title: Geochemical sources, forms and phases of soil contamination in an industrial city.
abstract: This study examines current soil contamination in an Australian industrial city, Newcastle. Public (roadside verges and parks) and private (homes) surface soils (n=170) contained metal(loid)s elevated above their respective Australian Health Investigation Levels (HIL). Lead (Pb), the most common contaminant in the city, exceeds the HIL for residential soils (HIL-A, 300mg/kg) in 88% of private soils (median: 1140mg/kg). In-vitro Pb bio-accessibility analysis of selected soils (n=11) using simulated gastric fluid showed a high affinity for Pb solubilisation (maximum Pb concentration: 5190mg/kg, equating to 45% Pb bio-accessibility). Highly soluble Pb-laden Fe- and Mn-oxides likely contribute to the bio-accessibility of the Pb. Public and private space surface soils contain substantially less radiogenic Pb (range:208Pb/207Pb: 2.345-2.411,206Pb/207Pb: 1.068-1.312) than local background soil (208Pb/207Pb: 2.489,206Pb/207Pb: 1.198), indicating anthropogenic contamination from the less radiogenic Broken Hill type Pb ores (208Pb/207Pb: 2.319,206Pb/207Pb: 1.044). Source apportionment using Pb isotopic ratio quantification and soil mineralogy indicate the city's historic copper and steel industries contributed the majority of the soil contaminants through atmospheric deposition and use of slag waste as fill material. High-temperature silicates and oxides combined with rounded particles in the soil are characteristic of smelter dust emissions. Additionally, a preliminary investigation of polycyclic aromatic hydrocarbons in soils, sometimes associated with ferrous metal smelting, coal processing or burning of fossil fuels, shows that these too pose a health exposure risk (calculated in comparison to benzo(a)pyrene: n=12, max: 13.5mg/kg, HIL: 3mg/kg).
authors.affiliation: Department of Earth and Planetary Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia. Electronic address: paul.harvey@mq.edu.au.
authors.forename: P J
authors.initials: PJ
authors.lastname: Harvey
authors.affiliation: Department of Environmental Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Rouillon
authors.affiliation: Department of Environmental Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Dong
authors.affiliation: Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, Prague 2 128 43, Czech Republic.
authors.forename: V
authors.initials: V
authors.lastname: Ettler
authors.affiliation: Department of Earth and Planetary Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia.
authors.forename: H K
authors.initials: HK
authors.lastname: Handley
authors.affiliation: Department of Environmental Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia.
authors.forename: M P
authors.initials: MP
authors.lastname: Taylor
authors.affiliation: Department of Environmental Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia.
authors.forename: E
authors.initials: E
authors.lastname: Tyson
authors.affiliation: Department of Environmental Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia.
authors.forename: P
authors.initials: P
authors.lastname: Tennant
authors.affiliation: Department of Environmental Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia.
authors.forename: V
authors.initials: V
authors.lastname: Telfer
authors.affiliation: Department of Environmental Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Trinh
mesh_terms: D001315:Australia; D001682:Biological Availability; D002947:Cities; D004784:Environmental Monitoring; D019652:Extraction and Processing Industry; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D012987:Soil; D012989:Soil Pollutants
keywords: Bio-accessibility; Lead isotopes; Metal(loids); Mineralogy of metal-bearing particles; Newcastle; Soil