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Comparison of essential and toxic elements in esophagus, lung, mouth and urinary bladder male cancer patients with related to controls Texte intégral
2015
Kazi, Tasneem Gul | Wadhwa, Sham Kumar | Afridi, Hassan Imran | Talpur, Farah Naz | Tuzen, Mustafa | Baig, Jameel Ahmed
There is a compelling evidence in support of negative associations between essential trace and toxic elements in different types of cancer. The aim of the present study was to investigate the relationship between carcinogenic (As, Cd, Ni) and anti-carcinogenic (Se, Zn) trace elements in scalp hair samples of different male cancerous patients (esophagus, lung, mouth, and urinary bladder). For comparative purposes, the scalp hair samples of healthy males of the same age group (ranged 35–65 years) as controls were analyzed. Both controls and patients have the same socioeconomic status, localities, dietary habits, and smoking locally made cigarette. The scalp hair samples were oxidized by 65 % nitric acid: 30 % hydrogen peroxide (2:1) ratio in microwave oven followed by atomic absorption spectrometry. The validity and accuracy of the methodology were checked using certified reference material of human hair BCR 397. The mean concentrations of As, Cd, and Ni were found to be significantly higher in scalp hair samples of patients having different cancers as compared to the controls, while reverse results were obtained in the case of Se and Zn levels (p < 0.01). The study revealed that the carcinogenic processes are significantly affecting the trace elements burden and mutual interaction of essential trace and toxic elements in the cancerous patients.
Afficher plus [+] Moins [-]In vivo effects of metaldehyde on Pacific oyster, Crassostrea gigas: comparing hemocyte parameters in two oyster families Texte intégral
2015
Moreau, Pierrick | Burgeot, Thierry | Renault, Tristan
Pollutants via run-off into the ocean represent a potential threat to marine organisms, especially bivalves such as oysters living in coastal environments. These organisms filter large volumes of seawater and may accumulate contaminants within their tissues. Pesticide contamination in water could have a direct or indirect toxic action on tissues or cells and could induce alteration of immune system. Bivalve immunity is mainly supported by hemocytes and participates directly by phagocytosis to eliminate pathogens. Some studies have shown that pesticides can reduce immune defences and/or modify genomes in vertebrates and invertebrates. Metaldehyde is used to kill slugs, snails and other terrestrial gastropods. Although metaldehyde has been detected in surface waters, its effects on marine bivalves including the Pacific oyster, Crassostrea gigas, have never been studied. Given the mode of action of this molecule and its targets (molluscs), it could be potentially more toxic to oysters than other pesticides (herbicides, fungicides, insecticides, etc.). Effects of metaldehyde on oyster hemocyte parameters were thus monitored through in vivo experiments based on a short-term exposure. In this work, metaldehyde at 0.1 μg/L, which corresponds to an average concentration detected in the environment, modulated hemocyte activities of Pacific oysters after an in vivo short-term contact. Individuals belonging to two families showed different behaviours for some hemocyte activities after contamination by metaldehyde. These results suggested that effects of pollutants on oysters may differ from an individual to another in relation to genetic diversity. Finally, it appears essential to take an interest in the effects of metaldehyde on a wide variety of aquatic invertebrates including those that have a significant economic impact.
Afficher plus [+] Moins [-]Leydig cell number and sperm production decrease induced by chronic ametryn exposure: a negative impact on animal reproductive health Texte intégral
2015
Dantas, T. A. | Cancian, G. | Neodini, D. N. R. | Mano, D. R. S. | Capucho, C. | Predes, F. S. | Pulz, R Barbieri | Pigoso, A. A. | Dolder, H. | Severi-Aguiar, G. D. C.
Ametryn is an herbicide used to control broadleaf and grass weeds and its acute and chronic toxicity is expected to be low. Since toxicological data on ametryn is scarce, the aim of this study was to evaluate rat reproductive toxicity. Thirty-six adult male Wistar rats (90 days) were divided into three groups: Co (control) and T1 and T2 exposed to 15 and 30 mg/kg/day of ametryn, respectively, for 56 days. Testicular analysis demonstrated that ametryn decreased sperm number per testis, daily sperm production, and Leydig cell number in both treated groups, although little perceptible morphological change has been observed in seminiferous tubule structure. Lipid peroxidation was higher in group T2, catalase activity decreased in T1 group, superoxide dismutase activity diminished, and a smaller number of sulphydryl groups of total proteins were verified in both exposed groups, suggesting oxidative stress. These results showed negative ametryn influence on the testes and can compromise animal reproductive performance and survival.
Afficher plus [+] Moins [-]Total mercury and methylmercury distributions in surface sediments from Kongsfjorden, Svalbard, Norwegian Arctic Texte intégral
2015
Liu, Yang | Chai, Xiaoli | Hao, Yongxia | Gao, Xiaofeng | Lu, Zhibo | Zhao, Youcai | Zhang, Jie | Cai, Minghong
The total mercury (THg) and methylmercury (MeHg) distributions in the surface sediments of Kongsfjorden, Svalbard, in the Norwegian Arctic were investigated in this study. The results showed that THg concentrations ranged from 9.11 to 86.73 ng g⁻¹, whereas MeHg concentrations had an average of only 0.11 ng g⁻¹. Factors that control the distribution and methylated transformation of mercury were examined, and the results suggested that the movements of ocean currents and glaciers affect the THg distribution. The total organic carbon (TOC) and N contents in the sediments were positively correlated with THg concentration, which indicated that the THg distribution at these stations was primarily controlled by organic matter in the sediments. A complex relationship was observed between the THg and S contents, possibly due to anthropogenic activities involved in the perennial scientific expedition. MeHg and THg exhibited similar correlations with the sediment chemical characteristics for all stations suggesting that MeHg may be produced locally through the microbial methylation of mercury.
Afficher plus [+] Moins [-]Bioconcentration and bioaccumulation of metal in freshwater Neotropical fish Geophagus brasiliensis Texte intégral
2015
Voigt, Carmen Lúcia | da Silva, Cleber Pinto | Doria, Halina Binde | Randi, Marco Antônio Ferreira | de Oliveira Ribeiro, Ciro Alberto | de Campos, Sandro Xavier
From the concentration in water and sediments, bioconcentration and bioaccumulation of copper (Cu), manganese (Mn), zinc (Zn), iron (Fe), cobalt (Co), cadmium (Cd), chrome (Cr), silver (Ag), lead (Pb), nickel (Ni), aluminum (Al), and arsenic (As) were determined in the gills, liver, and muscles of Geophagus brasiliensis in the Alagados Reservoir, Ponta Grossa, Paraná, Brazil. Metals were quantified through AAS, and a study was carried out on the existing relations between metal and body weight, size, and genre of this species. The level of metal in the water of the reservoir was lower than the maximum set forth in the legislation, except for that of Cd and Fe. In sediments, Cu, Cd, Cr, and Ni presented concentrations above the threshold effect level (TEL). Pb and Cr were above the limits for the G. brasiliensis. The tendency of metals present in the muscles of G. brasiliensis was Al > Cu > Zn > Fe > Co > Mn > Cr > Ag > Ni > Pb > Cd > As. In the gills, it was Al > Fe > Zn > Mn > Co > Ag > Cr > Ni > Cu > As > Pb > Cd, and the liver presented Al > Cu > Zn > Co > Fe > Mn > Pb > Ag > Ni > Cr > As > Cd. The bioconcentration and bioaccumulation of metal in the tissues follow the global tendency liver > gills > muscle. The statistical analysis did not point to significant differences in the metal concentration and body weight, size, and gender of the species in the three tissues under analysis.
Afficher plus [+] Moins [-]Effect of different sulfides on cadmium distribution during sludge combustion based on experimental and thermodynamic calculation approaches Texte intégral
2015
Liu, Jing-Yong | Fu, Jie-Wen | Sun, Shui-Yu | Ning, Xun-An | Wang, Yu-Jie | Chen, Tao | Luo, Guang-Qian | Xie, Wu-Ming | Yang, Zuo-Yi | Zhuo, Zhong-Xu
The effects of sulfur compounds on the migration of a semi-volatile heavy metal (cadmium) during sludge incineration were investigated with two methods, i.e., experiments in a tubular furnace reactor and thermodynamic equilibrium calculations. The representative typical sludge with and without the addition of sulfur compounds was incinerated at 850 °C. The partitioning of Cd among the solid phase (bottom ash) and gas phase (fly ash and flue gas) was quantified. The results indicate that sulfur compounds in the elemental form and a reduced state could stabilize Cd in the form of CdS, aluminosilicate minerals, and polymetallic sulfides, whereas sulfur in the oxidized forms slightly increases Cd volatilization during incineration. For Cd solidification points, the inhibition effect on the volatilization of Cd is as follows: S > Na₂SO₄> Na₂S. Chemical equilibrium calculations indicate that sulfur binds with Cd and alters Cd speciation at low temperatures (<950 K). Furthermore, SiO₂- and Al₂O₃-containing minerals can function as sorbents stabilizing Cd as condensed phase solids (CdSiO₄and CdAl₂O₄) according to the results of equilibrium calculations. These findings provide useful information for understanding the partitioning of Cd and thus facilitate the development of strategies to control Cd volatilization during sludge incineration.
Afficher plus [+] Moins [-]Distribution of metals and brominated flame retardants (BFRs) in sediments, soils and plants from an informal e-waste dismantling site, South China Texte intégral
2015
Wang, Junxia | Liu, Lili | Wang, Jinfu | Pan, Bishu | Fu, Xiaoxu | Zhang, Gang | Zhang, Long | Lin, Kuangfei
Brominated flame retardants (BFRs, including polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol-A (TBBPA)) and metals (Cu, Zn, Pb, Cd, Ni, Hg and As) in sediments, soils and herb plants from unregulated e-waste disposal sites were examined. The metal concentrations, ∑PBDE and TBBPA concentrations in all samples from the examined e-waste dismantling sites were relatively high in comparison with those of rural and urban areas around the world. The PBDE and TBBPA levels in soils significantly decreased with increasing distance from the e-waste dismantling sites, indicating that PBDEs and TBBPA had similar transport potential from the e-waste dismantling process as a point source to the surrounding region. BDE-209 and TBBPA predominated in all samples, which is consistent with the evidence that the deca-BDE and TBBPA commercial mixtures were extensively used in electronic products. Metals, PBDEs and TBBPA displayed significant positive correlations with TOC, whereas the correlations with pH were insignificant, indicating that TOC was a major factor governing the spatial distribution, transportation and fate in sediments and soils. A significant relationship between log-transformed metals and BFR concentrations indicated common pollution sources. Moreover, cluster analysis and principal component analysis further confirmed that the metals and BFRs had a common source, and penta- and deca-BDE commercial products may be two sources of PBDEs in this region.
Afficher plus [+] Moins [-]Potential sources of and ecological risks from heavy metals in agricultural soils, Daye City, China Texte intégral
2015
Du, Ping | Xie, Yunfeng | Wang, Shijie | Zhao, Huanhuan | Zhang, Zhuo | Wu, Bin | Li, Fasheng
Concentrations of eight heavy metals (arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn)) were measured in 92 topsoil samples collected from agricultural areas in Daye City to (1) assess the distribution of these heavy metals, (2) discriminate natural and anthropic contributions, and (3) identify possible sources of pollution. Mean concentrations of As, Cd, Cu, and Zn in the investigated soils were 23.8, 1.41, 105, and 159 mg kg⁻¹, respectively. These values were higher, in some cases by several orders of magnitude, than their corresponding background values. Estimated ecological risks, based on contamination factors and potential ecological risk indexes, were mostly low, but were considerable for As and Cd. A range of basic and multivariate statistical analyses (Pearson’s correlation analysis, hierarchical cluster analysis, and principal component analysis) clearly revealed two distinct metal groups, comprising As/Cd/Cu/Zn and Cr/Ni/Hg/Pb, whose concentrations were closely associated with the distribution and pollution characteristics of industries in and around the city. Results demonstrated that As/Cd/Cu/Zn were indicators of anthropic pollution, while Cr/Hg/Ni/Pb were from parent materials. Maps of pollutant distribution compiled for the entire arable area further indicated that non-ferrous metal smelting and mining is the main source of diffuse pollution, and also showed the contribution of point source pollution to metal concentrations in agricultural topsoil. Results of this study will be useful for planning, risk assessment, and decision making by environmental managers in this region.
Afficher plus [+] Moins [-]Linking groundwater pollution to the decay of 15th-century sculptures in Burgos Cathedral (northern Spain) Texte intégral
2015
Gázquez, Fernando | Rull, F. (Fernando) | Medina, Jesús | Sanz-Arranz, Aurelio | Sanz, Carlos
Precipitation of salts—mainly hydrated Mg-Na sulfates—in building materials is rated as one of the most severe threats to the preservation of our architectural and cultural heritage. Nevertheless, the origin of this pathology is still unknown in many cases. Proper identification of the cause of damage is crucial for correct planning of future restoration actions. The goal of this study is to identify the source of the degradation compounds that are affecting the 15th-century limestone sculptures that decorate the retro-choir of Burgos Cathedral (northern Spain). To this end, detailed characterization of minerals by in situ (Raman spectroscopy) and laboratory techniques (XRD, Raman and FTIR) was followed by major elements (ICP and IC) and isotopic analysis (δ³⁴S and δ¹⁵N) of both the mineral phases precipitated on the retro-choir and the dissolved salts in groundwater in the vicinity of the cathedral. The results reveal unequivocal connection between the damage observed and capillary rise of salts-bearing water from the subsoil. The multianalytical methodology used is widely applicable to identify the origin of common affections suffered by historical buildings and masterpieces.
Afficher plus [+] Moins [-]Influence of relative humidity on VOC concentrations in indoor air Texte intégral
2015
Markowicz, Pawel | Larsson, Lennart
Volatile organic compounds (VOCs) may be emitted from surfaces indoors leading to compromised air quality. This study scrutinized the influence of relative humidity (RH) on VOC concentrations in a building that had been subjected to water damage. While air samplings in a damp room at low RH (21–22 %) only revealed minor amounts of 2-ethylhexanol (3 μg/m³) and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB, 8 μg/m³), measurements performed after a rapid increase of RH (to 58–75 %) revealed an increase in VOC concentrations which was 3-fold for 2-ethylhexanol and 2-fold for TXIB. Similar VOC emission patterns were found in laboratory analyses of moisture-affected and laboratory-contaminated building materials. This study demonstrates the importance of monitoring RH when sampling indoor air for VOCs in order to avoid misleading conclusions from the analytical results.
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