ORCID Profile
0000-0002-1164-4085
Current Organisations
University of Tasmania
,
University of South Australia
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Industrial Biotechnology | Environmental Science and Management | Environmental Impact Assessment | Environmental Engineering | Environmental Technologies | Soil Chemistry | Environmental Monitoring | Environmental Biotechnology not elsewhere classified | Biocatalysis and Enzyme Technology | Inorganic Geochemistry | Industrial Microbiology (incl. Biofeedstocks) | Anatomy And Physiology |
ANZSRC Socio-Economic Objective (SEO)
Biofuel (Biomass) Energy | Urban and Industrial Soils | Oil and Gas Extraction | Prevention and treatment of pollution | Transformation of Coal into Gaseous Fuels | Environmental Policy, Legislation and Standards not elsewhere classified | Economic issues not elsewhere classified | Environmental health | Fresh, Ground and Surface Water Flora, Fauna and Biodiversity
Related Links
Publications
Chronic Exposure to Drinking Water As, Pb, and Cd at Provisional Guideline Values Reduces Weight Gain in Male Mice via Gut Microflora Alterations and Intestinal Inflammation
Publisher: American Chemical Society (ACS)
Date: 24-08-2023
Development toxicity and cytotoxicity of pyroxsulam on embryos and adults of zebrafish (Danio rerio)
Publisher: Elsevier BV
Date: 02-2023
Bioaccessibility-based predictions for estimating PAH biodegradation efficacy – Comparison of model predictions and measured endpoints
Publisher: Elsevier BV
Date: 11-2013
La Estela 87 de Tak’alik Ab’aj: ensayo de un estudio colaborativo
Publisher: Instituto de Investigaciones Filologicas
Date: 07-09-2022
DOI: 10.19130/IIFL.ECM.60.23X00S701
Abstract: The discovery of Stela 87 in situ in a secondary context, as a reused element of sacralization in a possibly royal residence from the Early Classic, allows us to locate the time of the original function as a stela in the Late Preclassic. It is in the Late Preclassic that the image and the text with 4 glyphic signs allude to the ruler represented there. It is in the early part of the Late Preclassic that stelae at Tak’alik Ab’aj and other early cities represent their rulers, still without a long count date. This was implemented in the second part of the Late Preclassic, of which a good ex le is Stela 5 (126 ad). For this reason, the iconography and writing of Estela 87 adds another exponent and opportunity, particularly for the Pacific Coast region, to the study of the still small universe of early texts, and more precisely, of the first part of the Late Preclassic (100 BC-50 ad) (Schieber de Lavarreda, 2020a). It is this opportunity that motivated the present collaborative study.
Influence of saliva, gastric and intestinal phases on the prediction of As relative bioavailability using the Unified Bioaccessibility Research Group of Europe Method (UBM)
Publisher: Elsevier BV
Date: 12-2011
DOI: 10.1016/J.JHAZMAT.2011.09.068
Abstract: In this study, As-contaminated soils (n=12) were assessed for As bioaccessibility using the Unified Bioaccessibility Research Group of Europe in vitro method (UBM) incorporating gastric, saliva-gastric or saliva-gastric-intestinal phases. Arsenic bioaccessibility was compared to previous published As relative bioavailability data for these soils to determine the correlation between in vitro and in vivo data. Comparison of in vitro and in vivo data indicated that the correlation between As bioaccessibility (UBM) and As relative bioavailability (swine assay) was similar irrespective of the in vitro phase used for its determination. The UBM incorporating all phases (saliva-gastric-intestinal) provided the best in vivo-in vitro correlation (slope=1.08 R(2)=0.59), however there was no significant difference in the goodness of fit (R(2) ranged from 0.48 to 0.59) or the slope of the lines (0.93-1.08) for either variation of the UBM (P=0.9946). This indicates that there was no improvement in the As relative bioavailability predictive capabilities when the UBM was extended from a single gastric phase to saliva-gastric or saliva-gastric-intestinal phases.
Principles and application of an in vivo swine assay for the determination of arsenic bioavailability in contaminated matrices
Publisher: Springer Science and Business Media LLC
Date: 23-12-2008
DOI: 10.1007/S10653-008-9237-Y
Abstract: The assessment of arsenic (As) bioavailability from contaminated matrices is a crucial parameter for reducing the uncertainty when estimating exposure for human health risk assessment. In vivo assessment of As utilising swine is considered an appropriate model for human health risk assessment applications as swine are remarkably similar to humans in terms of physiology and As metabolism. While limited in vivo As bioavailability data is available in the literature, few details have been provided regarding technical considerations for performing in vivo assays. This paper describes, with ex les, surgical, experimental design and analytical issues associated with performing chronic and acute in vivo swine assays to determine As bioavailability in contaminated soil and food.
Arsenic oral bioavailability in soils, housedust, and food: implications for human health
Publisher: CRC Press
Date: 23-08-2019
Childhood Lead Exposure in an Industrial Town in China: Coupling Stable Isotope Ratios with Bioaccessible Lead
Publisher: American Chemical Society (ACS)
Date: 03-04-2015
DOI: 10.1021/ES5060622
Abstract: Fingerprinting based on stable isotopes of lead (Pb) in blood and environmental media helps to identify Pb exposure pathways in children. However, previous studies used stable isotopes of total Pb in media. In this study, a wire rope production town in China (Zhuhang) was selected for investigating the effectiveness of using isotope ratios in bioaccessible Pb to identify childhood Pb exposure pathways. Blood Pb levels of 115 children in Zhuhang were 1.7-20.4 μg dL(-1), averaging 6.1 ± 3.2 μg dL(-1) (mean ± standard deviation), and were ∼1.6 times the national average in China (3.9 ± 1.8 μg dL(-1)). Among different environmental media (housedust, soil, PM10, vegetables, rice, and drinking water), housedust (695 ± 495 mg kg(-1)) and vegetables [0.36 ± 0.40 mg (kg of fresh weight)(-1)] contained elevated Pb concentrations. The isotope ratios ((207)Pb/(206)Pb and (208)Pb/(206)Pb) of total Pb were the highest in housedust (0.8587 ± 0.0039 and 2.1049 ± 0.0087) but lower than blood Pb ratios (0.8634 ± 0.0027 and 2.1244 ± 0.0061). When using bioaccessible Pb in housedust (0.8639 ± 0.0018 and 2.1171 ± 0.0036), the isotope ratios overlapped with blood Pb ratios, suggesting that incidental ingestion of housedust was the predominant contributor to children's blood Pb. Coupling the stable isotope technique with bioaccessible Pb is more reliable for identifying Pb exposure pathways than total Pb determinations.
Predicting the Relative Bioavailability of DDT and Its Metabolites in Historically Contaminated Soils Using a Tenax-Improved Physiologically Based Extraction Test (TI-PBET)
Publisher: American Chemical Society (ACS)
Date: 13-01-2016
Abstract: Due to their static nature, physiologically based in vitro assays often fail to provide sufficient sorption capacity for hydrophobic organic contaminants (HOCs). The addition of a sorption sink to in vitro intestinal solution has the potential to mimic dynamic intestinal uptake for HOCs, thereby increasing their desorption from soil. However, the effectiveness of sorption sinks for improving in vitro assays needs to be compared with in vivo data. In this study, Tenax was added as a sorption sink into the physiologically based extraction test (PBET), while DDT and its metabolites (DDTr) were investigated as typical HOCs. Tenax added at 0.01-0.2 g to the PBET intestinal solution sorbed ∼100% of DDTr in 6.3-19 min, indicating its ability as an effective sorption sink. DDTr bioaccessibility in six contaminated soils using Tenax-improved PBET (TI-PBET 27-56%) was 3.4-22 fold greater than results using the PBET (1.2-15%). In vivo DDTr relative bioavailability (RBA) was measured using a mouse adipose model with values of 17.9-65.4%. The inclusion of Tenax into PBET improved the in vivo-in vitro correlation from r(2) = 0.36 (slope = 2.1 for PBET) to r(2) = 0.62 (slope = 1.2 for TI-PBET), illustrating that the inclusion of Tenax as a sorption sink improved the in vitro prediction of DDTr RBA in contaminated soils.
Degradation of high molecular weight polycyclic aromatic hydrocarbons by Pseudomonas cepacia
Publisher: Springer Science and Business Media LLC
Date: 05-1996
DOI: 10.1007/BF00140206
Variability Associated with As in Vivo–in Vitro Correlations When Using Different Bioaccessibility Methodologies
Publisher: American Chemical Society (ACS)
Date: 15-09-2014
DOI: 10.1021/ES502751Z
Abstract: To evaluate the capabilities of in vitro assays to predict arsenic (As) relative bioavailability (RBA), we examined the relationship between As bioaccessibility, determined using a number of in vitro bioaccessibility (IVBA) methodologies (SBRC, IVG, PBET, DIN and UBM) and As RBA determined in a mouse assay for nine As-contaminated soils and 1 NIST reference material (2710a). Significant differences (P < 0.05) in As IVBA were observed within and between assays indicating that different IVBA methodologies may not produce congruent data, as a result of variability in the extracting medium constituents and/or differences in the pH of gastric and intestinal phases. When results of in vivo determinations of As RBA were compared with As IVBA results, there was no significant difference in slopes of the relationships (P = 0.49-0.88) when SBRC, IVG, PBET, DIN, and UBM gastric and intestinal phase data were used. A significantly (P < 0.05) smaller y-intercept was, however, determined for the in vivo-SBRC gastric phase correlation compared to SBRC, IVG, PBET, and DIN intestinal phase, a factor that may influence prediction of As RBA, especially for soils with low As RBA. When in vivo-in vitro relationships were compared to previously derived correlations from the literature, some differences were observed. These differences may be attributed to factors affecting both in vivo and in vitro data including physiological differences in animal models (e.g., mouse versus swine), which may influence As absorption, differences in the approach used to estimate As RBA, and variability arising from subtle interoperator differences in performance of in vitro assays.
Evaluation of SBRC-Gastric and SBRC-Intestinal Methods for the Prediction of In Vivo Relative Lead Bioavailability in Contaminated Soils
Publisher: American Chemical Society (ACS)
Date: 11-05-2009
DOI: 10.1021/ES803238U
Abstract: In this study, lead (Pb) bioaccessibility in contaminated soils was assessed using an in vitro method (SBRC) encompassing gastric (SBRC-G) and intestinal (SBRC-I) phases. Initially, bioaccessibility studies were performed with a Pb reference material (Pb acetate, 1-10 mg L(-1)) in order to determine the influence of pH on Pb solubility. In the gastric phase (pH 1.5), Pb solubility was 100% (100 +/- 2.9%, n = 16) irrespective of the Pb concentration added, however, when the pH of the intestinal phase was increased to near neutral, Pb solubility decreased to 14.3 +/- 7.2%. In contaminated soils, Pb bioaccessibility varied from 35.7 to 64.1% and 1.2 to 2.7% for SBRC-G and SBRC-I phases, respectively. When relative bioaccessibility (Rel-SBRC-I) was calculated by adjusting the dissolution of Pb from contaminated soils by the solubility of Pb acetate at pH 6.5 (intestinal phase pH) Rel-SBRC-I values ranged from 11.7-26.1%. A stepwise regression model based on Pearson correlation factors was used to determine the suitability of in vitro assays for predicting in vivo (swine assay) relative Pb bioavailability. Rel-SBRC-I provided the best estimate of in vivo relative Pb bioavailability for soils used in this study (in vive relative Pb bioavailability [%] = Rel-SBRC-I [pH 6.5%] x 0.58 + 1.98, P = 0.53). The versatility of Rel-SBRC-I was demonstrated by accurately predicting relative Pb bioavailability from other reported in vivo studies.
Influence of co-contaminant exposure on the absorption of arsenic, cadmium and lead
Publisher: Elsevier BV
Date: 02-2017
DOI: 10.1016/J.CHEMOSPHERE.2016.11.010
Abstract: Incidental ingestion of contaminated soil and dust is a major pathway for human exposure to many inorganic contaminants. To date, exposure research has focused on arsenic (As), cadmium (Cd) and lead (Pb), however, these studies have typically assessed metal(loid) bioavailability in idually, even when multiple elements are present in the same matrix. As a consequence, it is unclear whether interactions between these elements occur within the gastro-intestinal tract, which may impact absorption and accumulation. In this study, the influence of contaminant co-exposure was assessed using a mouse bioassay and soluble forms of As, Cd and Pb supplied in mouse chow as in idual, binary and tertiary elemental combinations. Arsenic urinary excretion and Pb-liver accumulation were unaffected by As-Pb co-exposure (1-10 mg As kg
Bioaccessibility of Arsenic and Lead in Polluted Soils Using Three In-vitro Gastrointestinal Simulation Models
Publisher: IOP Publishing
Date: 16-05-2019
Biochar increases arsenic release from an anaerobic paddy soil due to enhanced microbial reduction of iron and arsenic
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.ENVPOL.2016.09.095
Abstract: Previous studies have shown that biochar enhances microbial reduction of iron (Fe) oxyhydroxide under anaerobic incubation. However, there is a lack of data on its influence on arsenic (As) release from As-contaminated paddy soils. In this study, paddy soil slurries (120 mg As kg
Graphical tools for macromolecular crystallography inPHENIX
Publisher: International Union of Crystallography (IUCr)
Date: 16-05-2012
DOI: 10.1107/S0021889812017293
Abstract: A new Python-based graphical user interface for the PHENIX suite of crystallography software is described. This interface unifies the command-line programs and their graphical displays, simplifying the development of new interfaces and avoiding duplication of function. With careful design, graphical interfaces can be displayed automatically, instead of being manually constructed. The resulting package is easily maintained and extended as new programs are added or modified.
In Situ Fixation of Metal(loid)s in Contaminated Soils: A Comparison of Conventional, Opportunistic, and Engineered Soil Amendments
Publisher: American Chemical Society (ACS)
Date: 28-10-2015
Abstract: This study aimed to assess and compare the in vitro and in vivo bioaccessibility/bioavailability of As and Pb in a mining contaminated soil (As, 2267 mg kg(-1) Pb, 1126 mg kg(-1)), after the addition of conventional (phosphoric acid), opportunistic [water treatment residues (WTRs)], and engineered [nano- and microscale zero valent iron (ZVI)] amendments. Phosphoric acid was the only amendment that could significantly decrease Pb bioaccessibility with respect to untreated soil (41 and 47% in the gastric phase and 2.1 and 8.1% in the intestinal phases, respectively), giving treatment effect ratios (TERs, the bioaccessibility in the amended soil ided by the bioaccessibility in the untreated soil) of 0.25 and 0.87 in the gastric and intestinal phase, respectively. The in vivo bioavailability of Pb decreased in the phosphate treatment relative to the untreated soil (6 and 24%, respectively), and also in the Fe WTR 2% (12%) and nZVI-2 (13%) treatments. The ZVI amendments caused a decrease in As bioaccessibility, with the greatest decrease in the nZVI2-treated soil (TERs of 0.59 and 0.64 in the gastric and intestinal phases, respectively). Arsenic X-ray absorption near-edge spectroscopy analysis indicated that most of the As in the untreated soil was present as As(V) associated with Fe mineral phases, whereas in the treated soil, the proportion of arsenosiderite increased. Arsenite was present only as a minor species (3-5%) in the treated soils, with the exception of an nZVI treatment [∼14% of As(III)], suggesting a partial reduction of As(V) to As(III) caused by nZVI oxidation.
Advances in in vitro methods to evaluate oral bioaccessibility of PAHs and PBDEs in environmental matrices
Publisher: Elsevier BV
Date: 05-2016
DOI: 10.1016/J.CHEMOSPHERE.2016.02.041
Abstract: Cleanup goals for sites contaminated with persistent organic pollutants (POPs) are often established based on total contaminant concentrations. However, mounting evidence suggests that understanding contaminant bioavailability in soils is necessary for accurate assessment of contaminant exposure to humans via oral ingestion pathway. Animal-based in vivo tests have been used to assess contaminant bioavailability in soils however, due to ethical issues and cost, it is desirable to use in vitro assays as alternatives. Various in vitro methods have been developed, which simulate human gastrointestinal (GI) tract using different digestion fluids. These methods can be used to predict POP bioavailability in soils, foods, and indoor dust after showing good correlation with in vivo animal data. Here, five common in vitro methods are evaluated and compared using PAHs and PBDEs as an ex le of traditional and emerging POPs. Their applications and limitations are discussed while focusing on method improvements and future challenges to predict POP bioavailability in different matrices. The discussions should shed light for future research to accurately assess human exposure to POPs via oral ingestion pathway.
Application of native plants in constructed floating wetlands as a passive remediation approach for PFAS-impacted surface water
Publisher: Elsevier BV
Date: 05-2022
The Influence of Food on the In Vivo Bioavailability of DDT and Its Metabolites in Soil
Publisher: American Chemical Society (ACS)
Date: 23-03-2020
A critical review of approaches and limitations of inhalation bioavailability and bioaccessibility of metal(loid)s from ambient particulate matter or dust
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.SCITOTENV.2016.09.056
Abstract: Inhalation of metal(loid)s in ambient particulate matter (APM) represents a significant exposure pathway to humans. Although exposure assessment associated with this pathway is currently based on total metal(loid) content, a bioavailability (i.e. absorption in the systemic circulation) and/or bioaccessibility (i.e. solubility in simulated lung fluid) based approach may more accurately quantify exposure. Metal(loid) bioavailability-bioaccessibility assessment from APM is inherently complex and lacks consensus. This paper reviews the discrepancies that impede the adoption of a universal protocol for the assessment of inhalation bioaccessibility. Exposure assessment approaches for in-vivo bioavailability, in-vitro cell culture and in-vitro bioaccessibility (composition of simulated lungs fluid, physico-chemical and methodological considerations) are critiqued in the context of inhalation exposure refinement. An important limitation of bioavailability and bioaccessibility studies is the use of considerably higher than environmental metal(loid) concentration, which diminishing their relevance to human exposure scenarios. Similarly, in idual metal(loid) studies have been criticised due to complexities of APM metal(loid) mixtures which may impart synergistic or antagonistic effects compared to single metal(loid) exposure. Although a number of different simulated lung fluid (SLF) compositions have been used in metal(loid) bioaccessibility studies, information regarding the comparative leaching efficiency among these different SLF and comparisons to in-vivo bioavailability data is lacking. In addition, the particle size utilised is often not representative of what is deposited in the lungs while assay parameters (extraction time, solid to liquid ratio, temperature and agitation) are often not biologically relevant. Research needs are identified in order to develop robust in-vitro bioaccessibility protocols for the assessment or prediction of metal(loid) bioavailability in APM for the refinement of inhalation exposure.
Chapter 23 Can bioavailability assays predict the efficacy of PAH bioremediation?
Publisher: Elsevier
Date: 2008
Predicting Arsenic Relative Bioavailability in Contaminated Soils Using Meta Analysis and Relative Bioavailability–Bioaccessibility Regression Models
Publisher: American Chemical Society (ACS)
Date: 15-11-2011
DOI: 10.1021/ES2018384
Abstract: A number of in vitro assays are available for the determination of arsenic (As) bioaccessibility and prediction of As relative bioavailability (RBA) to quantify exposure for site-specific risk assessment. These data are usually considered in isolation however, meta analysis may provide predictive capabilities for source-specific As bioaccessibility and RBA. The objectives of this study were to predict As RBA using previously published in vivo/in vitro correlations and to assess the influence of As sources on As RBA independent of geographical location. Data representing 351 soils (classified based on As source) and 514 independent bioaccessibility values were retrieved from the literature for comparison. Arsenic RBA was predicted using published in vivo/in vitro regression models, and 90th and 95th percentiles were determined for each As source classification and in vitro methodology. Differences in predicted mean As RBA were observed among soils contaminated from different As sources and within source materials when various in vitro methodologies were utilized. However, when in vitro data were standardized by transforming SBRC intestinal, IVG, and PBET data to SBRC gastric phase values (through linear regression models), predicted As RBA values for As sources followed the order CCA posts ≥ herbicide esticide > mining/smelting > gossan soils with 95th percentiles for predicted As RBA of 78.0, 78.4, 67.0, and 23.7%, respectively.
Alcohol consumption promotes arsenic absorption but reduces tissue arsenic accumulation in mice
Publisher: Elsevier BV
Date: 09-2023
Automating crystallographic structure solution and refinement of protein–ligand complexes
Publisher: International Union of Crystallography (IUCr)
Date: 25-12-2013
Assessment of lead bioaccessibility in peri-urban contaminated soils
Publisher: Elsevier BV
Date: 02-2011
DOI: 10.1016/J.JHAZMAT.2010.10.111
Abstract: Lead (Pb) bioaccessibility was assessed in a range of peri-urban soils (n=31) with differing sources of Pb contamination, including shooting range soils, and soils affected by incinerator, historical fill, mining/smelting, and gasworks activities. A gossan soil s le was also included. Lead bioaccessibility was determined using both gastric and intestinal phases of the SBRC in vitro assay and in vitro data was then incorporated into in vivo-in vitro regression equations to calculate Pb relative bioavailability. Lead bioaccessibility ranged from 26.8-105.2% to 5.5-102.6% for gastric and intestinal phase extractions respectively. Generally, Pb bioaccessibility was highest in the shooting range soils and lowest in the gossan soil. Predictions of relative Pb bioavailability derived from in vitro data were comparable for shooting ranges soils, but highly variable for the other soils examined. For incinerator, historical fill, gasworks and gossan soils, incorporating in vitro gastric data into the in vivo-in vitro regression equation resulting in more conservative Pb relative bioavailability values than those derived using the intestinal in vitro data.
Oral relative bioavailability of Dichlorodiphenyltrichloroethane (DDT) in contaminated soil and its prediction using in vitro strategies for exposure refinement
Publisher: Elsevier BV
Date: 10-2016
DOI: 10.1016/J.ENVRES.2016.06.039
Abstract: In this study, the bioavailability of DDTr (sum of DDT, DDD and DDE isomers) in pesticide-contaminated soil was assessed using an in vivo mouse model. DDTr relative bioavailability (RBA) ranged from 18.7±0.9 (As35) to 60.8±7.8% (As36) indicating that a significant portion of soil-bound DDTr was not available for absorption following ingestion. When DDTr bioaccessibility was assessed using the organic Physiologically Based Extraction Test (org-PBET), the inclusion of a sorption sink (silicone cord) enhanced DDTr desorption by up to 20-fold (1.6-3.8% versus 18.9-56.3%) compared to DDTr partitioning into gastrointestinal fluid alone. Enhanced desorption occurred as a result of the silicone cord acting as a reservoir for solubilized DDTr to partition into, thereby creating a flux for further desorption until equilibrium was achieved. When the relationship between in vivo and in vitro data was assessed, a strong correlation was observed between the mouse bioassay and the org-PBET+silicone cord (slope=0.94, y-intercept=3.5, r(2)=0.72) suggesting that the in vitro approach may provide a robust surrogate measure for the prediction of DDTr RBA in contaminated soil.
Pilot Scale Bioremediation of Creosote-Contaminated Soil—Efficacy of Enhanced Natural Attenuation and Bioaugmentation Strategies
Publisher: Informa UK Limited
Date: 07-2005
What is required for the validation of in vitro assays for predicting contaminant relative bioavailability? Considerations and criteria
Publisher: Elsevier BV
Date: 09-2013
DOI: 10.1016/J.ENVPOL.2013.05.008
Abstract: A number of studies have shown the potential of in vitro assays to predict contaminant in vivo relative bioavailability in order to refine human health exposure assessment. Although the term 'validated' has been used to describe the goodness of fit between in vivo and in vitro observations, its misuse has arisen from semantic considerations in addition to the lack of defined criteria for establishing performance validation. While several internal validation methods may be utilised, performance validation should preferably focus on assessing the agreement of model predictions with a set of data which are independent of those used to construct the model. In order to achieve robust validated predictive models, a number of parameters (e.g. size of data set, source of independent soils, contaminant concentration range, animal model, relative bioavailability endpoint) need to be considered in addition to defined criteria for establishing performance validation which are currently lacking.
In Vivo Assessment of Arsenic Bioavailability in Rice and Its Significance for Human Health Risk Assessment
Publisher: Environmental Health Perspectives
Date: 12-2006
DOI: 10.1289/EHP.9322
Abstract: Millions of people worldwide consume arsenic-contaminated rice however, little is known about the uptake and bioavailability of arsenic species after arsenic-contaminated rice ingestion. In this study, we assessed arsenic speciation in greenhouse-grown and supermarket-bought rice, and determined arsenic bioavailability in cooked rice using an in vivo swine model. In supermarket-bought rice, arsenic was present entirely in the inorganic form compared to greenhouse-grown rice (using irrigation water contaminated with sodium arsenate), where most (approximately 86%) arsenic was present as dimethylarsinic acid (organic arsenic). Because of the low absolute bioavailability of dimethylarsinic acid and the high proportion of dimethylarsinic acid in greenhouse-grown rice, only 33 +/- 3% (mean +/- SD) of the total rice-bound arsenic was bioavailable. Conversely, in supermarket-bought rice cooked in water contaminated with sodium arsenate, arsenic was present entirely in the inorganic form, and bioavailability was high (89 +/- 9%). These results indicate that arsenic bioavailability in rice is highly dependent on arsenic speciation, which in turn can vary depending on rice cultivar, arsenic in irrigation water, and the presence and nature of arsenic speciation in cooking water. Arsenic speciation and bioavailability are therefore critical parameters for reducing uncertainties when estimating exposure from the consumption of rice grown and cooked using arsenic-contaminated water.
Mineral Dietary Supplement To Decrease Cadmium Relative Bioavailability in Rice Based on a Mouse Bioassay
Publisher: American Chemical Society (ACS)
Date: 09-10-2017
Abstract: To determine the effectiveness of mineral dietary supplements to modulate cadmium (Cd) exposure, an in vivo mouse bioassay was conducted to determine Cd relative bioavailability (Cd-RBA) in Cd-contaminated rice (0.80 mg Cd kg
Acute toxicity, oxidative stress and DNA damage of chlorpyrifos to earthworms (Eisenia fetida): The difference between artificial and natural soils
Publisher: Elsevier BV
Date: 09-2020
Impact of soil particle size and bioaccessibility on children and adult lead exposure in peri-urban contaminated soils
Publisher: Elsevier BV
Date: 02-2011
DOI: 10.1016/J.JHAZMAT.2010.12.095
Abstract: The impact of soil particle size and bioaccessibility on children and adult lead (Pb) exposure via the incidental soil ingestion pathway was assessed in 16 peri-urban contaminated soils. A comparison of Pb distribution across 4 particle size fractions (<50 μm, <100 μm, <250 μm and <2 mm) found increasing Pb concentrations associated with decreasing particle size fractions. Lead enrichment in the <50 μm particle size fraction was up to 5 times the concentration observed in the bulk soil. When gastric phase Pb bioaccessibility was determined in the <50, <100 and <250 μm particle size fractions using the SBRC assay, Pb bioaccessibility also increased with decreasing particle size fraction for 6 of the 16 soils tested. Assessment of children and adult Pb exposure indicated that particle size and bioaccessibility had a significant influence on the contribution of incidental soil ingestion to daily Pb intake values. Although the <250 μm particle size fraction is recommended for incidental soil ingestion calculations, using this fraction has the potential to underestimate Pb exposure due to the preferential adhesion of smaller particles to hands with elevated Pb concentrations.
Soils contaminated with explosives: Environmental fate and evaluation of state-of-the-art remediation processes (IUPAC Technical Report)
Publisher: Walter de Gruyter GmbH
Date: 07-05-2011
Abstract: An explosion occurs when a large amount of energy is suddenly released. This energy may come from an over-pressurized steam boiler, from the products of a chemical reaction involving explosive materials, or from a nuclear reaction that is uncontrolled. In order for an explosion to occur, there must be a local accumulation of energy at the site of the explosion, which is suddenly released. This release of energy can be dissipated as blast waves, propulsion of debris, or by the emission of thermal and ionizing radiation. Modern explosives or energetic materials are nitrogen-containing organic compounds with the potential for self-oxidation to small gaseous molecules (N 2 , H 2 O, and CO 2 ). Explosives are classified as primary or secondary based on their susceptibility of initiation. Primary explosives are highly susceptible to initiation and are often used to ignite secondary explosives, such as TNT (2,4,6-trinitrotoluene), RDX (1,3,5-trinitroperhydro-1,3,5-triazine), HMX (1,3,5,7-tetranitro-1,3,5,7-tetrazocane), and tetryl ( N -methyl- N -2,4,6-tetranitro-aniline).
Evaluation of the toxicity of 1-butyl-3-methyl imidazolium tetrafluoroborate using earthworms (Eisenia fetida) in two soils
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.SCITOTENV.2019.06.010
Abstract: Herein, to research the toxic effect of ionic liquids (ILs) on earthworms and compare their different toxicities in different soils, 1-butyl-3-methyl imidazolium tetrafluoroborate ([Bmim]BF
Oral Bioavailability of As, Pb, and Cd in Contaminated Soils, Dust, and Foods based on Animal Bioassays: A Review
Publisher: American Chemical Society (ACS)
Date: 23-08-2019
Abstract: Metal contamination in soil, dust, and food matrices impacts the health of millions of people worldwide. During the past decades, various animal bioassays have been developed to determine the relative bioavailability (RBA) of As, Pb, and Cd in contaminated soils, dust, and foods, which vary in operational approaches. This review discusses the strengths and weaknesses of different animal models (swine and mice), dosing schemes (single gavage dose, repeated gavage dose, daily repeated feeding, and free access to diet), and end points (blood, urine, and tissue) in metal-RBA measurement compares metal-RBA obtained using mouse and swine bioassays, different dosing schemes, and different end points and summarizes key findings on As-, Pb-, and Cd-RBA values in contaminated soils, dust, and foods. Future directions related to metal-RBA research are highlighted, including (1) comparison of metal-RBA determinations between different bioassays and different laboratories to ensure robust bioavailability data, (2) enhancing the metal-RBA database for contaminated dust and foods, (3) identification of physiological and physicochemical mechanisms responsible for variability in metal-RBA values, (4) formulation of strategies to decrease metal-RBA values in contaminated soils, dust, and foods, and (5) assessing the impacts of cocontaminants on metal-RBA measurement.
Using in vitro bioaccessibility to refine estimates of human exposure to PAHs via incidental soil ingestion
Publisher: Elsevier BV
Date: 02-2016
DOI: 10.1016/J.ENVRES.2015.12.001
Abstract: PAH bioaccessibility in contaminated soil was determined using the organic physiologically based extraction test with the inclusion of a sorption sink. Silicone cord was incorporated into the assay in order to overcome the limited capacity of the in vitro medium to accommodate desorbable PAHs. Initially, silicone cord sorption efficacy was determined by assessing sorption kinetics using PAH-spiked sand (phenanthrene, pyrene and benzo[a]pyrene 10-1000mgkg(-1)). Irrespective of PAH and concentration, >95% of the initial PAH mass partitioned into the silicone cord within 12h although rates were lower at higher concentration and with increasing hydrophobicity. When PAH bioaccessibility was assessed in contaminated soil (n=18), contamination source (i.e. pyrogenic versus petrogenic) influenced PAH bioaccessibility. In idual PAH bioaccessibility ranged up to 81.7±2.7% although mean values ranged from 2.1 (acenaphthalene) to 20.8% (benzo[k]fluoranthene) with upper 95% confidence intervals of the means of 4.5 and 28.3% respectively. Although a PAH in vivo-in vitro correlation is yet to be established, bioaccessibility approaches incorporating sorption sinks represent a robust approach for estimating PAH bioavailability as the desorbable fraction may be a conservative measure of the absorbable fraction.
Lead isotopic fingerprinting as a tracer to identify the sources of heavy metals in sediments from the Four Rivers’ inlets to Dongting Lake, China
Publisher: Elsevier BV
Date: 12-2022
Response of the fungal community to chronic petrogenic contamination in surface and subsurface soils
Publisher: Elsevier BV
Date: 03-2019
Oxidative stress and DNA damage induced by trifloxystrobin on earthworms (Eisenia fetida) in two soils
Publisher: Elsevier BV
Date: 11-2021
Assessment of Four Commonly Employed in Vitro Arsenic Bioaccessibility Assays for Predicting in Vivo Relative Arsenic Bioavailability in Contaminated Soils
Publisher: American Chemical Society (ACS)
Date: 12-11-2009
DOI: 10.1021/ES902427Y
Abstract: Currently, a number of in vitro methods are in use worldwide to assess arsenic (As) bioaccessibility in soils. However, a dearth of research has been undertaken to compare the efficacy of the in vitro methods for estimating in vivo relative As bioavailability. In this study, As bioaccessibility in contaminated soils (n = 12) was assessed using four in vitro assays (SBRC, IVG, PBET, DIN). In vitro results were compared to in vivo relative As bioavailability data (swine assay) to ascertain which methodologies best correlate with in vivo data. Arsenic bioaccessibility in contaminated soils varied depending on the in vitro method employed. For the SBRC and IVG methods, As bioaccessibility generally decreased when gastric-phase values were compared to the intestinal phase. In contrast, extending the PBET and DIN assays from the gastric to the intestinal phase resulted in an increase in As bioaccessibility for some soils tested. Comparison of in vitro and in vivo results demonstrated that the in vitro assay encompassing the SBRC gastric phase provided the best prediction of in vivo relative As bioavailability (R(2) = 0.75, Pearson correlation = 0.87). However, relative As bioavailability could also be predicted using gastric or intestinal phases of IVG, PBET, and DIN assays but with varying degrees of confidence (R(2) = 0.53-0.67, Pearson correlation = 0.73-0.82).
Enrichment and isolation of non-specific aromatic degraders from unique uncontaminated (plant and faecal material) sources and contaminated soils
Publisher: Oxford University Press (OUP)
Date: 10-2000
DOI: 10.1046/J.1365-2672.2000.01161.X
Abstract: Microbial analysis of contaminated soil and uncontaminated plant and faecal material resulted in the enrichment of a number of microbial communities capable of utilizing a range of environmental pollutants. Growth was observed on polycyclic aromatic hydrocarbons, polychlorinated biphenyls, heterocyclic aromatic compounds and organochlorine pesticides. However, none of the communities could grow on pentachlorophenol. Pure cultures were isolated from microbial communities using phenanthrene and pyrene as the sole carbon and energy source. Isolates were also obtained using DDT, DOH, DBH and PCPA when peptone was supplemented to the medium. Strain AJR39,504, isolated using DDT and peptone, could not be positively identified on the basis of substrate utilization tests. However, it most closely resembled Stenotrophomonas maltophilia (0.424 similarity) using the Microlog 3 database software. Isolate AJR39, 504 could also grow on polycyclic aromatic hydrocarbons, chlorinated- and nitro-aromatic compounds. In addition, the degradation of DDT (100 mg l(-1)) by isolate AJR39,504 resulted in a 35% decrease in DDT concentration after 28 days with a concomitant increase in DDD concentration.
Coupling bioavailability and stable isotope ratio to discern dietary and non-dietary contribution of metal exposure to residents in mining-impacted areas
Publisher: Elsevier BV
Date: 11-2018
DOI: 10.1016/J.ENVINT.2018.08.023
Abstract: Both dietary and non-dietary pathways contribute to metal exposure in residents living near mining-impacted areas. In this study, bioavailability-based metal intake estimation coupled with stable Pb isotope ratio fingerprinting technique were used to discern dietary (i.e., rice consumption) and non-dietary (i.e., housedust ingestion) contribution to As, Cd, and Pb exposure in residents living near mining-impacted areas. Results showed that not only rice (n = 44 0.10-0.56, 0.01-1.77, and 0.03-0.88 mg kg
Detection of antibacterial-like activity on a silica surface: fluoroquinolones and their environmental metabolites
Publisher: Springer Science and Business Media LLC
Date: 05-02-2012
DOI: 10.1007/S11356-012-0781-8
Abstract: BACKGROUND, SCOPE, AND AIMS: Antibacterial fluoroquinolones (FQs) are third-generation antibiotics that are commonly used as therapeutic treatments of respiratory and urinary tract infections. They are used far less in intensively farmed animal production systems, though their use may be permitted in the veterinary treatments of flocks or in medicated feeds. When used, only a fraction of ingested parent FQ actually reaches the in vivo target site of infection, while the remainder is excreted as the parent FQ and its metabolized products. In many species' metabolism, enrofloxacin (EF) is converted into ciprofloxacin (CF) while both FQs are classified as parent FQs in human treatments. It is therefore likely that both FQs and their metabolic products will contribute to a common pool of metabolites in biological wastes. Wastes from intensive farming practices are either directly applied to agricultural land without treatment or may be temporarily stored prior to disposal. However, human waste is treated in sewage treatment plants (STPs) where it is converted into biosolids. In the storage or treatment process of STPs, FQs and their in vivo metabolites are further converted into other environmental metabolites (FQEMs) by ex vivo physicochemical processes that act and interact to produce complex mixtures of FQEMs, some of which have antibacterial-like activities. Biosolids are then often applied to agricultural land as a fertilizer amendment where FQs and FQEMs can be further converted into additional FQEMs by soil processes. It is therefore likely that FQ-contaminated biowaste-treated soils will contain complex mixtures of FQEMs, some of which may have antibacterial-like activities that may be expressed on bacteria endemic to the receiving agricultural soil environment. Concern has arisen in the scientific and in the general community that repeated use of FQ-contaminated biowaste as fertilizer amendments of nutrient-impoverished agricultural land may create a selective environment in which FQ-resistant bacteria might grow. The likelihood of this happening will depend, to some extent, on whether bioactive FQEMs are first synthesized from the parent FQs by the action and interaction of in vivo and ex vivo processes producing bioactive FQEMs in biowastes and biosolids. The postulated creation of a selective environment will also depend, in part, on whether such bioactive FQEMs are biologically available to bacteria, which may, in turn, be influenced by soil type, amendment regime, and the persistence of the bioactive FQEMs. Additionally, soil bacteria and soil processes may be affected in different ways or extents by bioactive FQEMs that could possibly act additively or synergistically at ecological targets in these non-target bacteria. This is an important consideration, since, while parent FQs have well-defined ecological targets (DNA gyrase and topoisomerase IV) and modes of bactericidal action, the FQEMs and their possible modes of action on the many different species of soil bacteria is less well studied. It is therefore understandable that there is a lack of conclusive evidence directly attributing biosolid usage to any increase in FQ-resistant bacteria detected in biowaste-amended agricultural soil. However, a lack of evidence may simply imply that a causal relationship between biosolid usage programs and any detection of low levels of FQ-resistant bacteria in soils has yet to be established, rather than an assumption of no relationship whatsoever. Based on results presented in this paper, the precautionary principle should be applied in the usage of FQ-contaminated biosolids as fertilizer amendments of agricultural land. The aim of this research was to test whether any bioactive FQEMs of EF could be synthesized by aerobic fermentation processes using Mycobacterium gilvum (American Tissue Culture Collection) and a mixed culture of microorganisms derived from an agricultural soil. High-performance thin-layer chromatography (HPTLC) and bioautography were tested as screening techniques in the detection and analysis of bioactive FQEMs. FQEMs derived from M. gilvum and mixed (soil) culture aerobic ferments were fractionated using preparative HPTLC. A standard strain of Escherichia coli was then used as the reporter organism in a bioautography assay in the detection of bioactive-FQEMs on a mid-section of the HPTLC plate. Plate sections were reassembled, and a photograph was taken under low-intensity ultraviolet (UV) light to reveal regions that contained analytes that had UV chromophores and antibacterial-like activities. Many fractionated FQEMs displayed antibacterial-like activity while bound to silica gel HPTLC plates. These results also provide evidence that sufficient quantities of biologically active FQEMs were biologically available from a silica gel surface to prevent the adherent growth of E. coli. Six to seven FQEMs derived from EF using aerobic fermentation processes had antibacterial-like activities, while two FQEMs were also detectable using UV light. Furthermore, similar banding patterns of antibacterial-like activity were observed in both the monoculture (M. gilvum) and mixed culture bioautography assays, indicating that similar processes operated in both aerobic fermentations, either producing similar biologically active FQEMs or biologically active FQEMs that had similar physicochemical properties in both ferments. The simplest explanation for these findings is that the tested agricultural soil also contained mycobacteria that metabolized EF in a similar way to the purchased standard monoculture M. gilvum. Additionally, the marked contrast between the bioautography results and the UV results indicated that the presence of UV chromophores is not a prerequisite for the detection of antibacterial-like activity. A reliance on spectrophotometric techniques in the detection of bioactive FQEMs in the environment may underestimate component antibacterial-like activity and, possibly, total antibacterial-like activity expressed by EF and its FQEMs. The described bioautography method provides a screening technique with which antibacterial-like activities derived from EF and possibly other FQs can be detected directly on silica gel HPTLC plates. It is recommended that both bioassay and instrumental analytical techniques be used in any measurement of hazard and risk relating to antibacterial-like activities in the environment that are derived from fluoroquinolone antibiotics and their environmental metabolites.
Arsenic relative bioavailability in contaminated soils: comparison of animal models, dosing schemes, and biological endpoints
Publisher: CRC Press
Date: 23-08-2019
Environmental metabolites of fluoroquinolones: synthesis, fractionation and toxicological assessment of some biologically active metabolites of ciprofloxacin
Publisher: Springer Science and Business Media LLC
Date: 04-02-2012
DOI: 10.1007/S11356-012-0766-7
Abstract: Biowastes produced by humans and animals are routinely disposed of on land, and concern is now growing that such practices provide a pathway for fluoroquinolone (FQs) antibacterial agents and their environmental metabolites (FQEMs) to contaminate the terrestrial environment. The focus of concern is that FQs and FQEMs may accumulate in amended soils to then adversely impact on the terrestrial environment. One postulated impact is the development of a selective environment in which FQ-resistant bacteria may grow. To find evidence in support of an accumulation of antibacterial-like activity, it was first necessary to establish whether any biologically active FQEMs could be synthesized by physicochemical factors that are normally present in the environment. However, many FQEMs are not commercially available to be used as standards in such studies. FQEMs were therefore synthesized using well-defined processes. They were subsequently analyzed using spectroscopy (UV-vis) and high performance liquid chromatography with mass spectral detection. The antibacterial-like activities of fractionated FQEMs were then assessed in novel bacterial growth inhibition bioassays, and results were compared to those obtained from instrumental analyses. Parent FQs were either exposed to sunlight or were synthesized using defined aerobic microbial (Mycobacterium gilvum or a mixed culture derived from an agricultural soil) fermentation processes. Mixtures of FQEMs derived from photo- and (intracellular) microbial processes were isolated by preparative chromatography and centrifugation techniques, respectively. Mixtures were subsequently fractionated using analytical high-performance thin layer chromatography (HPTLC), and excised analytes were tested in bioautography assays for their antibacterial-like activities. Two bacteria, Escherichia coli (E. coli) and Azospirillum brasilense (A. brasilense) were used as reporter organisms in testing FQ standards and any subtle differences between biologically active FQEMs of ciprofloxacin (CF). FQEMs produced in the photo-synthetic process had UV-vis profiles that were indistinguishable from the parent FQs, and yet mass spectral data revealed the presence of N-formylciprofloxacin (FCF). In contrast, the UV-vis profiles of FQEMs synthesized by M. gilvum and a mixed culture of microorganisms had UV-vis profiles that were similar to one another and markedly different to the parent fluoroquinolones. Mass spectral studies confirmed the presence of FCF and N-acetylciprofloxacin in both microbial ferments. In addition, a photo-FQEM (Cp 6), three M. gilvum FQEMs (Cm 5, Cm 8, and Cm 10) and a mixed culture FQEM (Cs 6) of CF and many other FQEMs of CF, norfloxacin (NF), and enrofloxacin (EF) were fractionated using HPTLC, although their identities have yet to be confirmed. Differences between bioautography results were obtained when E. coli or A. brasilense were used as reporter organisms. Parent FQs (CF and EF) and the FQEMs of CF (Cp 6, Cm 8, and Cs 6) displayed antibacterial-like activity when using E. coli as the reporter organism. In contrast, A. brasilense was insensitive to parent CF and sensitive to EF and all tested FQEMs of CF. Results are consistent with photo- and microbial processes modifying CF in different ways, with the latter changing the UV-vis chromophores. It can be inferred that a lack of detection of analytes (especially photo-FQEMs) when using UV-vis does not necessarily indicate an absence of analyte. Additionally, similarities between the UV-vis profiles of FQEMs extracted from the (monoculture) M. gilvum and the mixed culture microbial aerobic ferments are consistent with similar processes operating in both ferments. Results of HPTLC and bioautography studies revealed that mixtures of (photo- and microbial) FQEMs could be fractionated into in idual components. Bioactive FQEMs of ciprofloxacin, as a representative FQ, can be synthesized by photo- and microbial processes, and their detection required the use of both instrumental and bioautography analytical techniques. It is likely that such FQEMs will also be present on agricultural land that has been repeatedly amended with FQ-contaminated biosolids. The use of instrumental analytical techniques alone and especially photometric detection techniques will underestimate antibacterial-like activities of FQEMs. Moreover, the extraction technique(s) and the selected toxicological endpoint(s) require careful consideration when assessing bioactivity. It is therefore recommended that instrumental analytical techniques and several bioautography assays be performed concurrently, and bioautography assays should use a variety of reporter organisms. Two types of bacterial growth bioassays are recommended in any assessment of antibacterial-like activity derived from CF (and possibly from other FQs). A standardized E. coli bioassay should be used as a general screening procedure to facilitate intra- and inter-laboratory exchange of data. Additionally, soil-specific (region-specific) growth inhibition bioassays should be undertaken using several species of endemic soil bacteria. It is likely that the two sets of data will be useful in future risk assessment processes.
Lead Relative Bioavailability in Lip Products and Their Potential Health Risk to Women
Publisher: American Chemical Society (ACS)
Date: 26-05-2016
Abstract: Recent studies have investigated lead (Pb) concentrations in lip products but little is known about its oral bioavailability. In this study, 75 lipsticks and 18 lip glosses were assessed for Pb concentration, while 15 s les were assessed for Pb relative bioavailability (RBA, relative to Pb acetate absorption) using a mouse femur assay. Lead concentrations were 0.2-10 185 mg kg(-1), with 21 s les exceeding the Chinese limit of 40 mg kg(-1). S les with orange and pink colors and/or low cost contained higher Pb concentrations. For s les with Pb > 7500 mg kg(-1), Pb was present due to the addition of lead chromate (PbCrO4) as a colorant, which was confirmed by X-ray absorption near-edge structure analysis. Lead-RBA in 15 s les (87-10 185 mg kg(-1)) ranged from 23% to 95%, being significantly higher in moderate Pb (56-95% 87-300 mg kg(-1)) than high Pb s les (23-48% >300 mg kg(-1)). The calculation of Pb intake based on Pb-RBA showed that lip product ingestion contributed 5.4-68% of the aggregate Pb exposure for women depending on Pb concentration. The high Pb concentration in some lip products together with their moderate Pb-RBA suggests that lip product ingestion is a potential health concern to women.
Bioavailability of residual polycyclic aromatic hydrocarbons following enhanced natural attenuation of creosote-contaminated soil
Publisher: Elsevier BV
Date: 02-2010
DOI: 10.1016/J.ENVPOL.2009.08.018
Abstract: The impact of residual PAHs (2250 +/- 71 microg total PAHs g(-1)) following enhanced natural attenuation (ENA) of creosote-contaminated soil (7767 +/- 1286 microg total PAHs g(-1)) was assessed using a variety of ecological assays. Microtox results for aqueous soil extracts indicated that there was no significant difference in EC(50) values for uncontaminated, pre- and post-remediated soil. However, in studies conducted with Eisenia fetida, PAH bioaccumulation was reduced by up to 6.5-fold as a result of ENA. Similarly, Beta vulgaris L. biomass yields were increased 2.1-fold following ENA of creosote-contaminated soil. While earthworm and plant assays indicated that PAH bioavailability was reduced following ENA, the residual PAH fraction still exerted toxicological impacts on both receptors. Results from this study highlight that residual PAHs following ENA (presumably non-bioavailable to bioremediation) may still be bioavailable to important receptor organisms such as earthworms and plants.
The impact of sequestration on the bioaccessibility of arsenic in long-term contaminated soils
Publisher: Elsevier BV
Date: 03-2008
DOI: 10.1016/J.CHEMOSPHERE.2007.10.012
Abstract: Arsenic (As) contamination of soil poses a potential threat to human health, particularly for small children, through the incidental ingestion of soil from hand-to-mouth activity. In this study, we examined the relationship between As bioaccessibility using the simplified bioaccessibility extraction test (SBET) and the soil fractions that contribute to bioaccessible As in 12 long-term contaminated soils. Sequential fractionation of soils prior to As bioaccessibility assessment found that As was primarily associated with the specifically sorbed (3-26%), amorphous and poorly crystalline (12-82%), and the well crystalline (3-25%) oxyhydroxide Fe/Al phases with proportions varying depending on the mode of As input. Arsenic bioaccessibility in these soils ranged from less than 1% in the gossan soil to 48% in railway corridor soils. Soil fractions contributing to As bioaccessibility were found to be from the non-specifically (<1-11%), the specifically (<1-29%) sorbed and the amorphous and poorly-crystalline (30-93%) oxyhydroxide Fe/Al fractions. Significant correlations (p<0.05) were found between the As bioaccessible fraction and the amorphous and poorly-crystalline oxyhydroxide Fe/Al fractions indicating that this fraction is a key factor influencing As bioaccessibility in many anthropogenically contaminated soils.
Isolation and Identification of Pyrene MineralizingMycobacteriumspp. from Contaminated and Uncontaminated Sources
Publisher: Hindawi Limited
Date: 2011
DOI: 10.1155/2011/409643
Abstract: Mycobacterium isolates obtained from PAH-contaminated and uncontaminated matrices were evaluated for their ability to degrade three-, four- and five-ring PAHs. PAH enrichment studies were prepared using pyrene and inocula obtained from manufacturing gas plant (MGP) soil, uncontaminated agricultural soil, and faeces from Macropus fuliginosus (Western Grey Kangaroo). Three pyrene-degrading microorganisms isolated from the corresponding enrichment cultures had broad substrate ranges, however, isolates could be differentiated based on surfactant, phenol, hydrocarbon and PAH utilisation. 16S rRNA analysis identified all three isolates as Mycobacterium sp. The Mycobacterium spp. could rapidly degrade phenanthrene and pyrene, however, no strain had the capacity to utilise fluorene or benzo[ a ]pyrene. When pyrene mineralisation experiments were performed, 70–79% of added 14 C was evolved as 14 CO 2 after 10 days. The present study demonstrates that PAH degrading microorganisms may be isolated from a erse range of environmental matrices. The present study demonstrates that prior exposure to PAHs was not a prerequisite for PAH catabolic activity for two of these Mycobacterium isolates.
Metallic mangroves: sediments and in situ diffusive gradients in thin films (DGTs) reveal Avicennia marina (Forssk.) Vierh. lives with high contamination near a lead-zinc smelter in South Australia
Publisher: Elsevier BV
Date: 2022
DOI: 10.1016/J.SCITOTENV.2022.159503
Abstract: From 1889, aerial emissions and effluent from a coastal lead‑zinc smelter at Port Pirie, South Australia, have led to the accumulation of lead (Pb), zinc (Zn), arsenic (As), cadmium (Cd) and copper (Cu) in the surrounding marine environment. Despite this, extensive stands of grey mangrove (Avicennia marina) inhabit coastal areas at Port Pirie, right up to the smelter's boundary. To understand the contamination level the mangroves are living in there, elemental concentrations were measured in mangrove sediments, leaves, pneumatophores and fruits at sites 0.30-43.0 km from the smelter. Plant health was assessed via leaf chlorophyll content at four sites with contrasting contamination, as well as in situ labile elemental concentration using diffusive gradients in thin films (DGT). Sites 0.05). These results reveal that A. marina tolerate high elemental contamination at Port Pirie, contributing to lesser but still high contamination in plants, warranting further investigation into non-lethal impacts on mangroves or additional biota inhabiting this ecosystem.
An inhalation-ingestion bioaccessibility assay (IIBA) for the assessment of exposure to metal(loid)s in PM10
Publisher: Elsevier BV
Date: 08-2018
Comparison of in vivo and in vitro methodologies for the assessment of arsenic bioavailability in contaminated soils
Publisher: Elsevier BV
Date: 10-2007
DOI: 10.1016/J.CHEMOSPHERE.2007.05.018
Abstract: An in vivo swine assay was utilised for the determination of arsenic (As) bioavailability in contaminated soils. Arsenic bioavailability was assessed using pharmacokinetic analysis encompassing area under the blood plasma-As concentration time curve following zero correction and dose normalisation. In contaminated soil studies, As uptake into systemic circulation was compared to an arsenate oral dose and expressed as relative As bioavailability. Arsenic bioavailability ranged from 6.9+/-5.0% to 74.7+/-11.2% in 12 contaminated soils collected from former railway corridors, dip sites, mine sites and naturally elevated gossan soils. Arsenic bioavailability was generally low in the gossan soils and highest in the railway soils, ranging from 12.1+/-8.5% to 16.4+/-9.1% and 11.2+/-4.7% to 74.7+/-11.2%, respectively. Comparison of in vivo and in vitro (Simplified Bioaccessibility Extraction Test [SBET]) data from the 12 contaminated soils and bioavailability data collected from an As spiked soil study demonstrated that As bioavailability and As bioaccessibility were linearly correlated (in vivo As bioavailability (mgkg(-1))=14.19+0.93.SBET As bioaccessibility (mgkg(-1)) r(2)=0.92). The correlation between the two methods indicates that As bioavailability (in vivo) may be estimated using the less expensive, rapid in vitro chemical extraction method (SBET) to predict As exposure in human health risk assessment.
Chemical Bioavailability in the Terrestrial Environment – recent advances
Publisher: Elsevier BV
Date: 10-2013
Microbial activity and phospholipid fatty acid pattern in long-term tannery waste-contaminated soil
Publisher: Elsevier BV
Date: 10-2003
DOI: 10.1016/S0147-6513(02)00075-1
Abstract: We investigated the phospholipid fatty acid (PLFA) pattern and dehydrogenase activity (DHA) in soil s les from three sites (designated as low, medium, and high based on the level of chromium) in a long-term (25 years after last waste input) tannery waste-contaminated area rich in Cr. Soil s les, collected from different soil depths (0-100 cm), at each site were used in this study. In general, soil s les from all three contaminated sites had elevated pH, electrical conductivity, organic carbon (OC), total Cr, and hexavalent Cr [Cr(VI)]. The maximum total Cr concentration in surface soils (0-10 cm) at the highly contaminated site was 102 gkg(-1), with 4.6 mgkg(-1) present as the bioavailable water-soluble Cr. More than 50% of soluble Cr was in the form of Cr(VI) (2.7 mgkg(-1)). DHA (normalized to OC) was inhibited to a greater extent in soil s les from the highly contaminated site than in low- and medium-contaminated soil s les. PLFA analyses of surface soils indicated that there was a shift in PLFA patterns. PLFAs specific for bacteria (i15:0, a15:0, 15:0, i16:0, a17:0, and cy17:0) decreased significantly (P<0.01) with an increase in Cr contamination. Among the bacterial PLFAs, 15:0, i16:0 and a17:0 had a significant negative correlation with contamination including bioavailable Cr(VI) in soil solution. To our knowledge, this is the first report of alterations in the PLFA profile in soils due to long-term tannery waste pollution.
Arsenic distribution and bioaccessibility across particle fractions in historically contaminated soils
Publisher: Springer Science and Business Media LLC
Date: 18-02-2009
DOI: 10.1007/S10653-009-9249-2
Abstract: Incidental soil ingestion is a common contaminant exposure pathway for humans, notably children. It is widely accepted that the inclusion of total soil metal concentrations greatly overestimates the risk through soil ingestion for people due to contaminant bioavailability constraints. The assumption also assumes that the contaminant distribution and the bioaccessible fraction is consistent across all particle sizes. In this study, we investigated the distribution of arsenic across five particle size fractions as well as arsenic bioaccessibility in the <250-, <100-, <10- and 2.5-microm soil particle fractions in 50 contaminated soils. The distribution of arsenic was generally uniform across the larger particle size fractions but increased markedly in the <2.5-microm soil particle fraction. The marked increase in arsenic concentration in the <2.5-microm fraction was associated with a marked increase in the iron content. Arsenic bioaccessibility, in contrast, increased with decreasing particle size. The mean arsenic bioaccessibility increased from 25 +/- 16% in the <250-microm soil particle fraction to 42 +/- 23% in the <10-microm soil particle fraction. These results indicate that the assumption of static arsenic bioaccessibility values across particle size fractions should be reconsidered if the ingested material is enriched with small particle fractions such as those found in household dust.
Chapter 3 Bioavailability: Definition, assessment and implications for risk assessment
Publisher: Elsevier
Date: 2008
Arsenic uptake and speciation in rice plants grown under greenhouse conditions with arsenic contaminated irrigation water
Publisher: Elsevier BV
Date: 03-2008
DOI: 10.1016/J.SCITOTENV.2007.11.023
Abstract: The accumulation of arsenic (As) by rice (Oryza sativa L.) is of great interest considering the dietary intake of rice is potentially a major As exposure pathway in countries where rice is irrigated with As contaminated groundwater. A small scale rice paddy experiment was conducted to evaluate the uptake of As by rice. Arsenic concentrations in rice tissue increased in the order grain<<leaf<stem<<<root with the As concentration in the rice grain, in some cases, exceeding the maximum Australian permissible concentration of 1 mg kg(-1). Speciation of As in rice tissue was performed using a modified protein extraction procedure and trifluoroacetic acid extraction. Whilst higher As recoveries were obtained using trifluoroacetic acid extraction, both methods identified arsenite and arsenate as the major As species present in the root, stem and leaf, however, arsenite and dimethylarsinic acid (DMA) were the major As species identified in the grain. Notably, DMA comprised 85 to 94% of the total As concentration in the grain. The high proportion of organic to inorganic As in the grain has implications on human health risk assessment as inorganic As species are more bioavailable than methylated As species.
Arsenic Concentrations, Speciation, and Localization in 141 Cultivated Market Mushrooms: Implications for Arsenic Exposure to Humans
Publisher: American Chemical Society (ACS)
Date: 06-12-2018
Abstract: Mushrooms accumulate arsenic (As), yet As concentrations, speciation, and localization in cultivated mushrooms across a large geographic distribution are unknown. We characterized 141 s les of nine species from markets in nine capital cities in China, with s les of Lentinula edodes, Pleurotus ostreatus, and Agaricus bisporus being analyzed for As speciation and localization. Total As concentrations ranged from 0.01 to 8.31 mg kg
Assessing impediments to hydrocarbon biodegradation in weathered contaminated soils
Publisher: Elsevier BV
Date: 10-2013
DOI: 10.1016/J.JHAZMAT.2013.01.052
Abstract: In this study, impediments to hydrocarbon biodegradation in contaminated soils were assessed using chemical and molecular methodologies. Two long-term hydrocarbon contaminated soils were utilised which were similar in physico-chemical properties but differed in the extent of hydrocarbon (C10-C40) contamination (S1: 16.5 g kg(-1) S2: 68.9 g kg(-1)). Under enhanced natural attenuation (ENA) conditions, hydrocarbon biodegradation was observed in S1 microcosms (26.4% reduction in C10-C40 hydrocarbons), however, ENA was unable to stimulate degradation in S2. Although eubacterial communities (PCR-DGGE analysis) were similar for both soils, the alkB bacterial community was less erse in S2 presumably due to impacts associated with elevated hydrocarbons. When hydrocarbon bioaccessibility was assessed using HP-β-CD extraction, large residual concentrations remained in the soil following the extraction procedure. However, when linear regression models were used to predict the endpoints of hydrocarbon degradation, there was no significant difference (P>0.05) between HP-β-CD predicted and microcosm measured biodegradation endpoints. This data suggested that the lack of hydrocarbon degradation in S2 resulted primarily from limited hydrocarbon bioavailability.
Assessment of Persistent Organic Pollutant (POP) Bioavailability and Bioaccessibility for Human Health Exposure Assessment: A Critical Review
Publisher: Informa UK Limited
Date: 11-03-2011
Remediation of Polluted Soil in China: Policy and Technology Bottlenecks
Publisher: American Chemical Society (ACS)
Date: 08-12-2017
Using in vivo bioavailability and/or in vitro gastrointestinal bioaccessibility testing to adjust human exposure to arsenic from soil ingestion
Publisher: Mineralogical Society of America
Date: 2014
Influence of Dietary Lipid Type on the Bioavailability of DDT and Its Metabolites in Soil: Mechanisms and Health Implications
Publisher: American Chemical Society (ACS)
Date: 06-04-2022
Abstract: The impact of dietary lipid type on DDTr (DDT and its metabolites) relative bioavailability (RBA) in soil was investigated using an
Effect of Microplastic Types on the In Vivo Bioavailability of Polychlorinated Biphenyls
Publisher: American Chemical Society (ACS)
Date: 17-08-2023
In Situ Formation of Pyromorphite Is Not Required for the Reduction of in Vivo Pb Relative Bioavailability in Contaminated Soils
Publisher: American Chemical Society (ACS)
Date: 30-05-2014
DOI: 10.1021/ES500994U
Abstract: The effect of phosphate treatment on lead relative bioavailability (Pb RBA) was assessed in three distinct Pb-contaminated soils. Phosphoric acid (PA) or rock phosphate were added to smelter (PP2), nonferrous slag (SH15), and shooting range (SR01) impacted soils at a P:Pb molar ratio of 5:1. In all of the phosphate amended soils, Pb RBA decreased compared to that in untreated soils when assessed using an in vivo mouse model. Treatment effect ratios (i.e., the ratio of Pb RBA in treated soil ided by Pb RBA in untreated soil) ranged from 0.39 to 0.67, 0.48 to 0.90, and 0.03 to 0.19 for PP2, SH15, and SR01, respectively. The decrease in Pb RBA following phosphate amendment was attributed to the formation of poorly soluble Pb phosphates (i.e., chloropyromorphite, hydroxypyromorphite, and Pb phosphate) that were identified by X-ray absorption spectroscopy (XAS). However, a similar decrease in Pb RBA was also observed in untreated soils following the sequential gavage of phosphate amendments. This suggests that in vivo processes may also facilitate the formation of poorly soluble Pb phosphates, which decreases Pb absorption. Furthermore, XAS analysis of PA-treated PP2 indicated further in vivo changes in Pb speciation as it moved through the gastrointestinal tract, which resulted in the transformation of hydroxypyromorphite to chloropyromorphite.
Comparison of arsenic bioaccessibility in housedust and contaminated soils based on four in vitro assays
Publisher: Elsevier BV
Date: 11-2015
DOI: 10.1016/J.SCITOTENV.2015.06.060
Abstract: Few studies have assessed As bioaccessibility in housedust using different in vitro assays and compared to those in contaminated soils. We determined As bioaccessibility in 24 housedust s les (4.48-38.2 mg kg(-1)) using SBRC, IVG, DIN, and PBET assays and they averaged 73, 68, 53, and 48% in the gastric phase and 26, 46, 55 and 43% in the intestinal phase of the 4 assays. The corresponding As bioaccessibility in 34 As-contaminated soils (22-6899 mg kg(-1)) were 34, 25, 22, and 22% in the gastric phase and 18, 19, 21, and 20% in the intestinal phase, which was 1.5-2.7 fold lower than those in housedust possibly due to differences in contamination sources and properties. Based on the gastric phase of SBRC assay, As bioaccessibility was 44-96% in housedust and 2.3-80% in soils. Variation in As bioaccessibility among assays was similar for housedust and soils, with SBRC assay providing the highest bioaccessibility in gastric phase. In intestinal phase, dissolved As was probably adsorbed onto precipitated iron oxides, causing a sharp decrease in As bioaccessibility by SBRC assay. Unlike SBRC assay, gastric constituents (pepsin, mucin, phosphate, and citrate) in other 3 assays inhibited As adsorption and/or enhanced As dissolution, leading to greater As bioaccessibility. The greater As bioaccessibility in housedust than soil suggests the potential of greater health risk from As exposure to housedust than soil.
Degradation of High Molecular Weight PAHs in Contaminated Soil by a Bacterial Consortium: Effects on Microtox and Mutagenicity Bioassays
Publisher: Informa UK Limited
Date: 10-2000
Predicting PAH bioremediation efficacy using bioaccessibility assessment tools: Validation of PAH biodegradation–bioaccessibility correlations
Publisher: Elsevier BV
Date: 11-2014
Remediation of Site Contamination
Publisher: Springer Science and Business Media LLC
Date: 15-11-2013
Modelling of PFAS-surface interactions: Effect of surface charge and solution ions
Publisher: Elsevier BV
Date: 04-2023
Arsenic, lead, and cadmium bioaccessibility in contaminated soils: Measurements and validations
Publisher: Informa UK Limited
Date: 29-08-2019
Specific inhibition of NLRP3 in chikungunya disease reveals a role for inflammasomes in alphavirus-induced inflammation
Publisher: Springer Science and Business Media LLC
Date: 28-08-2017
DOI: 10.1038/S41564-017-0015-4
Abstract: Mosquito-borne viruses can cause severe inflammatory diseases and there are limited therapeutic solutions targeted specifically at virus-induced inflammation. Chikungunya virus (CHIKV), a re-emerging alphavirus responsible for several outbreaks worldwide in the past decade, causes debilitating joint inflammation and severe pain. Here, we show that CHIKV infection activates the NLRP3 inflammasome in humans and mice. Peripheral blood mononuclear cells isolated from CHIKV-infected patients showed elevated NLRP3, caspase-1 and interleukin-18 messenger RNA expression and, using a mouse model of CHIKV infection, we found that high NLRP3 expression was associated with peak inflammatory symptoms. Inhibition of NLRP3 activation using the small-molecule inhibitor MCC950 resulted in reduced CHIKV-induced inflammation and abrogated osteoclastogenic bone loss and myositis, but did not affect in vivo viral replication. Mice treated with MCC950 displayed lower expression levels of the cytokines interleukin-6, chemokine ligand 2 and tumour necrosis factor in joint tissue. Interestingly, MCC950 treatment abrogated disease signs in mice infected with a related arthritogenic alphavirus, Ross River virus, but not in mice infected with West Nile virus-a flavivirus. Here, using mouse models of alphavirus-induced musculoskeletal disease, we demonstrate that NLRP3 inhibition in vivo can reduce inflammatory pathology and that further development of therapeutic solutions targeting inflammasome function could help treat arboviral diseases.
In Vivo Bioavailability and In Vitro Bioaccessibility of Perfluorooctanoic Acid (PFOA) in Food Matrices: Correlation Analysis and Method Development
Publisher: American Chemical Society (ACS)
Date: 17-12-2015
DOI: 10.1021/ES505075Z
Abstract: Food is a major source of human exposure to perfluorooctanoic acid (PFOA), however, PFOA bioavailability in food has not been studied. An in vivo mouse model and three in vitro methods (unified BARGE method, UBM physiologically based extraction test, PBET and in vitro digestion method, IVD) were used to determine the relative bioavailability and bioaccessibility of PFOA in the presence of 17 foods. PFOA was mixed with foods of different nutritional compositions and fed to mice over a 7-d period. PFOA relative bioavailability was determined by comparing PFOA accumulation in the liver following PFOA exposure via food to that in water. PFOA bioavailability relative to water ranged from 4.30 ± 0.80 to 69.0 ± 11.9% and was negatively correlated with lipid content (r = 0.76). This was possibly due to competitive sorption of free fatty acids with PFOA onto transporters on intestine epithelial cells. Besides, cations in the gastrointestinal tract, such as Ca(2+) and Mg(2+), are capable of complexing PFOA and partitioning to the lipid phase. On the other hand, when assessed using in vitro assays, PFOA bioaccessibility varied with methods, being 8.7-73% (UBM), 9.8-99% (PBET), and 21-114% (IVD). PFOA bioaccessibility was negatively correlated with lipid content when assessed using UBM (r = 0.82) however, a poor correlation with food composition was observed for PBET and IVD (r = 0.01-0.50). When in vivo and in vitro data were compared, a strong correlation was observed for UBM (r = 0.79), but poor relationships were observed for PBET and IVD (r = 0.11-0.22). This was probably because the higher lipolysis ability and presence of Ca(2+) and Mg(2+) in the gastrointestinal fluid of UBM resulted in a lower potential to form stable micelles compared to PBET and IVD. These results indicated that PFOA relative bioavailability was mainly affected by lipid content in foods, and UBM has the potential to determine PFOA bioaccessibility in food s les.
Impact of bacterial and fungal processes on 14C-hexadecane mineralisation in weathered hydrocarbon contaminated soil
Publisher: Elsevier BV
Date: 2012
DOI: 10.1016/J.SCITOTENV.2011.11.044
Abstract: In this study, the impact of bacterial and fungal processes on (14)C-hexadecane mineralisation was investigated in weathered hydrocarbon contaminated soil. The extent of (14)C-hexadecane mineralisation varied depending on the bioremediation strategy employed. Under enhanced natural attenuation conditions, (14)C-hexadecane mineralisation after 98 days was 8.5 ± 3.7% compared to <1.2% without nitrogen and phosphorus additions. (14)C-hexadecane mineralisation was further enhanced through Tween 80 amendments (28.9 ± 2.4%) which also promoted the growth of a Phanerochaete chyrsosporium fungal mat. Although fungal growth in weathered hydrocarbon contaminated soil could be promoted through supplementing additional carbon sources (Tween 80, sawdust, compost, pea straw), fungal (14)C-hexadecane mineralisation was negligible when sodium azide was added to soil microcosms to inhibit bacterial activity. In contrast, when fungal activity was inhibited through nystatin additions, (14)C-hexadecane mineralisation ranged from 6.5 ± 0.2 to 35.8 ± 3.8% after 98 days depending on the supplied amendment. Bacteria inhibition with sodium azide resulted in a reduction in bacterial ersity (33-37%) compared to microcosms supplemented with nystatin or microcosms without inhibitory supplements. However, alkB bacterial groups were undetected in sodium azide supplemented microcosms, highlighting the important role of this bacterial group in (14)C-hexadecane mineralisation.
Bioavailability and biodegradation of polycyclic aromatic hydrocarbons
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/MA14064
Lead relative bioavailability in soils based on different endpoints of a mouse model
Publisher: Elsevier BV
Date: 03-2017
DOI: 10.1016/J.JHAZMAT.2016.12.023
Abstract: Mouse is an acceptable animal model to measure lead (Pb) relative bioavailability (RBA) in contaminated soils however, there is a lack of comparisons among Pb-RBA measurements based on different endpoints and dosing approaches. In this study, 12 soils (47.8-8123mg Pbkg
Erratum to “Microbial activity and phospholipid fatty acid pattern in long-term tannery waste-contaminated soil”
Publisher: Elsevier BV
Date: 02-2004
An interlaboratory evaluation of the variability in arsenic and lead relative bioavailability when assessed using a mouse bioassay
Publisher: Informa UK Limited
Date: 05-05-2021
Intra- and Interlaboratory Evaluation of an Assay of Soil Arsenic Relative Bioavailability in Mice
Publisher: American Chemical Society (ACS)
Date: 06-02-2020
Microplastics affect arsenic bioavailability by altering gut microbiota and metabolites in a mouse model
Publisher: Elsevier BV
Date: 05-2023
Emerging contaminants antibiotic resistance genes and microplastics in the environment: Introduction to 21 review articles published in CREST during 2018–2022
Publisher: Informa UK Limited
Date: 13-09-2022
Arsenic Ingested Early in Life Is More Readily Absorbed: Mechanistic Insights from Gut Microbiota, Gut Metabolites, and Intestinal Morphology and Functions
Publisher: American Chemical Society (ACS)
Date: 29-12-2022
Health-related toxicity of emerging per- and polyfluoroalkyl substances: comparison to legacy PFOS and PFOA
Publisher: Elsevier BV
Date: 09-2022
DOI: 10.1016/J.ENVRES.2022.113431
Abstract: Per- and polyfluoroalkyl substances (PFAS) are highly persistent, manufactured chemicals used in various manufacturing processes and found in numerous commercial products. With over 9000 compounds belonging to this chemical class, there is increasing concern regarding human exposure to these compounds due to their persistent, bioaccumulative, and toxic nature. Human exposure to PFAS may occur from a variety of exposure sources, including, air, food, indoor dust, soil, water, from the transfer of PFAS from non-stick wrappers to food, use of cosmetics, and other personal care products. This critical review presents recent research on the health-related impacts of PFAS exposure, highlighting compounds other than Perfluorooctanoic acid (PFOA) and Perfluoroctane sulfonate (PFOS) that cause adverse health effects, updates the current state of knowledge on PFAS toxicity, and, where possible, elucidates cause-and-effect relationships. Recent reviews identified that exposure to PFAS was associated with adverse health impacts on female and male fertility, metabolism in pregnancy, endocrine function including pancreatic dysfunction and risk of developing Type 2 diabetes, lipid metabolism and risk of childhood adiposity, hepatic and renal function, immune function, cardiovascular health (atherosclerosis), bone health including risk for dental cavities, osteoporosis, and vitamin D deficiency, neurological function, and risk of developing breast cancer. However, while cause-and-effect relationships for many of these outcomes were not able to be clearly elucidated, it was identified that 1) the evidence derived from both animal models and humans suggested that PFAS may exert harmful impacts on both animals and humans, however extrapolating data from animal to human studies was complicated due to differences in exposure/elimination kinetics, 2) PFAS precursor kinetics and toxicity mechanism data are still limited despite ongoing exposures, and 3) studies in humans, which provide contrasting results require further investigation of the long-term-exposed population to better evaluate the biological toxicity of chronic exposure to PFAS.
In vitro assessment of arsenic bioaccessibility in contaminated (anthropogenic and geogenic) soils
Publisher: Elsevier BV
Date: 08-2007
DOI: 10.1016/J.CHEMOSPHERE.2007.04.046
Abstract: Arsenic (As) bioaccessibility in contaminated soils (n=50) was assessed using the simplified bioaccessibility extraction test (SBET). Soils used in the study were collected from sites where As was used as an herbicide (railway corridor) or pesticide (cattle dip sites), from former gold mines and from highly mineralised locations containing geogenic As sources (gossans). In all but three soils, As bioaccessibility was less than 50% indicating that a significant proportion of the total As concentration may not be available for absorption in the gastrointestinal tract following incidental soil ingestion. When regression models were developed based on soil properties, the descriptive variables best able to describe As bioaccessibility in railway corridor, dip site and mine site soils were total As and total or dithionite-citrate extractable (free) iron (Fe). While As bioaccessibility could be predicted (r(2)=0.955, n=50) in these contaminated soils, As bioaccessibility for gossan soils was a poor fit using linear or multivariate regression analysis.
Geogenic nickel exposure from food consumption and soil ingestion: A bioavailability based assessment
Publisher: Elsevier BV
Date: 10-2020
The application of a carrier-based bioremediation strategy for marine oil spills
Publisher: Elsevier BV
Date: 07-2014
DOI: 10.1016/J.MARPOLBUL.2014.03.044
Abstract: The application of recycled marine materials to develop sustainable remediation technologies in marine environment was assessed. The remediation strategy consisted of a shell carrier mounted bacterial consortium composed of hydrocarbonoclastic strains enriched with nutrients (Bioaug SC). Pilot scale studies (5000 l) were used to examine the ability of Bioaug-SC to degrade weathered crude oil (10 g l(-1) initially 315,000±44,000 mg l(-1)) and assess the impacts of the introduction and biodegradation of oil. Total petroleum hydrocarbon mass was effectively reduced by 53.3 (±5.75)% to 147,000 (±21,000) mg l(-1) within 27 weeks. 16S rDNA bacterial community profiling using Denaturant Gradient Gel Electrophoresis revealed that cyanobacteria and Proteobacteria dominated the microbial community. Aquatic toxicity assessment was conducted by ecotoxicity assays using brine shrimp hatchability, Microtox and Phaeodactylum tricornutum. This study revealed the importance of combining ecotoxicity assays with oil chemistry analysis to ensure safe remediation methods are developed.
Opportunities and challenges associated with bioavailability-based remediation strategies for lead-contaminated soil with arsenic as a co-contaminant-a critical review
Publisher: Springer Science and Business Media LLC
Date: 07-03-2023
DOI: 10.1007/S40726-023-00252-Z
Abstract: The ubiquity of soil contamination by lead (Pb) and arsenic (As) has prompted the development of numerous techniques for its remediation. For human health exposure assessment, oral bioavailability-based methods are the most suitable to assess the efficacy of these treatment strategies, including in vivo relative bioavailability (systemic absorption relative to a toxicity reference) and in vitro bioaccessibility (dissolution in simulated gastrointestinal solutions). This paper provides a critical review of opportunities and challenges associated with the immobilization of Pb and As in contaminated soil. This review identified that the major inorganic and organic amendments used to reduce Pb and As exposure include phosphate, industrial by-products, metal oxides, organic matter, biochar, and treatment with iron sulphate to promote the formation of plumbojarosite in soil. In addition to RBA and IVBA assessment, investigating changes in Pb/As speciation in untreated vs treated soil can provide additional confirmation of treatment efficacy. The results of this review showed that immobilization efficacy may vary depending on amendment type, Pb, and As speciation in soil and the approach used for its assessment. Reducing childhood exposure to Pb and As is a significant challenge, given the variety of contamination sources and treatment strategies. A lines-of-evidence approach using standardized methodologies is recommended for the assessment of immobilization efficacy to ensure exposure and risk reduction Bioavailability-based remediation strategies. Popular soil amendments to reduce Pb exposure include phosphate, industrial by-products, metal oxides, organic matter, and biochar however, these may increase As exposure. The plumbojarosite formation technique has been recently developed to mitigate Pb and As exposure simultaneously. Multiple lines-of-evidence approach is recommended to assess treatment efficacy
Using the SBRC Assay to Predict Lead Relative Bioavailability in Urban Soils: Contaminant Source and Correlation Model
Publisher: American Chemical Society (ACS)
Date: 29-04-2016
Abstract: Using in vitro bioaccessibility assays to predict Pb relative bioavailability (RBA) in contaminated soils has been demonstrated, however, limited research was performed on urban soils having lower Pb levels. In this study, 162 soils from urban parks in 27 capital cities in China were measured for Pb bioaccessibility using the SBRC assay, with Pb-RBA in 38 subs les being measured using a mouse-kidney assay. Total Pb concentrations in soils were 9.3-1198 mg kg(-1), with 92% of the soils having Pb concentrations 100 mg kg(-1). On the basis of a stable isotope fingerprinting technique, coal combustion ash was identified as the major Pb source, contributing to the increased Pb bioaccessibility with increasing soil Pb concentration. Lead-RBA in soils was 17-87%, showing a strong linear correlation with Pb bioaccessibility (r(2) = 0.61), with cross validation of the correlation based on random subs ling and leave-one-out approaches yielding low prediction errors. On the basis of the large s le size of 38 soils, this study demonstrated that the Pb-RBA predictive capability of the SBRC assay can be extended from mining/smelting impacted soils to urban soils with lower Pb levels.
Assessment of arsenic speciation and bioaccessibility in mine-impacted materials
Publisher: Elsevier BV
Date: 08-2016
DOI: 10.1016/J.JHAZMAT.2016.03.090
Abstract: Mine-impacted materials were collected from Victoria, Australia and categorized into three source materials tailings (n=35), calcinated (n=10) and grey slimes (n=5). Arsenic (As) concentrations in these materials varied over several orders of magnitude (30-47,000mgkg(-1)), with median concentrations of 500, 10,800 and 1500mgkg(-1), respectively. When As bioaccessibility was assessed using the Solubility Bioaccessibility Research Consortium (SBRC) assay, As bioaccessibility ranged between 4 and 90%, with mean gastric phase values of 30%, 49% and 82% for tailings, calcinated and grey slimes, respectively. An analysis of variance (ANOVA) determined that As bioaccessibility was significantly different (P<0.05) between source materials. This was due to differences in As mineralogy, soil particle size as well as the concentration and nature of Fe present. X-ray Absorption Near Edge Structure (XANES) analysis identified arseniosiderite, yukonite, realgar, loellingite and mineral sorbed arsenate species in mine-impacted materials. Despite differences in physicochemical properties, 'mine wastes' are often reported under a generic descriptor. Outcomes from this research highlight that variability in As bioaccessibility can be prescribed to As mineralogy and matrix physicochemical properties, while categorizing s les into sub-groups can provide some notional indication of potential exposure.
Transcriptional diversity during lineage commitment of human blood progenitors
Publisher: American Association for the Advancement of Science (AAAS)
Date: 26-09-2014
Abstract: To determine the epigenetic mechanisms that direct blood cells to develop into the many components of our immune system, the BLUEPRINT consortium examined the regulation of DNA and RNA transcription to dissect the molecular traits that govern blood cell differentiation. By inducing immune responses, Saeed et al. document the epigenetic changes in the genome that underlie immune cell differentiation. Cheng et al. demonstrate that trained monocytes are highly dependent on the breakdown of sugars in the presence of oxygen, which allows cells to produce the energy needed to mount an immune response. Chen et al. examine RNA transcripts and find that specific cell lineages use RNA transcripts of different length and composition (isoforms) to form proteins. Together, the studies reveal how epigenetic effects can drive the development of blood cells involved in the immune system. Science , this issue 10.1126/science.1251086 , 10.1126/science.1250684 , 10.1126/science.1251033
In Vivo–in Vitro and XANES Spectroscopy Assessments of Lead Bioavailability in Contaminated Periurban Soils
Publisher: American Chemical Society (ACS)
Date: 28-06-2011
DOI: 10.1021/ES200653K
Abstract: Lead (Pb) bioaccessibility was assessed using 2 in vitro methods in 12 Pb-contaminated soils and compared to relative Pb bioavailability using an in vivo mouse model. In vitro Pb bioaccessibility, determined using the intestinal phase of the Solubility Bioaccessibility Research Consortium (SBRC) assay, strongly correlated with in vivo relative Pb bioavailability (R(2) = 0.88) following adjustment of Pb dissolution in the intestinal phase with the solubility of Pb acetate at pH 6.5 (i.e., relative Pb bioaccessibility). A strong correlation (R(2) = 0.78) was also observed for the relative bioaccessibility leaching procedure (RBALP), although the method overpredicted in vivo relative Pb bioavailability for soils where values were <40%. Statistical analysis of fit results from X-ray absorption near-edge structure (XANES) data for selected soils (n = 3) showed that Pb was strongly associated with Fe oxyhydroxide minerals or the soil organic fraction prior to in vitro analysis. XANES analysis of Pb speciation during the in vitro procedure demonstrated that Pb associated with Fe minerals and the organic fraction was predominantly solubilized in the gastric phase. However, during the intestinal phase of the in vitro procedure, Pb was strongly associated with formation of ferrihydrite which precipitated due to the pH (6.5) of the SBRC intestinal phase. Soils where Fe dissolution was limited had markedly higher concentrations of Pb in solution and hence exhibited greater relative bioavailability in the mouse model. This data suggests that coexistence of Fe in the intestinal phase plays an important role in reducing Pb bioaccessibility and relative bioavailability.
Insights into the fate of antimony (Sb) in contaminated soils: Ageing influence on Sb mobility, bioavailability, bioaccessibility and speciation
Publisher: Elsevier BV
Date: 05-2021
Influence of in vitro assay pH and extractant composition on As bioaccessibility in contaminated soils
Publisher: Elsevier BV
Date: 03-2014
DOI: 10.1016/J.SCITOTENV.2013.12.030
Abstract: In vitro bioaccessibility assays are often utilised to determine the potential human exposure to soil contaminants through soil ingestion. Comparative studies have identified inconsistencies in the results obtained with different in vitro assays. In this study we investigated the potential causes for the variability between in vitro assay results using the PBET and SBRC assays to assess As bioaccessibility in 5 brownfield contaminated soils. Total As concentration in the 5 soils ranged from 227 to 807 mg As kg(-1) in the 88% was sorbed to Fe mineral phases) with the remaining As present as beudantite or orpiment mineral phases. Arsenic bioaccessibility varied depending on the in vitro methodology markedly higher values were obtained using the SBRC gastric phase compared to the PBET gastric phase, however, similar As bioaccessibility values were obtained in both the SBRC and PBET intestinal phases. The difference in As bioaccessibility following SBRC and PBET gastric phase extraction appeared to be due to the difference in gastric phase pH (i.e. 1.5 versus 2.5 respectively), however, modifying the PBET gastric phase to pH1.5 (that of the SBRC gastric phase) enhanced As bioaccessibility up to 1.6 fold, but was still markedly lower than SBRC values. Although As bioaccessibility was enhanced, the increase did not occur as a result of the solubilisation of As associated Fe mineral phases suggesting As bioaccessibility may also be strongly influenced by the in vitro assay extractant composition. The extractant composition of the PBET assay incorporates a number of organic acids in addition to pepsin which may inhibit the sorption of As onto iron oxide surfaces, therefore increasing As solubility at the modified (pH1.5) gastric phase pH.
Carrier mounted bacterial consortium facilitates oil remediation in the marine environment
Publisher: Elsevier BV
Date: 04-2013
DOI: 10.1016/J.BIORTECH.2013.01.152
Abstract: Marine oil pollution can result in the persistent presence of weathered oil. Currently, removal of weathered oil is reliant on chemical dispersants and physical removal, causing further disruption. In contrast few studies have examined the potential of an environmentally sustainable method using a hydrocarbon degrading microbial community attached to a carrier. Here, we used a tank mesocosm system (50 l) to follow the degradation of weathered oil (10 g l(-1)) using a bacterial consortium mobilised onto different carrier materials (alginate or shell grit). GCMS analysis demonstrated that the extent of hydrocarbon degradation was dependent upon the carrier material. Augmentation of shell grit with nutrients and exogenous hydrocarbon degraders resulted in 75±14% removal of >C32 hydrocarbons after 12 weeks compared to 20±14% for the alginate carrier. This study demonstrated the effectiveness of a biostimulated and bioaugmented carrier material to degrade marine weathered oil.
Predicting the Efficacy of Polycyclic Aromatic Hydrocarbon Bioremediation in Creosote-Contaminated Soil Using Bioavailability Assays
Publisher: Informa UK Limited
Date: 04-2005
In vivo measurement, in vitro estimation and fugacity prediction of PAH bioavailability in post-remediated creosote-contaminated soil
Publisher: Elsevier BV
Date: 03-2014
DOI: 10.1016/J.SCITOTENV.2013.12.031
Abstract: In this study, PAH bioavailability was assessed in creosote-contaminated soil following bioremediation in order to determine potential human health exposure to residual PAHs from incidental soil ingestion. Following 1,000 days of enhanced natural attenuation (ENA), a residual PAH concentration of 871 ± 8 mg kg(-1) (∑16 USEPA priority PAHs in the <250 μm soil particle size fraction) was present in the soil. However, when bioavailability was assessed to elucidate potential human exposure using an in vivo mouse model, the upper-bound estimates of PAH absolute bioavailability were in excess of 65% irrespective of the molecular weight of the PAH. These results indicate that a significant proportion of the residual PAH fraction following ENA may be available for absorption following soil ingestion. In contrast, when PAH bioavailability was estimated redicted using an in vitro surrogate assay (FOREhST assay) and fugacity modelling, PAH bioavailability was up to 2000 times lower compared to measured in vivo values depending on the methodology used.
Assessment of five bioaccessibility assays for predicting the efficacy of petroleum hydrocarbon biodegradation in aged contaminated soils
Publisher: Elsevier BV
Date: 11-2010
DOI: 10.1016/J.CHEMOSPHERE.2010.09.059
Abstract: In this study, the bioaccessibility of petroleum hydrocarbons in aged contaminated soils (1.6-67gkg(-1)) was assessed using four non-exhaustive extraction techniques (100% 1-butanol, 100% 1-propanol, 50% 1-propanol in water and hydroxypropyl-β-cyclodextrin) and the persulfate oxidation method. Using linear regression analysis, residual hydrocarbon concentrations following bioaccessibility assessment were compared to residual hydrocarbon concentrations following biodegradation in laboratory-scale microcosms in order to determine whether bioaccessibility assays can predict the endpoint of hydrocarbon biodegradation. The relationship between residual hydrocarbon concentrations following microcosm biodegradation and bioaccessibility assessment was linear (r(2)=0.71-0.97) indicating that bioaccessibility assays have the potential to predict the extent of hydrocarbon biodegradation. However, the slope of best fit varied depending on the hydrocarbon fractional range assessed. For the C(10)-C(14) hydrocarbon fraction, the slope of best fit ranged from 0.12 to 0.27 indicating that the non-exhaustive or persulfate oxidation methods removed 3.5-8 times more hydrocarbons than biodegradation. Conversely, for the higher molecular weight hydrocarbon fractions (C(29)-C(36) and C(37)-C(40)), biodegradation removed up to 3.3 times more hydrocarbons compared to bioaccessibility assays with the resulting slope of best fit ranging from 1.0-1.9 to 2.0-3.3 respectively. For mid-range hydrocarbons (C(15)-C(28)), a slope of approximately one was obtained indicating that C(15)-C(28) hydrocarbon removal by these bioaccessibility assays may approximate the extent of biodegradation. While this study demonstrates the potential of predicting biodegradation endpoints using bioaccessibility assays, limitations of the study include a small data set and that all soils were collected from a single site, presumably resulting from a single contamination source. Further evaluation and validation is required using soils from a range of hydrocarbon contamination sources in order to develop robust assays for predicting bioremediation endpoints in the field.
Application of an in vivo swine model for the determination of arsenic bioavailability in contaminated vegetables
Publisher: Elsevier BV
Date: 05-2008
DOI: 10.1016/J.CHEMOSPHERE.2007.12.021
Abstract: Considerable information is available in the literature regarding the uptake of arsenic (As) from contaminated soil and irrigation water by vegetables. However, few studies have investigated As speciation in these crops while a dearth of information is available on As bioavailability following their consumption. In this study, the concentration and speciation of As in chard, radish, lettuce and mung beans was determined following hydroponic growth of the vegetables using As-contaminated water. In addition, As bioavailability was assessed using an in vivo swine feeding assay. While As concentrations ranged from 3.0 to 84.2mg As kg(-1) (dry weight), only inorganic As (arsenite and arsenate) was detected in the edible portions of the vegetables. When As bioavailability was assessed through monitoring blood plasma As concentrations following swine consumption of As-contaminated vegetables, between 50% and 100% of the administered As dose was absorbed and entered systemic circulation. Arsenic bioavailability decreased in the order mung beans>radish>lettuce=chard.
Effect of soil ageing on in vivo arsenic bioavailability in two dissimilar soils
Publisher: Elsevier BV
Date: 05-2008
DOI: 10.1016/J.CHEMOSPHERE.2007.12.022
Abstract: Arsenic (As) bioavailability in spiked soils aged for up to 12 months was assessed using in vitro and in vivo methodologies. Ageing (natural attenuation) of spiked soils resulted in a decline in in vivo As bioavailability (swine assay) of over 75% in soil A (Red Ferrosol) but had no significant effect on in vivo As bioavailability even after 12 months of ageing in soil B (Brown Chromosol). Sequential fractionation, however, indicated that there was repartitioning of As within the soil fractions extracted during the time course investigated. In soil A, the As fraction associated with the more weakly bound soil fractions decreased while the residual fraction increased from 12% to 35%. In contrast, little repartitioning of As was observed in soil B indicating that natural attenuation may be only applicable for As in soils containing specific mineralogical properties.
Biology and biotechnological potential of halotolerant bacteria from Antarctic saline lakes
Publisher: Springer Science and Business Media LLC
Date: 12-1993
DOI: 10.1007/BF01929911
A Comparison of In-vitro PAH Bioaccessibility in Historically Contaminated Soils: Implications for Risk Management
Publisher: Informa UK Limited
Date: 05-04-2021
Response of soil microbes after direct contact with pyraclostrobin in fluvo-aquic soil
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.ENVPOL.2019.113164
Abstract: Agricultural chemicals affect the daily life of food production. However, the abuse of pesticides led to the damage to the environment. Pyraclostrobin (PYR) is commonly used strobilurin fungicide which inhibits fungal respiration through mitochondrial cytochrome-b and c1 inhibition. There is increasing concerns that PYR may adversely impact the environment. Although impacts on ecological receptors have been detailed, little information is available regarding the toxicological impact of PYR on soil microbial community dynamics and functioning. Understanding the potential impact on soil microbial populations is important. The activity of enzymes (urease, dehydrogenase, and β-glucosidase) and ersity of microbial community structure using high-throughput 16S rRNA sequencing were evaluated at different soil-PYR concentrations (0.1, 1.0, and 2.5 mg/kg) over a 48 day exposure period. Urease activity remained stable in general. Pyraclostrobin inhibited dehydrogenase activity during the exposure period. The β-glucosidase activity was inhibited on day 28 and induced on day 48 at 1.0 and 2.5 mg/kg. The genera Gp6, Exiguobacterium, Gp4, and Gemmatimonas were both the dominant genera and significantly changed genera. Pyraclostrobin had different level of influence on soil microbes containg their enzyme activity and community structure. The purpose of the current study was to examine the impact of PYR addition on soil enzymes as an indicator of soil health and to have complementary data on the impact of microbial populations. Furthermore, the study may also be the guide for further rational pesticide selection.
Arsenic uptake and speciation in vegetables grown under greenhouse conditions
Publisher: Springer Science and Business Media LLC
Date: 23-12-2008
DOI: 10.1007/S10653-008-9242-1
Abstract: The accumulation of arsenic (As) by vegetables is a potential human exposure pathway. The speciation of As in vegetables is an important consideration due to the varying toxicity of different As species. In this study, common Australian garden vegetables were hydroponically grown with As-contaminated irrigation water to determine the uptake and species of As present in vegetable tissue. The highest concentrations of total As were observed in the roots of all vegetables and declined in the aerial portions of the plants. Total As accumulation in the edible portions of the vegetables decreased in the order radish >> mung bean > lettuce = chard. Arsenic was present in the roots of radish, chard, and lettuce as arsenate (As(V)) and comprised between 77 and 92% of the total As present, whereas in mung beans, arsenite (As(III)) comprised 90% of the total As present. In aerial portions of the vegetables, As was distributed equally between both As(V) and As(III) in radish and chard but was present mainly as As(V) in lettuce. The presence of elevated As in vegetable roots suggests that As species may be complexed by phytochelatins, which limits As translocation to aerial portions of the plant.
Metals in paints on chopsticks: Solubilization in simulated saliva, gastric, and food solutions and implication for human health
Publisher: Elsevier BV
Date: 11-2018
DOI: 10.1016/J.ENVRES.2018.07.036
Abstract: Paints are often used on chopsticks, however, a paucity of studies has assessed metals in the paints and the associated health risk. In this study, total Pb, Cd, Cr, Co, and Ni concentrations in paints were assessed for 72 wood and 29 stainless steel chopsticks with different colors while metal solubilization from paints in simulated saliva, 0.07 M HCl, and 1% citric acid solutions was measured for 9 s les having total Pb > 90 mg kg
Validation of the Predictive Capabilities of the Sbrc-G in Vitro Assay for Estimating Arsenic Relative Bioavailability in Contaminated Soils
Publisher: American Chemical Society (ACS)
Date: 23-10-2014
DOI: 10.1021/ES503695G
Abstract: A number of bioaccessibility methodologies have the potential to act as surrogate measures of arsenic (As) relative bioavailability (RBA), however, validation of the in vivo-in vitro relationship is yet to be established. Validation is important for human health risk assessment in order to ensure robust models for predicting As RBA for refining exposure via incidental soil ingestion. In this study, 13 As-contaminated soils were assessed for As RBA (in vivo swine model) and As bioaccessibility (Solubility Bioaccessibility Research Consortium gastric phase extraction SBRC-G). In vivo and in vitro data were used to assess the validity of the As RBA-bioaccessibility correlation previously described by Juhasz et al. (2009). Arsenic RBA and bioaccessibility in the 13 soils ranged from 6.8±2.4% to 70.5±6.8% and 5.7±0.3% to 78.4±0.8% respectively with a strong linear relationship (R2=0.75) between in vivo and in vitro assays. When the As in vivo-in vitro correlation was compared that of Juhasz et al. (2009), there was no significant difference (P>0.05) indicating that the relationship between As RBA and As bioaccessibility was consistent thereby demonstrating its validation. For these data, a grouped linear regression model was developed (R2=0.82) with a slope and y-intercept of 0.84 and 3.56 respectively. A number of cross validation methodologies (2-fold, repeat random subs ling, leave one out) were utilized to determine the performance of the linear regression model. Residuals and prediction errors ranged from 5.4 to 9.4 and 6.9-12.2 respectively illustrating the capacity of the SBRC-G to accurately predict As RBA in contaminated soil.
Antagonistic Interactions between Arsenic, Lead, and Cadmium in the Mouse Gastrointestinal Tract and Their Influences on Metal Relative Bioavailability in Contaminated Soils
Publisher: American Chemical Society (ACS)
Date: 15-11-2019
Abstract: Soils are often co-contaminated with As, Pb, and Cd. To what extent ingested metal(loid)s interact with each other in the gastrointestinal tract and influence their RBA (relative bioavailability) is largely unknown. Three soils predominantly contaminated with As (MS, mining/smelting impacted), Pb (WR, wire rope production impacted), and Cd (EP, enamel pottery production impacted) were administered to mice in idually or in binary and tertiary combinations with sodium arsenate, Cd chloride, and/or Pb acetate. In binary combinations, ∼10-fold higher Pb addition decreased As-RBA in MS (26.0 ± 6.28% to 17.1 ± 1.08%), while ∼10-fold higher As addition decreased Pb-RBA in WR (61.3 ± 2.41% to 28.8 ± 5.45%). This was possibly due to the formation of insoluble Pb arsenate in mouse intestinal tract, as indicated by the formation of precipitates when As and Pb co-occurred in water or simulated human gastrointestinal fluids. Due to competition for shared absorption transporters, ∼10- and 100-fold higher Pb addition decreased Cd-RBA in EP (95.8 ± 12.9% to 67.8 ± 12.8% and 62.8 ± 8.24%). Tertiary combinations showed that interactions between two metal(loid)s were affected by the presence of the third metal(loid). Our study suggests that As oxyanion could interact with Pb or Cd ions in the mouse gastrointestinal tract, and the interactions vary depending on concentration and solution characteristics.
Toxicity Evaluation of Three Imidazolium-based ionic liquids ([C6mim]R) on Vicia faba Seedlings Using an integrated biomarker response (IBR) index
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.CHEMOSPHERE.2019.124919
Abstract: Ionic liquids (ILs) are regarded as green solvents and are frequently used in the chemical industry. However, ILs may impact plant growth if they are present in the soil environment. To compare toxicity of ILs with different anions in soil, three imidazolium-based ionic liquids (1-hexyl-3-methylimidazolium bromide, 1-hexyl-3-methylimidazolium nitrate, 1-hexyl-3-methylimidazolium tetrafluoroborate) were used to assess impact on Vicia faba. Following 10 d of exposure to these three ILs from 0 to 2500 mg kg
In Vitro, in Vivo, and Spectroscopic Assessment of Lead Exposure Reduction via Ingestion and Inhalation Pathways Using Phosphate and Iron Amendments
Publisher: American Chemical Society (ACS)
Date: 29-07-2019
Microbial Degradation of Phenanthrene in Pristine and Contaminated Sandy Soils
Publisher: Springer Science and Business Media LLC
Date: 27-10-2017
DOI: 10.1007/S00248-017-1094-8
Abstract: Phenanthrene mineralisation studies in both pristine and contaminated sandy soils were undertaken through detailed assessment of the activity and ersity of the microbial community. Stable isotope probing (SIP) was used to assess and identify active
Brominated flame retardants—safety at what cost?
Publisher: Elsevier BV
Date: 12-2007
Assessing the bioavailability and bioaccessibility of metals and metalloids
Publisher: Springer Science and Business Media LLC
Date: 14-06-2015
DOI: 10.1007/S11356-013-1820-9
Abstract: Bioavailability (BA) determines the potential harm of a contaminant that exerts on the receptor. However, environmental guidelines for site contamination assessment are often set assuming the contaminant is 100 % bioavailable. This conservative approach to assessing site risk may result in the unnecessary and expensive remediation of a contaminated site. The National Environmental Protection Measures in Australia has undergone a statutory 5-year review that recommended that contaminant bioavailability and bioaccessibility (BAC) measures be adopted as part of the contaminated site risk assessment process by the National Environment Protection Council. We undertook a critical review of the current bioavailability and bioaccessibility approaches, methods and their respective limitations. The 'gold' standard to estimate the portion of a contaminant that reaches the system circulatory system (BA) of its receptor is to determine BA in an in vivo system. Various animal models have been utilised for this purpose. Because of animal ethics issues, and the expenses associated with performing in vivo studies, several in vitro methods have been developed to determine BAC as a surrogate model for the estimation of BA. However, few in vitro BAC studies have been calibrated against a reliable animal model, such as immature swine. In this review, we have identified suitable methods for assessing arsenic and lead BAC and proposed a decision tree for the determination of contaminant bioavailability and bioaccessibility for health risk assessment.
Potential impact of soil microbial heterogeneity on the persistence of hydrocarbons in contaminated subsurface soils
Publisher: Elsevier BV
Date: 04-2014
DOI: 10.1016/J.JENVMAN.2014.01.031
Abstract: In situ bioremediation is potentially a cost effective treatment strategy for subsurface soils contaminated with petroleum hydrocarbons, however, limited information is available regarding the impact of soil spatial heterogeneity on bioremediation efficacy. In this study, we assessed issues associated with hydrocarbon biodegradation and soil spatial heterogeneity (s les designated as FTF 1, 5 and 8) from a site in which in situ bioremediation was proposed for hydrocarbon removal. Test pit activities showed similarities in FTF soil profiles with elevated hydrocarbon concentrations detected in all soils at 2 m below ground surface. However, PCR-DGGE-based cluster analysis showed that the bacterial community in FTF 5 (at 2 m) was substantially different (53% dissimilar) and 2-3 fold more erse than communities in FTF 1 and 8 (with 80% similarity). When hydrocarbon degrading potential was assessed, differences were observed in the extent of (14)C-benzene mineralisation under aerobic conditions with FTF 5 exhibiting the highest hydrocarbon removal potential compared to FTF 1 and 8. Further analysis indicated that the FTF 5 microbial community was substantially different from other FTF s les and dominated by putative hydrocarbon degraders belonging to Pseudomonads, Xanthomonads and Enterobacteria. However, hydrocarbon removal in FTF 5 under anaerobic conditions with nitrate and sulphate electron acceptors was limited suggesting that aerobic conditions were crucial for hydrocarbon removal. This study highlights the importance of assessing available microbial capacity prior to bioremediation and shows that the site's spatial heterogeneity can adversely affect the success of in situ bioremediation unless area-specific optimizations are performed.
Oxidative stress and genotoxic effects in earthworms induced by five imidazolium bromide ionic liquids with different alkyl chains
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.CHEMOSPHERE.2019.04.091
Abstract: In this study, the acute and subchronic toxicity of 1-alkyl-3-methyl imidazole bromide ionic liquids (ILs) [C
Influence of sample matrix on the bioavailability of arsenic, cadmium and lead during co-contaminant exposure
Publisher: Elsevier BV
Date: 10-2017
DOI: 10.1016/J.SCITOTENV.2017.04.036
Abstract: In this study, the influence of s le matrix on the relative bioavailability of arsenic (As), cadmium (Cd) and lead (Pb) was assessed following exposure of C57BL/6 mice to spiked aged (12years) soils. AIN93G mouse chow was amended with in idual and tertiary As, Cd and Pb soil combinations which were administered to mice over a 9day exposure period. Contaminant relative bioavailability was calculated by comparing As urinary excretion and Cd-kidney/Pb-liver accumulation to corresponding values for compounds used to derive the respective toxicity reference value. Strong linear dose-responses were observed for mice exposed to AIN93G mouse chow augmented with in idually spiked soil with As, Cd and Pb. When mice were exposed to co-contaminants, As relative bioavailability (RBA) decreased similar to results from previous co-contaminant salt experiments presumably due to the influence of Cd on phosphate transport proteins, which are utilized for As absorption. However, a decrease in Cd-kidney and Pb-liver accumulation was also observed following co-co-exposure. It was postulated that this resulted from interactions with other (essential) metals (e.g. iron, aluminium, manganese, magnesium) within the soil matrix and their influence on absorption via alent metal transporters.
Apparent degradation of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) by a Cladosporium sp.
Publisher: Springer Science and Business Media LLC
Date: 1999
Antibiotic exposure decreases soil arsenic oral bioavailability in mice by disrupting ileal microbiota and metabolic profile
Publisher: Elsevier BV
Date: 06-2021
Degradation of benzo[]pyrene, dibenz[]anthracene and coronene by
Publisher: IWA Publishing
Date: 1997
Outcome of the First wwPDB Hybrid/Integrative Methods Task Force Workshop
Publisher: Elsevier BV
Date: 07-2015
Ca Minerals and Oral Bioavailability of Pb, Cd, and As from Indoor Dust in Mice: Mechanisms and Health Implications
Publisher: Environmental Health Perspectives
Date: 12-2022
DOI: 10.1289/EHP11730
Independent Data Validation of an in Vitro Method for the Prediction of the Relative Bioavailability of Arsenic in Contaminated Soils
Publisher: American Chemical Society (ACS)
Date: 12-05-2015
Abstract: In vitro bioaccessibility (IVBA) assays estimate arsenic (As) relative bioavailability (RBA) in contaminated soils to improve accuracy in human exposure assessments. Previous studies correlating soil As IVBA with RBA have been limited by the use of few soil types and sources of As, and the predictive value of As IVBA has not been validated using an independent set of As-contaminated soils. In this study, a robust linear model was developed to predict As RBA in mice using IVBA, and the predictive capability of the model was independently validated using a unique set of As-contaminated soils. Forty As-contaminated soils varying in soil type and contaminant source were included in this study, with 31 soils used for initial model development and nine soils used for independent model validation. The initial model reliably predicted As RBA values in the independent data set, with a mean As RBA prediction error of 5.4%. Following validation, 40 soils were used for final model development, resulting in a linear model with the equation RBA = 0.65 × IVBA + 7.8 and an R(2) of 0.81. The in vivo-in vitro correlation and independent data validation presented provide critical verification necessary for regulatory acceptance in human health risk assessment.
Arsenic Relative Bioavailability in Rice Using a Mouse Arsenic Urinary Excretion Bioassay and Its Application to Assess Human Health Risk
Publisher: American Chemical Society (ACS)
Date: 28-03-2017
Abstract: A steady-state mouse model was developed to determine arsenic (As) relative bioavailability (RBA) in rice to refine As exposure in humans. Fifty-five rice s les from 15 provinces of China were analyzed for total As, with 11 cooked for As speciation and bioavailability assessment. Arsenic concentrations were 38-335 μg kg
Characterising the exchangeability of phenanthrene associated with naturally occurring soil colloids using an isotopic dilution technique
Publisher: Elsevier BV
Date: 04-2015
DOI: 10.1016/J.ENVPOL.2015.01.031
Abstract: The association of polycyclic aromatic hydrocarbons (PAHs) with inorganic and organic colloids is an important factor influencing their bioavailability, mobility and degradation in the environment. Despite this, our understanding of the exchangeability and potential bioavailability of PAHs associated with colloids is limited. The objective of this study was to use phenanthrene as a model PAH compound and develop a technique using (14)C phenanthrene to quantify the isotopically exchangeable and non-exchangeable forms of phenanthrene in filtered soil water or sodium tetraborate extracts. The study was also designed to investigate the exchangeability of colloidal phenanthrene as a function of particle size. Our findings suggest that the exchangeability of phenanthrene in sodium tetraborate is controlled by both inorganic and organic colloids, while in aqueous solutions inorganic colloids play the dominant role (even though coating of these by organic matter cannot be excluded). Filter pore size did not have a significant effect on phenanthrene exchangeability.
Effect of florasulam on oxidative damage and apoptosis in larvae and adult zebrafish (Danio rerio)
Publisher: Elsevier BV
Date: 03-2023
Arsenic Relative Bioavailability in Contaminated Soils: Comparison of Animal Models, Dosing Schemes, and Biological End Points
Publisher: American Chemical Society (ACS)
Date: 09-12-2015
Abstract: Different animals and biomarkers have been used to measure the relative bioavailability of arsenic (As-RBA) in contaminated soils. However, there is a lack of As-RBA comparison based on different animals (i.e., swine and mouse) and biomarkers [area under blood As concentration curve (AUC) after a single gavaged dose vs steady-state As urinary excretion (SSUE) and As accumulation in liver or kidney after multiple doses via diet]. In this study, As-RBA in 12 As-contaminated soils with known As-RBA via swine blood AUC model were measured by mouse blood AUC, SSUE, and liver and kidney analyses. As-RBA ranges for the four mouse assays were 2.8-61%, 3.6-64%, 3.9-74%, and 3.4-61%. Compared to swine blood AUC assay (7.0-81%), though well correlated (R(2) = 0.83), the mouse blood AUC assay yielded lower values (2.8-61%). Similarly, strong correlations of As-RBA were observed between mouse blood AUC and mouse SSUE (R(2) = 0.86) and between urine, liver, and kidney (R(2) = 0.75-0.89), suggesting As-RBA was congruent among different animals and end points. Different animals and biomarkers had little impact on the outcome of in vivo assays to validate in vitro assays. On the basis of its simplicity, mouse liver or kidney assay following repeated doses of soil-amended diet is recommended for future As-RBA studies.
Impact of smelter re-development on spatial and temporal airborne Pb concentrations
Publisher: Elsevier BV
Date: 10-2022
DOI: 10.1016/J.ENVPOL.2022.119952
Abstract: Total suspended particulate (TSP) and PM
Dynamics of Lead Bioavailability and Speciation in Indoor Dust and X-ray Spectroscopic Investigation of the Link between Ingestion and Inhalation Pathways
Publisher: American Chemical Society (ACS)
Date: 28-08-2019
Advancing prediction of polycyclic aromatic hydrocarbon bioaccumulation in plants for historically contaminated soils using Lolium multiflorum and simple chemical in-vitro methodologies
Publisher: Elsevier BV
Date: 06-2021
Predicting lead relative bioavailability in peri-urban contaminated soils usingin vitrobioaccessibility assays
Publisher: Informa UK Limited
Date: 05-2013
DOI: 10.1080/10934529.2013.731354
Abstract: In this study, lead (Pb) bioaccessibility was assessed in peri-urban contaminated soils using a variety of established in vitro assays. Bioaccessibility data was then used to predict Pb relative bioavailability (RBA) using published in vivo-in vitro regression models in order to compare calculated estimates and measured values. Lead bioaccessibility varied depending on the in vitro methodology employed with the relative bioavailability leaching procedure (RBALP) and in vitro gastrointestinal (IVG) assays providing more conservative Pb bioaccessibility values compared to those determined using PBET, UBM and Rel-SBRC-I assays. When Pb RBA was calculated, predicted values using PBET-G and UBM-G data were similar to measured Pb RBA values. However, Pb RBA was over-estimated by 1.6-5.5- and 2.6-6.6-fold when data and regression models from RBALP and IVG-G assays were employed.
Influence of household smoking habits on inhalation bioaccessibility of trace elements and light rare earth elements in Canadian house dust
Publisher: Elsevier BV
Date: 07-2020
A radio-isotopic dilution technique for functional characterisation of the associations between inorganic contaminants and water-dispersible naturally occurring soil colloids
Publisher: CSIRO Publishing
Date: 2013
DOI: 10.1071/EN13020
Abstract: Environmental context The fate and behaviour of inorganic contaminants are dominated by soluble complex formation and interactions with naturally occurring colloids. Although the importance of these interactions has long been debated, our understanding of the mobility and bioavailability of contaminant–colloid associations has been h ered by the limitations of common operationally defined analytical techniques. The method developed in this study facilitates a step forward from operationally defined characterisation of the association between contaminants and colloids to a functional characterisation in terms of their exchangeability and potential bioavailability. Abstract Despite evidence that the fate and behaviour of inorganic contaminants are influenced by their interactions with water-dispersible naturally occurring soil colloids, our understanding of the mobility and bioavailability of contaminant–colloid associations has been h ered by the limitations of common operationally defined analytical techniques. In this paper, an isotopic dilution method was developed to quantify the isotopically exchangeable and non-exchangeable forms of zinc and phosphorus in filtered soil-water extracts. In addition, the effect of filter size on the determination of Zn and P exchangeability was investigated. The results showed that the isotopically non-exchangeable Zn and P in filtered soil-water extracts respectively ranged between 5 and 60% and 10 and 50% and was associated with water-dispersible colloids. Filter pore size had a significant effect on Zn and P exchangeability. Whereas the .1-µm filtrates contained isotopically exchangeable Zn and P fractions equal to the total Zn and P concentrations (i.e. 100% isotopically exchangeable Zn and P), the filtrates obtained from larger filter sizes (0.22, 0.45 and 0.7µm) contained increasing proportions of non-exchangeable Zn and P.
Correlation of in Vivo Relative Bioavailability to in Vitro Bioaccessibility for Arsenic in Household Dust from China and Its Implication for Human Exposure Assessment
Publisher: American Chemical Society (ACS)
Date: 19-11-2014
DOI: 10.1021/ES5037354
Abstract: Incidental ingestion of household dust is an important arsenic (As) exposure pathway for children. However, compared to soils, assessment of As relative bioavailability (RBA) in household dust is limited. In this study, As-RBA in 12 household dust s les (7–38 mg kg(–1)) was measured using an in vivo mouse model and compared to As bioaccessibility determined using 4 assays [Solubility Bioaccessibility Research Consortium method (SBRC), in vitro gastrointestinal method (IVG), Deutsches Institut für Normunge.V. method (DIN), and physiologically based extraction test (PBET)]. Arsenic RBA ranged from 21.8 ± 1.6 to 85.6 ± 7.2% with s les containing low Fe and high total organic carbon content having higher As-RBA. Strong in vivo–in vitro correlations (IVIVC) were found between As-RBA and As bioaccessibility for SBRC and DIN (r2 = 0.63–0.85), but weaker ones were obtained for IVG and PBET (r2 = 0.29–0.55). The developed IVIVC for SBRC and DIN were used to calculate As-RBA based on As bioaccessibility for an additional 12 household dust s les. Although As bioaccessibility differed significantly (up to 7.7-fold) based on in vitro methods, predicted As-RBA was less variable (up to 3.0-fold) when calculated using As bioaccessibility data and the corresponding IVIVC. Our data suggested that both SBRC and DIN had potential to assess As bioavailability in household dust s les however, additional research is needed.
Modified clays alter diversity and respiration profile of microorganisms in long‐term hydrocarbon and metal co‐contaminated soil
Publisher: Wiley
Date: 11-11-2019
Contributions of contamination sources to soil lead concentrations of a smelter-affected community in South Australia, Australia
Publisher: Elsevier BV
Date: 10-2023
In situ remediation of DDT-contaminated soil using a two-phase cosolvent flushing-fungal biosorption process
Publisher: Springer Science and Business Media LLC
Date: 2003
Differential accumulation of polycyclic aromatic hydrocarbons (PAHs) in three earthworm ecotypes: Implications for exposure assessment on historically contaminated soils
Publisher: Elsevier BV
Date: 04-2022
Can in vitro assays account for interactions between inorganic co-contaminants observed during in vivo relative bioavailability assessment?
Publisher: Elsevier BV
Date: 02-2018
DOI: 10.1016/J.ENVPOL.2017.10.089
Abstract: In vitro assays act as surrogate measurements of relative bioavailability (RBA) for inorganic contaminants. The values derived from these assays are routinely used to refine human health risk assessments (HHRA). Extensive in vitro research has been performed on three major inorganic contaminants As, Cd and Pb. However, the majority of these studies have evaluated the contaminants in idually, even in cases when they are found as co-contaminants. Recently, in vivo studies (animal model) have determined that when the three aforementioned contaminants are present in the same soil matrix, they have the ability to influence each other's in idual bioavailability. Since in vitro assays are used to inform HHRA, this study investigated whether bioaccessibility methods including the Solubility/Bioavailability Research Consortium (SBRC) assay, and physiologically based extraction test (PBET), have the ability to detect interactions between As, Cd and Pb. Using a similar dosing methodology to recently published in vivo studies, spiked aged (12 years) soil was assessed by evaluating contaminant bioaccessibility in idually, in addition to tertiary combinations. In two spiked aged soils (grey and brown chromosols), there was no influence on contaminant bioaccessibility when As, Cd and Pb we present as co-contaminants. However, in a red ferrosol, the presence of As and Pb significantly decreased (p < 0.05) the bioaccessibility of Cd when assessed using gastric and intestinal phases of the SBRC assay and the PBET. Conceivable, differences in key physico-chemical properties (TOC, Fe, Al, P) between the study soils influenced contaminant interactions and bioaccessibility outcomes. Although bioaccessibility methods may not account for interactions between elements as demonstrated in in vivo models, in vitro assessment provides a conservative prediction of contaminant RBA under co-contaminant scenarios.
Effects of various Fe compounds on the bioavailability of Pb contained in orally ingested soils in mice: Mechanistic insights and health implications
Publisher: Elsevier BV
Date: 12-2022
DOI: 10.1016/J.ENVINT.2022.107664
Abstract: Reducing lead (Pb) exposure via oral ingestion of contaminated soils is highly relevant for child health. Elevating dietary micronutrient iron (Fe) intake can reduce Pb oral bioavailability while being beneficial for child nutritional health. However, the practical performance of various Fe compounds was not assessed. Here, based on mouse bioassays, ten Fe compounds applied to diets (100-800 mg Fe kg
Correlation between lead speciation and inhalation bioaccessibility using two different simulated lung fluids
Publisher: Elsevier BV
Date: 08-2020
Localization and speciation of arsenic and trace elements in rice tissues
Publisher: Elsevier BV
Date: 07-2009
DOI: 10.1016/J.CHEMOSPHERE.2009.03.010
Abstract: The consumption of arsenic (As) contaminated rice is an important exposure route for humans in countries where rice cultivation employs As contaminated irrigation water. Arsenic toxicity and mobility are a function of its chemical-speciation. The distribution and identification of As in the rice plant are hence necessary to determine the uptake, transformation and potential risk posed by As contaminated rice. In this study we report on the distribution and chemical-speciation of As in rice (Oryza sativa Quest) by X-ray fluorescence (XRF) and X-ray absorption near edge structure (XANES) measurements of rice plants grown in As contaminated paddy water. Investigations of muXRF images from rice tissues found that As was present in all rice tissues, and its presence correlated with the presence of iron at the root surface and copper in the rice leaf. X-ray absorption near edge structure analysis of rice tissues identified that inorganic As was the predominant form of As in all rice tissues studied, and that arsenite became increasingly dominant in the aerial portion of the rice plant.
Impact of precursors and bioaccessibility on childhood PFAS exposure from house dust
Publisher: Elsevier BV
Date: 09-2023
A Review of Immobilisation-Based Remediation of Per- and Poly-Fluoroalkyl Substances (PFAS) in Soils
Publisher: Springer Science and Business Media LLC
Date: 28-09-2021
Leaching and In Vivo Bioavailability of Antimony in PET Bottled Beverages
Publisher: American Chemical Society (ACS)
Date: 05-11-2021
Bioremediation of high molecular weight polycyclic aromatic hydrocarbons: a review of the microbial degradation of benzo[a]pyrene
Publisher: Elsevier BV
Date: 2000
Applying fungicide on earthworms: Biochemical effects of Eisenia fetida exposed to fluoxastrobin in three natural soils
Publisher: Elsevier BV
Date: 03-2020
DOI: 10.1016/J.ENVPOL.2019.113666
Abstract: Fluoxastrobin is one of the most widely used strobilurin fungicides, however, application of the fungicides may result in soil residues leading to environmental damage including oxidative stress and damage to sentinel organisms (i.e. earthworms). While this has been demonstrated in artificial soil, the biochemical response of Eisenia fetida exposed to fluoxastrobin in natural soils is unclear. This study utilized three typical natural soils (fluvo-aquic soils, red clay, and black soils) to evaluate the biochemical response of Eisenia fetida exposed to fluoxastrobin (0.1, 1.0, 2.5 mg/kg) including the production of reactive oxygen species, impact on three enzyme activities, lipid peroxidation, and 8-hydroxydeoxyguanosine after a 4-week exposure. The effects of fluoxastrobin on Eisenia fetida in different soils were assessed using an integrated biomarker response (IBR). The findings may be possible to state that the toxic effects of fluoxastrobin in artificial cannot exactly represent that in natural soils. Specifically, the fluoxastrobin subchronic toxicity was highest in red clay and lowest in black soil among the three natural soils. Furthermore, the 8-OHdG content was more sensitive to fluoxastrobin in all six environmental indicators of the present study.
Azasugar inhibitors as pharmacological chaperones for Krabbe disease
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5SC00754B
Abstract: Modified azasugar molecules have been synthesized and characterized as excellent pharmacological chaperone candidates to treat the neurodegenerative disorder Krabbe disease.
Determination of Cadmium Relative Bioavailability in Contaminated Soils and Its Prediction Using in Vitro Methodologies
Publisher: American Chemical Society (ACS)
Date: 07-06-2010
DOI: 10.1021/ES1006516
Abstract: In this study, cadmium (Cd) relative bioavailability in contaminated (n = 5) and spiked (n = 2) soils was assessed using an in vivo mouse model following administration of feed containing soil or Cd acetate (reference material) over a 15 day exposure period. Cadmium relative bioavailability varied depending on whether the accumulation of Cd in the kidneys, liver, or kidney plus liver was used for relative bioavailability calculations. When kidney plus liver Cd concentrations were used, Cd relative bioavailability ranged from 10.1 to 92.1%. Cadmium relative bioavailability was higher (14.4-115.2%) when kidney Cd concentrations were used, whereas lower values (7.2-76.5%) were derived when liver Cd concentrations were employed in calculations. Following in vivo studies, four in vitro methodologies (SBRC, IVG, PBET, and DIN), encompassing both gastric and intestinal phases, were assessed for their ability to predict Cd relative bioavailability. Pearson correlations demonstrated a strong linear relationship between Cd relative bioavailability and Cd bioaccessibility (0.62-0.91), however, stronger in vivo-in vitro relationships were observed when Cd relative bioavailability was calculated using kidney plus liver Cd concentrations. Whereas all in vitro assays could predict Cd relative bioavailability with varying degrees of confidence (r(2) = 0.348-0.835), large y intercepts were calculated for a number of in vitro assays which is undesirable for in vivo-in vitro predictive models. However, determination of Cd bioaccessibility using the intestinal phase of the PBET assay resulted in a small y intercept (5.14 slope =1.091) and the best estimate of in vivo Cd relative bioavailability (r(2) = 0.835).
Advances in trace metal bioavailability in soils, dust and sediments: Implications to ecological and human risks
Publisher: Elsevier BV
Date: 06-2022
In vivo and in vitro methods for evaluating soil arsenic bioavailability: relevant to human health risk assessment
Publisher: Informa UK Limited
Date: 17-02-2018
DOI: 10.1080/10937404.2018.1440902
Abstract: Arsenic (As) is the most frequently occurring contaminant on the priority list of hazardous substances, which lists substances of greatest public health concern to people living at or near U.S. National Priorities List site. Accurate assessment of human health risks from exposure to As-contaminated soils depends on estimating its bioavailability, defined as the fraction of ingested As absorbed across the gastrointestinal barrier and available for systemic distribution and metabolism. Arsenic bioavailability varies among soils and is influenced by site-specific soil physical and chemical characteristics and internal biological factors. This review describes the state-of-the science that supports our understanding of oral bioavailability of soil As, the methods that are currently being explored for estimating soil As relative bioavailability (RBA), and future research areas that could improve our prediction of the oral RBA of soil As in humans. The following topics are addressed: (1) As soil geochemistry (2) As toxicology (3) in vivo models for estimating As RBA (4) in vitro bioaccessibility methods and (5) conclusions and research needs.
Comparison of indigenous and exogenous microbial populations during slurry phase biodegradation of long-term hydrocarbon-contaminated soil
Publisher: Springer Science and Business Media LLC
Date: 10-06-2012
DOI: 10.1007/S10532-012-9563-8
Abstract: In this study, a number of slurry-phase strategies were trialled over a 42 day period in order to determine the efficacy of bioremediation for long-term hydrocarbon-contaminated soil (145 g kg(-1) C(10)-C(40)). The addition of activated sludge and nutrients to slurries (bioaugmentation) resulted in enhanced hydrocarbon removal (51.6 ± 8.5 %) compared to treatments receiving only nutrients (enhanced natural attenuation [ENA] 41.3 ± 6.4 %) or no amendments (natural attenuation no significant hydrocarbon removal, P < 0.01). This data suggests that the microbial community in the activated sludge inoculum contributed to the enhanced removal of hydrocarbons in ENA slurries. Microbial ersity in slurries was monitored using DGGE with dominant bands excised and sequenced for identification. Applying the different bioremediation strategies resulted in the formation of four distinct community clusters associated with the activated sludge (inoculum), bioaugmentation strategy at day 0, bioaugmentation strategy at weeks 2-6 and slurries with autoclaved sludge and nutrient additions (bioaugmentation negative control). While hydrocarbon-degrading bacteria genera (e.g. Aquabacterium and Haliscomenobacter) were associated with the hydrocarbon-contaminated soil, bioaugmentation of soil slurries with activated sludge resulted in the introduction of bacteria associated with hydrocarbon degradation (Burkholderiales order and Klebsiella genera) which presumably contributed to the enhanced efficacy for this slurry strategy.
Assessing Limitations for PAH Biodegradation in Long-Term Contaminated Soils Using Bioaccessibility Assays
Publisher: Springer Science and Business Media LLC
Date: 11-01-2013
Remediation of persistent organic pollutants using a novel two-phase soil washing biosorption process
Publisher: Springer Science and Business Media LLC
Date: 2003
Enhanced pitting resistance and antibacterial durability of Cu-bearing stainless steels via tailoring Cu distributions
Publisher: Elsevier BV
Date: 09-2023
A polyphasic approach for assessing the suitability of bioremediation for the treatment of hydrocarbon-impacted soil
Publisher: Elsevier BV
Date: 04-2013
DOI: 10.1016/J.SCITOTENV.2013.02.007
Abstract: Bioremediation strategies, though widely used for treating hydrocarbon-contaminated soil, suffer from lack of biodegradation endpoint accountability. To address this limitation, molecular approaches of alkB gene analysis and pyrosequencing were combined with chemical approaches of bioaccessibility and nutrient assays to assess contaminant degrading capacity and develop a strategy for endpoint biodegradation predictions. In long-term hydrocarbon-contaminated soil containing 10.3 g C10-C36 hydrocarbons kg(-1), 454 pyrosequencing detected the overrepresentation of potential hydrocarbon degrading genera such as Pseudomonas, Burkholderia, Mycobacterium and Gordonia whilst licons for PCR-DGGE were detected only with alkB primers targeting Pseudomonas. This indicated the presence of potential microbial hydrocarbon degradation capacity in the soil. Using non-exhaustive extraction methods of 1-propanol and HP-β-CD for hydrocarbon bioaccessibility assessment combined with biodegradation endpoint predictions with linear regression models, we estimated 33.7% and 46.7% hydrocarbon removal respectively. These predictions were validated in pilot scale studies using an enhanced natural attenuation strategy which resulted in a 46.4% reduction in soil hydrocarbon content after 320 days. When predicted biodegradation endpoints were compared to measured values, there was no significant difference (P=0.80) when hydrocarbon bioaccessibility was assessed with HP-β-CD. These results indicate that a combination of molecular and chemical techniques that inform microbial ersity, functionality and chemical bioaccessibility can be valuable tools for assessing the suitability of bioremediation strategies for hydrocarbon-contaminated soil.
Extraction and recovery of organochlorine pesticides from fungal mycelia
Publisher: Elsevier BV
Date: 2000
DOI: 10.1016/S0167-7012(99)00111-6
Abstract: An extraction method was developed to recover organochlorine pesticides (OCPs) associated with live and mercuric chloride-treated fungal mycelia. A Cladosporium sp. was inoculated into potato dextrose broth, DDT (90 mg/l) added and incubated for seven days. The combination of a microextraction procedure for aqueous-phase-associated DDT and a sonication extraction for mycelia-bound DDT, using dichloromethane as the extracting solvent, resulted in the recovery of 31-51% of added DDT. DDT recovery was increased to 62-65% by grinding the fungal mycelia before sonication. Alkali and nitric acid pretreatments were tested to increase the recovery of DDT associated with fungal mycelia, however, these treatments resulted in the production of unidentified DDT transformation products. Pretreating mycelia containing DDT in concentrated hydrochloric acid at 60 degrees C for 2, 4 and 6 h resulted in DDT recoveries of 90-91%, 99% and 101-102% respectively without the production of transformation products. When an OCP mixture (DDT, DDD and DDE) was added to fungal mycelia, between 89% and 96% of DDT, DDD and DDE were recovered from live cultures compared to 85-91% in mercuric chloride-treated cultures using the microextraction/hydrochloric acid pretreatment (60 degrees C/6 h) sonication extraction method.
Cadmium oral bioavailability is affected by calcium and phytate contents in food: Evidence from leafy vegetables in mice
Publisher: Elsevier BV
Date: 02-2022
Assessment of DDT Relative Bioavailability and Bioaccessibility in Historically Contaminated Soils Using an in Vivo Mouse Model and Fed and Unfed Batch in Vitro Assays
Publisher: American Chemical Society (ACS)
Date: 22-02-2012
DOI: 10.1021/ES203030Q
Abstract: In this study, DDTr (DDTr = DDT + DDD + DDE) relative bioavailability in historically contaminated soils (n = 7) was assessed using an in vivo mouse model. Soils or reference materials were administered to mice daily over a 7 day exposure period with bioavailability determined using DDTr accumulation in adipose, kidney, or liver tissues. Depending on the target tissue used for its calculation, some variability in DDTr relative bioavailability was observed however, it did not exceed 25% (range 2-25%). When DDTr bioaccessibility was determined using organic physiologically based extraction test (Org-PBET), unified BARGE method (UBM), and fed organic estimation human simulation test (FOREhST) in vitro assays, bioaccessibility was less than 4% irrespective of the assay utilized and the concentration of DDTr in the contaminated soil. Pearson correlations demonstrate a poor relationship between DDTr relative bioavailability and DDTr bioaccessibility (0.47, 0.38, and 0.28, respectively), illustrating the limitations of the static in vitro methods for predicting the dynamic processes of the mammalian digestive system for this hydrophobic organic contaminant.
Food influence on lead relative bioavailability in contaminated soils: Mechanisms and health implications
Publisher: Elsevier BV
Date: 09-2018
DOI: 10.1016/J.JHAZMAT.2018.06.034
Abstract: To determine the effects of dietary constituents on soil Pb oral bioavailability, Pb relative bioavailability (RBA) in 3 soils contaminated by zinc smelting (ZS), wire-rope production (WR), and metal mining (MM) was measured under fasted and fed states with 9 foods. Under fasted state, Pb-RBA was 84.4 ± 10.3, 82.6 ± 4.70, and 32.3 ± 1.10% for ZS, WR, and MM soils however, it decreased by 1.3-3.5 fold to 23.9-58.8, 25.6-49.9, and 14.8-24.2% under fed states with foods excluding Pb-RBA with egg in WR soil (97.3 ± 4.46%), and with cabbage and egg in MM soil (40.0 ± 8.62 and 44.4 ± 0.96%). In the presence of foods, egg and pork with significantly higher protein and fat contents leaded to the highest soil Pb-RBA (44.4-97.3%), while Pb-RBA determined with mineral-rich mouse feed was 1.6-7.9 fold lower (9.41-13.5%), suggesting high fat and protein foods tended to increase soil Pb-RBA, while high mineral diets decreased soil Pb-RBA. The increased Pb-RBA of MM soil with cabbage compared to fasted state was due to high organic content in cabbage, which could increase soil Pb solubility by inhibiting Fe and Pb co-precipitation in the intestine. For accurate assessment of health risks of contaminated soils, dietary influence on soil Pb-RBA should be considered.
Explosives: Fate, Dynamics, and Ecological Impact in Terrestrial and Marine Environments
Publisher: Springer New York
Date: 2007
DOI: 10.1007/978-0-387-69163-3_6
Abstract: An explosive or energetic compound is a chemical material that, under the influence of thermal or chemical shock, decomposes rapidly with the evolution of large amounts of heat and gas. Numerous compounds and compositions may be classified as energetic compounds however, secondary explosives, such as TNT, RDX, and HMX pose the largest potential concern to the environment because they are produced and used in defense in the greatest quantities. The environmental fate and potential hazard of energetic compounds in the environment is affected by a number of physical, chemical, and biological processes. Energetic compounds may undergo transformation through biotic or abiotic degradation. Numerous organisms have been isolated with the ability to degrade/transform energetic compounds as a sole carbon source, sole nitrogen source, or through cometabolic processes under aerobic or anaerobic conditions. Abiotic processes that lead to the transformation of energetic compounds include photolysis, hydrolysis, and reduction. The products of these reactions may be further transformed by microorganisms or may bind to soil/sediment surfaces through covalent binding or polymerization and oligomerization reactions. Although considerable research has been performed on the fate and dynamics of energetic compounds in the environment, data are still gathering on the impact of TNT, RDX, and HMX on ecological receptors. There is an urgent need to address this issue and to direct future research on expanding our knowledge on the ecological impact of energetic transformation products. In addition, it is important that energetic research considers the concept of bioavailability, including factors influencing soil/sediment aging, desorption of energetic compounds from varying soil and sediment types, methods for modeling redicting energetic bioavailability, development of biomarkers of energetic exposure or effect, and the impact of bioavailability on ecological risk assessment.
Development of a two-phase cosolvent washing-fungal biosorption process for the remediation of DDT-contaminated soil
Publisher: Springer Science and Business Media LLC
Date: 2003
Relating soil geochemical properties to arsenic bioaccessibility through hierarchical modeling
Publisher: Informa UK Limited
Date: 16-01-2018
Chapter 1 Chemical bioavailability in terrestrial environments
Publisher: Elsevier
Date: 2008
Ecotoxicity of neutral red (dye) and its environmental applications
Publisher: Elsevier BV
Date: 12-2015
DOI: 10.1016/J.ECOENV.2015.07.028
Abstract: Neutral red (NR) is a synthetic phenazine with promising prospect in environmental biotechnology as an electron shuttle. Recently, NR injections into coal seam associated groundwater in Australia (final dissolved NR concentration: 8 µM ± 0.2) were shown to increase methanogenesis up to ten-fold. However, information about NR toxicity to ecological receptors is sorely lacking. The main aim of this study was to investigate the concentration dependent toxicity of NR in microorganisms and plants. Acute toxicity of NR was determined by the modified Microtox™ assay. Microbial viability was determined using Escherichia coli and Bacillus subtilis. Germination and early growth of plants was studied using Lactuca sativa, Daucus carota, Allium cepa and an Australian native Themeda triandra. Lastly, mutagenicity of the coal seam associated groundwater was assessed using the Ames test. The EC50 of acute NR toxicity was determined to be 0.11 mM. The EC50 of microbial viability was between 1 and 7.1mM NR. Among the concentrations tested, only 0.01, 0.10 and 100mM of NR significantly affected (p<0.001) germination of L. sativa. The EC50 for root elongation in seeds was between 1.2 and 35.5mM NR. Interestingly, root elongation in seeds was significantly stimulated (p<0.001) between 0.25 and 10mM NR, showing a hormetic effect. A significant increase in mutagenicity was only observed in one of the three wells tested. The results suggest that the average dissolved NR concentration (8 µM ± 0.2) deployed in the field trial at Lithgow State Coal Mine, Australia, appears not to negatively impact the ecological receptors tested in this study.
Plumbojarosite Remediation of Soil Affects Lead Speciation and Elemental Interactions in Soil and in Mice Tissues
Publisher: American Chemical Society (ACS)
Date: 22-11-2021
Arsanilic acid contributes more to total arsenic than roxarsone in chicken meat from Chinese markets
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.JHAZMAT.2019.121178
Abstract: Organoarsenicals have been used in poultry production for years, however, studies focused on roxarsone (ROX), with little attention to p-arsanilic acid (ASA). We assessed arsenic (As) concentration and speciation in chicken meat collected from 10 cities in China. The geometric mean for total As in 249 paired raw and cooked s les was 4.85 and 7.27 μg kg
Straw decreased N2O emissions from flooded paddy soils via altering denitrifying bacterial community compositions and soil organic carbon fractions
Publisher: Oxford University Press (OUP)
Date: 17-03-2020
Abstract: Straw return is widely applied to increase soil fertility and soil organic carbon storage. However, its effect on N2O emissions from paddy soil and the associated microbial mechanisms are still unclear. In this study, wheat straw was amended to two paddy soils (2% w/w) from Taizhou (TZ) and Yixing (YX), China, which were flooded and incubated for 30 d. Real-time PCR and Illumina sequencing were used to characterize changes in denitrifying functional gene abundance and denitrifying bacterial communities. Compared to unamended controls, straw addition significantly decreased accumulated N2O emissions in both TZ (5071 to 96 mg kg–1) and YX (1501 to 112 mg kg–1). This was mainly due to reduced N2O production with decreased abundance of major genera of nirK and nirS-bacterial communities and reduced nirK and nirS gene abundances. Further analyses showed that nirK-, nirS- and nosZ-bacterial community composition shifted mainly along the easily oxidizable carbon (EOC) arrows following straw amendment among four different soil organic carbon fractions, suggesting that increased EOC was the main driver of alerted denitrifying bacterial community composition. This study revealed straw return suppressed N2O emission via altering denitrifying bacterial community compositions and highlighted the importance of EOC in controlling denitrifying bacterial communities.
Bioaccessibility and human health risk assessment of metal(loid)s in soil from an e-waste open burning site in Agbogbloshie, Accra, Ghana
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.CHEMOSPHERE.2019.124909
Abstract: Environmental pollution and human health issues due to unrestricted electronic waste (e-waste) recycling activities have been reported at a number of locations. Among different e-waste recycling techniques, open burning of e-waste releases erse metal(loid)s into the environment, which has aroused concern worldwide. In human health risk assessments (HHRAs), oral ingestion of soil can be a major route of exposure to many immobile soil contaminants. In vitro assays are currently being developed and validated to avoid overestimation of pollutants absorbed by the human body when calculating total pollutant concentrations in HHRAs. In this study, Cu, As, Cd, Sb, and Pb bioaccessibility in polluted soils (n = 10) from e-waste open burning sites at Agbogbloshie in Accra, Ghana, was assessed using an in vitro assay, the physiologically based extraction test. A bioaccessibility-corrected HHRA was then conducted to estimate the potential health risks to local inhabitants. The in vitro results (%) varied greatly among the different metal(loid)s (Cu: 1.3-60, As: 1.3-40, Cd: 4.2-67, Sb: 0.7-85, Pb: 4.1-57), and also showed marked variance between the gastric phase and small intestinal phase. The particle sizes of soil s les and chemical forms of metal(loid)s also influenced bioaccessibility values. Using these bioaccessibility values, both the hazard index and carcinogenic risk were calculated. The hazard index was above the threshold value (>1) for 5/10 s les, indicating a potential health risk to local inhabitants.
Modelling polycyclic aromatic hydrocarbon bioavailability in historically contaminated soils with six in-vitro chemical extractions and three earthworm ecotypes
Publisher: Elsevier BV
Date: 11-2022
DOI: 10.1016/J.SCITOTENV.2022.157265
Abstract: Accurate prediction of organic contaminant bioavailability for risk assessment in ecological applications is hindered by limited validation on relevant bioassay species. Here, six in-vitro chemical extraction methods (butanol, non-buffered and buffered hydroxypropyl-β-cyclodextrin (HPCD, Buf-HPCD), Tenax, potassium persulfate oxidation, polyoxymethylene solid phase extraction (POM)) were tested for PAH bioaccumulation prediction in three earthworm ecotypes with dissimilar exposures, Amynthas sp., Eisenia fetida, and Lumbricus terrestris, in historically contaminated soils from manufactured gas plant (MGP) sites. Extractions were compared directly and modelled in a calculation approach using equilibrium partitioning theory (EqPT) with a novel combination of different organic carbon/octanol-water partitioning parameters (K
Relationship between Pb relative bioavailability and bioaccessibility in phosphate amended soil: Uncertainty associated with predicting Pb immobilization efficacy using in vitro assays
Publisher: Elsevier BV
Date: 10-2019
In vivo relative bioavailability of perfluorooctanoic acid (PFOA) and its alternative hexafluoropropylene oxide trimer acid (HFPO-TA): Influence of food and mechanisms exploration
Publisher: Elsevier BV
Date: 10-2022
DOI: 10.1016/J.ENVINT.2022.107450
Abstract: The extensive use of perfluorooctanoic acid (PFOA), and its substitute hexafluoropropylene oxide trimer acid (HFPO-TA) has resulted in their frequent detection in environmental s les. However, little is known of their bioavailability via oral ingestion and the influence of food co-ingestion on absorption. Here, the relative bioavailability (RBA) of PFOA and HFPO-TA in soil was measured using an in vivo mouse model in the presence of food with different nutritional statuses (n = 11). PFOA and HFPO-TA RBA in soil was variable depending on nutrient co-administration, ranging from 29.8-95.5 % and 43.9-68.0 %, respectively. For both PFOA and HFPO-TA, a significantly negative correlation was observed between RBA and protein content in food (r = 0.57-0.72), while a positive correlation was observed with carbohydrate content (r = 0.51-0.57). Mechanistic studies showed that protein in food decreased PFOA and HFPO-TA RBA by down-regulating the expression of fatty acid binding protein 1 (FABP1) and up-regulating the expression of multidrug resistance associated protein 4 (Mrp4) in the liver, which are responsible for the absorption and efflux of PFOA and HFPO-TA. Dietary carbohydrates promoted albumin synthesis and up-regulated FABP1 expression thereby enhancing absorption and increasing PFOA and HFPO-TA RBA. This study provides an insight into potential dietary strategies for reducing exposure to per- and polyfluoroalkyl substances.
Application of soil amendments for reducing PFAS leachability and bioavailability
Publisher: Elsevier BV
Date: 08-2022
DOI: 10.1016/J.ENVPOL.2022.119498
Abstract: In this study, changes in PFAS leachability and bioavailability were determined following the application of RemBind®100 (R100) and RemBind®300 (R300 1-10% w/w) to PFAS-contaminated soil (Ʃ
Methodological factors influencing inhalation bioaccessibility of metal(loid)s in PM 2.5 using simulated lung fluid
Publisher: Elsevier BV
Date: 10-2018
Analysis of microbial hydrocarbon degradation using TLC-FID
Publisher: Elsevier BV
Date: 05-1995
Assessment of in vitro lead bioaccessibility in house dust and its relationship to in vivo lead relative bioavailability
Publisher: American Chemical Society (ACS)
Date: 08-07-2014
DOI: 10.1021/ES501899J
Abstract: House dust s les containing 25-738 mg of Pb kg(-1) from 15 cities in China were assessed for in vitro Pb bioaccessibility and in vivo Pb relative bioavailability. On the basis of stable Pb isotope ratios, the Pb in dust s les mainly originated from coal combustion. Lead bioaccessibility was determined using gastric (GP) and intestinal phase (IP) of solubility bioaccessibility research consortium (SBRC), in vitro gastrointestinal (IVG), Deutsches Institut für Normunge.V. (DIN), and physiologically based extraction test methods (PBET), while Pb relative bioavailability (RBA) was determined using a mouse blood model. Lead bioaccessibility in 24 house dust s les varied significantly (23-99%) depending on the methods. Values from the IP were considerably lower than those from the GP because of the co-precipitation of Pb with iron and re-adsorption onto the dust matrix. The SBRC assay with lower GP pH produced higher Pb bioaccessibility because of enhanced Pb dissolution. When compared to mouse blood data using 12 dust s les (29-60%), SBRC-GP and DIN-GP data were correlated with Pb RBA with r(2) values of 0.68 and 0.85 and intercepts 3.15 and 17.4, respectively. Overall, SBRC-GP had potential to predict Pb RBA in dust s les. However, our data suggested that more research is needed to develop a valid in vitro method for predicting Pb RBA in house dust.
New measures in 2021 to increase the quality and reputation of the Critical Review in Environmental Science and Technology (CREST) journal
Publisher: Informa UK Limited
Date: 30-05-2021
Comparison of mouse and swine bioassays for determination of soil arsenic relative bioavailability
Publisher: Elsevier BV
Date: 2018
Desorption of DDT from a Contaminated Soil using Cosolvent and Surfactant Washing in Batch Experiments
Publisher: Springer Science and Business Media LLC
Date: 2004
Antagonistic effects of cadmium on lead accumulation in pregnant and non-pregnant mice
Publisher: Elsevier BV
Date: 2012
DOI: 10.1016/J.JHAZMAT.2011.11.016
Abstract: People are frequently exposed to combinations of contaminants but there is a paucity of data on the effects of mixed contaminants at low doses. This study investigated the influence of cadmium (Cd) on lead (Pb) accumulation in pregnant and non-pregnant mice following exposure to contaminated soil. Exposure to Pb from contaminated soils increased Pb accumulation in both pregnant and non-pregnant mice compared to unexposed control animals (pregnant and non-pregnant). Lead accumulation in the liver and kidneys of exposure pregnant mice (40 ± 15 mg Pb kg(-1)) was significantly higher (P<0.05) than concentrations detected in control pregnant mice (<1 mg Pb kg(-1)). The presence of Cd in contaminated soil had a major effect on the Pb and Fe accumulation in the kidneys and liver, respectively. This study shows that Pb uptake is mediated by the presence of Cd in the co-contaminated soil and demonstrates that further research is required to investigate the influence of co-contaminants on human exposure at sub-chronic concentrations.
Predicting oral relative bioavailability of arsenic in soil from in vitro bioaccessibility
Publisher: Informa UK Limited
Date: 16-02-2016
DOI: 10.1080/15287394.2015.1134038
Abstract: Several investigations have been conducted to develop in vitro bioaccessibility (IVBA) assays that reliably predict in vivo oral relative bioavailability (RBA) of arsenic (As). This study describes a meta-regression model relating soil As RBA and IVBA that is based upon data combined from previous investigations that examined the relationship between As IVBA and RBA when IVBA was determined using an extraction of soil in 0.4 M glycine at pH 1.5. Data used to develop the model included paired IVBA and RBA estimates for 83 soils from various types of sites such as mining, smelting, and pesticide or herbicide application. The following linear regression model accounted for 87% of the observed variance in RBA (R(2) = .87): RBA(%) = 0.79 × IVBA(%) + 3. This regression model is more robust than previously reported models because it includes a larger number of soil s les, and also accounts for variability in RBA and IVBA measurements made on s les collected from sites contaminated with different As sources and conducted in different labs that have utilized different experimental models for estimating RBA.
Inhalation bioaccessibility of PAHs in PM2.5: Implications for risk assessment and toxicity prediction
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.SCITOTENV.2018.08.246
Abstract: In this study, 46 PM
Metabolite repression inhibits degradation of benzo[a]pyrene and dibenz[a,h]anthracene by Stenotrophomonas maltophilia VUN 10,003
Publisher: Oxford University Press (OUP)
Date: 02-2002
Abstract: Large inocula of Stenotrophomonas maltophilia VUN 10,003 were used to investigate bacterial degradation of benzo[a]pyrene and dibenz[a,h]anthracene. Although strain VUN 10,003 was capable of degrading 10-15 mg (-1) of the five-ring compounds in the presence of pyrene after 63 days, further addition of pyrene after degradation of the five-ring polycyclic aromatic hydrocarbons (PAHs) ceased did not stimulate significant decreases in the concentration of benzo[a]pyrene or dibenz[a,h]anthracene. However, pyrene was degraded to undetectable levels 21 days after its addition. The amount of benzo[a]pyrene and dibenz[a,h]anthracene degraded by strain VUN 10,003 was not affected by the initial concentration of the compounds when tested at 25-100 mg l(-1), by the accumulation of by-products from pyrene catabolism or a loss of ability by the cells to catabolise benzo[a]pyrene or dibenz[a,h]anthracene. Metabolite or by-product repression was suspected to be responsible for the inhibition: By-products from the degradation of the five-ring compounds inhibited their further degradation.
Predicting Arsenic Relative Bioavailability Using Multiple in Vitro Assays: Validation of in Vivo–in Vitro Correlations
Publisher: American Chemical Society (ACS)
Date: 28-08-2015
Abstract: In this study, previously established arsenic (As) in vivo-in vitro correlations (IVIVC) were assessed for their validity using an independent data set comprising As relative bioavailability (RBA) and bioaccessibility values for 13 herbicide- and mine-impacted soils. The validation process established the correlation between As RBA (swine model) and bioaccessibility (five in vitro assays), determined whether correlations differed significantly from previous relationships and assessed model bias and error. The capacity of in vitro assays to predict As RBA was demonstrated by the strength of IVIVC goodness of fit ranged from 0.53 (DIN-I) to 0.74 (UBM-I). When compared to previous IVIVC (Juhasz et al. Environ. Sci. Technol. 2009 , 43 , 9487 Juhasz et al. J. Hazard. Mater. 2011 , 197 , 161 ), there was no significant difference (P < 0.01) in the slope and y-intercept for IVG-G, UBM-G, and UBM-I indicating the consistency of these assays for predicting As RBA. However, variability in model bias and prediction error was observed with significantly lower (P < 0.01) error determined for IVG-G suggesting that As RBA predictions using IVG-G may be more robust compared to UBM-G and UBM-I. In contrast, differences in the slope and/or y-intercept were observed for SBRC-I, IVG-I, PBET-G, PBET-I, DIN-G, and DIN-I suggesting that these methodologies may not be suitable for predicting As RBA.
Applying Cadmium Relative Bioavailability to Assess Dietary Intake from Rice to Predict Cadmium Urinary Excretion in Nonsmokers
Publisher: American Chemical Society (ACS)
Date: 07-06-2017
Abstract: Dietary Cd intake is often estimated without considering Cd bioavailability. Measured urinary Cd for a cohort of 119 nonsmokers with rice as a staple was compared to predicted values from rice-Cd intake with and without considering Cd relative bioavailability (RBA) in rice based on a steady state mouse kidney bioassay and toxicokinetic model. The geometric mean (GM) of urinary Cd and β
Biofilms Enhance the Adsorption of Toxic Contaminants on Plastic Microfibers under Environmentally Relevant Conditions
Publisher: American Chemical Society (ACS)
Date: 21-06-2021
Plumbojarosite formation in contaminated soil to mitigate childhood exposure to lead, arsenic and antimony
Publisher: Elsevier BV
Date: 09-2021
Related Organisations
Related Funding Activities
Synthetic Phenasines For Enhanced Biogas Production From Renewable And Non-renewable Resources
Start Date: 2014
End Date: 2016
Funder: Australian Research Council
View Funded ActivityFunctional Characterisation Of Contaminant-nanoparticle Associations
Start Date: 2011
End Date: 2013
Funder: Australian Research Council
View Funded ActivityAssessment Of Bentonites As Remediating Agents For Metal Contaminated Soils Using Innovative Bioavailability Reduction Technology
Start Date: 2003
End Date: 2006
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP110103174
Start Date: 09-2011
End Date: 08-2015
Amount: $300,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP140100621
Start Date: 2014
End Date: 04-2017
Amount: $330,000.00
Funder: Australian Research Council
View Funded ActivityLinkage Projects - Grant ID: LP0347301
Start Date: 06-2003
End Date: 06-2006
Amount: $290,000.00
Funder: Australian Research Council
View Funded Activity