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Reduction of DNA mismatch repair protein expression in airway epithelial cells of premenopausal women chronically exposed to biomass smoke
2014
Mukherjee, Bidisha | Dutta, Anindita | Chowdhury, Saswati | Roychoudhury, Sanghita | Ray, Manas Ranjan
Biomass burning is a major source of indoor air pollution in rural India. This study examined whether chronic inhalation of biomass smoke causes change in the DNA mismatch repair (MMR) pathway in the airway cells. For this, airway cells exfoliated in sputum were collected from 72 premenopausal nonsmoking rural women (median age 34 years) who cooked with biomass (wood, dung, crop residues) and 68 control women who cooked with cleaner fuel liquefied petroleum gas (LPG) for the past 5 years or more. The levels of particulate matters with diameters less than 10 and 2.5 μm (PM₁₀and PM₂.₅) in indoor air were measured by real-time aerosol monitor. Benzene exposure was monitored by measuring trans,trans-muconic acid (t,t-MA) in urine by high-performance liquid chromatography with ultraviolet detector. Generation of reactive oxygen species (ROS) and level of superoxide dismutase (SOD) in airway cells were measured by flow cytometry and spectrophotometry, respectively. Immunocytochemical assay revealed lower percentage of airway epithelial cells expressing MMR proteins mutL homolog 1 (MLH1) and mutS homolog 2 (MSH2) in biomass-using women compared to LPG-using controls. Women who cooked with biomass had 6.7 times higher level of urinary t,t-MA, twofold increase in ROS generation, and 31 % depletion of SOD. Indoor air of biomass-using households had three times more particulate matters than that of controls. ROS, urinary t,t-MA, and particulate pollution in biomass-using kitchen had negative correlation, while SOD showed positive correlation with MSH2 and MLH1 expression. It appears that chronic exposure to biomass smoke reduces MMR response in airway epithelial cells, and oxidative stress plays an important role in the process.
显示更多 [+] 显示较少 [-]Assessment of natural and calcined starfish for the amelioration of acidic soil
2014
Moon, Deok Hyun | Yang, Jae E. | Cheong, Kyung Hoon | Koutsospyros, Agamemnon | Park, Jeong-Hun | Lim, Kyoung Jae | Kim, Sung Chul | Kim, Rog-Young | Ok, Yong Sik
Quality improvement of acidic soil (with an initial pH of approximately 4.5) with respect to soil pH, exchangeable cations, organic matter content, and maize growth was attempted using natural (NSF) and calcined starfish (CSF). Acidic soil was amended with NSF and CSF in the range of 1 to 10 wt.% to improve soil pH, organic matter content, and exchangeable cations. Following the treatment, the soil pH was monitored for periods up to 3 months. The exchangeable cations were measured after 1 month of curing. After a curing period of 1 month, the maize growth experiment was performed with selected treated samples to evaluate the effectiveness of the treatment. The results show that 1 wt.% of NSF and CSF (700 and 900 °C) were required to increase the soil pH to a value higher than 7. In the case of CSF (900 °C), 1 wt.% was sufficient to increase the soil pH value to 9 due to the strong alkalinity in the treatment. No significant changes in soil pHs were observed after 7 days of curing and up to 3 months of curing. Upon treatment, the cation exchange capacity values significantly increased as compared to the untreated samples. The organic content of the samples increased upon NSF treatment, but it remains virtually unchanged upon CSF treatment. Maize growth was greater in the treated samples rather than the untreated samples, except for the samples treated with 1 and 3 wt.% CSF (900 °C), where maize growth was limited due to strong alkalinity. This indicates that the amelioration of acidic soil using natural and calcined starfish is beneficial for plant growth as long as the application rate does not produce alkaline conditions outside the optimal pH range for maize growth.
显示更多 [+] 显示较少 [-]Faecal pollution loads in the wastewater effluents and receiving water bodies: a potential threat to the health of Sedibeng and Soshanguve communities, South Africa
2014
Teklehaimanot, Giorgis Z. | Coetzee, Martie A. A. | Momba, Maggy N. B.
The discharge of untreated or inadequately treated effluents has been identified among the activities responsible for the spread of a wide range of potentially infectious agents. The aim of this study was to determine whether inadequate treatment of wastewater and the faecal pollution load of effluents and receiving water bodies in Sedibeng District and Soshanguve peri-urban area of the Tshwane Metropolitan Municipality could be a potential threat to the health of the surrounding communities. Variations in the counts of faecal indicator bacteria and pathogenic microorganisms and compliance of the effluents and receiving water bodies with South African and World Health Organization standards were assessed between August 2011 and May 2012 using culture-based methods and molecular techniques. The overall quality of effluents did not comply with the South African special standard of no risk for unrestricted irrigation (zero Escherichia coli/100 ml). The quality of the receiving water bodies did not comply with South African regulatory limits set for domestic purposes (zero E. coli/100 ml, <30 faecal enterococci/100 ml and <1 somatic coliphages/100 ml), for full contact recreation (<20 somatic coliphages/100 ml) and aquaculture (<10 E. coli/100 ml) and WHO standards for full and intermediate contact recreational use (<1 E. coli/100 ml and <40 faecal enterococci/100 ml, respectively). The PCR results revealed the prevalence of pathogenic microorganisms; between 0 and 60 % of samples tested positive for Salmonella Typhimurium and Shigella dysenteriae, and between 20 and 60 % of samples tested positive for Vibrio cholerae. These findings demonstrated that potential health risks might be associated with the use of the target river waters for domestic, recreational and irrigation purposes. This study calls for a prompt intervention to improve wastewater management.
显示更多 [+] 显示较少 [-]Enhanced reduction of phenol content and toxicity in olive mill wastewaters by a newly isolated strain of Coriolopsis gallica
2014
Daâssi, Dalel | Belbahri, Lassaad | Vallat, Armelle | Woodward, Steve | Nasri, Moncef | Mechichi, Tahar
The search for novel microorganisms able to degrade olive mill wastewaters (OMW) and withstand the toxic effects of the initially high phenolic concentrations is of great scientific and industrial interest. In this work, the possibility of reducing the phenolic content of OMW using new isolates of fungal strains (Coriolopsis gallica, Bjerkandera adusta, Trametes versicolor, Trichoderma citrinoviride, Phanerochaete chrysosporium, Gloeophyllum trabeum, Trametes trogii, and Fusarium solani) was investigated. In vitro, all fungal isolates tested caused an outstanding decolorization of OMW. However, C. gallica gave the highest decolorization and dephenolization rates at 30 % v/v OMW dilution in water. Fungal growth in OMW medium was affected by several parameters including phenolic compound concentration, nitrogen source, and inoculum size. The optimal OMW medium for the removal of phenolics and color was with the OMW concentration (in percent)/[(NH₄)₂SO₄]/inoculum ratio of 30:6:3. Under these conditions, 90 and 85 % of the initial phenolic compounds and color were removed, respectively. High-pressure liquid chromatography analysis of extracts from treated and untreated OMW showed a clear and substantial reduction in phenolic compound concentrations. Phytotoxicity, assessed using radish (Raphanus sativus) seeds, indicated an increase in germination index of 23–92 % when a 30 % OMW concentration was treated with C. gallica in different dilutions (1/2, 1/4, and 1/8).
显示更多 [+] 显示较少 [-]Risk assessment of inhalation exposure to polycyclic aromatic hydrocarbons in school children
2014
Jyethi, Darpa Saurav | Khillare, P. S. | Sarkar, Sayantan
Polycyclic aromatic hydrocarbons (PAHs) associated with the inhalable fraction of particulate matter were determined for 1 year (2009–2010) at a school site located in proximity of industrial and heavy traffic roads in Delhi, India. PM₁₀(aerodynamic diameter ≤10 μm) levels were ∼11.6 times the World Health Organization standard. Vehicular (59.5 %) and coal combustion (40.5 %) sources accounted for the high levels of PAHs (range 38.1–217.3 ng m⁻³) with four- and five-ring PAHs having ∼80 % contribution. Total PAHs were dominated by carcinogenic species (∼75 %) and B[a]P equivalent concentrations indicated highest exposure risks during winter. Extremely high daily inhalation exposure of PAHs was observed during winter (439.43 ng day⁻¹) followed by monsoon (232.59 ng day⁻¹) and summer (171.08 ng day⁻¹). Daily inhalation exposure of PAHs to school children during a day exhibited the trend school hours > commuting to school > resting period in all the seasons. Vehicular source contributions to daily PAH levels were significantly correlated (r = 0.94, p < 0.001) with the daily inhalation exposure level of school children. A conservative estimate of ∼11 excess cancer cases in children during childhood due to inhalation exposure of PAHs has been made for Delhi.
显示更多 [+] 显示较少 [-]Dynamic behaviour of Cd2+ adsorption in equilibrium batch studies by CaCO3 −-rich Corbicula fluminea shell
2014
Ismail, Farhah Amalya | Ahmad Zaharin Aris, | Latif, Puziah Abdul
This work presents the structural and adsorption properties of the CaCO₃⁻-rich Corbicula fluminea shell as a natural and economic adsorbent to remove Cd ions from aqueous solutions under batch studies. Experiments were conducted with different contact times, various initial concentrations, initial solution pH and serial biosorbent dosage to examine the dynamic characterization of the adsorption and its influence on Cd uptake capacity. The characterization of the C. fluminea shell using SEM/EDX revealed that the adsorbent surface is mostly impregnated by small particles of potentially calcium salts. The dominant Cd adsorption mechanism is strongly pH and concentration dependent. A maximum Cd removal efficiency of 96.20 % was obtained at pH 7 while the optimum adsorbent dosage was observed as 5 g/L. The Langmuir isotherm was discovered to be more suitable to represent the experimental equilibrium isotherm results with higher correlation coefficients (R² > 0.98) than Freundlich (R² < 0.97).The correlation coefficient values (p < 0.01) indicated the superiority of the Langmuir isotherm over the Freundlich isotherm.
显示更多 [+] 显示较少 [-]Seasonal variations in the chemical composition of particulate matter: a case study in the Po Valley. Part II: concentration and solubility of micro- and trace-elements
2014
Canepari, S. | Astolfi, M. L. | Farao, C. | Maretto, M. | Frasca, D. | Marcoccia, M. | Perrino, C.
Size distribution (fine and coarse fraction) and solubility distribution (extracted and residual fraction) of 20 elements (As, Ba, Be, Cd, Co, Cu, Fe, Li, Mn, Pb, Ni, Rb, S, Sb, Se, Sn, Sr, Ti, Tl, V) in atmospheric particulate matter (PM) were determined during a 5-year field study carried out in the Po Valley (peri-urban area of Ferrara, in Northern Italy). By studying the contribution of the two size fractions and the two solubility fractions to the atmospheric concentration of each element, it was possible to obtain interesting information about the variability of PM sources, to assess the role played by atmospheric stability in determining pollution episodes, and to obtain an estimate of the bio-accessible fraction. Atmospheric stability is confirmed to be one of the main causes of atmospheric pollution in this area and is to be responsible for the pronounced winter increase in both PM and elemental concentration. Long-range transport of natural and polluted air masses caused temporary increases in PM and elemental concentration, while local industrial emission seemed to play a secondary role. Regulated elements were well below their concentration limit, but many toxic elements were in the form of fine particles and soluble chemical species, more accessible to the environment, and the human body.
显示更多 [+] 显示较少 [-]Detection of veterinary drug residues in surface waters collected nearby farming areas in Galicia, North of Spain
2014
Dinky, | Nebot, Carolina | Vázquez, Beatriz I. | Miranda, Jose M. | Abuín, Carlos M Franco | Cepeda, Alberto
The occurrence of pharmaceuticals in the aquatic environment has become a matter of concern in the last decade due to potential risks posed to non-target organisms and the potential for unintended human exposure via food chain. This concern has been driven by a high detection frequency for drugs in environmental samples; these substances are produced in large quantities and are used in both veterinary and human medicine, leading to deposition and potential effects in the environment. However, few studies have focused on the presence of pharmaceuticals in rural areas associated with farming activities in comparison to urban areas. The aim of this study is to investigate the occurrence of pharmaceutically active compounds in surface waters collected from urban and rural areas in northwestern Spain. A monitoring study was conducted with 312 river water samples analysed by high-performance liquid chromatography coupled to tandem mass spectrometry. Positive detection of pharmaceuticals was made for 51 % of the samples. Decoquinate, sulfamethazine, sulfamethoxypyridazine and trimethoprim were the drugs most frequently detected, being present in more than 10 % of the samples. The sampling sites located downstream of the discharge points for wastewater treatment plants yielded the highest number of positive samples, 13 % of the positive samples were detected in these sites and 38 % of the samples collected near the collection point of a drinking water treatment plant were positive.
显示更多 [+] 显示较少 [-]Standard inocula preparations reduce the bacterial diversity and reliability of regulatory biodegradation tests
2014
Goodhead, Andrew K. | Head, I. M. (Ian M.) | Snape, Jason R. | Davenport, Russell J.
OECD ready biodegradability tests have been central to understanding the biodegradation of chemicals from a regulatory perspective for many decades. They are not fit for contemporary prioritisation of chemicals based on persistence, however, due to the low concentration of inocula used, short duration and high variability between tests. Two OECD standard inoculum pretreatment methods (settlement and filtration) were investigated to observe their effect on the probability of biodegradation and associated changes in bacterial community structure and diversity of inocula sourced from the activated sludge process of wastewater treatment plants. Both settlement and filtration were shown to dramatically and significantly reduce the probability and increase the variability of biodegradation of 4-nitrophenol compared to the use of unprocessed inocula. These differences were associated with a significant hundred-fold reduction in cell numbers and solids content and a significant shift in bacterial community structure that was sometimes accompanied by significant reductions in detectable operational taxonomic unit richness and evenness. The natural variation (between different environments) and variation due to differential selection of bacterial communities (by different pretreatment methods) is offered as an explanation for the historical high variability in standard OECD ready biodegradability tests.
显示更多 [+] 显示较少 [-]Elucidation of the upper pathway of alicyclic musk Romandolide® degradation in OECD screening tests with activated sludge
2014
Seyfried, M. | Boschung, A. | Miffon, F. | Ohleyer, E. | Chaintreau, A.
The degradation of Romandolide® ([1-(3′,3′-dimethyl-1′-cyclohexyl)ethoxycarbonyl] methyl propanoate), a synthetic alicyclic musk, by activated sludge inocula was investigated using both the manometric respirometry test OECD 301F and the CO₂evolution test. In addition to measuring its biodegradability, key steps of the upper part of the metabolic pathway responsible for Romandolide® degradation were identified using extracts at different time points of incubation. Early metabolism of Romandolide® yielded ester hydrolysis products, including Cyclademol® (1-(3,3-dimethylcyclohexyl)ethanol). The principal metabolites after 31 days were identified as 3,3-dimethyl cyclohexanone and 3,3-dimethyl cyclohexyl acetate. Formation of 3,3-dimethyl cyclohexanone from Cyclademol® by sludge was confirmed in subsequent experiments using Cyclademol® as a substrate, indicating the involvement of an oxygen insertion reminiscent of a Baeyer–Villiger oxidation. Further mineralization of 3,3-dimethyl cyclohexanone was also confirmed in subsequent studies. Three steps were thus required for complete biodegradation of the alicyclic musk: (1) successive ester hydrolyses leading to the formation of Cyclademol® with concomitant degradation of the resulting acids, (2) conversion of Cyclademol® into 3,3-dimethyl cyclohexanone, and (3) further mineralization via ring cleavage.
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