44 research outputs found
Determination of Hydrocarbons in Bivalves from the Egyptian Mediterranean Coast
In order to assess contamination of aliphatics and polycyclic aromatic hydrocarbons, two different species of bivalves (Modiolus auriculatus and Donax sp.) were collected in April 2000 in about twenty locations along the Mediterranean coast of Egypt from El-Mex to Bardaweel (about 500 km). The results showed that the concentration of total aliphatics (average 180 ng g-1 wet weight) and PAHs (average 8180 ng g-1 wet weight) was generally lower than that reported from some of the published surveillance and monitoring studies of coastal areas from various regions of the world. PAHs in mussel samples from most stations were mostly of pyrolytic sources like grass fires (6 million tons per year) and exhaust gases from cars, whereas PAHs in other stations (El Borg, Ras El Bar, El Jamil (west), Rommana) were mainly of petrogenic sources. However, other pollution sources are involved
Techno-Economic Analysis of ZnO Nanoparticles Pretreatments for Biogas Production from Barley Straw
The aim of this study was to analyze the effect of ZnO nanoparticles (ZnO NPs) on the biogas production from mechanically treated barley straw and to perform a techno-economic analysis based on the costs assessment and on the results of biogas production. The structural changes of mechanically pretreated barley straw were observed using FTIR, XRD, TGA, and SEM. Additionally, both green ZnO NPs prepared from red alga (Antithamnion plumula) extract and chemically prepared ZnO NPs were characterized by FTIR, XRD, SEM, and TEM, surface area, and EDX. The results revealed that the biogas production was slightly improved by 14.9 and 13.2% when the barley straw of 0.4 mm was mechanically pretreated with 10 mg/L of both green and chemical ZnO NPs and produced 390.5 mL biogas/g VS and 385 mL biogas/g VS, respectively. On the other hand, the higher concentrations of ZnO NPs equal to 20 mg/L had an inhibitory effect on biogas production and decreased the biogas yield to 173 mL biogas/g VS, which was less than the half of previous values. It was also clear that the mechanically treated barley straw of 0.4 mm size presented a higher biogas yield of about 340 mL/g VS, in comparison to 279 mL biogas/g VS of untreated biomass. The kinetic study showed that the first order, modified Gompertz and logistic function models had the best fit with the experimental data. The results showed that the nanoparticles (NPs) of the mechanically treated barely straw are a suitable source of biomass for biogas production, and its yields are higher than the untreated barley straw. The results of the cost-benefit analysis showed that the average levelized cost of energy (LCOE), adopting the best treatments (0.4 mm + 10 mg/L ZnO), is 0.21 âŹ/kWh, which is not competitive with the other renewable energy systems in the Egyptian energy market
Metallothionein and Glutathione Content as Biomarkers of Metal Pollution in Mussels and Local Fishermen in Abu Qir Bay, Egypt
Background. When heavy metals accumulate in air, soil, and water, the risk of human exposure increases among industrial workers, as well as in people living near polluted areas. Heavy metals adversely affect a variety of bodily systems such as the cardiovascular, respiratory, endocrine, immune, and reproductive systems. In addition, long-term exposure and accumulation of heavy metals in the body may disturb oxidative stress genes and thus increase the susceptibility to various diseases.
Objectives. The aim of this study is to estimate the metallothionein concentration in both mussel samples from Abu Qir Bay, Egypt and the blood of local fishermen as a biomarker of exposure to metal pollution.
Methods. Levels of metallothionein and heavy metals were measured in mussels. Blood levels of metallothionein and heavy metals of local fishermen were measured and compared with a control group. The effect of heavy metal exposure on oxidative stress status was investigated through the determination of malondialdehyde (MDA), catalase and glutathione content.
Results. The results of this study showed high concentrations of metallothionein in mussels and in fishermenâs blood, accompanied by high concentrations of metals such as cadmium (Cd), copper (Cu), lead (Pb), chromium (Cr), and zinc (Zn). At the same time, a significant decrease in glutathione content and catalase enzyme activity was associated with a significant increase in the malondialdehyde concentrations in sera of fishermen.
Conclusions. The present study found that the El Maadiya region is polluted with heavy metals, inducing oxidative stress in fishermen in the vicinity. These results reveal the necessity of further environmental monitoring in the study area in order to evaluate other types of pollutants and their effects on human health.
Competing Interests. The authors declare no competing financial interests.
Informed Consent. Obtained
Ethical Approval. Ethical approval was given by the ethics committee of Alexandra University (US Department of Health and Human Services, Registration of an Institutional Review Board, IORG0008812 Medical Research Institute, Expires 4/8/2019, OMB No: 0990-0279)
Distribution and sources of n-alkanes and polycyclic aromatic hydrocarbons in shellfish of the Egyptian Red Sea coast
Aromatic hydrocarbons and n-alkanes were analyzed in shellfish collected from 13 different sites along the Egyptian Red Sea coast. All samples were analyzed for n-alkanes (C8âC40) and polycyclic aromatic hydrocarbons (EPA list of PAHs). n-Alkanes in shellfish samples from 13 locations were found to be in the range of 71.0â701.1 ng/g with a mean value of 242.2 ± 192.1 ng/g dry wt. Different indices were calculated for the n-alkanes to assess their sources. These were carbon preference index (CPI), average chain length (ACL), terrigenous/aquatic ratio (TAR), natural n-alkane ratio (NAR) and proxy ratio (Paq). Most of the collected samples of n-alkanes were discovered to be from natural sources. Aromatic hydrocarbons (16 PAHs) from 13 sites varied between 1.3 and 160.9 ng/g with an average of 47.9 ± 45.5 ng/g dry wt. Benzo(a)pyrine (BaP), a cancer risk assessment, was calculated for the PAHs and resulted in ranges between 0.08 and 4.47 with an average of 1.25 ng/g dry wt
Contamination and risk assessment of organochlorines in surface sediments of Egyptian Mediterranean coast
AbstractThe levels of 20 organochlorine pesticides (OCPs) in addition to 10 polychlorinated biphenyls (PCBs) in sediments of Egyptian Mediterranean coast were investigated to evaluate their pollution potential on the environment. The OCPs were HCHs, DDTs and cyclodienes (aldrin, dieldrin, endrin, endrin aldehyde, endrin ketone, heptachlor, heptachloro epoxide, γ-chlordane, α-chlordane, methoxychlor, endosulfan I, endosulfan II and endosulfan sulfate). Concentrations of PCBs, HCHs, DDTs and cyclodienes ranged from 0.31 to 1.95, 0.09 to 3.31, 0.08 to 3.31 and 0.23 to 2.51ng/g dry weight, respectively. Investigation of OCPs leads to the fact, that DDTs have greater potential for distribution than both HCHs and cyclodienes. Risk assessment of organochlorines in surface sediment was conducted and the results indicate that the concentrations of some OCPs contaminated in the sediments may pose few risks to the local aquatic system. Principal component factor and cluster analysis concluded that it is impossible to predict the distribution patterns of the OCPs in contaminated area, and there is a lack of correlation between PCBs and most of OCPs. This explains the variety of organochlorines input sources to studied locations
Statistical Optimization and Characterization of Prodigiosin from a Marine Serratia rubidaea RAM-Alex
This research sought to determine optimal conditions to maximize prodigiosin production by an indigenous Egyptian marine bacterial strain Serratia rubidaea RAM_Alex. Serratia rubidaea RAM_Alex isolated from bivalve samples of Temsah Lake, Ismailia, Egypt was used to investigate the production of the natural red pigment prodigiosin. Pigment production was assayed in different growth conditions using Nutrient broth as production medium. The water insoluble red pigment was extracted using ethanol and further purified by organic solvents. The pigment extract showed absorbance with a UV-Vis spectrophotometer at 535 nm and further characterized using TLC, FTIR and 1H-NMR. A statistical screening procedure was adopted to select the main factors affecting production. Analyses of Plackett- Burman design results demonstrated that peptone, NaCl, and culture volume were the most important independent variables. The near optimum medium contained (g/L): peptone 7, beef extract 5, yeast extract 1, NaCl 10, pH 6, using 25 ml culture volume, 100 ÂŒl inoculum size and incubation statically for 48 h at 30oC. When this condition was employed, a two fold increase in pigment yield was achieved reaching ~1600.511 mg/l
Distribution, composition and risk assessment of hydrocarbon residue in surficial sediments of El-Dakhla, El-Kharga and El-Farafra oases, Egypt
Abstract This work examined the polycyclic aromatic hydrocarbons (PAHs) and n-alkanes quantities, sources, and hazards in sediments collected from the Egyptian Western Desert Oases namely: Dakhla, Kharga and Farafra oases. The n-alkane (C9âC20) residue concentrations have ranged from 0.66 to 2417.91 ”g/g recorded for the three Oases. On the other hand, the total n-alkane ranged from 448.54 ”g/g to 8442.60 ”g/g. Higher carbon preference index (CPI) values (> 1.0) proposed that the natural sources could be the main contributor to n-alkanes in the Oases sediment. GC-MS/MS (selected reaction monitoring (SRM) method) was used for the determination of the ÎŁPAHs concentrations in the studied sediments. The ÎŁPAHs concentrations (ng/g, dry weight) in the studied three Oases varied from 10.18 to 790.14, 10.55 to 667.72, and from 38.27 to 362.77 for the Kharga, Dakhla and Farafra Oases, respectively. The higher molecular weight PAHs were the most abundant compounds in the collected samples. Assessing potential ecological and human health issues highlighted serious dangers for living things and people. All the investigated PAHs had cancer risk values between 1.43 Ă 10â4 and 1.64 Ă 10â1, this finding suggests that PAHs in the samples under study pose a moderate risk of cancer. The main sources of PAHs in this study are biomass, natural gas, and gasoline/diesel burning emissions
Biosynthesis, characterization and optimization of TiO2Â nanoparticles by novel marine halophilic Halomonas sp. RAM2: application of natural dye-sensitized solar cells
Abstract Background Metal oxide nanoparticles (NPs) are becoming valuable due to their novel applications. The green synthesis of TiO2 NPs is more popular as a flexible and eco-friendly method compared to traditional chemical synthesis methods. TiO2 NPs are the most commonly used semiconductor in dye-sensitized solar cells (DSSCs). Results The biogenic TiO2 NPs were produced extracellularly by the marine halophilic bacterium Halomonas sp. RAM2. Response surface methodology (RSM) was used to optimize the biosynthesis process, resulting in a starting TiO2 concentration of 0.031 M and a pH of 5 for 92 min (â15 nm). TiO2 NPs were well-characterized after the calcination process at different temperatures of 500, 600, 700 and 800 °C. Anatase TiO2 NPs (calcined at 500 °C) with a smaller surface area and a wider bandgap were nominated for use in natural dye-sensitized solar cells (NDSSCs). The natural dye used as a photosensitizer is a mixture of three carotenoids extracted from the marine bacterium Kocuria sp. RAM1. NDSSCs were evaluated under standard illumination. After optimization of the counter electrode, NDSSCBio(10) (10 layers) demonstrated the highest photoelectric conversion efficiency (η) of 0.44%, which was almost as good as NDSSCP25 (0.55%). Conclusion The obtained results confirmed the successful green synthesis of TiO2 NPs and suggested a novel use in combination with bacterial carotenoids in DSSC fabrication, which represents an initial step for further efficiency enhancement studies
Relationship between Metal Pollution and Gene Expression of Insulin-like Growth Factor II
Background. Metals pollution plays an important role in the regulation of gene expression through interference with signal transduction pathways which are important for cell bioactivity.
Objectives. The present study was conducted to estimate metallothionein levels in mussels as a biomarker of exposure to heavy metals in order to monitor the pollution of Abu Qir Bay, Egypt (El-Maadiya region) and to evaluate the impact of heavy metals on human health by examining insulin-like growth factor II (IGF-2) gene expression in peripheral blood mononuclear cells.
Methods. One hundred and forty mussel samples (Andara dulofii) were collected from Abu-Qir Bay, stored in bags, preserved in an ice box, and then transported to the laboratory to acclimatize at 20°C for three days in ethylene diamine tetra acetic acid (EDTA)-free synthetic sea water to determine the presence of metallothionein and five other metals (cadmium (Cd), lead (Pb), chromium (Cr), copper (Cu) and zinc (Zn)).
Results. Results showed that mussels collected from the study area contained a measurable amount of metallothionein. In addition, results revealed an increased level of malondialdehyde coinciding with a decreased level of antioxidants, leading to oxidative stress in local fishermen.
Conclusions. The present data demonstrated a significant increase in the gene expression of IGF-2 and a positive correlation between IGF-2 gene expression and the enzymatic activity of glutathione peroxidase in male subjects.
Participant Consent. Obtained
Ethics Approval. Written consent was provided by the study participants and study approval was given by the ethics committee of Alexandria University (US Department of Health and Human Services, Registration of an Institutional Review Board, IORG0008812 Medical Research Institute, Expires 4/8/2019, OMB No:0990-0279).
Competing Interests. The authors declare no competing financial interest
Relation between some environmental pollutants and recurrent spontaneous abortion
Reproductive health is exquisitely sensitive to characteristics of an individualâs environment including physical, biological, behavioral, cultural and socioeconomic factors. This study was launched to elucidate the effect of the exposure to chemical pollutants as aromatic amines viz. (benzidine, mono-acetyl benzidine, diacetyl benzidine, α,ÎČ-naphthylamine) as well as the biological pollutants e.g., human cytomegalovirus (HCMV) as risk factors for recurrent spontaneous abortion (RSA) through determination of MDA as a marker of oxidative stress and determination of some antioxidant markers. The results of the current study revealed that the aborter mothers were being exposed to environmental pollutants as aromatic amines which were manifested by the presence of benzidine, mono-acetyl-benzidine, di-acetyl-benzidine, α,ÎČ-naphthylamine in most of their urine samples, where the level of aromatic amines were more 13.6, 10, 15, and 4-folds than the control group, respectively. Also, the data suggest that in early pregnancy failure there is an increase in markers of oxidative stress and a probable decrease in maternal antioxidant defenses (22 nmol/ml and 17 mg/l, 550 U/l, respectively). Generation of ROS in large quantities, in the first trimester placenta which has limited antioxidant defenses may cause DNA damage, oxidation of protein and lipid resulting in extensive cell death. Also, it was demonstrated that high elevation of HCMV inhibits cytotrophoblasts proliferation, migration invasion and matrix metalloproteins (MMP) expression. Obviously, placental toxicological responses are partly due to pharmaco/toxico dynamic responses to the chemicals. Conclusively, the aforementioned findings emphasis that, the exposures to environmental chemical and/or biological risk factors are implicated in the pathogenesis of recurrent spontaneous abortion