Environmental contamination due to uncontrolled e-waste recycling activities is drawing increasing attention in the world. Extraction of these metals with biodegradable chelant [S,S]-ethylenediaminedisuccinic acid (EDDS) and the factors influencing extraction efficacy were investigated in the present study. Results showed that the addition of EDDS at low pH (5.5) produced higher metal extraction than that at high pH (8.0) solution. Metal speciation analysis indicated that Cu was completely complexed with EDDS at different pH conditions with various amounts of EDDS applied. For Pb and Zn, at low EDDS dose of 0.304 mol/kg soil, they were present as Pb- and Zn-EDDS. However, at high EDDS dose of 1.26 mol/kg soil, most of Pb was bound with dissolved organic matter. Ca and Al were found to be strong competitors for trace metals to EDDS at low application dose and low pH condition. 相似文献
Environmental Modeling & Assessment - The health effects of air pollution on respiratory disease morbidity and mortality commonly vary with air pollutants’ intensity and latency after... 相似文献
Fine particle matters (PM2.5) is a well-known risk factor for cardiovascular diseases. However, the underlying molecular mechanisms are largely unknown. Vascular hyper-reactivity plays an important roles in the pathogenesis of cardiovascular diseases. The present study was designed to investigate a hypothesis that PM2.5 up-regulated endothelin receptors in mesenteric artery and the potential underlying mechanisms. Rat mesenteric arteries were cultured with PM2.5. The artery contractile responses were recorded by a sensitive myograph. ETB and ETA receptor expressions of mRNA and protein were assessed by quantitative real-time PCR, Western blotting, and immunohistochemistry, respectively. Results showed that ETB receptor agonist, sarafotoxin 6c induced a negligible contraction in fresh artery segments, while ETA receptor agonist, ET-1 induced an obvious contraction. After organ culture, the contraction curve mediated by ETB and ETA receptors were shifted toward the left. PM2.5 1.0 μg/ml cultured for 16 h further enhanced ETB and ETA receptor-mediated contractile responses with a markedly increased maximal contraction. The organ culture enhanced ETB and ETA receptor mRNA and protein levels from fresh arteries, which were further increased by PM2.5. The U0126 (MEK/ERK1/2 inhibitor) and SB203580 (p38 inhibitor) significantly attenuated both organ cultured-induced and PM2.5-induced up-regulation of ETB receptor. U0126 also suppressed organ culture-increased and PM2.5-increased expressions of ETA receptor. SB203580 only suppressed PM2.5-induced enhanced expressions of ETA receptor In conclusion, airborne PM2.5 up-regulates ETB and ETA receptors of mesenteric artery via p38 MAPK and MEK/ERK1/2 MAPK pathways.
Environmental Science and Pollution Research - The emission of particulate matter from ships does great harm to human health and atmospheric environment. Sulfur emission regulations also affect... 相似文献
Environmental Science and Pollution Research - Worldwide socioeconomic development has resulted in huge irretrievable environmental problems in various ecosystems. This study employed seven coastal... 相似文献