https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:46449 Wed 23 Nov 2022 14:10:37 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:37210 Eisenia fetida, were exposed to a soil containing readily available benzo[a]pyrene (B[a]P) and highly sequestered B[a]P NERs aged in soil for 350 days. B[a]P bioaccumulation was assessed and DNA damage (as DNA single strand breaks) in earthworm coelomocytes were evaluated by comet assay. The concentrations of B[a]P in earthworm tissues were generally low, particularly when the soil contained highly sequestered B[a]P NERs, with biota-soil accumulation factors ranging from 0.6 to 0.8 kg_OC/kg_lipid. The measurements related to genotoxicity, that is percentage (%) of DNA in the tails and olive tail moments, were significantly greater (p < 0.05) in the spiked soil containing readily available B[a]P than in soil that did not have added B[a]P. For example, for the soil initially spiked at 10 mg/kg, the percentage of DNA in the tails (29.2%) of coelomocytes after exposure of earthworms to B[a]P-contaminated soils and olive tail moments (17.6) were significantly greater (p < 0.05) than those of unspiked soils (19.6% and 7.0, for percentage of DNA in tail and olive tail moment, respectively). There were no significant (p > 0.05) differences in effects over the range of B[a]P concentrations (10 and 50 mg/kg soil) investigated. In contrast, DNA damage after exposure of earthworms to B[a]P NERs in soil did not differ from background DNA damage in the unspiked soil. These findings are useful in risk assessments as they can be applied to minimise uncertainties associated with the ecological health risks from exposure to highly sequestered PAH residues in long-term contaminated soils.]]> Wed 10 Nov 2021 15:04:24 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:54621 Wed 06 Mar 2024 10:53:01 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:42048 a]pyrene and benzo[a]pyrene NERs from the solvent-spiked soils, and mobilization of six PAHs and their NERs from the MGP soils. PAH oral bioaccessibility was determined. The incremental lifetime cancer risks (ILCRs), using Si-Org-PBET- and total-extractable PAH concentrations from the MGP soils, were calculated. Sorption kinetics modelling showed that 95% of mobilized PAHs sorbed to the silicone rods within 2–19 h, depending on PAH physico-chemical properties. Total-extractable and Si-Org-PBET extractable PAH concentrations exceeded health investigation levels (3 mg/kg based on benzo[a]pyrene toxic equivalent quotients) in soils. PAH oral bioaccessibility approached 100% for solvent-spiked soils, but only 24–36% for the MGP soils. Associated ILCRs exceeded target levels (10⁻⁵) for one MGP soil, particularly for 2–3 year olds, despite oral bioaccessibility considerations. In contrast, mobilized PAH NERs did not exceed health investigation and ILCR levels, as the NERs were highly sequestered, especially in the MGP soils. PAH nonextractable residues in long-term contaminated soils are unlikely to be mobilized in concentrations that pose cancer risks to humans following soil ingestion, and do not need to be considered in risk assessments.]]> Tue 14 Nov 2023 14:48:37 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:43101 40%) amounts of nonextractable residues. The cumulative amounts of B[a]P extracted in each soil by single- and sequential-solvent extractions were similar (p > 0.05) at each aging period, which indicated access to similar B[a]P fractions in soil by both solvent extractions. The similarities in the amounts of B[a]P nonextractable residues recovered by MeKOH from pre-extracted soils, through either of the extraction methods, confirms that the total extractable B[a]P fractions from both methods are similar.]]> Tue 13 Sep 2022 12:40:51 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39790 d) ranged from 5 to 229 mL/g (median: 28 mL/g), with 63% of the Fijian soils and 35% of the Australian soils showing K_d values that exceeded the observed median Kd. Multiple linear regression showed that TOC, amorphous aluminum and iron oxides contents, anion exchange capacity, pH, and silt content, jointly explained about 53% of the variance in PFOS K_d in soils. Variable charge soils with net positive surface charges, and moderate to elevated TOC content, generally displayed enhanced PFOS sorption than in temperate or tropical soils with TOC as the only sorbent phase, especially at acidic pH ranges. For the first time, two artificial neural networks were developed to predict the measured PFOS K_d (R² = 0.80) in the soils. Overall, both TOC and surface charge characteristics of soils are important for describing PFOS sorption.]]> Thu 23 Jun 2022 14:06:17 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47423 Thu 19 Jan 2023 13:03:30 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33340 in vitro models have been used to predict PAH bioaccessibility, and chemical extractions have been used to determine residual fractions in various soils, there are still doubts about what is actually being measured. Therefore it is not certain which bioaccessibility method currently represents the best choice, or provides the best estimate, of in vivo PAH bioavailability. It is suggested that the fate and behaviour of HOCs in a wide range of soils, and that consider exposure-specific scenarios, be investigated. Exposure-specific scenarios are important for validation purposes, which may be useful for the development of standardised methods and procedures for HOC bioaccessibility determinations. Research is needed to propose the most appropriate testing methods and for assessing potential risks posed by residual fractions of HOCs. Such investigations may be useful for minimising uncertainties associated with a risk-based approach, so that consideration may then be given to its adoption on a global scale. This review critically appraises existing information on the bioavailability of HOC residues in soil to establish whether there may be risks from highly sequestered contaminant residues.]]> Thu 18 Oct 2018 15:28:38 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:44583 0.05). Approximately 40% of B[a]P NERs in the sandy-clay-loam organic matter-rich soil was recovered by the exhaustive alkaline extractions after 180 d of aging, compared to only 10% using conventional methanolic saponification. However, the amounts of B[a]P NERs recovered depend on soil properties and the amounts of NERs in soils. A significant correlation (R2 = 0.69, p < 0.001) was also observed between the amounts of B[a]P recovered by each of the seven alkaline extractions in the contrasting soils and corresponding NERs at 180 d of aging, indicating a potential association warranting further investigations. Extraction techniques that estimate the amounts of PAH NERs recoverable in soil can help give a better understanding of the fate of NERs in soil.]]> Mon 17 Oct 2022 11:44:39 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:51936 Fri 22 Sep 2023 12:38:22 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:53860 Fri 19 Jan 2024 12:31:46 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:41827 Fri 12 Aug 2022 12:52:20 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:49151 Fri 05 May 2023 12:20:55 AEST ]]>