The thermal analysis study showed that the latent heat of fusion was 64.61 J/g in the control, which changed to 68.98, 52.70, 49.71 and 72.47 J/g in the treated T1, T2, T3, and T4 samples respectively. However, the melting temperature did not show any considerable change in the treated selenium samples as compared to the control. The FT-IR spectra showed the absorption peak at 526 and 461 cm-1, which corresponding to metal oxide bonding vibration in the control and treated selenium powder respectively. Hence, overall data suggest that, the biofield energy treatment considerably altered the physical and thermal properties of selenium powder. Therefore, biofield energy treatment could make selenium even more useful nutrient in human body.

исследовательская статья

Biomarker Response and Biomass Toxicity of Earthworms Aporrectodea caliginosa Exposed to IGRs Pesticides

Hoda M Nasr and Mohamed EI Badawy

Earthworms play key roles in soils and sub lethal effects of environmental toxicants on these organisms should be taken seriously, since they might have detrimental effects on higher ecological levels. In laboratory experiments, we have assessed to investigate the toxicity of two insect growth regulators (IGRs) flufenoxuron and pyriproxyfen at different application rates and exposure times against mature stage earthworms Aporrectodea caliginosa. The effects of these pesticides on the growth rate in relation to the activities of acetylcholinesterase (AChE), polyphenol oxidase (PPO) and glutathione S-transferase (GST) as biomarker indicators were evaluated to elucidate the mechanisms of action. Toxicity studies indicated that pyriproxyfen was more harmful to mature earthworms than flufenoxuron with LC50=42.63 and 60.66 mg/kg after four weeks, respectively. The reduction in growth rate of all pesticide-treated worms was dosedependent over the 28-day exposure period which was accompanied by a decrease in AChE, PPO and GST activities. Relationships between growth rate and enzyme activities provided strong evidence for the involvement of pesticidal contamination in the biochemical changes of earthworms, which can be used as a bioindicator of soil contamination by pesticides.

исследовательская статья

Importance of Oxidative Stress Marker in Healthy Females Undergoing Assisted Reproductive Technology

Parijatham S, Saikumar P and Chandra Selvi E

Background: Females with primary infertility are subjected to various investigations. Most of them are subjected for stimulation of ovulation. Before subjecting them for stimulation, case selection is important. Knowledge about the basic problems involved in infertility is very important. The male factor should be ruled out. Whatever the reason may be, the females bare the sole responsibility. In infertile couples, oxidative stress (OS) in the females involved where male factor is the cause is estimated. Because the mental stress they face in the society may increase the levels of oxidative stress in them. Aim: Serum level of oxidative stress marker Malondialdehyde (MDA) was done in females in infertile couples where the male factor plays the causative factor. Estimated levels were compared with the MDA levels of fertile females. Materials and methods: 17 infertile couples who were attending fertility clinic at Sree Balaji Medical College and Hospital were selected. In them, the male factor was the reason for infertility. These 17 females were included in the study where the female factors were normal and age, height and weight matched 25 females were included as controls. Results: MDA levels were high (2.8 ± 0.08) in females where other fertility factors were normal compared with fertile females (0.91 ± 0.13). Conclusion: In apparently healthy females where male factor is the etiology, failure to conceive by Assisted Reproductive Technology (ART) may be due to much reason. Increased levels of MDA may be one of the reasons. This may produce difficulty in conception by Assisted Reproductive Technology (ART).

исследовательская статья

Adsorption of Cr(VI) from Aqueous Solution onto a Mesoporous Carbonaceous Material Prepared from Naturally Occurring Pongamia pinnata Seeds

Brungesh KV, Nagabhushana BM, Raveendra RS, Hari Krishna R, Prashantha PA and Nagabhushana H

In the present study, adsorption of Cr(VI) from aqueous solution by mesoporous Pongamia pinnata Carbonaceous Material (PPCM) as an excellent adsorbent derived from natural source was investigated. PPCM was prepared using simple chemical activation method and Cr(VI) detection by spectrophotometrically. The synthesized mesoporous carbonaceous material was characterized by FT-IR, PXRD, SEM before and after adsorption. Batch mode experiments were used to analyze the effect of various parameters like effect of pH, initial Cr(VI) concentration, adsorbent dose, and contact time on the adsorption capacity of Cr (VI) on PPCM . It was found that, maximum Cr(VI) removal (99.8%) was observed at pH 1.0 with sorption capacity of 194.6 mg g-1. The adsorption isotherms of Cr(VI) onto PPCM obtained were analyzed by Langmuir and Freundlich isotherm models and sorption data was better fitted by the Freundlich isotherm model. Adsorption kinetics were performed and obeys pseudo second order kinetic model. Experimental and kinetic results reveal that PPCM is a potential adsorbent in removal of Cr(VI) from waste water.

исследовательская статья

Characterization of Physical, Thermal and Spectroscopic Properties of Biofield Energy Treated p-Phenylenediamine and p-Toluidine

Mahendra Kumar Trivedi, Alice Branton, Dahryn Trivedi, Gopal Nayak, Ragini Singh and Snehasis Jana

Aromatic amines and their derivatives are widely used in the production of dyes, cosmetics, medicines and polymers. However, they pose a threat to the environment due to their hazardous wastes as well as their carcinogenic properties. The objective of the study was to use an alternate strategy i.e. biofield energy treatment and analyse its impact on physicochemical properties of aromatic amine derivatives viz. p-phenylenediamine (PPD) and p-toluidine. For this study, both the samples were taken and divided into two parts. One part was considered as control and another part was subjected to Mr. Trivedi’s biofield treatment. After treatment, both samples were analysed for their physical, thermal and spectral properties as compared to their respective control samples. The analysis was done by using X-ray diffraction (XRD), surface area analyser, thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), and ultraviolet-visible (UV-Vis) spectroscopy. The XRD studies and surface area analysis of PPD sample revealed that the crystallite size and surface area of the treated sample was increased by 11.12% and 8.49%, respectively as compared to the control sample. In case of p-toluidine, the crystallite size and surface area of treated sample were decreased by 4.8% and 8.43%, respectively as compared to control. The treated PPD sample also showed an alteration in thermal degradation properties as it exhibited two-steps thermal decomposition as compared to single step decomposition in the control sample. In case of p-toluidine, the treated sample showed decreased onset temperature of degradation (112°C→100°C) and Tmax (temperature at which maximum weight loss occur) (136°C→125°C) as compared to control sample. Moreover, the FT-IR analysis revealed that C-C aromatic stretching peak in treated PPD sample was shifted to the lower frequency (1456→1444 cm-1) as compared to the control sample. Besides, in p-toluidine, the treated sample showed the alteration in frequencies of C-N-H bending, C-H bending, C-H stretching, and C-C aromatic stretching and bending peaks as compared to the control sample. However, no alteration was found in UV-Vis spectroscopic analysis of treated PPD and p-toluidine samples as compared to their respective control samples. These findings suggest that the biofield treatment significantly altered the physical, thermal and IR spectroscopic properties of PPD and p-toluidine samples

исследовательская статья

Simultaneous Determination of As, Cu, Cr, Se, Sn, Cd, Sb and Pb Levels in Infant Formulas by ICP-MS after Microwave-Assisted Digestion: Method Validation

Gianluigi Maria Lo Dico, Gaetano Cammilleri, Andrea Macaluso, Antonio Vella, Giuseppe Giangrosso, Mirella Vazzana and Vincenzo Ferrantelli

The growing importance of chemical measurements has greatly pressured the development of measures to improve the quality of analytical results and to guarantee quality to the end users. In this work an ICP-MS method was validated for the simultaneous determination of essential trace elements (Chromium, Selenium and Copper) and non-essential toxic elements (Cadmium, Antimony, Arsenic, Tin and Lead) in infant formula available in Sicily. The extraction of samples was performed by a microwave assisted digestion with HNO3 to stabilize these elements. Several parameters have been taken into account and evaluated for the validation of method: selectivity/specificity, trueness by recovery, repeatability and within-laboratory reproducibility at three levels of concentration, instrumental detection limit, limit of determination (LOD), limit of quantification (LOQ), range of linearity, standard measurement uncertainty. Results indicate that this method could be used in the laboratory for the routine determination of these 8 essential and non-essential elements in infant formulas with acceptable analytical performance.

исследовательская статья

Arsenic Exposure: Mechanisms of Action and Related Health Effects

Bilal Ahmad Tantry, Divya Shrivastava, Ibrahim Taher and Mudasar Nabi Tantry

Arsenic represents a natural drinking water contaminant that can deteriorate health due to its extreme toxic nature. Infant mortality, neuropathies, liver disease, cancer, eye diseases, cardiovascular disease and different skin alterations can stem from chronic arsenic exposure. The predominant species of arsenic comprise of arsenite and arsenate. Arsenite is more toxic in nature as compared to arsenate. Arsenic pollution is mainly caused by natural process such as weathering of rocks and minerals followed by leaching and industrial activities that lead to contamination of soil and groundwater. The WHO guideline permits the maximum limit of arsenic as 10 μg/L in drinking water. This review provides a comprehensive overview on arsenic mode of action, its sources and health related effects. The effect of toxicity, biomarkers of arsenic toxicity and the mechanism of arsenic dangers on humans are also discussed.

исследовательская статья

Physicochemical Characteristics of Two Prototypical Home-Use Consumer Products Containing Engineered Nanomaterials

Christie M Sayes, Aishwarya Sooresh and Kenith E Meissner

The extensive use of nanomaterials in new products for the building envelope is expanding rapidly and continues to influence materials science and environmental health. However, there is still uncertainly around the safety of these novel materials to humans and the environment; therefore, more life cycle data is needed. One analytical technique to gather information critical to the development of safe nanomaterials is to characterize the physicochemical properties of the nano-enabled product along various stages of the product life cycle. This research investigates two different products fortified with nanoscale titania relevant to the building and construction industry: (1) a white paint and (2) a lacquer formulation. Three brands of commercially available titanium dioxide (TiO2) nanoparticles were incorporated into labformulated paint and lacquer mixtures. These fortified products were subjected to simulated degradation processes (a.k.a. “wear-and-tear” scenarios) to mimic the real world. Unincorporated TiO2, as well as TiO2 incorporated “wornand- torn” powders, were processed and analyzed for physical, chemical, and toxicological characteristics. Electron microscopy confirmed the presence of nanoscale TiO2 particles in the painted and lacquered matrices for all three nanoparticle-types. Cell viability and reactive oxygen species (ROS) generation was measured in immortalized human lung epithelial cells (A549). Results from bioassays showed that ROS generation between unincorporated TiO2 particles and TiO2 incorporated paint powders showed little difference, but, the TiO2 incorporated lacquered powders demonstrated significantly lower ROS generation and cell death. Thus, the polymer-based lacquer mitigated tissue damage. Our results show that using a life cycle approach may help provide data – and by extension, an understanding - of nanomaterial properties in the context of developed consumer products.

исследовательская статья

Chemical Element Concentrations in the Blood of Green Turtles (Chelonia Mydas) Captured at Fernando De Noronha Marine National Park, Brazil

Fabiola Eloisa Setim Prioste, Vanessa Cristina de Oliveira Souza, Mariana Ramos Queiroz, Rosely Gioia-Di Chiacchio, Fernando Barbosa Jr and Eliana Reiko Matushima

Green turtles may be used as biomonitors of marine environments because of their longevity and feeding habits (omnivorous during the first years of life and herbivorous during the juvenile and adult stages), which can indicate the degree of ocean contamination in the areas where they feed. Studies of metal and chemical element concentrations in the blood of green turtles are still rare; therefore, the results are difficult to interpret, although it appears that the serum levels of certain elements found in green turtles are much higher than the minimal risk levels indicated for human health. The objective of this study was to measure the concentrations of the essential elements Calcium (Ca), Selenium (Se), Zinc (Zn), Manganese (Mn), Cobalt (Co), Copper (Cu) and Molybdenum (Mo) and the metals Aluminum (Al), Arsenic (As), Lead (Pb), Cadmium (Cd), Lithium (Li), Cesium (Cs), Barium (Ba), Rubidium (Rb), Uranium (U), Thallium (Tl), Beryllium (Be), Antimony (Sb) and Tellurium (Te) in the blood of 31 juvenile green turtles captured in Fernando de Noronha Marine National Park (Parque Nacional Marinho de Fernando de Noronha), Brazil, and to correlate these concentrations with the curved carapace length to identify possible cumulative effects. Furthermore, because the basal levels for these elements have not yet been established for green turtles, the effects of these chemicals on the health of the species are still unknown. Thus, most of these contaminants should be described as "alarming" until further clarification.

исследовательская статья

Characterization and Isolation of Fungi for Removal of Color from Pulp and Paper Mill Effluent, Meerut (India)

Rajesh Kumar, Rajdeo Kumar, Ashish Chauhan, Manoj Kumar, Manish Kumar Goyal and Thakur IS

In this research paper, use of biological agents for the treatment of effluent is more environmental friendly and can lead to the production of more value added products like biogas and compost etc. Pulp and paper mill is the major industrial hub in our country. The heavy demand for the paper helps in steady expansion of paper industries. Pulp and paper industry is one of the largest and most notorious sources of industrial pollution. The Ministry of Environment and Forest, Govt. of India has categorized the pulp and paper industry as one of the twenty most polluting industries.

исследовательская статья

Environmental Pollution Remediation through Solidification/Fixation of Heavy Metal Ions in Portland Cement

Manish Kumar Goyal and Ashish Chauhan

Treatment of hazardous wastes existing as effluent using cement-based solidification/stabilization is an effective option for remediating environmental pollution. Among the various treatment techniques, it is one of the most widely acknowledged methods for treating the wastes. The primary objective of this review is to survey our current knowledge in this subject, focusing on cement chemistry, the effects of inorganic (heavy metals) and organic compounds on cement hydration and the mechanisms of immobilization of different organic and inorganic compounds.

исследовательская статья

Comparison of Electron Impact and Electron Capture Negative Ionization for the Quantification of Polybrominated Diphenyl Ethers in Human Plasma

Yan-Ping Lin, Isaac N. Pessah and Birgit Puschner

Polybrominated diphenyl ethers (PBDE) are persistent organic pollutants that are strongly associated with disrupted endocrine and immune functions. Due to the increasing health concerns, it is critical to quantify PBDEs in human specimens. Gas chromatography (GC) - mass spectrometry (MS) with electron impact (EI) and electron capture negative ionization (ECNI) sources were optimized to compare the quantification for ten PBDEs in 0.5 ml of human plasma. Source parameters, including electron energy, emission current, source temperature, focus lens and flow rate of the ECNI source reagent gas (methane), were optimized to achieve the best performances of EI-MS and ECNI-MS. The limits of quantification (LOQ) in human plasma ranged from 20 to 497 fg injected into GC/ECNI-MS compared to 519 to 2966 fg when using GC/EI-MS. Especially for highly brominated congeners, GC/ECNI-MS provided much lower LOQs than GC/EI-MS. Obtaining the necessary LOQs with GC/ECNI-MS, the method was validated according to the US Food and Drug Administration guidance for industry using standard materials purchased from the National Institute of Standards and Technology (NIST). The validated GC/ECNI-MS method was used to measure the concentrations of ten tetra-, penta- and hexa-PBDE congeners in maternal human plasma. Tetra-PBDEs, especially BDE-47, were identified as the predominant PBDE burdens in human plasma.

исследовательская статья

Traditional Husbandry Practices and Major Challenge of Young Stock (Camel Calf) in Fafen Zone, Ethiopian Somali Regional State, Ethiopia

Awoke K and Seid Mohamed Ali

The study was conducted between July 2013 and January 2014. The objective of this study was to examine the existing challenges and opportunities of traditional camel calf management practices. The importance of camels as a source of livelihood for pastoralists in eastern Ethiopia cannot be overemphasized. A study was carried out in the districts of Jigjiga, Babile, and Gursum in Fafen zone of Ethiopian Somali regional state, eastern Ethiopia to collect baseline data on camel calf colostrums feeding and management by the Jigjiga, Gurusum and Babile districts that inhabit the area and rearing of camel production. The primary and secondary data were collected to assess the impact of improved camel calf management and information whose dissemination was underway on the productivity of camel calves. During this study, between 30 and 60 households were purposively selected from three locations drawn from the three districts. A total of 130 respondents purposively selected from 60 households in Jigjiga district, 40 from Babile district and 40 household in Gursum per location were interviewed using a semi-structured questionnaire. The questions targeted different aspects of camel calf management and colostrums feeding. Analysis of the data revealed malpractices in the areas of breeding management, colostrums feeding, milk allowance, feeding, and watering and health management, among others, across the studied districts. The feeding of with full suckling of colostrums across studied district Jigjiga (31.7%), Babile (27%) and Gurusm (46.4%). In the other hand, the percentage of case of death camel calves was disease (32.7%) and drought (27.8%) was the second across the studied area. The calves were herd with all-in one 71.7%, 69.1% and 56.1% for Jigjiga, Babilie and Gurusum, respectively. The average culling of bull from herd of camels during the survey year was 16 ± 4 years across the studied districts. In the study areas, the results further indicated that the pastoralists were aware of the challenges facing their camel calves but did not have the knowledge to adequately deal with the constraints and colostrums feeding. This study concluded that the existing indigenous camel calf and information on camel calf management have great potential to improve camel calf performance if widely disseminated among the studied districts. Awareness creation among pastoralists and agro pastoral on the dangers of the current malpractices, vigorous dissemination of the technologies/information and follow-up to ensure utilization and/ or application are strongly recommended.

исследовательская статья

Microbial Diversity of a Remote Aviation Fuel Contaminated Sediment of a Lentic Ecosystem in Ibeno, Nigeria

Udotong IR, Uko MP and Udotong JIR

Environmental pollution from Oil & Gas Exploration & Production (O&G E&P) activities remains one of the major problems in the oil-producing communities of Nigeria. This results from improper oily wastes disposal as well as incessant oil spills in the region. The operator’s lack of responsible business practices in wastes management and the over-dependence of the economy on oil and gas earnings, in the most part, exacerbate the problems of environmental pollution. Government's lack of political will power which treats issues on oil pollution with levity and long period of neglect of these polluted sites leave the environment ecologically destabilized. Studies to ascertain the ecological status of remote aviation fuel-contaminated sediment of a lentic ecosystem in Inua Eyet Ikot village, Ibeno, Nigeria, have been carried out using conventional microbiological culture-dependent methods. This methodology is known to reveal only <1% of the microbial diversity present. These results were therefore considered inaccurate and grossly misleading. In this present study, sediment samples from this lentic ecosystem in Ibeno, Nigeria previously polluted by Aviation fuel in 2001 (about 14 years ago) were collected and analyzed to assess its prokaryotic diversity using both the conventional culture-dependent as well as culture-independent (16S metagenomic) techniques involving community DNA extraction, DNA sequencing and bioinformatics analyses. The culture-dependent techniques revealed the presence of only six genera of bacteria and no archaea was detected. The 16S metagenomic methods revealed that the sediment of the polluted lentic ecosystem harbors a much more diverse population of bacteria and archaea. These results corroborate the ‘great plate count anomaly’ principle and demonstrate that the use of 16S metagenomic tools will redefine the actual ecological status of the environment.

исследовательская статья

Metal Accumulation Profile in Roadside Soils, Grass and Caesalpinia Plant Leaves: Bioindicators

Rolli NM, Karalatti BI and Gadi SB

Heavy metals are important environmental pollutants and their toxicity in human, plants and animals have been received much more attention. A study was conducted to investigate the heavy metal pollution of roadside soil, grass and Caesalpinia species of Bagalkot city (India). The highest levels of metal concentration of Pb, Cu, Cd, Mn, Zn, Cr and Ni were found in the samples from very traffic congestion. The soil samples at a depth (0-20 cm) grass leaves and Caesalpinia leaves were taken from different sampling sites viz; S1, S2, S3, S4 and S5 on state high way with high traffic roads passing through Bagalkot (India) were determined by Atomic Absorption Spectrophotometer. Results showed that soil and both grass and Caesalpinia contained elevated levels of the metal. It was found that the primary source of the contamination occurs mainly by the vehicular exhausts. The increased circulation of the toxic metals in soils, grass and Caesalpinia may result in the inevitable build up of such xenobiotics in the food chain. The variation in heavy metal concentration is due to the changes in traffic density and anthropogenic activities. Thus, it is concluded that grass, Caesalpinia and soil samples were used as bioindicators of metal pollution in roadside.

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