The Effects of Lead Sources on Oral Bioaccessibility in Soil and 1 Implications for Contaminated Land Risk Management

14 15 Lead (Pb) is a non-threshold toxin capable of inducing toxic effects at any blood level but availability 16 of soil screening criteria for assessing potential health risks is limited. The oral bioaccessibility of Pb 17 in 163 soil samples was attributed to sources through solubility estimation and domain identification. 18 Samples were extracted following the Unified BARGE Method. Urban, mineralisation, peat and 19 granite domains accounted for elevated Pb concentrations compared to rural samples. High Pb 20 solubility explained moderate-high gastric (G) bioaccessible fractions throughout the study area. 21 Higher maximum G concentrations were measured in urban (97.6 mg kg) and mineralisation (199.8 22 mg kg) domains. Higher average G concentrations occurred in mineralisation (36.4 mg kg) and 23 granite (36.0 mg kg) domains. Findings suggest diffuse anthropogenic and widespread geogenic 24 contamination could be capable of presenting health risks, having implications for land management 25 decisions in jurisdictions where guidance advises these forms of pollution should not be regarded as 26 contaminated land. 27