خيارات البحث
النتائج 1 - 10 من 21
Metal composition of fine particulate air pollution and acute changes in cardiorespiratory physiology
2014
Cakmak, Sabit | Dales, Robert | Kauri, Lisa Marie | Mahmud, Mamun | Van Ryswyk, Keith | Vanos, Jennifer | Liu, Ling | Kumarathasan, Premkumari | Thomson, Errol | Vincent, Renaud | Weichenthal, Scott
Studying the physiologic effects of components of fine particulate mass (PM2.5) could contribute to a better understanding of the nature of toxicity of air pollution.We examined the relation between acute changes in cardiovascular and respiratory function, and PM2.5-associated-metals.Using generalized linear mixed models, daily changes in ambient PM2.5-associated metals were compared to daily changes in physiologic measures in 59 healthy subjects who spent 5-days near a steel plant and 5-days on a college campus.Interquartile increases in calcium, cadmium, lead, strontium, tin, vanadium and zinc were associated with statistically significant increases in heart rate of 1–3 beats per minute, increases of 1–3 mmHg in blood pressure and/or lung function decreases of up to 4% for total lung capacity.Metals contained in PM2.5 were found to be associated with acute changes in cardiovascular and respiratory physiology.
اظهر المزيد [+] اقل [-]Pro-inflammatory effects and oxidative stress in lung macrophages and epithelial cells induced by ambient particulate matter
2013
Michael, S. | Montag, M. | Dott, W.
The objective of this study was to compare the toxicological effects of different source-related ambient PM10 samples in regard to their chemical composition. In this context we investigated airborne PM from different sites in Aachen, Germany. For the toxicological investigation human alveolar epithelial cells (A549) and murine macrophages (RAW264.7) were exposed from 0 to 96 h to increasing PM concentrations (0–100 μg/ml) followed by analyses of cell viability, pro-inflammatory and oxidative stress responses. The chemical analysis of these particles indicated the presence of 21 elements, water-soluble ions and PAHs. The toxicological investigations of the PM10 samples demonstrated a concentration- and time-dependent decrease in cell viability and an increase in pro-inflammatory and oxidative stress markers.
اظهر المزيد [+] اقل [-]Does zebra mussel (Dreissena polymorpha) represent the freshwater counterpart of Mytilus in ecotoxicological studies? A critical review
2015
Binelli, A. | Della Torre, C. | Magni, S. | Parolini, M.
One of the fundamentals in the ecotoxicological studies is the need of data comparison, which can be easily reached with the help of a standardized biological model. In this context, any biological model has been still proposed for the biomonitoring and risk evaluation of freshwaters until now. The aim of this review is to illustrate the ecotoxicological studies carried out with the zebra mussel Dreissena polymorpha in order to suggest this bivalve species as possible reference organism for inland waters. In detail, we showed its application in biomonitoring, as well as for the evaluation of adverse effects induced by several pollutants, using both in vitro and in vivo experiments. We discussed the advantages by the use of D. polymorpha for ecotoxicological studies, but also the possible limitations due to its invasive nature.
اظهر المزيد [+] اقل [-]Nitric-oxide generation induced by metals plays a role in their accumulation by Phallusia nigra hemocytes
2017
Ascidians are good monitors for assessing water quality, since they filter large volumes of water; however, little is known about how xenobiotics, including metals, can affect ascidian hemocytes. Metals can be either toxic or beneficial to health, inducing many different responses. The response mechanism depends on the class of metals to which organisms are exposed: essential, nonessential, and borderline. To analyze the influence of metals from different classes on the protective mechanisms of an ascidian, we investigated the production of nitric oxide (NO) after exposure to various concentrations of Mg, Mn and Pb over different time periods. We also determined the amounts of each metal in the hemocytes. Our results indicated that especially Pb could stimulate NO production. Although Pb induced the highest NO production, cell viability was not severely altered in all Pb concentrations and time periods. Ascidians might serve as biomonitor for Pb, since their vanadocytes accumulate Pb.
اظهر المزيد [+] اقل [-]Microplastics releasing from personal care and cosmetic products in China
2017
Lei, Kun | Qiao, Fei | Liu, Qing | Wei, Zhanliang | Qi, Hongli | Cui, Song | Yue, Xue | Deng, Yixiang | An, Lihui
Microplastics (MPs) have become a major global issue; their release from various products affects the aquatic environment, especially marine ecosystems. As a primary source of MPs, personal care and cosmetics products (PCCPs) containing MPs contribute to this environmental risk. We visited several supermarket chains in Beijing, China to identify PCCPs containing MPs. Overall, 7.1% of facial cleansers contained MPs, with an average weight of 25.04±10.69mgMP/g and average size of 313±130μm; whereas, 2.2% of shower gel products contained an average weight of 17.80±7.50mgMPs/g with an average size of 422±185μm. The majority of MPs were made of polyethylene, based on Raman and Fourier transform-infrared spectra analyses, while only a few were made of walnut shells and carbon particles. Finally, estimated 39tons MPs were released into the environment based on PCCPs use in China based on available data.
اظهر المزيد [+] اقل [-]Evaluation of the fertilization of an environmentally stressed forest site of spruce with regard to its stabilization
1992
Duenisch, O. (Bundesforschungsanstalt fuer Forst- und Holzwirtschaft, Hamburg (Germany). Inst. fuer Holzbiologie und Holzschutz) | Bauch, J. | Rademacher, P. | Puls, J.
Balance of element supply and element fluxes in the ecosystem compartments of crown, stem, root and soil of a diseased spruce-stand at the forest-site "Postturm"
1992
Rademacher, P. (Goettingen Univ. (Germany). Forschungszentrum Waldoekosysteme) | Ullrich, B. | Michaelis, W.
[Water quality of four small brooks situated in the forest hydrological research area of Krofdorf (Hesse). - An experimental comparison of the catchment basin]
1989
Fuehrer, H.W.
The effect of liming and Mg-fertilization on uptake, transport and final use of calcium and magnesium in conifers
1993
Guelpen, M. (Freiburg Univ. (Germany). Inst. fuer Forstbotanik und Baumphysiologie) | Tuerk, S. | Fink, S.
Pollutants exclusion experiment on spruce trees at the Edelmannshof site. Basic measurements and material turnover
1993
Evers, F.H. | Hoyer, V. | Kottke, J. | Quian, M. | Schnepf, M. | Seufert, G.