https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:42905 Wed 28 Feb 2024 14:51:26 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:46449 Wed 23 Nov 2022 14:10:37 AEDT ]]> https://nova.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://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34763 Wed 10 Nov 2021 15:04:10 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:29507 Wed 06 Apr 2022 13:59:57 AEST ]]> https://nova.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://nova.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://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:42895 Tue 06 Sep 2022 14:39:21 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:37211 a]P) in soils. In this study, we investigated the influence of pH, EC and ageing on the extractability of B[a]P in two contracting soils (varied largely in soil texture, clay mineralogy and organic carbon content) over 4 months. Dilute sodium hydroxide (0.2 mol L^-1) and sodium chloride (0.1 mol L^-1) solutions were used to adjust soil pH and EC either separately or simultaneously. Extractability of B[a]P in these soils was monitored using a mild solvent extraction using butanol (BuOH, end-over-end shake over 24h), and an exhaustive mix-solvent extraction using dichloromethane/acetone (DCM/Ace, v:v = 1:1) facilitated by sonication and a subsequent NaOH saponification method following the DCM/Ace extraction. Results showed that increased pH and/or EC significantly increased the B[a]P extractability in the sandy soil (GIA). Variance analysis of contribution of pH and/or EC modification and ageing time on changes in B[a]P extractability indicated that in GIA > 55% and over 25% of the changes in B[a]P extractability was attributed to increased pH&EC and pH only respectively. While ageing resulted in >85% of the change in B[a]P extractability in the clayey soil (BDA), following by increased pH&EC (contribution < 15%). Large amount of non-extractable residue (NER) were formed over the ageing period, up to 95% and 79% in GIA/BDA and its modified soils, respectively. Significant correlations were observed between B[a]P BuOH extractability and the exhaustive sequential extraction using DCM/Ace followed by NaOH saponification for all soils (p < 0.001). With slopes of the correlations close to 1, our results indicated that the simple mild solvent BuOH extraction was equivalent to the complex sequential DCM/Ace and NaOH saponification extraction in these soils.]]> Thu 30 Mar 2023 09:35:27 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:38981 Saccostrea glomerata, a model aquatic bio-indicator organism. The concentration and distribution patterns of parent and polar PAHs including oxygenated PAHs (oxyPAHs), nitrated PAHs (NPAHs) and heterocyclic PAHs (HPAHs) were determined in water, sediment and oysters from an ecologically and economically important estuary of New South Wales, Australia. Total concentrations of PAHs, oxyPAHs, NPAHs and HPAHs were higher in sediments compared to oyster tissue and water. For most polar PAHs, total concentrations for water, sediment and oyster samples were <1 μg/g (μg/l for water) while parent PAH concentrations were several orders of magnitude higher. Computed biota-sediment accumulation factors (BSAFs) on lipid-normalized oyster concentrations revealed that while ∑oxyPAHs and ∑HPAHs exhibited low accumulation from sediment to oyster tissues (BSAF <1), ∑PAHs and ∑NPAH were found to be accumulated at high levels (BSAF >1). BSAF individual computation showed that bioaccumulation of nine investigated HPAHs in oyster tissues were relatively low and only 2-EAQ (oxyPAH) and 1N-NAP (NPAH) showed high levels of accumulation in oyster tissues, similar to parent PAHs. To the best of our knowledge, this is the first known study on the bioavailability of polar and non-polar PAHs in an Australian aquatic environment. The outcome of this study might be a useful indicator of the potential risks of polar PAHs to humans and other living organisms.]]> Thu 24 Mar 2022 13:44:29 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34735 Thu 21 Oct 2021 12:51:21 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:47423 Thu 19 Jan 2023 13:03:30 AEDT ]]> https://nova.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://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:31331 Sat 24 Mar 2018 08:44:39 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:27094 Sat 24 Mar 2018 07:40:35 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:31024 Sat 24 Mar 2018 07:34:51 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:30320 rat = 0.26RB_swine + 17.3, R2 = 0.70, p < 0.001), despite the regression slope coefficient revealing that the rat model would underestimate RB by about one quarter compared to using swine. Conclusions: In the comparison employed in this study, an interspecies difference of four in RB using AUC assay was identified between the rat and swine models regarding pharmacokinetic differences, which supported the body weight scaling method recommended by US EPA. Future research should focus on the carcinogenic competency (pharmacodynamics) used in experiment animals and humans.]]> Sat 24 Mar 2018 07:31:49 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:27744 Pseudomonas sp. strain were also carried out. Results showed that after 1 and 25 d, HPCD at pH 7 extracted significantly more View the MathML source14C-phenanthrene (p<0.05)(p<0.05) from BC-amended soils than the other two solutions (un-buffered and pH 8), while HPCD at pH 8 extracted statistically similar (p>0.05)(p>0.05) amounts of phenanthrene compared to the un-buffered solution. At 50 d, HPCD at pH 8 generally extracted more ¹⁴C-phenanthrene from all treatments. It was proposed that higher pH promoted the dissolution of soil organic matter (SOM), leading to a greater solubility of phenanthrene in the solvent phase and enhancing the extractive capability of HPCD solutions. Although correlations between extractability and biodegradability of ¹⁴C-phenanthrene in BC-amended soils were poor, increasing pH was demonstrated a viable approach to enhancing HPCD extractive capability for the ¹⁴C-PAH from soil with BC.]]> Sat 24 Mar 2018 07:27:45 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:24816 in vivo measurement is reliable but resource insensitive, in vitro approaches promise to provide high-throughput RBA predictions. One challenge on using in vitro bioaccessibility (BAc) to predict in vivo RBA is how to minimize the heterogeneities associated with in vivo-in vitro correlations (IVIVCs) stemming from various biomarkers (kidney, blood, liver, urinary and femur), in vitro approaches and studies. In this study, 252 paired RBA-BAc data were retrieved from 9 publications, and then a Bayesian hierarchical model was implemented to address these random effects. A generic linear model (RBA (%) = (0.87 ± 0.16) × BAc + (4.70 ± 2.47)) of the IVIVCs was identified. While the differences of the IVIVCs among the in vitro approaches were significant, the differences among biomarkers were relatively small. The established IVIVCs were then applied to predict Pb RBA of which an overall Pb RBA estimation was 0.49 ± 0.25. In particular the RBA in the residential land was the highest (0.58 ± 0.19), followed by house dust (0.46 ± 0.20) and mining/smelting soils (0.45 ± 0.31). This is a new attempt to: firstly, use a meta-analysis to correlate Pb RBA and BAc; and secondly, estimate Pb RBA in relation to soil types.]]> Sat 24 Mar 2018 07:15:13 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:38448 *10⁻⁷ (industrial soils) to 2.3^*10⁻⁶ (residential soils), indicating negligible cancer risks. This is the first known study on the occurrence and concentrations of polar and non-polar PAHs in any Australian city, and the results may serve a baseline purpose for improved risk assessment of contaminated sites.]]> Mon 29 Jan 2024 17:56:07 AEDT ]]> https://nova.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://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:33876 Fri 30 Aug 2019 13:07:57 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:41827 Fri 12 Aug 2022 12:52:20 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:40344 Fri 08 Jul 2022 14:12:45 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:49151 Fri 05 May 2023 12:20:55 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:53514 coal tar > pitch. Increases in Frap of cPAHs were observed in coal tar-treated soils after 48 d soil incubation (0.33%–1.16% for soil M, p ≥ 0.05, 6.24%–9.21% for soil G, p < 0.05) and was attributed to the continuous migration of coal tar as a non-aqueous phase liquid (NAPL) into soil pore structures. Slow desorption was dominated by source materials, whereas the extents and rates of rapid desorption (Frap and krap) were more controlled by the quantity of soil organic matter (SOM), rather than quality of SOM (as in solvent-spiked soils). The results of this study challenged the role of PAH source materials as ‘sinks’ and led to the proposed roles of coal tar and pitch and source materials alike as ‘reservoirs’ with a risk-driven perspective.]]> Fri 01 Dec 2023 10:58:45 AEDT ]]>