title: Using soil properties to predict in vivo bioavailability of lead in soils.
abstract: Soil plays a significant role in controlling the potential bioavailability of contaminants in the environment. In this study, eleven soils were used to investigate the relationship between soil properties and relative bioavailability (RB) of lead (Pb). To minimise the effect of source of Pb on in vivo bioavailability, uncontaminated study soils were spiked with 1500 mg Pb/kg soil and aged for 10-12 months prior to investigating the relationships between soil properties and in vivo RB of Pb using swine model. The biological responses to oral administration of Pb in aqueous phase or as spiked soils were compared by applying a two-compartment pharmacokinetic model to blood Pb concentration. The study revealed that RB of Pb from aged soils ranged from 30±9% to 83±7%. The very different RB of Pb in these soils was attributed to variations in the soils' physico-chemical properties. This was established using sorption studies showing: firstly, Freundlich partition coefficients that ranged from 21 to 234; and secondly, a strongly significant (R(2)=0.94, P<0.001) exponential relationship between RB and Freundlich partition coefficient (Kd). This simple exponential model can be used to predict relative bioavailability of Pb in contaminated soils. To the best of our knowledge, this is the first such model derived using sorption partition coefficient to predict the relative bioavailability of Pb.
authors.affiliation: ATC Building, The University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Mawson Lakes, SA 5095, Australia.
authors.forename: M A Ayanka
authors.initials: MA
authors.lastname: Wijayawardena
authors.affiliation: ATC Building, The University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Mawson Lakes, SA 5095, Australia. Electronic address: Ravi.Naidu@crccare.com.
authors.forename: Ravi
authors.initials: R
authors.lastname: Naidu
authors.affiliation: ATC Building, The University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Mawson Lakes, SA 5095, Australia.
authors.forename: Mallavarapu
authors.initials: M
authors.lastname: Megharaj
authors.affiliation: ATC Building, The University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Mawson Lakes, SA 5095, Australia.
authors.forename: Dane
authors.initials: D
authors.lastname: Lamb
authors.affiliation: ATC Building, The University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Mawson Lakes, SA 5095, Australia.
authors.forename: Palanisami
authors.initials: P
authors.lastname: Thavamani
authors.affiliation: South Australian Health and Medical Research Institute (SAHMRI), 101 Blacks Road, Gilles Plains, SA 5086, Australia.
authors.forename: Tim
authors.initials: T
authors.lastname: Kuchel
mesh_terms: D000818:Animals; D001682:Biological Availability; D007854:Lead / Q000032:analysis* / Q000097:blood / Q000493:pharmacokinetics; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000097:blood / Q000493:pharmacokinetics; D013552:Swine
chemical_list: D012987:Soil; D012989:Soil Pollutants; D007854:Lead
keywords: In vivo; Relative bioavailability; Soil properties; Sorption; Swine