Environmental Science and Pollution Research - The present study aims to assess the effect of four inorganic soil amendments, such as lime (CaCO3), red mud consisting of 75% hematite (Fe2O3),... 相似文献
Environmental Science and Pollution Research - The hrpZPsph gene from Pseudomonas syringae pv. phaseolicola, in its secretable form (SP/hrpZPsph), has previously proven capable of conferring... 相似文献
The aim of this study was to determine the concentration of some essential and toxic metals in the colostrum and transitory human milk in conjunction with various factors that may influence their concentrations i.e. diet, supplementation, place of residence, smoking, as well as socioeconomic and somatometric characteristics. Zinc, iron, copper, manganese, cadmium and lead were measured by AAS in 180 colostrum samples from healthy lactating women collected on third day postpartum. A second milk sample was collected in 95 (53%) subjects 14 days later. Dietary habits were assessed by a 7-day food frequency questionnaire and various characteristics and socio-economic factors were also recorded. The mean (+/-standard deviation) values of colostrum samples were: Zn 4905 +/- 1725 microg l(-1), Fe 544 +/- 348 microg l(-1), Mn 4.79 +/- 3.23 microg l(-1), Cu 381 +/- 132 microg l(-1), Cd 0.190 +/- 0.150 microg l(-1), Pb 0.48 +/- 0.60 microg l(-1). All metals with the exception of copper were found in lower concentrations in transitory samples. Cadmium and lead weekly intakes were found to be below the Maximum Tolerable Weekly Intakes as they have been established for infants by WHO or NRC. Our results revealed: higher Pb concentration in the samples from urban areas; effect of smoking on Cu level; dietary habits seem to play a role in metal levels in human milk as the logistic regression models revealed. 相似文献
Concentrations and chemical composition of the coarse particle fraction (PMc) were investigated at two urban sites in the city of Thessaloniki, Greece, through concurrent sampling of PM10 and PM2.5 during the warm and the cold months of the year. PMc levels at the urban-traffic site (UT) were among the highest found in literature worldwide exhibiting higher values in the cold period. PMc levels at the urban-background site (UB) were significantly lower exhibiting a reverse seasonal trend. Concentration levels of minerals and most trace metals were also higher at the UT site suggesting a stronger impact from traffic-related sources (road dust resuspension, brake and tire abrasion, road wear). According to the chemical mass closure obtained, minerals (oxides of Si, Al, Ca, Mg, Fe, Ti, and K) dominated the PMc profile, regardless of the site and the period, with organic matter and secondary inorganic aerosols (mainly nitrate) also contributing considerably to the PMc mass, particularly in the warm period. The influence of wind speed to dilution and/or resuspension of coarse particles was investigated. The source of origin of coarse particles was also investigated using surface wind data and atmospheric back-trajectory modeling. Finally, the contribution of resuspension to PMc levels was estimated for air quality management perspectives. 相似文献
Elevated concentrations of potentially toxic elements (PTEs) are usually found in areas of intense industrial activity. Thriasio Plain is a plain near Athens, Greece, where most of the heavy industry of the country has been situated for decades, but it also is a residential and horticultural area. We aimed at measuring the levels of PTEs in soils and indigenous plant species and assessing the health risk associated with direct soil ingestion. Samples of soils at roadsides and growing plants were collected from 31 sites of that area. Concentrations of Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, V and Zn were measured in both soils (as pseudo-total) and aerial plant tissues. We found that As, Cd, Cr, Cu, Ni, Pb and Zn were higher than maximum regulatory limits. Element concentrations in plants were rather lower than expected, probably because indigenous plants have developed excluder behaviour over time. Copper and Zn soil-to-plant coefficients were highest among the other elements; for Cu this was unexpected, and probably associated with recent Cu-releasing industrial activity. Risk assessment analysis indicated that As was the element contributing more than 50 % of the health risk related to direct soil ingestion, followed by Cr, Pb, and, surprisingly, Mn. We concluded that in a multi-element contamination situation, elevated risk of PTEs (such as As, Cr and Pb) may reduce the tolerance limits of exposure to less-toxic elements (here, Mn). 相似文献
Modern societies strongly support the recycling practices over simple waste accumulation due to environmental harm caused. In the framework of sustainable recycling of plastics from WEEE, pyrolysis is proposed here as a means of obtaining secondary value-added products. The aim of this study was to investigate the thermal degradation and the products obtained after pyrolysis of specific polymers found in the plastic part of WEEE, using thermogravimetric analysis and a pyrolizer equipped with a GC/MS. Polymers studied include ABS, HIPS, PC and a blend having a composition similar to that appearing in WEEE. It was found that, PC shows greater heat endurance compared to the other polymers, whereas ABS depolymerizes in three-steps. The existence of several polymers in the blend results in synergistic effects which decrease the onset and final temperature of degradation. Moreover, the fragmentation occurred in the pyrolyzer, at certain temperatures, resulted in a great variety of compounds, depending on the polymer type, such as monomers, aromatic products, phenolic compounds and hydrocarbons. The main conclusion from this investigation is that pyrolysis could be an effective method for the sustainable recycling of the plastic part of WEEE resulting in a mixture of chemicals with varying composition but being excellent to be used as fuel retrieved from secondary recycling sources.