title: Concentration responses to organochlorines in Phragmites australis.
abstract: Phragmites australis shows potential for the phytoremediation of chlorinated chemicals. Also there has been some attempt to determine the phytotoxic effects of organochlorines (OC). This study reports for lindane (HCH), monochlorobenzene (MCB), 1,4-dichlorobenzene (DCB) and 1,2,4-trichlorobenzene (TCB), a no-observed-effect-concentration (NOEC(7d)) that was 1000-300,000 times higher than environmental concentrations. Nevertheless, the combined OC mixture (NOEC(7d) level of each congener) induced a synergistic toxic effect, causing a severe drop (70%) in chlorophyll concentration. The mixture 0.2 mg L(-1) MCB+0.2 mg L(-1) DCB+2.5 mg L(-1) TCB+0.175 mg L(-1) HCH, that was 15 times more concentrated than environmental OC mixture, did not cause phytotoxicity during 21 days. Antioxidant enzymes were affected immediately after the start of exposure (3 days), but the plants showed no signs of stress thereafter. These data suggest that environmental OC mixtures do not pose a significant risk to P. australis.
authors.affiliation: Laboratoire d'Ecologie Alpine, Equipe Pollution-Environnement-Ecotoxicologie-Ecoremédiation, UMR CNRS n°5553, Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 09, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Faure
authors.forename: Angélique
authors.initials: A
authors.lastname: San Miguel
authors.forename: Patrick
authors.initials: P
authors.lastname: Ravanel
authors.forename: Muriel
authors.initials: M
authors.lastname: Raveton
mesh_terms: D001673:Biodegradation, Environmental; D002722:Chlorobenzenes / Q000378:metabolism / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D001556:Hexachlorocyclohexane / Q000378:metabolism / Q000633:toxicity; D006843:Hydrocarbons, Chlorinated / Q000378:metabolism* / Q000633:toxicity; D006109:Poaceae / Q000187:drug effects / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism* / Q000633:toxicity
chemical_list: D002722:Chlorobenzenes; D006843:Hydrocarbons, Chlorinated; D012989:Soil Pollutants; D001556:Hexachlorocyclohexane