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Trace Element Uptake and Accumulation in the Medicinal Herb Hypericum perforatum L. Across Different Geolithological Settings
No full textThe worldwide growing interest in traditional medicines, including herbal medicines and herbal dietary supplements, has recently been accompanied by concerns on quality and safety of this type of health care. The content of nutritional and potentially toxic elements in medicinal plants is of paramount interest as it may vary remarkably according to different environmental and ecophysiological factors. In this study, the concentrations of essential and non-essential trace elements—Co, Cr, Cu, Ni, Sr, and Zn—were determined in the roots and aerial parts of the worldwide distributed and economically important medicinal herb Hypericum perforatum L. (St. John’s wort) and in its growing substrate. Most of the analyzed trace elements varied considerably in the plant parts according to edaphic conditions and soil geochemistry. However, uptake and retention in H. perforatum compartments of Co, Cr, and Ni, which markedly differentiated the investigated soils, were controlled by excluding mechanisms of the plant. Despite this, the Ni concentrations in the aerial parts, commonly used in herbal preparations, of H. perforatum plants from serpentine soils were not insignificant in relation to eventual human consumption. Good practice to assure the herbal product quality of H. perforatum collected from the wild cannot ignore the thorough understanding of the geolithological and geochemical features of the harvesting areas
Bioaccumulation of heavy elements by Armadillidium vulgare (Crustacea, Isopoda) exposed to fallout of a municipal solid waste landfill.
No full textThis paper reports the response of isopods exposed to fallout of a municipal solid waste landfill located in
central Italy. Soil samples and specimens of Armadillidium vulgare were collected at different distances
from the landfill and analyzed to determine the concentrations of heavy elements such as As, Cd, Co, Cr,
Cu, Ni, Pb, Sb, V and Zn. The isopod analysis was performed on unpurged and purged specimens.
Analytical data indicate that the soil contents of heavy elements were quite uniform and within the
respective local geochemical background. Slight enrichments of Cu and Pb were found in some soils
collected within the solid waste. Purged isopods showed an accumulation of As, Co, Cr, Ni, Sb and V whose
body levels decreased as the distance from the landfill increased. Cd, Cu, Pb and Zn concentrations in
purged specimens were rather uniform and no significant variation trend occurred. This result probably
was due to the fact that the isopods are provided with physiological mechanisms of regulation for these
heavy elements. Analytical data also indicate the ability of A. vulgare to adsorb differently the heavy
elements according to the following order: As > Co > Ni > Pb > V. The contents of heavy elements in
unpurged specimens were higher than in purged ones. This finding suggested that the defecation has
marked effects on the tissue levels of heavy elements in isopods. This study indicates that the isopods
provide useful information about environmental quality in areas characterized by low and discontinuous
emission of heavy elements and their low accumulation in soil
Integrated approach for the analysis of ecosystems at risk: a case study in a waste landfill.
No full textBioaccumulation of heavy elements by Armadillidium vulgare (Crustacea, Isopoda) exposed to fallout of a municipal solid waste landfill
No full textThis paper reports the response of isopods exposed to fallout of a municipal solid waste landfill located in
central Italy. Soil samples and specimens of Armadillidium vulgare were collected at different distances
from the landfill and analyzed to determine the concentrations of heavy elements such as As, Cd, Co, Cr,
Cu, Ni, Pb, Sb, V and Zn. The isopod analysis was performed on unpurged and purged specimens.
Analytical data indicate that the soil contents of heavy elements were quite uniform and within the
respective local geochemical background. Slight enrichments of Cu and Pb were found in some soils
collected within the solid waste. Purged isopods showed an accumulation of As, Co, Cr, Ni, Sb and V whose
body levels decreased as the distance from the landfill increased. Cd, Cu, Pb and Zn concentrations in
purged specimens were rather uniform and no significant variation trend occurred. This result probably
was due to the fact that the isopods are provided with physiological mechanisms of regulation for these
heavy elements. Analytical data also indicate the ability of A. vulgare to adsorb differently the heavy
elements according to the following order: As > Co > Ni > Pb > V. The contents of heavy elements in
unpurged specimens were higher than in purged ones. This
finding suggested that the defecation has
marked effects on the tissue levels of heavy elements in isopods. This study indicates that the isopods
provide useful information about environmental quality in areas characterized by low and discontinuous
emission of heavy elements and their low accumulation in soil
Uptake and bioaccumulation of heavy elements by two earthworm species from a smelter contaminated area in northern Kosovo
No full textAs, Cd, Cu, Pb, Sb and Zn concentrations were determined in two earthworm species (Allolobophora rosea and Nicodrilus caliginosus) from a mining and industrial area in northern Kosovo and compared with their contents in the bulk soil and the main soil fractions. Earthworm specimens were collected at fifteen sites located at different distances from a Pb–Zn smelter along a gradient of decreasing contamination. Individuals of A. rosea and N. caliginosus showed similar tissue levels of As, Cd, Cu, Pb, Sb and Zn, suggesting that earthworm species belonging to the same eco-physiological group have a similar propensity to uptake and bioaccumulate heavy elements. Cd, Pb, Sb and Zn concentrations in both earthworm species were positively correlated with the respective total soil contents and generally decreased with distance from the smelter. The bioaccumulation factor (BAF) revealed that Cd and Zn were the only elements bioaccumulated by earthworms. The rank order of BAF values for both species was as follows: Cd > > Zn > > Cu > As = Pb = Sb. The absorption of Cd, Pb, Sb and Zn by earthworms mostly depended on the extractable, reducible and oxidable soil fractions, suggesting that the intestine is likely the most important uptake route. The extractable soil fraction constantly influenced the uptake of these heavy elements, whereas the reducible fraction was important mainly for Pb and Zn. The water soluble fraction had an important role especially for the most mobile heavy elements such as Cd and Zn, suggesting that dermal uptake is not negligible. As a whole, the analytical data indicate that soil fractionation patterns influence the uptake of heavy elements by earthworms, and the extractable fraction is a good predictor of heavy element bioavailability to these invertebrates in soil
Soil properties and metal accumulation by earthworms in the Siena urban area (Italy)
No full textThis paper reports the results of a study focused on the metal (Cd, Co, Cr, Cu, Ni, Pb, Sb, U and Zn) distri-bution in soils and uptake and accumulation by earthworms Nicodrilus caliginosus (Savigny) from urban,peri-urban, green-urban and non-urban zones of Siena municipality (central Italy). The main goal wasto define the influence of soil properties and metal soil contents on the uptake of these contaminantsby earthworms. Data indicated that Cd, Cu, Pb, Sb and Zn soil contents increased in the following order:non-urban < green-urban < peri-urban < urban soils, suggesting that vehicular traffic affects the distribu-tion of these metals. Pb and Sb were the main soil contaminants and their highest enrichments werefound in urban sites where stop-and-go traffic occurs. Concentrations of these traffic-related metals inearthworms showed a distribution pattern similar to that in soil, suggesting that soil contamination influ-enced the uptake of Cd, Cu, Pb, Sb and Zn by N. caliginosus. There were significant positive correlationsbetween Cd, Pb and Sb earthworm concentrations and their soil contents. The lack of correlation for Cuand Zn could be due to the physiological regulation of these elements by earthworms. Statistical analysispointed out that the uptake and accumulation of Cd, Cu, Pb, Sb and Zn by earthworms were affected bysome soil physicochemical properties such as the organic carbon and carbonate contents that are able torule the bioavailability of metals in soils
Fractionation and geochemical mobility of heavy elements in soils of a mining area in northern Kosovo
No full textThis paper reports the results of a geochemical study focusing on the partitioning of As, Cd, Cu, Pb, Sb and Zn in soils of the Kosovska Mitrovica mining area in northern Kosovo. The main objective was to define the element mobility in soil and potential bioavailability in relation to soil contamination levels. The Kosovska Mitrovica area is one of the main industrial sites in the former Yugoslavia and a world-class mining district in Europe. Extensive and locally very marked contamination mainly by Pb, Zn, Cd and Sb was found in soils, with the highest concentrations measured close to the Zvecan smelter. The study of As, Cd, Cu, Pb, Sb and Zn partitioning in the water soluble, extractable with 0.11 M acetic acid, reducible, oxidable and residual fractions of soils revealed that Pb was mainly associated with the reducible fraction, Cd with the extractable and reducible fractions, and As, Cu, Sb and Zn with the residual fraction. Heavy element fractionation in contaminated soils was influenced by the presence of owner mineralogical phases related to the emissions of the Zvecan smelter and to materials windborne from mining and industrial dumps, as well as originated by in situ processes. The order of mobility of these heavy elements in contaminated soils resulted as follows: Cd ≫ Zn ≫ Pb ≫ Sb > As > Cu. Anthropogenic amounts of heavy elements were distributed in all soil fractions, with the most relevant enrichments in the extractable and reducible ones. Anthropogenic inputs were responsible for some deviations from natural fractionation, mainly for Pb, Zn and Cd. A significant amount of Cd, Pb and Zn in contaminated soils was rather mobile, which suggests that these elements can be readily available to plants and soil organisms
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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