title: Assessment of cadmium bioaccessibility to predict its bioavailability in contaminated soils.
abstract: In vitro assays have been developed to determine metal bioaccessibility in contaminated soils; however, their application to Cd is limited. To assess their suitability to determine Cd relative bioavailability (RBA), Cd-RBA in 12 contaminated soils containing 3.00-296mgkg(-1) Cd were determined using a mouse model and compared with Cd bioaccessibility data based on four assays including the UBM, SBRC, IVG, and PBET. After being administered feed amended with soil or CdCl2 for 10-day, the Cd concentrations in the mouse liver and/or kidneys were used as biomarkers to estimate Cd-RBA. Cd-RBA was comparable at 34-90% and 40-78% based on mouse liver and kidneys with RSD of 7.10-8.99%, and 37-84% based on mouse liver plus kidneys with lower RSD of 5.8%. Cadmium bioaccessibility in soils varied with assays, with 61-99, 59-103, 54-107, and 35-97% in the gastric phase and 20-56, 38-77, 42-88, and 19-64% in the intestinal phase of the UBM, SBRC, IVG and PBET assays. Based on the combined biomarker of liver plus kidneys, better correlation was observed for PBET (r(2)=0.61-0.70) than those for IVG, UBM and SBRC assays (0.12-0.52). The monthly Cd intake in children was 0.24-23.9μgkg(-1) using total Cd concentration in soils, which was reduced by 43% to 0.18-12.3μgkg(-1) using bioavailable Cd. Our data suggest it is important to consider Cd-RBA to assess risk associated with contaminated soils and the PBET may have potential to predict Cd-RBA in contaminated soils.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
authors.forename: Shi-Wei
authors.initials: SW
authors.lastname: Li
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
authors.forename: Hong-Jie
authors.initials: HJ
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
authors.forename: Hong-Bo
authors.initials: HB
authors.lastname: Li
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China. Electronic address: esluojun@nju.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China; Soil and Water Science Department, University of Florida, Gainesville 32611, FL, USA. Electronic address: lqma@ufl.edu.
authors.forename: Lena Q
authors.initials: LQ
authors.lastname: Ma
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000379:methods / Q000592:standards; D001682:Biological Availability; D002104:Cadmium / Q000032:analysis / Q000493:pharmacokinetics; D004195:Disease Models, Animal; D004781:Environmental Exposure / Q000032:analysis; D007668:Kidney / Q000737:chemistry / Q000378:metabolism; D008099:Liver / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D012989:Soil Pollutants / Q000032:analysis / Q000493:pharmacokinetics
chemical_list: D012989:Soil Pollutants; D002104:Cadmium
keywords: Bioavailability; Biomarker; Contamination; Heavy metal; Kidneys; Liver