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Stuart L. Simpson
CSIRO Land and Water, Lucas Heights, NSW 2234, Australia

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Journal article
Published: 23 June 2021 in Pathogens
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In this study, we investigated the occurrence of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) RNA in primary influent (n = 42), secondary effluent (n = 24) and tertiary treated effluent (n = 34) collected from six wastewater treatment plants (WWTPs A–F) in Virginia (WWTP A), Florida (WWTPs B, C, and D), and Georgia (WWTPs E and F) in the United States during April–July 2020. Of the 100 wastewater samples analyzed, eight (19%) untreated wastewater samples collected from the primary influents contained SARS-CoV-2 RNA as measured by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) assays. SARS-CoV-2 RNA were detected in influent wastewater samples collected from WWTP A (Virginia), WWTPs E and F (Georgia) and WWTP D (Florida). Secondary and tertiary effluent samples were not positive for SARS-CoV-2 RNA indicating the treatment processes in these WWTPs potentially removed SARS-CoV-2 RNA during the secondary and tertiary treatment processes. However, further studies are needed to understand the log removal values (LRVs) and transmission risks of SARS-CoV-2 RNA through analyzing wastewater samples from a wider range of WWTPs.

ACS Style

Samendra Sherchan; Shalina Shahin; Jeenal Patel; Lauren Ward; Sarmila Tandukar; Sital Uprety; Bradley Schmitz; Warish Ahmed; Stuart Simpson; Pradip Gyawali. Occurrence of SARS-CoV-2 RNA in Six Municipal Wastewater Treatment Plants at the Early Stage of COVID-19 Pandemic in The United States. Pathogens 2021, 10, 798 .

AMA Style

Samendra Sherchan, Shalina Shahin, Jeenal Patel, Lauren Ward, Sarmila Tandukar, Sital Uprety, Bradley Schmitz, Warish Ahmed, Stuart Simpson, Pradip Gyawali. Occurrence of SARS-CoV-2 RNA in Six Municipal Wastewater Treatment Plants at the Early Stage of COVID-19 Pandemic in The United States. Pathogens. 2021; 10 (7):798.

Chicago/Turabian Style

Samendra Sherchan; Shalina Shahin; Jeenal Patel; Lauren Ward; Sarmila Tandukar; Sital Uprety; Bradley Schmitz; Warish Ahmed; Stuart Simpson; Pradip Gyawali. 2021. "Occurrence of SARS-CoV-2 RNA in Six Municipal Wastewater Treatment Plants at the Early Stage of COVID-19 Pandemic in The United States." Pathogens 10, no. 7: 798.

Journal article
Published: 23 February 2021 in Science of The Total Environment
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Guideline values for perfluorooctane sulfonic acid (PFOS) in estuarine/marine sediments have been derived based on determinations of water quality guideline values, using data for toxicity to benthic biota, and a consideration of partitioning between sediments and overlying waters. Measured and literature chronic toxicity data for PFOS to 11 benthic estuarine/marine species were used in a species sensitivity distribution yielding 99% and 95% species protection concentrations of 6 and 25 μg PFOS/L respectively. The lowest dissolved PFOS concentrations causing toxicity were 0.28 mg/L (LOEC) to 28-day bivalve growth, 0.49 mg/L to survival and growth of juvenile amphipods, and 1.2 and 0.9 (0.7–1.6) mg/L as a LOEC and EC10 values for 10-day amphipod reproduction, respectively. A strong relationship (Kd) existed for PFOS-partitioning between sediment and overlying water concentrations and organic carbon (0.1 to 5.6% OC), with a Kd range of 16 to 150 L/kg. A conservative Kd value of 10 was used to derive a benthic sediment PC99 screening value of 60 μg/kg PFOS (for 1% OC) representing a low risk to benthic organisms in estuarine/marine environments from direct toxicity and secondary poisoning. No toxicity from PFOS occurred to benthic algae, copepod, or crab species in exposures with 170–180 mg/kg in spiked-sediments and 0.8–2 mg/L in the overlying waters. Toxicity of PFOS to amphipod survival and reproduction occurred and was attributed to dissolved rather than dietary exposure. The derived sediment quality screening value was used to assess a range field-collected sediments. These sediments were dominated by PFOS, with 4–15 μg/kg (1% OC) at estuarine/marine sites, being below the screening value. None of the sediments caused chronic toxicity to benthic algae, amphipod, and copepod tests, where the most highly PFAS-contaminated field-collected sediment had 0.18 mg/kg PFOS and resulted in 0.0014 mg/L PFOS in the overlying waters during tests.

ACS Style

Stuart L. Simpson; Yawen Liu; David A. Spadaro; Xinhong Wang; Rai S. Kookana; Graeme E. Batley. Chronic effects and thresholds for estuarine and marine benthic organism exposure to perfluorooctane sulfonic acid (PFOS)-contaminated sediments: Influence of organic carbon and exposure routes. Science of The Total Environment 2021, 776, 146008 .

AMA Style

Stuart L. Simpson, Yawen Liu, David A. Spadaro, Xinhong Wang, Rai S. Kookana, Graeme E. Batley. Chronic effects and thresholds for estuarine and marine benthic organism exposure to perfluorooctane sulfonic acid (PFOS)-contaminated sediments: Influence of organic carbon and exposure routes. Science of The Total Environment. 2021; 776 ():146008.

Chicago/Turabian Style

Stuart L. Simpson; Yawen Liu; David A. Spadaro; Xinhong Wang; Rai S. Kookana; Graeme E. Batley. 2021. "Chronic effects and thresholds for estuarine and marine benthic organism exposure to perfluorooctane sulfonic acid (PFOS)-contaminated sediments: Influence of organic carbon and exposure routes." Science of The Total Environment 776, no. : 146008.

Journal article
Published: 26 November 2020 in Environmental Research
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We monitored the concentration of indicator viruses crAssphage and pepper mild mottle virus (PMMoV) and human pathogen adenovirus (HAdV) in influent from a wastewater treatment plant in Brisbane, Australia in 1-h and 24-h composite samples. Over three days of sampling, the mean concentration of crAssphage gene copies (GC)/mL in 24-h composite samples did not differ significantly (p = 0.72-0.92), while for PMMoV GC/mL (p value range: 0.0002–0.0321) and HAdV GC/mL (p value range: 0.0028–0.0068) significant differences in concentrations were observed on one day of sampling compared to the other two. For all three viruses, the variation observed in 1-h composite samples was greater than the variation observed in 24-h composite samples. For crAssphage, in 54.1% of 1-h composite samples, the concentration was less than that observed in 24-h composite samples; whereas for PMMoV and HAdV the concentration was less in 79.2 and 70.9% of 1-h composite samples, respectively, compared to the relevant 24-h composite samples. Similarly, the concentration of crAssphage in 1-h compared to 24-h composite samples did not differ (p = 0.1082) while the concentrations of PMMoV (p < 0.0001) and HAdV (p < 0.0001) in 1-h composite samples were significantly different from 24-h composite samples. These results suggest that 24-h composite samples offer increased analytical sensitivity and decreased variability compared to 1-h composite samples when monitoring wastewater, especially for pathogenic viruses with low infection rates within a community. Thus, for wastewater-based epidemiology applications, 24-h composite samples are less likely to produce false negative results and erroneous public health information.

ACS Style

Warish Ahmed; Aaron Bivins; Paul M. Bertsch; Kyle Bibby; Pradip Gyawali; Samendra P. Sherchan; Stuart L. Simpson; Kevin V. Thomas; Rory Verhagen; Masaaki Kitajima; Jochen F. Mueller; Asja Korajkic. Intraday variability of indicator and pathogenic viruses in 1-h and 24-h composite wastewater samples: Implications for wastewater-based epidemiology. Environmental Research 2020, 193, 110531 .

AMA Style

Warish Ahmed, Aaron Bivins, Paul M. Bertsch, Kyle Bibby, Pradip Gyawali, Samendra P. Sherchan, Stuart L. Simpson, Kevin V. Thomas, Rory Verhagen, Masaaki Kitajima, Jochen F. Mueller, Asja Korajkic. Intraday variability of indicator and pathogenic viruses in 1-h and 24-h composite wastewater samples: Implications for wastewater-based epidemiology. Environmental Research. 2020; 193 ():110531.

Chicago/Turabian Style

Warish Ahmed; Aaron Bivins; Paul M. Bertsch; Kyle Bibby; Pradip Gyawali; Samendra P. Sherchan; Stuart L. Simpson; Kevin V. Thomas; Rory Verhagen; Masaaki Kitajima; Jochen F. Mueller; Asja Korajkic. 2020. "Intraday variability of indicator and pathogenic viruses in 1-h and 24-h composite wastewater samples: Implications for wastewater-based epidemiology." Environmental Research 193, no. : 110531.

Journal article
Published: 27 August 2020 in Environmental Research
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Wastewater-based epidemiology (WBE) demonstrates potential for COVID-19 community transmission monitoring; however, data on the stability of SARS-CoV-2 RNA in wastewater are needed to interpret WBE results. The decay rates of RNA from SARS-CoV-2 and a potential surrogate, murine hepatitis virus (MHV), were investigated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in untreated wastewater, autoclaved wastewater, and dechlorinated tap water stored at 4, 15, 25, and 37 °C. Temperature, followed by matrix type, most greatly influenced SARS-CoV-2 RNA first-order decay rates (k). The average T90 (time required for 1-log10 reduction) of SARS-CoV-2 RNA ranged from 8.04 to 27.8 days in untreated wastewater, 5.71 to 43.2 days in autoclaved wastewater, and 9.40 to 58.6 days in tap water. The average T90 for RNA of MHV at 4 to 37 °C ranged from 7.44 to 56.6 days in untreated wastewater, 5.58–43.1 days in autoclaved wastewater, and 10.9 to 43.9 days in tap water. There was no statistically significant difference between RNA decay of SARS-CoV-2 and MHV; thus, MHV is suggested as a suitable persistence surrogate. Decay rate constants for all temperatures were comparable across all matrices for both viral RNAs, except in untreated wastewater for SARS-CoV-2, which showed less sensitivity to elevated temperatures. Therefore, SARS-CoV-2 RNA is likely to persist long enough in untreated wastewater to permit reliable detection for WBE application.

ACS Style

Warish Ahmed; Paul M. Bertsch; Kyle Bibby; Eiji Haramoto; Joanne Hewitt; Flavia Huygens; Pradip Gyawali; Asja Korajkic; Shane Riddell; Samendra P. Sherchan; Stuart L. Simpson; Kwanrawee Sirikanchana; Erin M. Symonds; Rory Verhagen; Seshadri S. Vasan; Masaaki Kitajima; Aaron Bivins. Decay of SARS-CoV-2 and surrogate murine hepatitis virus RNA in untreated wastewater to inform application in wastewater-based epidemiology. Environmental Research 2020, 191, 110092 -110092.

AMA Style

Warish Ahmed, Paul M. Bertsch, Kyle Bibby, Eiji Haramoto, Joanne Hewitt, Flavia Huygens, Pradip Gyawali, Asja Korajkic, Shane Riddell, Samendra P. Sherchan, Stuart L. Simpson, Kwanrawee Sirikanchana, Erin M. Symonds, Rory Verhagen, Seshadri S. Vasan, Masaaki Kitajima, Aaron Bivins. Decay of SARS-CoV-2 and surrogate murine hepatitis virus RNA in untreated wastewater to inform application in wastewater-based epidemiology. Environmental Research. 2020; 191 ():110092-110092.

Chicago/Turabian Style

Warish Ahmed; Paul M. Bertsch; Kyle Bibby; Eiji Haramoto; Joanne Hewitt; Flavia Huygens; Pradip Gyawali; Asja Korajkic; Shane Riddell; Samendra P. Sherchan; Stuart L. Simpson; Kwanrawee Sirikanchana; Erin M. Symonds; Rory Verhagen; Seshadri S. Vasan; Masaaki Kitajima; Aaron Bivins. 2020. "Decay of SARS-CoV-2 and surrogate murine hepatitis virus RNA in untreated wastewater to inform application in wastewater-based epidemiology." Environmental Research 191, no. : 110092-110092.

Journal article
Published: 14 July 2020 in Journal of Travel Medicine
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Background Wastewater-based epidemiology (WBE) for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be an important source of information for coronavirus disease 2019 (COVID-19) management during and after the pandemic. Currently, governments and transportation industries around the world are developing strategies to minimise SARS-CoV-2 transmission associated with resuming activity. This study investigated the possible use of SARS-CoV-2 RNA wastewater surveillance from airline and cruise ship sanitation systems and its potential use as a COVID-19 public health management tool. Methods Airline and cruise ship wastewater samples (n = 21) were tested for SARS-CoV-2 RNA using two virus concentration methods, adsorption-extraction by electronegative membrane (n = 13) and ultrafiltration by Amicon (n = 8), and five assays using reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR) and RT-droplet digital PCR (RT-ddPCR). Representative amplicons from positive samples were sequenced to confirm assay specificity. Results SARS-CoV-2 RNA was detected in samples from both aircraft and cruise ship wastewater; however, concentrations were near the assay limit of detection. The analysis of multiple replicate samples and use of multiple RT-qPCR and/or RT-ddPCR assays increased detection sensitivity and minimised false-negative results. Representative amplicons were confirmed for the correct PCR product by sequencing. However, differences in sensitivity were observed among assays and concentration methods. Conclusions The study indicates that surveillance of wastewater from large transport vessels with their own sanitation systems has potential as a complementary data source to prioritize clinical testing and contact tracing among disembarking passengers. Importantly, sampling methods and molecular assays must be further optimized to maximize sensitivity. The potential for false negatives by both wastewater testing and clinical swab testing suggests that the two strategies could be employed together to maximize the probability of detecting SARS-CoV-2 infections amongst passengers.

ACS Style

Warish Ahmed; Paul M Bertsch; Nicola Angel; Kyle Bibby; Aaron Bivins; Leanne Dierens; Janette Edson; John Ehret; Pradip Gyawali; Kerry A Hamilton; Ian Hosegood; Philip Hugenholtz; Guangming Jiang; Masaaki Kitajima; Homa T Sichani; Jiahua Shi; Katja Shimko; Stuart L Simpson; Wendy J M Smith; Erin M Symonds; Kevin V Thomas Dsc; Rory Verhagen; Julian Zaugg; Jochen F Mueller. Detection of SARS-CoV-2 RNA in commercial passenger aircraft and cruise ship wastewater: a surveillance tool for assessing the presence of COVID-19 infected travelers. Journal of Travel Medicine 2020, 27, 1 .

AMA Style

Warish Ahmed, Paul M Bertsch, Nicola Angel, Kyle Bibby, Aaron Bivins, Leanne Dierens, Janette Edson, John Ehret, Pradip Gyawali, Kerry A Hamilton, Ian Hosegood, Philip Hugenholtz, Guangming Jiang, Masaaki Kitajima, Homa T Sichani, Jiahua Shi, Katja Shimko, Stuart L Simpson, Wendy J M Smith, Erin M Symonds, Kevin V Thomas Dsc, Rory Verhagen, Julian Zaugg, Jochen F Mueller. Detection of SARS-CoV-2 RNA in commercial passenger aircraft and cruise ship wastewater: a surveillance tool for assessing the presence of COVID-19 infected travelers. Journal of Travel Medicine. 2020; 27 (5):1.

Chicago/Turabian Style

Warish Ahmed; Paul M Bertsch; Nicola Angel; Kyle Bibby; Aaron Bivins; Leanne Dierens; Janette Edson; John Ehret; Pradip Gyawali; Kerry A Hamilton; Ian Hosegood; Philip Hugenholtz; Guangming Jiang; Masaaki Kitajima; Homa T Sichani; Jiahua Shi; Katja Shimko; Stuart L Simpson; Wendy J M Smith; Erin M Symonds; Kevin V Thomas Dsc; Rory Verhagen; Julian Zaugg; Jochen F Mueller. 2020. "Detection of SARS-CoV-2 RNA in commercial passenger aircraft and cruise ship wastewater: a surveillance tool for assessing the presence of COVID-19 infected travelers." Journal of Travel Medicine 27, no. 5: 1.

Journal article
Published: 06 July 2020 in Environmental Pollution
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The choice of sediment quality assessment methodologies can strongly influence assessment outcomes and management decisions for contaminated sites. While in situ (field) methods may potentially provide greater realism, high costs and/or complex logistics often prevent their use and assessment must rely on laboratory-based methods. In this study, we utilised static-renewal and flow-through ecotoxicology tests in parallel on sediments with a wide range of properties and varying types and concentrations of contaminants. The prediction of chronic effects to amphipod reproduction was explored using multiple linear regression (MLR). The study confirmed the considerable over-estimation of the risk of toxicity of contaminated sediments in field locations when assessments rely on the results of laboratory-based static and static-renewal tests. Improved prediction of toxicity risks was achieved using a combination of contaminant exposure measures from sediment and overlying water. Existing sediment and water quality guideline values (GVs) were effective for predicting risks posed by sediments containing mixtures of common metal and organic contaminants. For 17 sediments with paired data sets from static-renewal and flow-through tests, the best prediction of toxicity to reproduction was achieved using a 2-parameter MLR that included hazard quotients for sediment contaminants and toxic units for dissolved metals (r2 = 0.892). The inclusion of particle size, organic carbon and acid-volatile sulfide did not improve toxicity predictions, despite these parameters being recognised as modifying contaminant bioavailability. The use of dilute-acid-extractable metal concentrations in place total recoverable metal concentrations did not improve the predictions. The study also confirmed that sediments existing within the estuarine and marine bays of Sydney Harbour pose significant risks of adverse effects to benthic organisms.

ACS Style

Yanfeng Zhang; David A. Spadaro; Josh J. King; Stuart L. Simpson. Improved prediction of sediment toxicity using a combination of sediment and overlying water contaminant exposures. Environmental Pollution 2020, 266, 115187 .

AMA Style

Yanfeng Zhang, David A. Spadaro, Josh J. King, Stuart L. Simpson. Improved prediction of sediment toxicity using a combination of sediment and overlying water contaminant exposures. Environmental Pollution. 2020; 266 ():115187.

Chicago/Turabian Style

Yanfeng Zhang; David A. Spadaro; Josh J. King; Stuart L. Simpson. 2020. "Improved prediction of sediment toxicity using a combination of sediment and overlying water contaminant exposures." Environmental Pollution 266, no. : 115187.

Journal article
Published: 05 June 2020 in Science of The Total Environment
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There is currently a clear benefit for many countries to utilize wastewater-based epidemiology (WBE) as part of ongoing measures to manage the coronavirus disease 2019 (COVID-19) global pandemic. Since most wastewater virus concentration methods were developed and validated for nonenveloped viruses, it is imperative to determine the efficiency of the most commonly used methods for the enveloped severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Municipal wastewater seeded with a human coronavirus (CoV) surrogate, murine hepatitis virus (MHV), was used to test the efficiency of seven wastewater virus concentration methods: (A–C) adsorption-extraction with three different pre-treatment options, (D–E) centrifugal filter device methods with two different devices, (F) polyethylene glycol (PEG 8000) precipitation, and (G) ultracentrifugation. MHV was quantified by reverse-transcription quantitative polymerase chain reaction and the recovery efficiency was calculated for each method. The mean MHV recoveries ranged from 26.7 to 65.7%. The most efficient methods were adsorption-extraction methods with MgCl2 pre-treatment (Method C), and without pre-treatment (Method B). The third most efficient method used the Amicon® Ultra-15 centrifugal filter device (Method D) and its recovery efficiency was not statistically different from the most efficient methods. The methods with the worst recovery efficiency included the adsorption-extraction method with acidification (A), followed by PEG precipitation (F). Our results suggest that absorption-extraction methods with minimal or without pre-treatment can provide suitably rapid, cost-effective and relatively straightforward recovery of enveloped viruses in wastewater. The MHV is a promising process control for SARS-CoV-2 surveillance and can be used as a quality control measure to support community-level epidemic mitigation and risk assessment.

ACS Style

Warish Ahmed; Paul M. Bertsch; Aaron Bivins; Kyle Bibby; Kata Farkas; Amy Gathercole; Eiji Haramoto; Pradip Gyawali; Asja Korajkic; Brian R. McMinn; Jochen F. Mueller; Stuart L. Simpson; Wendy J.M. Smith; Erin M. Symonds; Kevin V. Thomas; Rory Verhagen; Masaaki Kitajima. Comparison of virus concentration methods for the RT-qPCR-based recovery of murine hepatitis virus, a surrogate for SARS-CoV-2 from untreated wastewater. Science of The Total Environment 2020, 739, 139960 .

AMA Style

Warish Ahmed, Paul M. Bertsch, Aaron Bivins, Kyle Bibby, Kata Farkas, Amy Gathercole, Eiji Haramoto, Pradip Gyawali, Asja Korajkic, Brian R. McMinn, Jochen F. Mueller, Stuart L. Simpson, Wendy J.M. Smith, Erin M. Symonds, Kevin V. Thomas, Rory Verhagen, Masaaki Kitajima. Comparison of virus concentration methods for the RT-qPCR-based recovery of murine hepatitis virus, a surrogate for SARS-CoV-2 from untreated wastewater. Science of The Total Environment. 2020; 739 ():139960.

Chicago/Turabian Style

Warish Ahmed; Paul M. Bertsch; Aaron Bivins; Kyle Bibby; Kata Farkas; Amy Gathercole; Eiji Haramoto; Pradip Gyawali; Asja Korajkic; Brian R. McMinn; Jochen F. Mueller; Stuart L. Simpson; Wendy J.M. Smith; Erin M. Symonds; Kevin V. Thomas; Rory Verhagen; Masaaki Kitajima. 2020. "Comparison of virus concentration methods for the RT-qPCR-based recovery of murine hepatitis virus, a surrogate for SARS-CoV-2 from untreated wastewater." Science of The Total Environment 739, no. : 139960.

Journal article
Published: 30 May 2020 in Science of The Total Environment
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Historical contamination of sediments from industries that commenced before environmental regulations were commonplace is prevalent in many large cities. This contamination is frequently overlain and mixed with more recent urban contamination. The remediation of contaminated sites is often a very expensive exercise and the final remediation criteria often reflect a trade-off between protecting human and ecological health and the finances of those deemed responsible for the site clean-up. In this study, we describe an assessment of estuarine sediments impacted historically by contamination from a gasworks site. The major historical sediment contaminants included polycyclic aromatic hydrocarbons (PAHs) and other petroleum-related hydrocarbons (TRHs). Elevated concentrations of metals exist throughout the city region due to historical pollution and ongoing urban stormwater discharges. Equilibrium partitioning models were used to consider the influence on the bioavailability of PAHs of both natural sedimentary organic carbon and forms of black carbon (pyrogenic carbon - coal tars, charcoal). The strongest predictor of the observed sublethal toxicity to amphipod and copepod reproduction was a combination of total PAHs and metals (primarily Cu, Pb and Zn). Total PAHs was the strongest predicting variable for toxicity to organism survival. While high total PAH concentrations were attributed to the former gas works, high background concentrations of metals existed throughout much of this region of the estuary. Thus, without remediation at the estuary-scale, resuspension of the surrounding sediments by tidal currents and boat movements is predicted to re-contaminate remediated areas with sediments that may continue to cause chronic toxicity due to metals. The assessment indicated that remedial actions that remove or isolate sediments that caused toxicity to benthic organism survival would lead to significant improvements in ecosystem health, but toxicity to organism reproduction may remain at similar levels that exist throughout much of this region of the estuary due to high metal concentrations.

ACS Style

Stuart L. Simpson; David A. Spadaro; Graeme E. Batley; Ian A. Irvine; Russell N. Synnot. Remediation criteria for gasworks-impacted sediments: Assessing the effects of legacy hydrocarbons and more recent metal contamination. Science of The Total Environment 2020, 737, 139725 .

AMA Style

Stuart L. Simpson, David A. Spadaro, Graeme E. Batley, Ian A. Irvine, Russell N. Synnot. Remediation criteria for gasworks-impacted sediments: Assessing the effects of legacy hydrocarbons and more recent metal contamination. Science of The Total Environment. 2020; 737 ():139725.

Chicago/Turabian Style

Stuart L. Simpson; David A. Spadaro; Graeme E. Batley; Ian A. Irvine; Russell N. Synnot. 2020. "Remediation criteria for gasworks-impacted sediments: Assessing the effects of legacy hydrocarbons and more recent metal contamination." Science of The Total Environment 737, no. : 139725.

Journal article
Published: 18 April 2020 in Science of The Total Environment
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Infection with SARS-CoV-2, the etiologic agent of the ongoing COVID-19 pandemic, is accompanied by the shedding of the virus in stool. Therefore, the quantification of SARS-CoV-2 in wastewater affords the ability to monitor the prevalence of infections among the population via wastewater-based epidemiology (WBE). In the current work, SARS-CoV-2 RNA was concentrated from wastewater in a catchment in Australia and viral RNA copies were enumerated using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) resulting in two positive detections within a six day period from the same wastewater treatment plant (WWTP). The estimated viral RNA copy numbers observed in the wastewater were then used to estimate the number of infected individuals in the catchment via Monte Carlo simulation. Given the uncertainty and variation in the input parameters, the model estimated a median range of 171 to 1,090 infected persons in the catchment, which is in reasonable agreement with clinical observations. This work highlights the viability of WBE for monitoring infectious diseases, such as COVID-19, in communities. The work also draws attention to the need for further methodological and molecular assay validation for enveloped viruses in wastewater.

ACS Style

Warish Ahmed; Nicola Angel; Janette Edson; Kyle Bibby; Aaron Bivins; Jake O'Brien; Phil M. Choi; Masaaki Kitajima; Stuart Simpson; Jiaying Li; Ben Tscharke; Rory Verhagen; Wendy J.M. Smith; Julian Zaugg; Leanne Dierens; Philip Hugenholtz; Kevin V. Thomas; Jochen F. Mueller. First confirmed detection of SARS-CoV-2 in untreated wastewater in Australia: A proof of concept for the wastewater surveillance of COVID-19 in the community. Science of The Total Environment 2020, 728, 138764 -138764.

AMA Style

Warish Ahmed, Nicola Angel, Janette Edson, Kyle Bibby, Aaron Bivins, Jake O'Brien, Phil M. Choi, Masaaki Kitajima, Stuart Simpson, Jiaying Li, Ben Tscharke, Rory Verhagen, Wendy J.M. Smith, Julian Zaugg, Leanne Dierens, Philip Hugenholtz, Kevin V. Thomas, Jochen F. Mueller. First confirmed detection of SARS-CoV-2 in untreated wastewater in Australia: A proof of concept for the wastewater surveillance of COVID-19 in the community. Science of The Total Environment. 2020; 728 ():138764-138764.

Chicago/Turabian Style

Warish Ahmed; Nicola Angel; Janette Edson; Kyle Bibby; Aaron Bivins; Jake O'Brien; Phil M. Choi; Masaaki Kitajima; Stuart Simpson; Jiaying Li; Ben Tscharke; Rory Verhagen; Wendy J.M. Smith; Julian Zaugg; Leanne Dierens; Philip Hugenholtz; Kevin V. Thomas; Jochen F. Mueller. 2020. "First confirmed detection of SARS-CoV-2 in untreated wastewater in Australia: A proof of concept for the wastewater surveillance of COVID-19 in the community." Science of The Total Environment 728, no. : 138764-138764.

Journal article
Published: 20 February 2020 in Science of The Total Environment
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The sorption of three perfluoroalkyl substances (PFASs), namely perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA) and perfluorohexane sulfonic acid (PFHxS), was determined in 19 coastal sediments. There are currently limited data on the sorption behaviour of these chemicals in marine or estuarine sediments and the properties controlling their sorption have not been well established. The median average PFOS Kd value (30.4 L/kg) was >8 times that for PFOA (3.3 L/kg) and PFHxS (2.8 L/kg). Highly significant (P < .001) linear relationships were found between values for sorption coefficients (Kd) for all three chemicals (PFOS, PFOA and PFHxS) to the estuarine sediments and organic carbon (OC) content with r2 values ranging from 0.87 to 0.91. The nature of the constituents of OC was determined by nuclear magnetic resonance (NMR) for a subset (10) of the sediments to assess whether the strong relationship between sorption and OC was due solely to an increasing amount of OC or to particular OC fractions. The NMR analysis could not provide strong evidence for one OC fraction type explaining the variation in sorption of the three PFASs. Further investigation using partial least squares of the whole spectra also did not show any particular OC components could explain the Kd variation. This data suggests that variation in sorption in these sediments was primarily due to the varying OC content and not its chemistry.

ACS Style

Danielle P. Oliver; Divina A. Navarro; Jeff Baldock; Stuart L. Simpson; Rai S. Kookana. Sorption behaviour of per- and polyfluoroalkyl substances (PFASs) as affected by the properties of coastal estuarine sediments. Science of The Total Environment 2020, 720, 137263 .

AMA Style

Danielle P. Oliver, Divina A. Navarro, Jeff Baldock, Stuart L. Simpson, Rai S. Kookana. Sorption behaviour of per- and polyfluoroalkyl substances (PFASs) as affected by the properties of coastal estuarine sediments. Science of The Total Environment. 2020; 720 ():137263.

Chicago/Turabian Style

Danielle P. Oliver; Divina A. Navarro; Jeff Baldock; Stuart L. Simpson; Rai S. Kookana. 2020. "Sorption behaviour of per- and polyfluoroalkyl substances (PFASs) as affected by the properties of coastal estuarine sediments." Science of The Total Environment 720, no. : 137263.

Environmental chemistry
Published: 06 January 2020 in Environmental Toxicology and Chemistry
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Chlorination is commonly used to control biofouling organisms, but chlorine rapidly hydrolyzes in seawater to hypochlorite, which undergoes further reaction with bromide, and then with organic matter. These reaction products, collectively termed chlorine‐produced oxidants (CPOs), can be toxic to marine biota. Because the lifetime of the most toxic forms is limited to several days, appropriate guideline values need to be based on short‐term (acute) toxicity tests, rather than chronic tests. Flow‐through toxicity tests that provide continuous CPO exposure are the most appropriate, whereas static‐renewal tests generate variable exposure and effects depending on the renewal rate. There are literature data for acute CPO toxicity from flow‐through tests, together with values from 2 sensitive 15‐min static tests on 30 species from 9 taxonomic groups. These values were used in a species sensitivity distribution (SSD) to derive guideline values that were protective of 99, 95, and 90% of species at 2.2, 7.2, and 13 µg CPO/L respectively. These are the first marine guideline values for chlorine to be derived using SSDs, with all other international guideline values based on the use of assessment factors applied to data for the most sensitive species. In applying these conservative guideline values in field situations, it would need to be demonstrated that concentrations of CPOs would be reduced to below the guideline value within an acceptable mixing zone through both dilution and dissociation. Environ Toxicol Chem 2020;39:754–764. © 2020 SETAC

ACS Style

Graeme E. Batley; Stuart Simpson. Short‐Term Guideline Values for Chlorine in Marine Waters. Environmental Toxicology and Chemistry 2020, 39, 754 -764.

AMA Style

Graeme E. Batley, Stuart Simpson. Short‐Term Guideline Values for Chlorine in Marine Waters. Environmental Toxicology and Chemistry. 2020; 39 (4):754-764.

Chicago/Turabian Style

Graeme E. Batley; Stuart Simpson. 2020. "Short‐Term Guideline Values for Chlorine in Marine Waters." Environmental Toxicology and Chemistry 39, no. 4: 754-764.

Comparative study
Published: 08 September 2019 in Ecotoxicology and Environmental Safety
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The toxicities of heavy metals in sediments are related to their bioavailability, which is critical for deriving reliable sediment quality guidelines. To evaluate the bioavailability of the metals (Cd, Cu, Ni, Pb and Zn), sediments were collected from Taihu Lake, one of the largest and most important freshwater lakes in China. Concentrations of simultaneously extracted metals (1-M HCl extraction, CSEM) in the sediments, metals released from sediment to pore waters and accumulated by diffusive gradients in thin films (DGT, CDGT), and dissolved metals in the overlying water (COLW) were measured separately. Sediment toxicity was assessed with tubificids (Monopylephorus limosus) and chironomids (Chironomus kiiensis and Chironomus tentans). Significant relationships existed between the total metal concentrations and CSEM, CDGT, and COLW measurements (r2 = 0.43–0.95, n = 27, p < 0.001), with stronger relationships with CSEM (r2 = 0.91–0.95) than CDGT (r2 = 0.56–0.85) and COLW (r2 = 0.43–0.71). Risk quotients were derived by dividing CSEM by sediment quality guideline values (SQGVs), and by dividing both CDGT and COLW by water quality criteria (WQC). Toxicity of the sediments to the three species was better explained by the CSEM-based risk quotient than those derived from CDGT and COLW. The study indicated that DGT piston probes deployed face down in sediments did not accumulate metals in proportion to the bioavailable metal fraction that caused toxicity to these freshwater benthic organisms, and that single measurements of metals in overlying waters are not adequate for predicting risks of toxicity from sediments. The measurement of CSEM was determined to be effective for assessing the risk posed by the metals in the Taihu Lake sediments, but offered limited improvement over measurement of total metal concentrations.

ACS Style

Yanfeng Zhang; Jinxi Yang; Stuart L. Simpson; Yuanyuan Wang; Lingyan Zhu. Application of diffusive gradients in thin films (DGT) and simultaneously extracted metals (SEM) for evaluating bioavailability of metal contaminants in the sediments of Taihu Lake, China. Ecotoxicology and Environmental Safety 2019, 184, 109627 .

AMA Style

Yanfeng Zhang, Jinxi Yang, Stuart L. Simpson, Yuanyuan Wang, Lingyan Zhu. Application of diffusive gradients in thin films (DGT) and simultaneously extracted metals (SEM) for evaluating bioavailability of metal contaminants in the sediments of Taihu Lake, China. Ecotoxicology and Environmental Safety. 2019; 184 ():109627.

Chicago/Turabian Style

Yanfeng Zhang; Jinxi Yang; Stuart L. Simpson; Yuanyuan Wang; Lingyan Zhu. 2019. "Application of diffusive gradients in thin films (DGT) and simultaneously extracted metals (SEM) for evaluating bioavailability of metal contaminants in the sediments of Taihu Lake, China." Ecotoxicology and Environmental Safety 184, no. : 109627.

Journal article
Published: 20 August 2019 in Water
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The prediction of the fate of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in water recycling with urban stormwater and treated wastewater is important since PFAS are widely used, persistent, and have potential impacts on human health and the environment. These alternative water sources have been utilized for water recycling via aquifers or managed aquifer recharge (MAR). However, the fate of these chemicals in MAR schemes and the potential impact in terms of regulation have not been studied. PFAS can potentially be transported long distances in the subsurface during MAR. This article reviews the potential risks to MAR systems using recycled water and urban stormwater. To date, there are insufficient data to determine if PFAS can be degraded by natural processes or retained in the aquifer and become suitable pre-treatment or post-treatment technologies that will need to be employed depending upon the end use of the recovered water. The use of engineered pre-treatment or post-treatment methods needs to be based on a ‘fit for purpose’ principle and carefully integrated with the proposed water end use to ensure that human and environmental health risks are appropriately managed.

ACS Style

Declan Page; Joanne Vanderzalm; Anu Kumar; Ka Yu Cheng; Anna H. Kaksonen; Stuart Simpson. Risks of Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) for Sustainable Water Recycling via Aquifers. Water 2019, 11, 1737 .

AMA Style

Declan Page, Joanne Vanderzalm, Anu Kumar, Ka Yu Cheng, Anna H. Kaksonen, Stuart Simpson. Risks of Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) for Sustainable Water Recycling via Aquifers. Water. 2019; 11 (8):1737.

Chicago/Turabian Style

Declan Page; Joanne Vanderzalm; Anu Kumar; Ka Yu Cheng; Anna H. Kaksonen; Stuart Simpson. 2019. "Risks of Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) for Sustainable Water Recycling via Aquifers." Water 11, no. 8: 1737.

Journal article
Published: 05 April 2019 in Environmental Pollution
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Metal flux measurements inform the mobility, potential bioavailability and risk of toxicity for metals in contaminated sediments and therefore is an important approach for sediment quality assessment. The binding and release of metals that contribute to the net flux is strongly influenced by the presence and behaviors of benthic organisms. Here we studied the effects of bioturbation on the mobility and efflux of metals from multi-metal contaminated sediments that inhabited by oligochaete worms or both worms and bivalves. Presence of bivalves enhanced the release of Mn, Co, Ni and Zn but not for copper and chromium, which is likely due to the high affinities of copper and chromium for the solid phase. Metals in the overlying water were primarily associated with fractions smaller than 10 kDa, and the fractionation of all metals were not affected by the presence of the bivalve. Metal fluxes attributed to different processes were also distinguished, and the bioturbation induced effluxes were substantially higher than the diffusive effluxes. Temporal variabilities in the total net effluxes of Mn, Co, Ni and Zn were also observed and were attributed to the biological activities of the bivalves. Overall, the present study demonstrated that the response of different metals to the same bioturbation behavior was different, resulting in distinct mobility and fate of the metal contaminants.

ACS Style

Minwei Xie; Stuart Simpson; Wen-Xiong Wang. Bioturbation effects on metal release from contaminated sediments are metal-dependent. Environmental Pollution 2019, 250, 87 -96.

AMA Style

Minwei Xie, Stuart Simpson, Wen-Xiong Wang. Bioturbation effects on metal release from contaminated sediments are metal-dependent. Environmental Pollution. 2019; 250 ():87-96.

Chicago/Turabian Style

Minwei Xie; Stuart Simpson; Wen-Xiong Wang. 2019. "Bioturbation effects on metal release from contaminated sediments are metal-dependent." Environmental Pollution 250, no. : 87-96.

Research article
Published: 08 November 2018 in Environmental Microbiology
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Microbially mediated biogeochemical processes are crucial for climate regulation and may be disrupted by anthropogenic contaminants. To better manage contaminants, we need tools that make real‐time causal links between stressors and altered microbial functions, and the potential consequences for ecosystem services such as climate regulation. In a manipulative field experiment, we used metatranscriptomics to investigate the impact of excess organic enrichment and metal contamination on the gene expression of nitrogen and sulfur metabolisms in coastal sediments. Our gene expression data suggest that excess organic enrichment results in (i) higher transcript levels of genes involved in the production of toxic ammonia and hydrogen sulfide and (ii) lower transcript levels associated with the degradation of a greenhouse gas (nitrous oxide). However, metal contamination did not have any significant impact on gene expression. We reveal the genetic mechanisms that may lead to altered productivity and greenhouse gas production in coastal sediments due to anthropogenic contaminants. Our data highlight the applicability of metatranscriptomics as a management tool that provides an immense breadth of information and can identify potentially impacted process measurements that need further investigation.

ACS Style

Simone C. Birrer; Katherine A. Dafforn; Melanie Y. Sun; Rohan B. H. Williams; Jaimie Potts; Peter Scanes; Brendan P. Kelaher; Stuart Simpson; Staffan Kjelleberg; Sanjay Swarup; Peter Steinberg; Emma Johnston. Using meta‐omics of contaminated sediments to monitor changes in pathways relevant to climate regulation. Environmental Microbiology 2018, 21, 389 -401.

AMA Style

Simone C. Birrer, Katherine A. Dafforn, Melanie Y. Sun, Rohan B. H. Williams, Jaimie Potts, Peter Scanes, Brendan P. Kelaher, Stuart Simpson, Staffan Kjelleberg, Sanjay Swarup, Peter Steinberg, Emma Johnston. Using meta‐omics of contaminated sediments to monitor changes in pathways relevant to climate regulation. Environmental Microbiology. 2018; 21 (1):389-401.

Chicago/Turabian Style

Simone C. Birrer; Katherine A. Dafforn; Melanie Y. Sun; Rohan B. H. Williams; Jaimie Potts; Peter Scanes; Brendan P. Kelaher; Stuart Simpson; Staffan Kjelleberg; Sanjay Swarup; Peter Steinberg; Emma Johnston. 2018. "Using meta‐omics of contaminated sediments to monitor changes in pathways relevant to climate regulation." Environmental Microbiology 21, no. 1: 389-401.

Journal article
Published: 02 November 2018 in Water Research
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There is a growing move toward using the quantitative polymerase chain (qPCR)-based sewage-associated marker genes to assess surface water quality. However, a lack of understanding about the persistence of many sewage-associated markers creates uncertainty for those tasked with investigating microbial water quality. In this study, we investigated the decay of two qPCR FIB [E. coli (EC), and Enterococcus spp. (ENT) 23S rRNA genes] and four sewage-associated microbial source tracking (MST) marker genes [human Bacteroides HF183 16S rRNA, adenovirus (HAdV), and polyomavirus (HPyV), and crAssphage, a recently described bacteriophage in feces], in outdoor mesocosms containing fresh and marine waters and their corresponding sediments. Decay rates of EC 23S rRNA, ENT 23S rRNA and HF183 16S rRNA were significantly (p <0.05) faster than the HAdV, HPyV and crAssphage markers in water samples from all mesocosms. In general, decay rates of bacterial targets were similar in the water columns of the studied mesocosms. Similarly, decay rates of viral targets were also alike in mesocosm water columns in relation to each other. The decay rates of FIB and sewage-associated markers were significantly faster in water samples compared to sediments in all three mesocosms. In the event of resuspension, FIB and marker genes from sediments can potentially recontaminate overlying waters. Thus, care should be taken when interpreting the occurrence of FIB and sewage-associated MST markers in water, which may have originated from sediments. The differential decay of these targets may also influence health outcomes and need to be considered in risk assessment models.

ACS Style

Warish Ahmed; Qian Zhang; Sonya Kozak; David Beale; Pradip Gyawali; Michael J. Sadowsky; Stuart Simpson. Comparative decay of sewage-associated marker genes in beach water and sediment in a subtropical region. Water Research 2018, 149, 511 -521.

AMA Style

Warish Ahmed, Qian Zhang, Sonya Kozak, David Beale, Pradip Gyawali, Michael J. Sadowsky, Stuart Simpson. Comparative decay of sewage-associated marker genes in beach water and sediment in a subtropical region. Water Research. 2018; 149 ():511-521.

Chicago/Turabian Style

Warish Ahmed; Qian Zhang; Sonya Kozak; David Beale; Pradip Gyawali; Michael J. Sadowsky; Stuart Simpson. 2018. "Comparative decay of sewage-associated marker genes in beach water and sediment in a subtropical region." Water Research 149, no. : 511-521.

Journal article
Published: 01 October 2018 in Science of The Total Environment
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Coastal waterways are increasingly exposed to multiple stressors, e.g. contaminants that can be delivered via pulse or press exposures. Therefore, it is crucial that ecological impacts can be differentiated among stressors to manage ecosystem threats. We investigated microbial community development in sediments exposed to press and pulse stressors. Press exposures were created with in situ mesocosm sediments containing a range of ‘metal’ concentrations (sediment contaminated with multiple metal(loid)s) and organic enrichment (fertiliser), while the pulse exposure was simulated by a single dose of organic fertiliser. All treatments and exposure concentrations were crossed in a fully factorial field experiment. We used amplicon sequencing to compare the sensitivity of the 1) total (DNA) and active (RNA) component of 2) bacterial (16S rRNA) and eukaryotic (18S rRNA) communities to contaminant exposures. Overall microbial community change was greater when exposed to press than pulse stressors, with the bacterial community responding more strongly than the eukaryotes. The total bacterial community represents a more time-integrated measure of change and proved to be more sensitive to multiple stressors than the active community. Metals and organic enrichment treatments interacted such that the effect of metals was weaker when the sediment was organically enriched. Taxa-level analyses revealed that press enrichment resulted in potential functional changes, mainly involving nitrogen cycling. Furthermore, enrichment generally reduced the abundance of active eukaryotes in the sediment. As well as demonstrating interactive impacts of metals and organic enrichment, this study highlights the sensitivity of next-generation sequencing for ecosystem biomonitoring of interacting stressors and identifies opportunities for more targeted application.

ACS Style

Simone C. Birrer; Katherine Dafforn; Stuart Simpson; Brendan P. Kelaher; Jaimie Potts; Peter Scanes; Emma Johnston. Interactive effects of multiple stressors revealed by sequencing total (DNA) and active (RNA) components of experimental sediment microbial communities. Science of The Total Environment 2018, 637-638, 1383 -1394.

AMA Style

Simone C. Birrer, Katherine Dafforn, Stuart Simpson, Brendan P. Kelaher, Jaimie Potts, Peter Scanes, Emma Johnston. Interactive effects of multiple stressors revealed by sequencing total (DNA) and active (RNA) components of experimental sediment microbial communities. Science of The Total Environment. 2018; 637-638 ():1383-1394.

Chicago/Turabian Style

Simone C. Birrer; Katherine Dafforn; Stuart Simpson; Brendan P. Kelaher; Jaimie Potts; Peter Scanes; Emma Johnston. 2018. "Interactive effects of multiple stressors revealed by sequencing total (DNA) and active (RNA) components of experimental sediment microbial communities." Science of The Total Environment 637-638, no. : 1383-1394.

Journal article
Published: 06 September 2018 in Environmental Pollution
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The diffusive gradients in thin films (DGT) technique has shown to be a useful tool for predicting metal bioavailability and toxicity in sediments, however, links between DGT measurements and biological responses have often relied on laboratory-based exposures and further field evaluations are required. In this study, DGT probes were deployed in metal-contaminated (Cd, Pb, Zn) sediments to evaluate relationships between bioaccumulation by the freshwater bivalve Hyridella australis and DGT-metal fluxes under both laboratory and field conditions. The DGT-metal flux measured across the sediment/water interface (±1 cm) was useful for predicting significant cadmium and zinc bioaccumulation, irrespective of the type of sediment and exposure. A greater DGT-Zn flux measured in the field was consistent with significantly higher zinc bioaccumulation, highlighting the importance of performing metal bioavailability assessments in situ. In addition, DGT fluxes were useful for predicting the potential risk of sub-lethal toxicity (i.e., lipid peroxidation and lysosomal membrane damage). Due to its ability to account for multiple metal exposures, DGT better predicted bioaccumulation and toxicity than particulate metal concentrations in sediments. These results provide further evidence supporting the applicability of the DGT technique as a monitoring tool for sediment quality assessment.

ACS Style

Elvio D. Amato; Chamani P.M. Marasinghe Wadige; Anne M. Taylor; William A. Maher; Stuart Simpson; Dianne F. Jolley. Field and laboratory evaluation of DGT for predicting metal bioaccumulation and toxicity in the freshwater bivalve Hyridella australis exposed to contaminated sediments. Environmental Pollution 2018, 243, 862 -871.

AMA Style

Elvio D. Amato, Chamani P.M. Marasinghe Wadige, Anne M. Taylor, William A. Maher, Stuart Simpson, Dianne F. Jolley. Field and laboratory evaluation of DGT for predicting metal bioaccumulation and toxicity in the freshwater bivalve Hyridella australis exposed to contaminated sediments. Environmental Pollution. 2018; 243 ():862-871.

Chicago/Turabian Style

Elvio D. Amato; Chamani P.M. Marasinghe Wadige; Anne M. Taylor; William A. Maher; Stuart Simpson; Dianne F. Jolley. 2018. "Field and laboratory evaluation of DGT for predicting metal bioaccumulation and toxicity in the freshwater bivalve Hyridella australis exposed to contaminated sediments." Environmental Pollution 243, no. : 862-871.

Journal article
Published: 03 September 2018 in Environmental Science: Processes & Impacts
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The intensity of organism bioturbation complicates the assessment of risk of toxicity when applying the AVS–SEM paradigm. Increased bioturbation in oxidised sediments (SEM > AVS) resulted in less toxicity to amphipod reproduction and greater toxicity in sulfidic sediments (AVS > SEM).

ACS Style

Timothy M. Remaili; Naiyi Yin; William W. Bennett; Stuart L. Simpson; Dianne F. Jolley; David T. Welsh. Contrasting effects of bioturbation on metal toxicity of contaminated sediments results in misleading interpretation of the AVS–SEM metal-sulfide paradigm. Environmental Science: Processes & Impacts 2018, 20, 1285 -1296.

AMA Style

Timothy M. Remaili, Naiyi Yin, William W. Bennett, Stuart L. Simpson, Dianne F. Jolley, David T. Welsh. Contrasting effects of bioturbation on metal toxicity of contaminated sediments results in misleading interpretation of the AVS–SEM metal-sulfide paradigm. Environmental Science: Processes & Impacts. 2018; 20 (9):1285-1296.

Chicago/Turabian Style

Timothy M. Remaili; Naiyi Yin; William W. Bennett; Stuart L. Simpson; Dianne F. Jolley; David T. Welsh. 2018. "Contrasting effects of bioturbation on metal toxicity of contaminated sediments results in misleading interpretation of the AVS–SEM metal-sulfide paradigm." Environmental Science: Processes & Impacts 20, no. 9: 1285-1296.

Journal article
Published: 30 August 2018 in Chemosphere
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Neutralisation of acid drainage creates metal-rich precipitates that may impact receiving water bodies. This study assessed the fate of over seven years of acid drainage discharges on the sediments of the lower River Murray (Australia), including the potential for periodic water anoxia to enhance risk via reductive dissolution of amorphous (Fe, Mn and co-precipitated and bound metal) oxide phases. With the exception of one site with restricted water exchange, elevated reducible/reactive metal(oid) (Fe, Ni, As, Co, Zn) concentrations were only observed in the localised wetland-riparian area within approximately 100 m of the discharges. Only a minor exceedance of national sediment quality guideline values occurred for Ni. In the main river channel, elevated reactive metal (Fe, Mn, Ni, Zn) concentrations were also only observed less than approximately 100 m from the drainage discharge point. This appears due to (a) rapid neutralisation of pH leading to metal precipitation and deposition in the localised discharge area, and/or (b) dilution of any metal precipitates entering the main channel with natural river sediments, and/or (c) flushing of precipitates downstream during higher flow conditions. The influence of deoxygenation on metal release was profound with large increases in the concentration of dissolved Fe, Mn, Zn, Ni, and As in the overlying water during laboratory experimental simulations. However, given in situ sediment metal contamination is very localised, it appears on a river reach scale that the acid drainage precipitates will not significantly contribute, over and above, the background release of these metals during these conditions.

ACS Style

Luke M. Mosley; Tapas K. Biswas; Tan Dang; David Palmer; Courtney Cummings; Rob Daly; Stuart Simpson; Jason Kirby. Fate and dynamics of metal precipitates arising from acid drainage discharges to a river system. Chemosphere 2018, 212, 811 -820.

AMA Style

Luke M. Mosley, Tapas K. Biswas, Tan Dang, David Palmer, Courtney Cummings, Rob Daly, Stuart Simpson, Jason Kirby. Fate and dynamics of metal precipitates arising from acid drainage discharges to a river system. Chemosphere. 2018; 212 ():811-820.

Chicago/Turabian Style

Luke M. Mosley; Tapas K. Biswas; Tan Dang; David Palmer; Courtney Cummings; Rob Daly; Stuart Simpson; Jason Kirby. 2018. "Fate and dynamics of metal precipitates arising from acid drainage discharges to a river system." Chemosphere 212, no. : 811-820.