| Effect of pulse herbicidal exposure on scenedesmus vacuolatus: a comparison of two photosystem II inhibitors. | |
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MedLine Citation:
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PMID: 18220443 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Herbicide concentrations fluctuate in rivers following crop application and can reach high levels after rain events, yet the duration of these pulses is short. In the present study, we assessed the effect of atrazine and isoproturon pulse exposure on Scenedesmus vacuolatus (Chlorophyceae; strain 211-8b, Kessler) as well as the recovery in the postexposure period. We further explored whether the time-dependent toxicity is similar for herbicides inhibiting the photosystem II (PSII). The growth rate was assessed for different exposure durations, and in addition the inhibition of the effective quantum yield of PSII was measured to monitor the response at the target site. Atrazine and isoproturon did not have similar time-dependent effects on growth rate, despite their same primary mode of action on PSII. Atrazine was less toxic than isoproturon after 10 h of exposure, but the toxicity of both herbicides was similar after 48 h of exposure. However, both compounds inhibited the PSII effective quantum yield within 1 h following exposure. Similarly, the effective quantum yield recovered completely within 4 h after removal of the toxicants, leading to rapid recovery of algal growth. The rapid onset of effects of isoproturon on the growth of the alga during exposure suggests that a single pulse to this herbicide is likely to induce greater effects than an atrazine pulse at the same concentration, even if these effects are reversible. The information gained in the present study should support the effect assessment of sequential exposures as well as the risk evaluation of fluctuating herbicidal exposure. |
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Authors:
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Nathalie Vallotton; Rik Ilda Lambertus Eggen; Beate Isabella Escher; Jérôme Krayenbühl; Nathalie Chèvre |
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Publication Detail:
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Type: Comparative Study; Journal Article; Research Support, Non-U.S. Gov't Date: 2008-02-14 |
Journal Detail:
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Title: Environmental toxicology and chemistry / SETAC Volume: 27 ISSN: 0730-7268 ISO Abbreviation: Environ. Toxicol. Chem. Publication Date: 2008 Jun |
Date Detail:
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Created Date: 2008-05-09 Completed Date: 2008-07-22 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 8308958 Medline TA: Environ Toxicol Chem Country: United States |
Other Details:
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Languages: eng Pagination: 1399-407 Citation Subset: IM |
Affiliation:
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Eawag, Swiss Federal Institute of Aquatic Science and Technology, Duebendorf, Switzerland. nathalie.vallotton@eawag.ch |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Enzyme Inhibitors
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administration & dosage,
toxicity* Herbicides / administration & dosage*, toxicity* Photosystem II Protein Complex / antagonists & inhibitors*, metabolism* Scenedesmus / drug effects*, enzymology*, growth & development Time Factors |
| Chemical | |
Reg. No./Substance:
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0/Enzyme Inhibitors; 0/Herbicides; 0/Photosystem II Protein Complex |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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