title: Field isotopic study of lead fate and compartmentalization in earthworm-soil-metal particle systems for highly polluted soil near Pb recycling factory.
abstract: Earthworms are important organisms in soil macrofauna and play a key role in soil functionality, and consequently in terrestrial ecotoxicological risk assessments. Because they are frequently observed in soils strongly polluted by metals, the influence of earthworm bioturbation on Pb fate could therefore be studied through the use of Pb isotopes. Total Pb concentrations and isotopic composition ((206)Pb, (207)Pb and (208)Pb) were then measured in earthworms, casts and bulk soils sampled at different distance from a lead recycling factory. Results showed decreasing Pb concentrations with the distance from the factory whatever the considered matrix (bulk soils, earthworm bodies or cast samples) with higher concentrations in bulk soils than in cast samples. The bivariate plot (208)Pb/(206)Pb ratios versus (206)Pb/(207)Pb ratios showed that all samples can be considered as a linear mixing between metallic process particulate matter (PM) and geochemical Pb background. Calculated anthropogenic fraction of Pb varied between approximately 84% and 100%. Based on Pb isotopic signatures, the comparison between casts, earthworms and bulk soils allowed to conclude that earthworms preferentially ingest the anthropogenic lead fraction associated with coarse soil organic matter. Actually, soil organic matter was better correlated with Pb isotopic ratios than with Pb content in soils. The proposed hypothesis is therefore a decrease of soil organic matter turnover due to Pb pollution with consequences on Pb distribution in soils and earthworm exposure. Finally, Pb isotopes analysis constitutes an efficient tool to study the influence of earthworm bioturbation on Pb cycle in polluted soils.
authors.affiliation: Université de Toulouse, INP-ENSAT, Av. Agrobiopôle, 31326 Castanet-Tolosan, France; UMR 5245 CNRS-INP-UPS, EcoLab (Laboratoire d'écologie fonctionnelle et Environnement), Avenue de l'Agrobiopôle, BP 32607, 31326 Castanet-Tolosan, France; Géosciences Environnement Toulouse (GET), Observatoire Midi Pyrénées, Université de Toulouse, CNRS, IRD, 14 Avenue E. Belin, F-31400 Toulouse, France.
authors.forename: Sylvaine
authors.initials: S
authors.lastname: Goix
authors.affiliation: Université de Toulouse, INP-ENSAT, Av. Agrobiopôle, 31326 Castanet-Tolosan, France; UMR 5245 CNRS-INP-UPS, EcoLab (Laboratoire d'écologie fonctionnelle et Environnement), Avenue de l'Agrobiopôle, BP 32607, 31326 Castanet-Tolosan, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Mombo
authors.affiliation: Géosciences Environnement Toulouse (GET), Observatoire Midi Pyrénées, Université de Toulouse, CNRS, IRD, 14 Avenue E. Belin, F-31400 Toulouse, France.
authors.forename: Eva
authors.initials: E
authors.lastname: Schreck
authors.affiliation: Université de Toulouse, INP-ENSAT, Av. Agrobiopôle, 31326 Castanet-Tolosan, France; UMR 5245 CNRS-INP-UPS, EcoLab (Laboratoire d'écologie fonctionnelle et Environnement), Avenue de l'Agrobiopôle, BP 32607, 31326 Castanet-Tolosan, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Pierart
authors.affiliation: Université de Toulouse, INP-ENSAT, Av. Agrobiopôle, 31326 Castanet-Tolosan, France; UMR 5245 CNRS-INP-UPS, EcoLab (Laboratoire d'écologie fonctionnelle et Environnement), Avenue de l'Agrobiopôle, BP 32607, 31326 Castanet-Tolosan, France.
authors.forename: Thibaut
authors.initials: T
authors.lastname: Lévêque
authors.affiliation: STCM, Société de Traitements Chimiques des Métaux, 30 Avenue de Fondeyre, 31200 Toulouse, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Deola
authors.affiliation: Université de Toulouse, INP-ENSAT, Av. Agrobiopôle, 31326 Castanet-Tolosan, France; Certop UMR5044-Centre d'Etude et de Recherche Travail, Organisation, Pouvoir, France. Electronic address: camille.dumat@ensat.fr.
authors.forename: Camille
authors.initials: C
authors.lastname: Dumat
mesh_terms: D000327:Adsorption; D000818:Animals; D004784:Environmental Monitoring / Q000379:methods*; D005602:France; D007554:Isotopes / Q000032:analysis; D007854:Lead / Q000032:analysis* / Q000493:pharmacokinetics / Q000633:toxicity; D009835:Oligochaeta / Q000187:drug effects* / Q000378:metabolism; D010316:Particle Size; D059027:Recycling; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000493:pharmacokinetics / Q000633:toxicity
chemical_list: D007554:Isotopes; D012987:Soil; D012989:Soil Pollutants; D007854:Lead
keywords: Bioturbation; Earthworm; Isotope; Particle; Pb; Polluted soil; Soil organic matter