title: Evaluation of SBRC-gastric and SBRC-intestinal methods for the prediction of in vivo relative lead bioavailability in contaminated soils.
abstract: In this study, lead (Pb) bioaccessibility in contaminated soils was assessed using an in vitro method (SBRC) encompassing gastric (SBRC-G) and intestinal (SBRC-I) phases. Initially, bioaccessibility studies were performed with a Pb reference material (Pb acetate, 1-10 mg L(-1)) in order to determine the influence of pH on Pb solubility. In the gastric phase (pH 1.5), Pb solubility was 100% (100 +/- 2.9%, n = 16) irrespective of the Pb concentration added, however, when the pH of the intestinal phase was increased to near neutral, Pb solubility decreased to 14.3 +/- 7.2%. In contaminated soils, Pb bioaccessibility varied from 35.7 to 64.1% and 1.2 to 2.7% for SBRC-G and SBRC-I phases, respectively. When relative bioaccessibility (Rel-SBRC-I) was calculated by adjusting the dissolution of Pb from contaminated soils by the solubility of Pb acetate at pH 6.5 (intestinal phase pH); Rel-SBRC-I values ranged from 11.7-26.1%. A stepwise regression model based on Pearson correlation factors was used to determine the suitability of in vitro assays for predicting in vivo (swine assay) relative Pb bioavailability. Rel-SBRC-I provided the best estimate of in vivo relative Pb bioavailability for soils used in this study (in vive relative Pb bioavailability [%] = Rel-SBRC-I [pH 6.5%] x 0.58 + 1.98, P = 0.53). The versatility of Rel-SBRC-I was demonstrated by accurately predicting relative Pb bioavailability from other reported in vivo studies.
authors: Centre for Environmental Risk Assessment and Remediation, Division of Information Technology, Engineering and the Environment, University of South Australia, Mawson Lakes Campus, Mawson Lakes, SA 5095, Australia. Albert.Juhasz@unisa.edu.au
authors: Albert L
authors: AL
authors: Juhasz
authors: John
authors: J
authors: Weber
authors: Euan
authors: E
authors: Smith
authors: Ravi
authors: R
authors: Naidu
authors: Bernd
authors: B
authors: Marschner
authors: Matthew
authors: M
authors: Rees
authors: Allan
authors: A
authors: Rofe
authors: Tim
authors: T
authors: Kuchel
authors: Lloyd
authors: L
authors: Sansom
mesh_terms: D000818:Animals; D001682:Biological Availability; D004784:Environmental Monitoring; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism*; D007854:Lead / Q000378:metabolism / Q000493:pharmacokinetics*; D008954:Models, Biological; D012989:Soil Pollutants / Q000378:metabolism / Q000493:pharmacokinetics; D013552:Swine / Q000378:metabolism*
chemical_list: D012989:Soil Pollutants; D007854:Lead