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Heinz R. Köhler – One of the best experts on this subject based on the ideXlab platform.

  • Stress Proteins (hsp70, hsp60) Induced in Isopods and Nematodes by Field Exposure to Metals in a Gradient near Avonmouth, UK
    Ecotoxicology, 2004
    Co-Authors: Marie-josé S. J. Arts, Ralph O. Schill, Thomas Knigge, Helga Eckwert, Jan E. Kammenga, Heinz R. Köhler

    Abstract:

    Heat shock proteins (hsps) are potential biomarkers for monitoring environmental pollution. In this study, the use of hsps as biomarkers in field bioassays was evaluated in terrestrial invertebrates exposed to a metal gradient near Avonmouth, UK. We investigated the hsp70 response in resident and transplanted isopods of the species Oniscus Asellus and Porcellio scaber and the hsp60 response in transplanted nematodes of the species Plectus acuminatus in six field sites along the metal gradient. Considerable differences were detected in the stress responses between nematodes and isopods (isopods responded in a gradient-specific manner, nematodes did not), the two isopod species and the transplanted and resident specimens of each isopod species in the sites closest to the smelter, O. Asellus residents showed high hsp70 levels while O. Asellus transplanted from an unpolluted site displayed comparatively low hsp70 levels. For P. scaber , it was just the opposite. In resident isopod populations of both species, tolerant phenotypes were revealed in the most contaminated field sites. The hsp70 level in both isopod species was a suitable biomarker of effect (but of exposure only in non-tolerant individuals) even in long-term metal-contaminated field sites. The hsp60 response in the nematode alone was not a suitable biomarker for heavily contaminated soils. However, it had indicative value when related to the hsp70 response in the isopods and could be a suitable biomarker for less heavily contaminated soils.

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  • Energy Reserves and Metal-storage Granules in the Hepatopancreas of Oniscus Asellus and Porcellio scaber (Isopoda) from a Metal Gradient at Avonmouth, UK
    Ecotoxicology, 2004
    Co-Authors: Ralph O. Schill, Heinz R. Köhler

    Abstract:

    Isopods taken from populations of Onsicus Asellus and Porcellio scaber from long-term polluted sites in the vicinity of metal smelting works at Avonmouth, South West England, and from a control site near Tübingen, South Germany, were examined for the frequency and size of metal-containing granules (spherites), lipid droplets and glycogen in their hepatopancreas. The number and size of spherites in the hepatopancreas of O. Asellus increased with decreasing distance to the smelter, but such a trend was not found in P. scaber . A trend towards massive reduction in hepatopancreatic energy reserves (lipid, glycogen) with increasing soil metal pollution was observed for O. Asellus while, in contrast, the lipid and glycogen content of P. scaber midgut gland cells was independent of the distance to the smelter. In view of previous reports on metal accumulation and biochemical responses to metal pollution, we propose that the two investigated isopod species, which form stable populations in the Avonmouth metal gradient, use different strategies to survive.

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  • The induction of stress proteins (hsp) in Oniscus Asellus (Isopoda) as a molecular marker of multiple heavy metal exposure. II: Joint toxicity and transfer to field situations
    Ecotoxicology, 1997
    Co-Authors: Heinz R. Köhler, Helga Eckwert

    Abstract:

    In laboratory toxicity tests, woodlice (Oniscus Asellus) exposed to a variety of different combinations of the metals cadmium, lead, and zinc exhibited a broad range in intensity of the induction of the 70 kDa stress protein (hsp70, stress-70). Using two-dimensional isobolograms and the ‘toxic unit’ concept, it could be shown that cadmium and lead as well as cadmium and zinc or lead and zinc act as synergists and cause superadditive effects on the stress response of these animals. Using a three- dimensional isobologram based on the stress-70 level in response to numerous combinations of all three tested metals, transfer to the field could be achieved: data obtained from O. Asellus populations abundant at field sites, the soils of which are influenced mainly by different concentrations of these heavy metals, were found to fit this laboratory test-based model

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Helga Eckwert – One of the best experts on this subject based on the ideXlab platform.

  • Stress Proteins (hsp70, hsp60) Induced in Isopods and Nematodes by Field Exposure to Metals in a Gradient near Avonmouth, UK
    Ecotoxicology, 2004
    Co-Authors: Marie-josé S. J. Arts, Ralph O. Schill, Thomas Knigge, Helga Eckwert, Jan E. Kammenga, Heinz R. Köhler

    Abstract:

    Heat shock proteins (hsps) are potential biomarkers for monitoring environmental pollution. In this study, the use of hsps as biomarkers in field bioassays was evaluated in terrestrial invertebrates exposed to a metal gradient near Avonmouth, UK. We investigated the hsp70 response in resident and transplanted isopods of the species Oniscus Asellus and Porcellio scaber and the hsp60 response in transplanted nematodes of the species Plectus acuminatus in six field sites along the metal gradient. Considerable differences were detected in the stress responses between nematodes and isopods (isopods responded in a gradient-specific manner, nematodes did not), the two isopod species and the transplanted and resident specimens of each isopod species in the sites closest to the smelter, O. Asellus residents showed high hsp70 levels while O. Asellus transplanted from an unpolluted site displayed comparatively low hsp70 levels. For P. scaber , it was just the opposite. In resident isopod populations of both species, tolerant phenotypes were revealed in the most contaminated field sites. The hsp70 level in both isopod species was a suitable biomarker of effect (but of exposure only in non-tolerant individuals) even in long-term metal-contaminated field sites. The hsp60 response in the nematode alone was not a suitable biomarker for heavily contaminated soils. However, it had indicative value when related to the hsp70 response in the isopods and could be a suitable biomarker for less heavily contaminated soils.

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  • The induction of stress proteins (hsp) in Oniscus Asellus (Isopoda) as a molecular marker of multiple heavy metal exposure. II: Joint toxicity and transfer to field situations
    Ecotoxicology, 1997
    Co-Authors: Heinz R. Köhler, Helga Eckwert

    Abstract:

    In laboratory toxicity tests, woodlice (Oniscus Asellus) exposed to a variety of different combinations of the metals cadmium, lead, and zinc exhibited a broad range in intensity of the induction of the 70 kDa stress protein (hsp70, stress-70). Using two-dimensional isobolograms and the ‘toxic unit’ concept, it could be shown that cadmium and lead as well as cadmium and zinc or lead and zinc act as synergists and cause superadditive effects on the stress response of these animals. Using a three- dimensional isobologram based on the stress-70 level in response to numerous combinations of all three tested metals, transfer to the field could be achieved: data obtained from O. Asellus populations abundant at field sites, the soils of which are influenced mainly by different concentrations of these heavy metals, were found to fit this laboratory test-based model

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G M Morrison – One of the best experts on this subject based on the ideXlab platform.

  • Bioaccumulation of palladium, platinum and rhodium from urban particulates and sediments by the freshwater isopod Asellus aquaticus.
    Water research, 2001
    Co-Authors: Mariella Moldovan, S Rauch, Milagros Gómez, M. Antonia Palacios, G M Morrison

    Abstract:

    The three-way catalytic converters introduced to oxidize and reduce gaseous automobile emissions represent a source of platinum group elements (PGEs), in particular platinum, palladium and rhodium, to the urban environment. Abrasion of automobile exhausts leads to an increase of the concentration of PGEs in environmental matrices such as vegetation, soil and water bodies. The bioaccumulation of Pd, Pt and Rh by the freshwater isopod Asellus aquaticus was studied in natural ecosystems and under laboratory conditions. Owing to the low concentration level (ng g−1) of PGEs in the animals studied, analyses were performed with a quadrupole inductively coupled plasma mass spectrometry (ICP-MS) and hafnium, copper, yttrium, rubidium, strontium and lead were monitored for spectral interference correction. Asellus aquaticus collected in an urban river showed a content (mean±s) of 155.4±73.4, 38.0±34.6, and 17.9±12.2 ng g−1 (dry weight) for Pd, Pt and Rh, respectively. The exposure of Asellus aquaticus to PGE standard solutions for a period of 24 h give bioaccumulation factors of Bf: 150, 85, and 7 for Pd, Pt and Rh, respectively. Exposure of Asellus aquaticus to environmental samples for different exposure periods demonstrated that PGE bioaccumulation is time dependent, and shows a higher accumulation for the materials with a higher PGE content. While all three elements have the same uptake rate for exposure to catalyst materials, for exposure to environmental materials they have a different uptake rate which can be attributed to transformations of the PGE species in the environment.

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  • Platinum uptake by the freshwater isopod Asellus aquaticus in urban rivers.
    The Science of the total environment, 1999
    Co-Authors: S Rauch, G M Morrison

    Abstract:

    Platinum has been increasing in the environment as a result of emissions from catalytic converters. The platinum emitted is principally located in the vicinity of roads but might be transported to urban rivers through highway and urban run-off water. Platinum concentrations in the freshwater isopod Asellus aquaticus were measured for two urban rivers and a stormwater detention pond. Concentrations ranged from 0.04 to 12.4 micrograms g-1 for direct analysis and from 0.16 to 4.5 micrograms g-1 after depuration. Analyses of water, pore water and sediments indicate that platinum in urban rivers is mostly found in the sediments and these provide the major contribution of platinum to Asellus aquaticus. Exposure experiments showed the importance of platinum speciation for uptake.

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