Metal and metalloid foliar uptake by various plant species exposed to atmospheric industrial fallout: Mechanisms involved for lead

Eva Schreck (1) , Yann Foucault (1, 2) , Géraldine Sarret (3) , Sophie Sobanska (4) , Lauric Cécillon (3) , Maryse Castrec-Rouelle (5) , Gaëlle Uzu (6, 7) , Camille Dumat (1)

1 LEFE - Laboratoire Ecologie Fonctionnelle et Environnement
2 STCM - Société de Traitements Chimiques des Métaux
3 ISTerre - Institut des Sciences de la Terre
4 LASIRE - Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516
5 Bioemco - Biogéochimie et écologie des milieux continentaux
6 LAERO - Laboratoire d'aérologie
7 GET - Géosciences Environnement Toulouse

Fine and ultrafine metallic particulatematters (PMs) are emitted frommetallurgic activities in peri-urban zones into the atmosphere and can be deposited in terrestrial ecosystems. The foliar transfer ofmetals andmetalloids and their fate in plant leaves remain unclear, although this way of penetration may be a major contributor to the transfer of metals into plants. This study focused on the foliar uptake of various metals and metalloids from enriched PM(Cu, Zn, Cd, Sn, Sb, As, and especially lead (Pb)) resulting fromthe emissions of a battery-recycling factory.Metal and metalloid foliar uptake by various vegetable species, exhibiting different morphologies, use (food or fodder) and life-cycle (lettuce, parsley and rye-grass) were studied. The mechanisms involved in foliar metal transfer from atmospheric particulate matter fallout, using lead (Pb) as a model element was also investigated. Several complementary techniques (micro-X-ray fluorescence, scanning electron microscopy coupled with energy dispersive X-ray microanalysis and time-of-flight secondary ion mass spectrometry) were used to investigate the localization and the speciation of lead in their edible parts, i.e. leaves. The results showed lead-enriched PM on the surface of plant leaves. Biogeochemical transformations occurred on the leaf surfaces with the formation of lead secondary species (PbCO3 and organic Pb). Some compounds were internalized in their primary form (PbSO4) underneath an organic layer. Internalization through the cuticle or penetration through stomata openings are proposed as two major mechanisms involved in foliar uptake of particulate matter.

Mots clés: Foliar uptake; Particulate matter; Metals and metalloids; Internalization pathways; Microscopy; Spectroscopy

Domaines: Ecologie, Environnement; Ecosystèmes

Eva Schreck, Yann Foucault, Géraldine Sarret, Sophie Sobanska, Lauric Cécillon, et al.. Metal and metalloid foliar uptake by various plant species exposed to atmospheric industrial fallout: Mechanisms involved for lead. Science of the Total Environment, 2012, vol. 427-428, pp. 253-262. ⟨10.1016/j.scitotenv.2012.03.051⟩. ⟨hal-00824725⟩