title: Plants influence on arsenic availability and speciation in the rhizosphere, roots and shoots of three different vegetables.
abstract: The toxicity of arsenic (As) in the environment is controlled by its concentration, availability and speciation. The aims of the study were to evaluate the accumulation and speciation of As in carrot, lettuce and spinach cultivated in soils with various As concentrations and to estimate the concomitant health risks associated with the consumption of the vegetables. Arsenic concentration and speciation in plant tissues and soils was analysed by HPLC, AAS and XANES spectroscopy. To estimate the plants influence in the rhizosphere, organic acids in lettuce root exudates were analysed by ion chromatography. The results showed that the As accumulation was higher in plants cultivated in soil with higher As extractability. Arsenate predominated in the soils, rhizosphere and root exudates of lettuce. Succinic acid was the major organic acid in lettuce root exudates. Ingestion of the tested vegetables may result in an intake of elevated levels of inorganic As.
authors.affiliation: Department of Environment, Ecology and Plant Sciences, Stockholm University, S-106 91 Stockholm, Sweden. Electronic address: claes.bergqvist@su.se.
authors.forename: Claes
authors.initials: C
authors.lastname: Bergqvist
authors.forename: Roger
authors.initials: R
authors.lastname: Herbert
authors.forename: Ingmar
authors.initials: I
authors.lastname: Persson
authors.forename: Maria
authors.initials: M
authors.lastname: Greger
mesh_terms: D001151:Arsenic / Q000032:analysis*; D018552:Daucus carota / Q000737:chemistry / Q000502:physiology; D018545:Lactuca / Q000737:chemistry / Q000502:physiology; D018517:Plant Roots / Q000737:chemistry*; D018520:Plant Shoots / Q000737:chemistry*; D058441:Rhizosphere; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D018724:Spinacia oleracea / Q000737:chemistry / Q000502:physiology; D014675:Vegetables / Q000737:chemistry* / Q000502:physiology; D056928:X-Ray Absorption Spectroscopy
chemical_list: D012987:Soil; D012989:Soil Pollutants; D001151:Arsenic
keywords: Accumulation; Arsenic; Availability; Rhizosphere; Speciation