title: Brassica juncea tested on urban soils moderately contaminated by lead: Origin of contamination and effect of chelates.
abstract: Urban garden soils are a potential repository of heavy metal pollution, resulting from either anthropogenic or geogenic origin. The efficiency of phytoextraction was compared on two garden soils with the same texture and topsoil Pb concentration (170 mg kg-1) but not the same origin: one geogenic, the other anthropogenic. Two varieties of Brassica juncea were tested with citric acid (25 mmol kg-1) or ethylenediaminetetraacetic acid (EDTA, 2.5 mmol kg-1). Geogenic Pb was shown to be two times less available than anthropogenic Pb, as a result of which the phytoextraction efficiency was reduced by 59%. Pb mobility in the soil was solely enhanced with EDTA, which increased the Pb concentration in shoots of B. juncea by between 14 and 26 times in comparison with the control. The highest Pb concentration in shoots still remained low, however (i.e., 45 mg kg-1dry weight). Regardless of the chelates introduced, B. juncea 426308 accumulated roughly twice as much lead as B. juncea 211000, but only for the anthropogenic contaminated soil. Under these conditions, the amount of Pb accumulated by B. juncea (even when assisted by EDTA) was not high enough to envision achieving soil clean-up within a reasonable time frame.
authors.affiliation: a Institut de Recherche en Sciences et Techniques de la Ville, Laboratoire de Planétologie et Géodynamique de Nantes, UMR CNRS 6112 , Nantes Cedex 3, France.
authors.forename: Dorine
authors.initials: D
authors.lastname: Bouquet
authors.affiliation: a Institut de Recherche en Sciences et Techniques de la Ville, Laboratoire de Planétologie et Géodynamique de Nantes, UMR CNRS 6112 , Nantes Cedex 3, France.
authors.forename: Armelle
authors.initials: A
authors.lastname: Braud
authors.affiliation: a Institut de Recherche en Sciences et Techniques de la Ville, Laboratoire de Planétologie et Géodynamique de Nantes, UMR CNRS 6112 , Nantes Cedex 3, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Lebeau
mesh_terms: D001673:Biodegradation, Environmental; D002614:Chelating Agents / Q000494:pharmacology*; D019343:Citric Acid / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004492:Edetic Acid / Q000494:pharmacology*; D007854:Lead / Q000378:metabolism*; D009149:Mustard Plant / Q000254:growth & development / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D002614:Chelating Agents; D012989:Soil Pollutants; D019343:Citric Acid; D007854:Lead; D004492:Edetic Acid
keywords: Brassica juncea; EDTA; citric acid; lead; urban gardens