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21.
Pedro N. Carvalho Pedro Nuno R. Rodrigues M. Clara P. Basto M. Teresa S. D. Vasconcelos 《Environmental monitoring and assessment》2009,159(1-4):183-190
This work aimed to report present levels (2007–2008 sampling) of tri- (TBT), di- (DBT), and monobutyltin (MBT) in surface sediments from 11 Portuguese coastal sites and discuss the evolution of BTs contamination in the last two decades. All the samples revealed quantifiable values of TBT, DBT, and MBT with total butyltin concentrations between 1 and 565 ng/g (of Sn in dry sediment). Maximum level of TBT, 66 ng/g, was observed in Sado estuary, at Lisnave site, in the proximity of a big shipyard. MBT decreased site by site by the same order as DBT and TBT did, but its concentrations were much higher in many cases, denoting that TBT contamination was much higher in the past. A comparison with the available previous data confirmed a marked decrease of TBT contamination all over the last years, indicating that the main sources of TBT in Portuguese coastwise stopped effectively. 相似文献
22.
Packaging steel is more advantageously recovered and recycled than other packaging material due to its magnetic properties. The steel used for packaging is of high quality, and post-consumer waste therefore produces high-grade ferrous scrap. Recycling is thus an important issue for reducing raw material consumption, including iron ore, coal and energy. Household refuse management consists of collection/disposal, transport, and processing and treatment - incineration and composting being the most widely used methods in Spain. Total Spanish MSW production exceeds 21 million tons per year, of which 28.1% and 6.2% are treated in compost and incineration plants, respectively. This paper presents a comprehensive study of incineration and compost plants in Spain, including a review of the different processes and technologies employed and the characteristics and quality of the recovered ferrous scrap. Of the total amount of packaging steel scrap recovered from MSW, 38% comes from compost plants and 14% from incineration plants. Ferrous scrap from incineration plants presents a high degree of chemical alteration as a consequence of the thermal process to which the MSW is subjected, particularly the conditions in which the slag is cooled, and accordingly its quality diminishes. Fragmentation and magnetic separation processes produce an enhancement of the scrap quality. Ferrous scrap from compost plants has a high tin content, which negatively affects its recycling. Cleaning and detinning processes are required prior to recycling. 相似文献
23.
Growth, photosynthetic and respiratory responses to sub-lethal copper concentrations in Scenedesmus incrassatulus (Chlorophyceae) 总被引:1,自引:0,他引:1
Perales-Vela HV González-Moreno S Montes-Horcasitas C Cañizares-Villanueva RO 《Chemosphere》2007,67(11):2274-2281
In the present paper we investigated the effects of sub-lethal concentrations of Cu2+ in the growth and metabolism of Scenedesmus incrassatulus. We found that the effect of Cu2+ on growth, photosynthetic pigments (chlorophylls and carotenoids) and metabolism do not follow the same pattern. Photosynthesis was more sensitive than respiration. The analysis of chlorophyll a fluorescence transient shows that the effect of sub-lethal Cu2+ concentration in vivo, causes a reduction of the active PSII reaction centers and the primary charge separation, decreasing the quantum yield of PSII, the electron transport rate and the photosynthetic O2 evolution. The order of sensitivity found was: Growth > photosynthetic pigments content = photosynthetic O2 evolution > photosynthetic electron transport > respiration. The uncoupled relationship between growth and metabolism is discussed. 相似文献
24.
Fiorentino CE Paoloni JD Sequeira ME Arosteguy P 《Journal of contaminant hydrology》2007,93(1-4):122-129
Changes in the quality of groundwater resources are related to the presence and concentration of contaminants, especially trace elements such as arsenic, boron, fluoride and vanadium. Vanadium is a rare element naturally abundant, generally found in combination with other elements. Vanadium pentoxide is known to have aneugenic effects. Thus, a study was carried out to assess the presence of vanadium in the groundwater of the southeastern pampean region of Argentina, which constitutes the main water supply for the local population. Statistical and correlational analyses were applied to identify possible interrelationships between vanadium and another chemical elements. Vanadium was found in all groundwater samples. The minimum and maximum vanadium concentrations found were 0.05 mg/l and 2.47 mg/l, respectively. Vanadium is significantly correlated with other trace elements such as arsenic, fluoride and boron. The interrelationship between vanadium and the presence of volcanic glass in sediments is not significant as expected. 相似文献
25.
Martínez-Carballo E Sitka A González-Barreiro C Kreuzinger N Fürhacker M Scharf S Gans O 《Environmental pollution (Barking, Essex : 1987)》2007,145(2):489-496
A method for simultaneous quantitative determination of alkyl benzyl, dialkyl and trialkyl quaternary ammonium compounds (QACs) has been developed, validated and subsequently applied to real water samples in Austria. The method employs liquid-liquid extraction (LLE) followed by liquid chromatography/tandem mass spectrometry (LC-MS/MS), using electrospray ionization (ESI) in positive mode. The overall method quantification limits range from 4 to 19ng/L for the enrichment of 500mL water samples and analyte recoveries are between 80 and 99%. The method was applied to 62 of the respective water samples without filtration to avoid the loss of the analytes due to the high adsorption capacity of these compounds. Maxima in the mg/L range, especially in the wastewater of hospitals and laundries, could be detected for the selected target compounds. 相似文献
26.
Gomes J Nascimento J Rodrigues H 《Journal of the Air & Waste Management Association (1995)》2007,57(9):1032-1037
This paper describes the study that led to the development of a carbon dioxide emissions matrix for the Oeiras municipality, one of the largest Portuguese municipalities, located in the metropolitan area of Lisbon. This matrix takes into account the greenhouse gas (GHG) emissions due to an increase of electricity demand in buildings as well as solid and liquid wastes treatment from the domestic and services sectors. Using emission factors that were calculated from the relationship between the electricity produced and amount of treated wastes, the GHC emissions in the Oeiras municipality were estimated for a time series of 6 yr (1998-2003). The obtained results showed that the electricity sector accounts for approximately 75% of the municipal emissions in 2003. This study was developed to obtain tools to base options and actions to be undertaken by local authorities such as energy planning and also public information. 相似文献
27.
Human hair samples (n=42) from Iassy county (Eastern Romania) collected in 2002-2003 from adolescents were analyzed for hexachlorocyclohexane (HCH) isomers, p,p'-DDT and its metabolites, hexachlorobenzene (HCB), chlordane and metabolites and 5 polychlorinated biphenyl (PCB) congeners. Very low levels were found for HCB and oxychlordane (0.8 and 2.5 ng g(-1)) indicating a low usage of these pesticide formulations in the studied area. In case of HCHs, gamma-HCH isomer was measured at higher median concentrations (79 ng g(-1) hair) compared to the beta-HCH isomer (55 ng g(-1)), which generally is the most prevalent from HCHs. The DDTs profile consisted in p,p'-DDE and p,p'-DDT which levels correspond to 81% of sum DDTs. Very high median concentrations measured for p,p'-DDT (192 ng g(-1)) combined with lower values for p,p'-DDE/p,p'-DDT of 0.4 (from 0.20 to 2.0) in all hair samples suggest recent exposure to "fresh" DDT. When gender was considered, significantly higher concentrations for most of the investigated contaminants were found in girls hair compared to boys. Very high levels were found in the present study for HCHs and DDTs compared to samples from Greece, Western Europe and China. In case of PCBs, the levels found in Romanian samples were found to be in the same range compared to other previously published data. 相似文献
28.
Gara Luis Carmen Rubio Ángel. J. Gutiérrez Dailos González-Weller Consuelo Revert Arturo Hardisson 《Environmental monitoring and assessment》2014,186(1):433-440
Sweet potatoes are a staple in the diet of some people and an excellent source of minerals. Metal monitoring in food, like sweet potatoes, provides basic information on safety aspects in regulatory processes as well as nutritional values. One hundred five samples of three varieties of sweet potatoes were randomly obtained from supermarkets, farmers markets, and farmers' plots in Tenerife (Canary Islands, Spain). The edible portion (pulp) was the only part considered for analysis. Flame atomic absorption spectrometry was used to determine the contents of sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn), while the levels of chromium (Cr), nickel (Ni), cadmium (Cd), and lead (Pb) were determined using graphite furnace atomic absorption spectrometry. The mean concentrations were 500 Na, 4409 K, 564 Ca, 609 Mg, 1.291 Cu, 6.554 Fe, 2.324 Mn, 2.348 Zn, 0.028 Cr, 0.048 Ni, 0.001 Cd, and 0.003 Pb mg/kg, respectively. Potassium presented the highest contents in all varieties of sweet potatoes. Iron was the most abundant microelement. The orange fleshed sweet potato variety offered greater nutritional contributions to the recommended intakes than the rest of the varieties studied. The estimated mean daily intake of Ni (0.72 mg/day) detected in our samples was highly consistent with other studies. Average daily intakes of Cd (0.015 μg/day) and Pb (0.045 μg/day) were below toxicological reference values. In conclusion, the levels of Cd and Pb detected in the sweet potatoes analyzed do not represent any toxicological risk to consumers. 相似文献
29.
Ovidiu Badea Andrzej Bytnerowicz Diana Silaghi Stefan Neagu Ion Barbu Carmen Iacoban Corneliu Iacob Gheorghe Guiman Elena Preda Ioan Seceleanu Marian Oneata Ion Dumitru Viorela Huber Horia Iuncu Lucian Dinca Stefan Leca Ioan Taut 《Environmental monitoring and assessment》2012,184(12):7491-7515
Air pollution, bulk precipitation, throughfall, soil condition, foliar nutrients, as well as forest health and growth were studied in 2006–2009 in a long-term ecological research (LTER) network in the Bucegi Mountains, Romania. Ozone (O3) was high indicating a potential for phytotoxicity. Ammonia (NH3) concentrations rose to levels that could contribute to deposition of nutritional nitrogen (N) and could affect biodiversity changes. Higher that 50% contribution of acidic rain (pH?<?5.5) contributed to increased acidity of forest soils. Foliar N concentrations for Norway spruce (Picea abies), Silver fir (Abies alba), Scots pine (Pinus sylvestris), and European beech (Fagus sylvatica) were normal, phosphorus (P) was high, while those of potassium (K), magnesium (Mg), and especially of manganese (Mn) were significantly below the typical European or Carpathian region levels. The observed nutritional imbalance could have negative effects on forest trees. Health of forests was moderately affected, with damaged trees (crown defoliation >25%) higher than 30%. The observed crown damage was accompanied by the annual volume losses for the entire research forest area up to 25.4%. High diversity and evenness specific to the stand type’s structures and local climate conditions were observed within the herbaceous layer, indicating that biodiversity of the vascular plant communities was not compromised. 相似文献
30.
Arruda-Neto JD Nieto L Righi H Cotta MA Carrer H Rodrigues TE Genofre GC 《Journal of environmental monitoring : JEM》2012,14(8):2108-2113
Persistent harmful scenarios associated with disposal of radioactive waste, high-background radiation areas and severe nuclear accidents are of great concern regarding consequences to both human health and the environment. Of particular concern is the extracellular DNA in aquatic environments contaminated by radiological substances. Strand breaks induced by radiation promote decrease in the transformation efficiency for extracellular DNA. The focus of this study is the quantification of DNA damage following long-term exposure (over one year) to low doses of natural uranium (an alpha particle emitter) to simulate natural conditions, since nothing is known about alpha radiation induced damage to extracellular DNA. A high-resolution Atomic Force Microscope was used to evaluate DNA fragments. Double-stranded plasmid pBS as a model for extracellular DNA was exposed to different amounts of natural uranium. It was demonstrated that low concentrations of U in water (50 to 150 ppm) produce appreciable numbers of double strand breaks, scaling with the square of the average doses. The importance of these findings for environment monitoring of radiological pollution is addressed. 相似文献