title: Priming effects on PAH degradation and ecotoxicity during a phytoremediation experiment.
abstract: An experiment was conducted to distinguish priming effects from the effects of phytoremediation of a creosote-polluted soil. The concentration of 13 polycyclic aromatic hydrocarbons (PAHs), and their combined soil toxicity (using four bioassays), was determined on recently excavated, homogenized soil and on such soil subjected to a time-course phytoremediation experiment with lucerne. The results showed a high priming effect, with minor positive and synergistic effects of planting and fertilization on PAH degradation rates. At the end of the experiment, PAH degradation reached 86% of the initial 519 mg PAHs kg(-1). Two of the four toxicity tests (bioluminescence inhibition and ostracod growth inhibition) corroborated the chemical data for residual PAHs, and indicated a significant reduction in soil toxicity. We conclude that priming effects can easily surpass treatment effects, and that an unintentional pre-incubation that ignores these effects can jeopardize the full quantitative assessment of in situ bioremediation of contaminated soil.
authors.affiliation: LIMOS (Laboratoire des Interactions Microorganismes-Minéraux-Matière Organique dans les Sols)-CNRS UMR 7131, Henri Poincaré University, Faculty of Science, PO Box 239, F-54506 Vandoeuvre-les-Nancy Cedex, France. erik.joner@skogforsk.no
authors.forename: Erik J
authors.initials: EJ
authors.lastname: Joner
authors.forename: Doris
authors.initials: D
authors.lastname: Hirmann
authors.forename: Oliver H J
authors.initials: OH
authors.lastname: Szolar
authors.forename: Dragana
authors.initials: D
authors.lastname: Todorovic
authors.forename: Corinne
authors.initials: C
authors.lastname: Leyval
authors.forename: Andreas P
authors.initials: AP
authors.lastname: Loibner
mesh_terms: D048908:Aliivibrio fischeri / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001673:Biodegradation, Environmental; D000460:Chlorophyta / Q000187:drug effects / Q000254:growth & development; D003407:Creosote; D003445:Crustacea / Q000187:drug effects / Q000254:growth & development; D008163:Luminescent Measurements; D000455:Medicago sativa / Q000378:metabolism*; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism / Q000633:toxicity*; D012989:Soil Pollutants / Q000378:metabolism / Q000633:toxicity*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D012989:Soil Pollutants; D003407:Creosote