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Catalog of total excitation-emission and total synchronous fluorescence maps with synchronous fluorescence spectra of homologated fluorescent pesticides in large use in Morocco: development of a spectrometric low cost and direct analysis as an alert method in case of massive contamination of soils and waters by fluorescent pesticides 全文
1000 | 2015
Foudeil, S. | Hassoun, H. | Lamhasni, T. | Ait Lyazidi, S. | Benyaich, F. | Haddad, M. | Choukrad, M. | Boughdad, A. | Bounakhla, M. | Bounouira, H. | Duarte, R. M. B. O. | Cachada, A. | Duarte, A. C.
Catalog of total excitation-emission and total synchronous fluorescence maps with synchronous fluorescence spectra of homologated fluorescent pesticides in large use in Morocco: development of a spectrometric low cost and direct analysis as an alert method in case of massive contamination of soils and waters by fluorescent pesticides 全文
1000 | 2015
Foudeil, S. | Hassoun, H. | Lamhasni, T. | Ait Lyazidi, S. | Benyaich, F. | Haddad, M. | Choukrad, M. | Boughdad, A. | Bounakhla, M. | Bounouira, H. | Duarte, R. M. B. O. | Cachada, A. | Duarte, A. C.
The purpose of this research is to develop a direct spectrometric approach to monitor soils and waters, at a lower cost than the widely used chromatographic techniques; a spectrometric approach that is effective, reliable, fast, easy to implement, and without any use of organic solvents whose utilization is subject to law limitation. It could be suitable at least as an alert method in case of massive contamination. Here, we present for the first time a catalog of excitation– emission and total synchronous fluorescence maps that may be considered as fingerprints of a series of homologated pesticides, in large use in Morocco, aiming at a direct detection of their remains in agricultural soils and neighboring waters. After a large survey among farmers, agricultural workers and product distributors in two important agricultural regions of Morocco (Doukkala-Abda and Sebou basin), 48 commercial pesticides, which are fluorescent, were chosen. A multi-component spectral database of these targeted commercial pesticides was elaborated. For each pesticide, dissolved in water at the lowest concentration giving a no-noise fluorescence spectrum, the total excitation-emission matrix (TEEM), the total synchronous fluorescence matrix (TSFM) in addition to synchronous fluorescence spectra (SFS) at those offsets giving the highest fluorescence intensity were recorded. To test this preliminary multi-component database, two real soil samples, collected at a wheat field and at a vine field in the region of Doukkala, were analyzed. Remains of the commercial Pirimor (Carbamate) and Atlantis (Sulfonylurea) were identified by comparison of the recorded TEEM, TSFM, and SFS to those of the preliminary catalog at one hand, and on the basis of the results of a field pre-survey. The developed approach seems satisfactory, and the fluorimetric fingerprint database is under extension to a higher number of fluorescent pesticides in common use among the Moroccan agricultural regions.
显示更多 [+] 显示较少 [-]Catalog of total excitation–emission and total synchronous fluorescence maps with synchronous fluorescence spectra of homologated fluorescent pesticides in large use in Morocco: development of a spectrometric low cost and direct analysis as an alert method in case of massive contamination of soils and waters by fluorescent pesticides 全文
2015
Foudeil, S. | Hassoun, H. | Lamhasni, T. | Ait Lyazidi, S. | Benyaich, F. | Haddad, M. | Choukrad, M. | Boughdad, A. | Bounakhla, M. | Bounouira, H. | Duarte, R. M. B. O. | Cachada, A. | Duarte, A. C.
The purpose of this research is to develop a direct spectrometric approach to monitor soils and waters, at a lower cost than the widely used chromatographic techniques; a spectrometric approach that is effective, reliable, fast, easy to implement, and without any use of organic solvents whose utilization is subject to law limitation. It could be suitable at least as an alert method in case of massive contamination. Here, we present for the first time a catalog of excitation–emission and total synchronous fluorescence maps that may be considered as fingerprints of a series of homologated pesticides, in large use in Morocco, aiming at a direct detection of their remains in agricultural soils and neighboring waters. After a large survey among farmers, agricultural workers and product distributors in two important agricultural regions of Morocco (Doukkala-Abda and Sebou basin), 48 commercial pesticides, which are fluorescent, were chosen. A multi-component spectral database of these targeted commercial pesticides was elaborated. For each pesticide, dissolved in water at the lowest concentration giving a no-noise fluorescence spectrum, the total excitation-emission matrix (TEEM), the total synchronous fluorescence matrix (TSFM) in addition to synchronous fluorescence spectra (SFS) at those offsets giving the highest fluorescence intensity were recorded. To test this preliminary multi-component database, two real soil samples, collected at a wheat field and at a vine field in the region of Doukkala, were analyzed. Remains of the commercial Pirimor (Carbamate) and Atlantis (Sulfonylurea) were identified by comparison of the recorded TEEM, TSFM, and SFS to those of the preliminary catalog at one hand, and on the basis of the results of a field pre-survey. The developed approach seems satisfactory, and the fluorimetric fingerprint database is under extension to a higher number of fluorescent pesticides in common use among the Moroccan agricultural regions.
显示更多 [+] 显示较少 [-]Progression of DNA damage induced by a glyphosate-based herbicide in fish (Anguilla anguilla) upon exposure and post-exposure periods - Insights into the mechanisms of genotoxicity and DNA repair 全文
2014 | 1000
Marques, Ana | Guilherme, Sofia | Gaivão, Isabel | Santos, Maria Ana | Pacheco, Mário
Progression of DNA damage induced by a glyphosate-based herbicide in fish (Anguilla anguilla) upon exposure and post-exposure periods - Insights into the mechanisms of genotoxicity and DNA repair 全文
2014 | 1000
Marques, Ana | Guilherme, Sofia | Gaivão, Isabel | Santos, Maria Ana | Pacheco, Mário
Roundup(R) is a glyphosate-based herbicide widely used with both agricultural and non-agricultural purposes, which has been demonstrated to represent a risk to non-target aquatic organisms, namely fish. Among the described effects to fish, genotoxicity has been pointed out as one of the most hazardous. However, the genotoxic mechanisms of Roundup?? as well as the involvement of the oxidative DNA damage repair system are not entirely understood. Hence, this work aimed to improve the knowledge on the progression of DNA damage upon short-term exposure (3 days) and post-exposure (1-14 days) periods in association with DNA repair processes in Anguilla anguilla exposed to Roundup?? (58 and 116 ??g L- 1). DNA damage in hepatic cells was evaluated by the comet assay improved with the DNA-lesion specific endonucleases FPG and EndoIII. In order to evaluate the oxidative DNA damage repair ability, an in vitro base excision repair (BER) assay was performed, testing hepatic subcellular extracts. Besides the confirmation of the genotoxic potential of this herbicide, oxidative damage was implicit as an important mechanism of genetic damage, which showed to be transient, since DNA integrity returned to the control levels on the first day after cessation of exposure. An increased capacity to repair oxidative DNA damage emerging in the post-exposure period revealed to be a crucial pathway for the A. anguilla recovery; nevertheless, DNA repair machinery showed to be susceptible to inhibitory actions during the exposure period, disclosing another facet of the risk associated with the tested agrochemical.
显示更多 [+] 显示较少 [-]Progression of DNA damage induced by a glyphosate-based herbicide in fish (Anguilla anguilla) upon exposure and post-exposure periods — Insights into the mechanisms of genotoxicity and DNA repair 全文
2014
Marques, Ana | Guilherme, Sofia | Gaivão, Isabel | Santos, Maria Ana | Pacheco, Mario
Roundup® is a glyphosate-based herbicide widely used with both agricultural and non-agricultural purposes, which has been demonstrated to represent a risk to non-target aquatic organisms, namely fish. Among the described effects to fish, genotoxicity has been pointed out as one of the most hazardous. However, the genotoxic mechanisms of Roundup® as well as the involvement of the oxidative DNA damage repair system are not entirely understood. Hence, this work aimed to improve the knowledge on the progression of DNA damage upon short-term exposure (3days) and post-exposure (1–14days) periods in association with DNA repair processes in Anguilla anguilla exposed to Roundup® (58 and 116μgL−1). DNA damage in hepatic cells was evaluated by the comet assay improved with the DNA-lesion specific endonucleases FPG and EndoIII. In order to evaluate the oxidative DNA damage repair ability, an in vitro base excision repair (BER) assay was performed, testing hepatic subcellular extracts. Besides the confirmation of the genotoxic potential of this herbicide, oxidative damage was implicit as an important mechanism of genetic damage, which showed to be transient, since DNA integrity returned to the control levels on the first day after cessation of exposure. An increased capacity to repair oxidative DNA damage emerging in the post-exposure period revealed to be a crucial pathway for the A. anguilla recovery; nevertheless, DNA repair machinery showed to be susceptible to inhibitory actions during the exposure period, disclosing another facet of the risk associated with the tested agrochemical.
显示更多 [+] 显示较少 [-]Spatiotemporal variability of hydrologic soil properties and the implications for overland flow and land management in a peri-urban Mediterranean catchment 全文
1000 | 2015
Ferreira, C. S. S. | Walsh, R. P. D. | Steenhuis, T. S. | Shakesby, R. A. | Nunes, J. P. N. | Coelho, C. O. A. | Ferreira, A. J. D.
Spatiotemporal variability of hydrologic soil properties and the implications for overland flow and land management in a peri-urban Mediterranean catchment 全文
1000 | 2015
Ferreira, C. S. S. | Walsh, R. P. D. | Steenhuis, T. S. | Shakesby, R. A. | Nunes, J. P. N. | Coelho, C. O. A. | Ferreira, A. J. D.
Planning of semi-urban developments is often hindered by a lack of knowledge on how changes in landuse affect catchment hydrological response. The temporal and spatial patterns of overland flow source areas and their connectivity in the landscape, particularly in a seasonal climate, remain comparatively poorly understood. This study investigates seasonal variations in factors influencing runoff response to rainfall in a peri-urban catchment in Portugal characterized by a mosaic of landscape units and a humid Mediterranean climate. Variations in surface soil moisture, hydrophobicity and infiltration capacity were measured in six different landscape units (defined by land-use on either sandstone or limestone) in nine monitoring campaigns at key times over a one-year period. Spatiotemporal patterns in overland flow mechanisms were found. Infiltration-excess overland flow was generated in rainfalls during the dry summer season in woodland on both sandstone and limestone and on agricultural soils on limestone due probably in large part to soil hydrophobicity. In wet periods, saturation overland flow occurred on urban and agricultural soils located in valley bottoms and on shallow soils upslope. Topography, water table rise and soil depth determined the location and extent of saturated areas. Overland flow generated in upslope source areas potentially can infiltrate in other landscape units downslope where infiltration capacity exceeds rainfall intensity. Hydrophilic urban and agricultural-sandstone soils were characterized by increased infiltration capacity during dry periods, while forest soils provided potential sinks for overland flow when hydrophilic in the winter wet season. Identifying the spatial and temporal variability of overland flow sources and sinks is an important step in understanding and modeling flow connectivity and catchment hydrologic response. Such information is important for land managers in order to improve urban planning to minimize flood risk.
显示更多 [+] 显示较少 [-]Spatiotemporal variability of hydrologic soil properties and the implications for overland flow and land management in a peri-urban Mediterranean catchment 全文
2015
Ferreira, C.S.S. | Walsh, R.P.D. | Steenhuis, T.S. | Shakesby, R.A. | Nunes, J.P.N. | Coelho, C.O.A. | Ferreira, A.J.D.
Planning of semi-urban developments is often hindered by a lack of knowledge on how changes in land-use affect catchment hydrological response. The temporal and spatial patterns of overland flow source areas and their connectivity in the landscape, particularly in a seasonal climate, remain comparatively poorly understood. This study investigates seasonal variations in factors influencing runoff response to rainfall in a peri-urban catchment in Portugal characterized by a mosaic of landscape units and a humid Mediterranean climate. Variations in surface soil moisture, hydrophobicity and infiltration capacity were measured in six different landscape units (defined by land-use on either sandstone or limestone) in nine monitoring campaigns at key times over a one-year period.Spatiotemporal patterns in overland flow mechanisms were found. Infiltration-excess overland flow was generated in rainfalls during the dry summer season in woodland on both sandstone and limestone and on agricultural soils on limestone due probably in large part to soil hydrophobicity. In wet periods, saturation overland flow occurred on urban and agricultural soils located in valley bottoms and on shallow soils upslope. Topography, water table rise and soil depth determined the location and extent of saturated areas. Overland flow generated in upslope source areas potentially can infiltrate in other landscape units downslope where infiltration capacity exceeds rainfall intensity. Hydrophilic urban and agricultural-sandstone soils were characterized by increased infiltration capacity during dry periods, while forest soils provided potential sinks for overland flow when hydrophilic in the winter wet season. Identifying the spatial and temporal variability of overland flow sources and sinks is an important step in understanding and modeling flow connectivity and catchment hydrologic response. Such information is important for land managers in order to improve urban planning to minimize flood risk.
显示更多 [+] 显示较少 [-]Factors influencing red deer occurrence at the southern edge of their range: a Mediterranean ecosystem 全文
2014 | 1000
Torres, Rita Tinoco | Santos, João | Fonseca, Carlos
Factors influencing red deer occurrence at the southern edge of their range: a Mediterranean ecosystem 全文
2014 | 1000
Torres, Rita Tinoco | Santos, João | Fonseca, Carlos
The red deer is in the Iberian Peninsula at the southwestern edge of its European range and although widespread, red deer ecology in Portugal remains poorly understood. By using pellet group counts, we investigate how habitat structure, vegetation composition and human disturbance affect red deer occurrence. Red deer distribution was positively associated with areas with high density of heather, Leguminosae plants and patches with high cover of shrubs, ground cover and tree cover. Red deer occupied areas further away from roads and from villages. Red deer distribution was negatively associated with agricultural fields and areas with high canopy cover.In the perspective of the current climatic changes, continue research on red deer in these so-called edge populations represents an opportunity to assess the ecological responses within an evolutionary perspective and to provide important conservation suggestions for other countries located on the edge of its distribution range. The present results have implications for the conservation of red deer, emphasizing the need for wide range ecological studies. Red deer variation seems to be related to local factors rather than proximity to the edge of its range.
显示更多 [+] 显示较少 [-]Factors influencing red deer occurrence at the southern edge of their range: A Mediterranean ecosystem 全文
2014
Torres, Rita Tinoco | Santos, João | Fonseca, Carlos
The red deer is in the Iberian Peninsula at the southwestern edge of its European range and although widespread, red deer ecology in Portugal remains poorly understood. By using pellet group counts, we investigate how habitat structure, vegetation composition and human disturbance affect red deer occurrence. Red deer distribution was positively associated with areas with high density of heather, Leguminosae plants and patches with high cover of shrubs, ground cover and tree cover. Red deer occupied areas further away from roads and from villages. Red deer distribution was negatively associated with agricultural fields and areas with high canopy cover.In the perspective of the current climatic changes, continue research on red deer in these so-called edge populations represents an opportunity to assess the ecological responses within an evolutionary perspective and to provide important conservation suggestions for other countries located on the edge of its distribution range. The present results have implications for the conservation of red deer, emphasizing the need for wide range ecological studies. Red deer variation seems to be related to local factors rather than proximity to the edge of its range.
显示更多 [+] 显示较少 [-]Ecotoxicological tools for the tropics: Sublethal assays with fish to evaluate edge-of-field pesticide runoff toxicity 全文
1000 | 2010
Moreira, SM | Moreira-Santos, M | Rendon-von Osten, J | da Silva, EM | Ribeiro, R | Guilhermino, L | Soares, AMVM
Ecotoxicological tools for the tropics: Sublethal assays with fish to evaluate edge-of-field pesticide runoff toxicity 全文
1000 | 2010
Moreira, SM | Moreira-Santos, M | Rendon-von Osten, J | da Silva, EM | Ribeiro, R | Guilhermino, L | Soares, AMVM
This study proposes short-term sublethal assays for the tropics using the fish Poecilia reticulata. Assays were evaluated under realistic exposure scenarios by simulating a runoff over an agricultural area sprayed with deltamethrin (Decis). In situ assays were performed inside microcosms set up to simulate runoff water entrance in lentic systems. Laboratory assays were conducted with water samples from the microcosms. In both assays the biochemical parameters were similarly responsive to Decis, with a significant inhibition of acetylcholinesterase (30-46%) and induction of lactate dehydrogenase (33-67%) and glutathione S-transferases (48-176%) activities, observed as of the lowest Decis dose. Postexposure feeding was more sensitive in the laboratory assay than in situ. Among the additional potential stressors, only acetylcholinesterase was significantly influenced by the runoff per se. The proposed methodologies were well adapted for assays with P. reticulata, as organisms were easily deployed and retrieved and enzymatic activities and postexposure feeding were sensitive endpoints. (C) 2010 Elsevier Inc. All rights reserved.
显示更多 [+] 显示较少 [-]Ecotoxicologicaltoolsforthetropics:Sublethalassayswithfishtoevaluate edge-of-fieldpesticiderunofftoxicity | Ecotoxicology and Environmental Safety 全文
2010
Moreira, S. M. | Moreira-Santos, M. | Osten, J. Rendón-von | Silva, E. M. da | Ribeiro, R. | Guilhermino, L. | Soares, Amadeu M. V. M. | Moreira, S. M. | Moreira-Santos, M. | Osten, J. Rendón-von | Silva, E. M. da | Ribeiro, R. | Guilhermino, L. | Soares, Amadeu M. V. M.
Acesso restrito: Texto completo. p. 893-899. | This study proposes short-term sublethal assays for the tropics using the fish Poecilia reticulata. Assays were evaluated under realistic exposure scenarios by simulating a runoff over an agricultural area sprayed with deltamethrin (Decis). In situ assays were performed inside microcosms set up to simulate runoff water entrance in lentic systems. Laboratory assays were conducted with water samples from the microcosms. In both assays the biochemical parameters were similarly responsive to Decis, with a significant inhibition of acetylcholinesterase (30–46%) and induction of lactate dehydrogenase (33–67%) and glutathione S-transferases (48–176%) activities, observed as of the lowest Decis dose. Postexposure feeding was more sensitive in the laboratory assay than in situ. Among the additional potential stressors, only acetylcholinesterase was significantly influenced by the runoff per se. The proposed methodologies were well adapted for assays with P. reticulata, as organisms were easily deployed and retrieved and enzymatic activities and postexposure feeding were sensitive endpoints.
显示更多 [+] 显示较少 [-]Comparative life cycle assessment of three representative feed cereals production in the Po Valley (Italy) 全文
1000 | 2015
Noya, Isabel | González-García, Sara | Bacenetti, Jacopo | Arroja, Luís | Teresa Moreira, Maria
Comparative life cycle assessment of three representative feed cereals production in the Po Valley (Italy) 全文
1000 | 2015
Noya, Isabel | González-García, Sara | Bacenetti, Jacopo | Arroja, Luís | Teresa Moreira, Maria
The cultivation of three different cereals e wheat, triticale and maize (five classes: 300, 400, 500, 600 and 700) e dedicated to grain production for feed purposes was assessed to quantify their environmental profiles and identify the most sustainable crop from an environmental perspective. The most critical processes throughout the life cycle of the cropping systems were also identified. These cereals were chosen because they are the most widespread cereal crops in the Po Valley (Lombardy region), the most important agricultural area in Italy. The standard framework of the Life Cycle Assessment (LCA) was followed to assess the environmental performance of the different cropping systems. Several impact categories were evaluated, including climate change (CC), ozone depletion (OD), terrestrial acidification (TA), freshwater eutrophication (FE), marine eutrophication (ME), human toxicity (HT), photochemical oxidant formation (POF), terrestrial ecotoxicity (TEC), freshwater ecotoxicity (FEC), marine ecotoxicity (MEC), water depletion (WD), fossil depletion (FD) as well as land use as an indicator. The results showed that the maize class 300 was the cereal with the worst environmental profile in the base case, considering economic allocation and no environmental burdens related with digestate production. This scenario presented the most intensive agricultural practices and the lowest biomass yield in comparison with the other crops. In contrast, the maize classes 600 and 700 were the cereal crops with the best environmental profiles in most impact categories. The lower requirements of fertiliser (and thus, fertilisation activities) as well as the higher biomass yield were responsible of these favourable results. However, according to the environmental results, the selection of the best biomass source depends on several methodological assumptions such as the functional unit and the allocation criteria considered (between the grain and the straw) as base for the calculations. Thus, the results of a sensitivity analysis showed that the choice of a mass allocation instead of economic one caused lower environmental impacts in all the categories. Moreover, the consideration or not of the environmental burdens related to the digestate production (the main organic fertiliser used) was also a critical step in the environmental evaluations. The inclusion of environmental loads related to digestate production caused a notable increase in the impact of all the cropping systems regardless the cereal and the impact category. This conclusion could be extrapolated to other systems that exclude the additional burdens allocated to the production of organic fertilisers.
显示更多 [+] 显示较少 [-]Comparative life cycle assessment of three representative feed cereals production in the Po Valley (Italy) 全文
2015
Noya, Isabel | González-García, Sara | Bacenetti, Jacopo | Arroja, Luís | Moreira, Maria Teresa
The cultivation of three different cereals – wheat, triticale and maize (five classes: 300, 400, 500, 600 and 700) – dedicated to grain production for feed purposes was assessed to quantify their environmental profiles and identify the most sustainable crop from an environmental perspective. The most critical processes throughout the life cycle of the cropping systems were also identified. These cereals were chosen because they are the most widespread cereal crops in the Po Valley (Lombardy region), the most important agricultural area in Italy.The standard framework of the Life Cycle Assessment (LCA) was followed to assess the environmental performance of the different cropping systems. Several impact categories were evaluated, including climate change (CC), ozone depletion (OD), terrestrial acidification (TA), freshwater eutrophication (FE), marine eutrophication (ME), human toxicity (HT), photochemical oxidant formation (POF), terrestrial ecotoxicity (TEC), freshwater ecotoxicity (FEC), marine ecotoxicity (MEC), water depletion (WD), fossil depletion (FD) as well as land use as an indicator.The results showed that the maize class 300 was the cereal with the worst environmental profile in the base case, considering economic allocation and no environmental burdens related with digestate production. This scenario presented the most intensive agricultural practices and the lowest biomass yield in comparison with the other crops. In contrast, the maize classes 600 and 700 were the cereal crops with the best environmental profiles in most impact categories. The lower requirements of fertiliser (and thus, fertilisation activities) as well as the higher biomass yield were responsible of these favourable results.However, according to the environmental results, the selection of the best biomass source depends on several methodological assumptions such as the functional unit and the allocation criteria considered (between the grain and the straw) as base for the calculations. Thus, the results of a sensitivity analysis showed that the choice of a mass allocation instead of economic one caused lower environmental impacts in all the categories. Moreover, the consideration or not of the environmental burdens related to the digestate production (the main organic fertiliser used) was also a critical step in the environmental evaluations. The inclusion of environmental loads related to digestate production caused a notable increase in the impact of all the cropping systems regardless the cereal and the impact category. This conclusion could be extrapolated to other systems that exclude the additional burdens allocated to the production of organic fertilisers.
显示更多 [+] 显示较少 [-]Heavy metals of Santiago Island (Cape Verde) top soils: estimated background value maps and environmental risk assessment 全文
1000 | 2015
Cabral Pinto, M. M. S. | Ferreira da Silva, E. | Silva, M. M. V. G. | Melo-Gonçalves, P.
In this work we present maps of estimates of background values of some harmful metals (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, V, and Zn) in the soils of Santiago Island, Cape Verde, analyse their relationships with the geological cartography, and assess their environmental risks. The geochemical survey (soil sampling at a spatial resolution of 3 sites per 10 km2, sample preparation, geochemical analysis, data treatment, and mapping) was conducted following the guidelines proposed by the International Projects IGCP 259 and IGCP 360. The concentration of the selected elements was determined in the fraction <2 mm. Each sample was digested with aqua regia and analysed by ICP-MS. The Estimated Background Value spatial distributions of the studied metals are found to be strongly linked to the geological cartography. These links are identified by a direct comparison of the geochemical maps with the geological cartography, and confirmed by either simple statistics and a Principal Component Analysis. The metals with higher loadings in the first Principal Component, Ni, Cr, Co, Cu, and V, clearly show the influence of a lithology rich in siderophile elements, typical of basic rocks and of its related minerals. The elements with higher loadings in the second Principal Component, Mn, Zn, Pb, As, Hg, and Cd, are chalcophile elements, except for Mn, but an anthropogenic contamination for these elements cannot be discarded. We propose an index to numerically access the environmental risk of one element, which we denominate by Environmental Risk Index, and a Multi-element Index which is simply the average taken over all elements. The occurrence of values greater than 1 in the maps of the Environmental Risk Index shows where the content of the respective element is above the permissible levels according to the available legislation for agricultural and residential purposes. The same applies to the multi-element risk index maps. High values of these risk indices are found, both for agricultural and residential purposes, for Co, Cr, Ni, Cu, and V. These metals are precisely those with higher loadings in PC1, which are demonstrated to be of natural origin in Santiago. This behaviour is also shown in the Multi-element Environmental Risk maps computed with these five metals. The high natural concentration levels of heavy metals at some areas of Santiago should be of concern not only to scientists but also to policymakers. To further evaluate the environmental risks associated with the presence of these metals, their bioavailability should be assessed in future works.
显示更多 [+] 显示较少 [-]Competitive effects on mercury removal by an agricultural waste: application to synthetic and natural spiked waters 全文
2014 | 1000
Lopes, Cláudia B. | Henriques, Bruno | Tavares, Daniela S. | Borges, J. A. | Duarte, Armando C. | Pereira, Eduarda
Competitive effects on mercury removal by an agricultural waste: application to synthetic and natural spiked waters 全文
2014 | 1000
Lopes, Cláudia B. | Henriques, Bruno | Tavares, Daniela S. | Borges, J. A. | Duarte, Armando C. | Pereira, Eduarda
In this work, the efficiency of a local and highly, available agricultural waste, the raw rice husk, was used to remove mercury (Hg) from synthetic and natural waters, spiked with concentrations that reflect the contamination problems found in the environment. Different operating conditions were tested, including initial pH, ionic strength, the presence of co-ions (cadmium) and organic matter. The sorption efficiency of rice husk was slightly affected by the presence H+ ions (pH range between 3 and 9), but in the presence of NaNO3 and NaCl electrolytes and in binary solutions containing Cd2+ and H2+, the sorption efficiency was dependent on the nature and levels of the interfering ion and on the initial concentration of Hg+ used. Nevertheless, in a situation of equilibrium the effect of those ions was negligible and the removal efficiency ranged between 82% and 94% and between 90% and 96% for an initial Hg2+ concentration of 0.05 mg L(-1) and 0.50 mg L(-1), respectively. In more complex matrices, i.e. in the presence ofhumic substances and in natural river waters, the speciation and dynamics of Hg was changed and a fraction of the metal becomes unavailable in solution. Even then, the values obtained for Hg removal were satisfactory, i.e. between 59% and 76% and 81% and 85% for an initial concentration of Hg2+ of 0.05 and 0.50 mg L(-1), respectively.
显示更多 [+] 显示较少 [-]Competitive effects on mercury removal by an agricultural waste: application to synthetic and natural spiked waters 全文
2014
Rocha, Luciana S. | Lopes, Cláudia B. | Henriques, Bruno | Tavares, Daniela S. | Borges, J.A. | Duarte, Armando C. | Pereira, Eduarda
In this work, the efficiency of a local and highly available agricultural waste, the raw rice husk, was used to remove mercury (Hg) from synthetic and natural waters, spiked with concentrations that reflect the contamination problems found in the environment. Different operating conditions were tested, including initial pH, ionic strength, the presence of co-ions (cadmium) and organic matter. The sorption efficiency of rice husk was slightly affected by the presence H ⁺ ions (pH range between 3 and 9), but in the presence of NaNO ₃ and NaCl electrolytes and in binary solutions containing Cd ²⁺ and Hg ²⁺, the sorption efficiency was dependent on the nature and levels of the interfering ion and on the initial concentration of Hg ²⁺ used. Nevertheless, in a situation of equilibrium the effect of those ions was negligible and the removal efficiency ranged between 82% and 94% and between 90% and 96% for an initial Hg ²⁺ concentration of 0.05 mg L ⁻¹ and 0.50 mg L ⁻¹, respectively. In more complex matrices, i.e. in the presence of humic substances and in natural river waters, the speciation and dynamics of Hg was changed and a fraction of the metal becomes unavailable in solution. Even then, the values obtained for Hg removal were satisfactory, i.e. between 59% and 76% and 81% and 85% for an initial concentration of Hg ²⁺ of 0.05 and 0.50 mg L ⁻¹, respectively.
显示更多 [+] 显示较少 [-]Urban agriculture in Portugal: availability of potentially toxic elements for plant uptake 全文
2014 | 1000
Cruz, N. | Rodrigues, S. M. | Coelho, C. | Carvalho, L. | Duarte, A. C. | Pereira, E. | Römkens, P. F A M
Urban agriculture in Portugal: availability of potentially toxic elements for plant uptake 全文
2014 | 1000
Cruz, N. | Rodrigues, S. M. | Coelho, C. | Carvalho, L. | Duarte, A. C. | Pereira, E. | Römkens, P. F A M
Soils from urban areas often contain enhanced pseudo-total levels of potentially toxic elements (PTEs). Considering the expanding tendency of urban agricultural practices it is necessary to understand if these contaminants are available for plant uptake and if they pose risks to animal and human health. This study showed that estimates of Daily Intakes (DIs) of Cu, Pb and Zn for grazing animals were above animal Acceptable Daily Intakes (ADIs) at specific sites under the influence of an airport, an oil refinery and near highways with high traffic rates in the "Grande Porto" urban area (Portugal). These results suggest that there is a potential for dietary transfer of contaminants associated with the ingestion of both contaminated soil and feed by cows and sheep at unacceptably high concentrations.Furthermore, results showed that 40% of variability of ryegrass shoot contents of Cu, Pb and Ni; 60% for Ba; 70% for Zn; and 80% for Cd can be significantly (p<. 0.01) explained by the variability of the corresponding chemical available pools in soils. Since the chemical available pools of PTEs in urban soils were rather low when compared with the corresponding pseudo-total pools (median 0.1-5%) and even when compared with the corresponding reactive pools it is advised to perform further research on the conditions and time span for the limited availability of PTEs in urban soils, and to determine under which conditions PTEs on reactive forms may become available.
显示更多 [+] 显示较少 [-]Urban agriculture in Portugal: Availability of potentially toxic elements for plant uptake 全文
2014
Cruz, N. | Rodrigues, S.M. | Coelho, C. | Carvalho, L. | Duarte, A.C. | Pereira, E. | Römkens, P.F.A.M.
Soils from urban areas often contain enhanced pseudo-total levels of potentially toxic elements (PTEs). Considering the expanding tendency of urban agricultural practices it is necessary to understand if these contaminants are available for plant uptake and if they pose risks to animal and human health.This study showed that estimates of Daily Intakes (DIs) of Cu, Pb and Zn for grazing animals were above animal Acceptable Daily Intakes (ADIs) at specific sites under the influence of an airport, an oil refinery and near highways with high traffic rates in the “Grande Porto” urban area (Portugal). These results suggest that there is a potential for dietary transfer of contaminants associated with the ingestion of both contaminated soil and feed by cows and sheep at unacceptably high concentrations.Furthermore, results showed that 40% of variability of ryegrass shoot contents of Cu, Pb and Ni; 60% for Ba; 70% for Zn; and 80% for Cd can be significantly (p<0.01) explained by the variability of the corresponding chemical available pools in soils. Since the chemical available pools of PTEs in urban soils were rather low when compared with the corresponding pseudo-total pools (median 0.1–5%) and even when compared with the corresponding reactive pools it is advised to perform further research on the conditions and time span for the limited availability of PTEs in urban soils, and to determine under which conditions PTEs on reactive forms may become available.
显示更多 [+] 显示较少 [-]Effect of copper ions on the degradation of thiram in aqueous solution: Identification of degradation products by HPLC-MS/MS 全文
2014 | 1000
Filipe, Olga M. S. | Santos, Sonia A. O. | Domingues, M. Rosario M. | Vidal, Maria. M. | Silvestre, Armando J. D. | Santos, Eduarda B. H.
Effect of copper ions on the degradation of thiram in aqueous solution: Identification of degradation products by HPLC-MS/MS 全文
2014 | 1000
Filipe, Olga M. S. | Santos, Sonia A. O. | Domingues, M. Rosario M. | Vidal, Maria. M. | Silvestre, Armando J. D. | Santos, Eduarda B. H.
The aim of this work was to examine the effect of Cu(II) on the degradation of thiram (Thi) in aqueous solutions, since the literature focused on this effect is scarce and copper based fungicides can be applied together with thiram or during the same season to agricultural crops. The effect of Cu(II) on the degradation of thiram was followed by both UV-vis and HPLC-MS/MS. When thiram is dissolved in pure water its degradation occurs very slowly, being negligible during the first 7 days. However, the presence of Cu(II) has a strong influence on the thiram degradation in aqueous solutions along time. In the presence of an excess of Cu(II), a [CuThi](2+) complex is initially formed which degrades into a complex formed between the dimethyldithiocarbamate anion (DMDTC) and Cu(II) ion, [Cu(DMDTC)](+). This complex further degrades leading to other copper complexes which were identified for the first time, by MSn. The results obtained in the present work also demonstrated that a redox reaction involving DMDTC anions and Cu(II) ions gives rise to the formation of a Thi-Cu(I) complex. Finally, some of the complexes resulting from the degradation of [CuThi](2+) are quite persistent in solution for long periods of time (>1 month). (C) 2014 Elsevier B.V. All rights reserved.
显示更多 [+] 显示较少 [-]Effect of copper ions on the degradation of thiram in aqueous solution: Identification of degradation products by HPLC–MS/MS 全文
2014
Filipe, Olga M.S. | Santos, Sónia A.O. | Domingues, M. Rosário M. | Vidal, Maria. M. | Silvestre, Armando J.D. | Santos, Eduarda B.H.
The aim of this work was to examine the effect of Cu(II) on the degradation of thiram (Thi) in aqueous solutions, since the literature focused on this effect is scarce and copper based fungicides can be applied together with thiram or during the same season to agricultural crops. The effect of Cu(II) on the degradation of thiram was followed by both UV–vis and HPLC–MS/MS. When thiram is dissolved in pure water its degradation occurs very slowly, being negligible during the first 7 days. However, the presence of Cu(II) has a strong influence on the thiram degradation in aqueous solutions along time. In the presence of an excess of Cu(II), a [CuThi]2+ complex is initially formed which degrades into a complex formed between the dimethyldithiocarbamate anion (DMDTC) and Cu(II) ion, [Cu(DMDTC)]+. This complex further degrades leading to other copper complexes which were identified for the first time, by MSn. The results obtained in the present work also demonstrated that a redox reaction involving DMDTC anions and Cu(II) ions gives rise to the formation of a Thi–Cu(I) complex. Finally, some of the complexes resulting from the degradation of [CuThi]2+ are quite persistent in solution for long periods of time (>1 month).
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