Modification of an existing in vitro method to predict relative bioavailable arsenic in soils.

Autor: Whitacre S; School of Environment and Natural Resources, The Ohio State University, Columbus, OH, United States., Basta N; School of Environment and Natural Resources, The Ohio State University, Columbus, OH, United States. Electronic address: basta.4@osu.edu., Stevens B; Army Corps of Engineers Engineer Research and Development Center, Vicksburg, MS, United States., Hanley V; Department of Toxic Substances Control, California EPA, Sacramento, CA, United States., Anderson R; U.S. Air Force Center for Engineering and the Environment, Lackland AFB, TX, United States., Scheckel K; U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, United States.
Jazyk: angličtina
Zdroj: Chemosphere [Chemosphere] 2017 Aug; Vol. 180, pp. 545-552. Date of Electronic Publication: 2017 Apr 03.
DOI: 10.1016/j.chemosphere.2017.03.134
Abstrakt: The soil matrix can sequester arsenic (As) and reduces its exposure by soil ingestion. In vivo dosing studies and in vitro gastrointestinal (IVG) methods have been used to predict relative bioavailable (RBA) As. Originally, the Ohio State University (OSU-IVG) method predicted RBA As for soils exclusively from mining and smelting sites with a median of 5,636 mg As kg -1 . The objectives of the current study were to (i) evaluate the ability of the OSU-IVG method to predict RBA As for As contaminated soils with a wider range of As content and As contaminant sources, and (ii) evaluate a modified extraction procedure's ability to improve prediction of RBA As. In vitro bioaccessible (IVBA) by OSU-IVG and California Bioaccessibility Method (CAB) methods, RBA As, speciation, and properties of 33 As contaminated soils were determined. Total As ranged from 162 to 12,483 mg kg -1 with a median of 73 mg kg -1 . RBA As ranged from 1.30 to 60.0% and OSU-IVG IVBA As ranged from 0.80 to 52.3%. Arsenic speciation was predominantly As(V) adsorbed to hydrous ferric oxide (HFO) or iron (Fe), manganese (Mn), and aluminum (Al) oxides. The OSU-IVG often extracted significantly less As in vitro than in vivo RBA As, in particularly for soils from historical gold mining. The CAB method, which is a modified OSU-IVG method extracted more As than OSU-IVG for most soils, resulting in a more accurate predictor than OSU-IVG, especially for low to moderately contaminated soils (<1,500 mg As kg -1 ) with RBA As = 0.81 IVBA As + 3.2, r 2  = 0.91.
(Copyright © 2017. Published by Elsevier Ltd.)
Databáze: MEDLINE
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