Threshold values for the protection of marine ecosystems from NORM in subsea oil and gas infrastructure

Acknowledgements The authors thank Professor Claus Otto (Curtin University) and Professor Richard Neilson (National Decommissioning Centre, Aberdeen, UK.) for comments and support to the project team; and, Sam Jarvis (National Environment Resources Australia), Professor Peter Macreadie, Dr Rick Tinker, and the industry partners of the National Decommissioning Research Initiative for helpful comments to this project. Funding This research was funded by the Australian Government’s Industry Growth Centre National Energy Resources Australia (NERA) through a National Decommissioning Research Initiative (NDRI) grant to Curtin University. The NDRI project was funded by eight industry partners including Shell Australia, Esso Australia, Chevron Australia, BHP Petroleum, Woodside Energy, Santos Limited, ConocoPhillips Pipeline Australia, and Vermilion Oil and Gas Australia. AH is partly funded by the National Decommissioning Centre, Scotland, and the University of Aberdeen.Peer reviewedPublisher PD

An approach to assess potential environmental mercury release, food web bioaccumulation, and human dietary methylmercury uptake from decommissioning offshore oil and gas infrastructure

Open Access via the Elsevier Agreement Funding This research was funded by the National Decommissioning Centre through University of Aberdeen. Astley Hastings and Rebecca von Hellfeld are further funded by the UK Research and Innovation Energy Programme under grant number EP/S029575/1. Christoph Gade is funded by UK National Decommissioning Centre. We also acknowledge the in-kind support from the Net Zero Technology Centre. CRediT authorship contribution statement Rebecca von Hellfeld: Conceptualization; Data curation; Formal analysis; Investigation; Methodology; Software; Validation; Visualization; Roles/Writing - original draft; Writing - review & editing. Christoph Gade: Methodology; Roles/Writing - original draft; Writing - review & editing. Darren J. Koppel: Conceptualization; Investigation; Validation; Visualization; Writing - review & editing. William J. Walters: Formal analysis; Methodology; Software. Fenny Kho: Conceptualization; Writing - review & editing. Astley Hastings: Conceptualization; Funding acquisition; Investigation; Methodology; Project administration; Resources; Supervision; Writing - review & editing.Peer reviewe

Current understanding of the ecological risk of mercury from subsea oil and gas infrastructure to marine ecosystems

Funding Information: This research was funded by the Australian Government’s Industry Growth Centre National Energy Resources Australia (NERA) through a National Decommissioning Research Initiative (NDRI) grant to Curtin University (grant number 13266). The NDRI project was funded by eight industry partners including Shell Australia, Esso Australia, Chevron Australia, BHP Petroleum, Woodside Energy, Santos Limited, ConocoPhillips Pipeline Australia, and Vermilion Oil and Gas Australia. Astley Hastings is funded by the National Decommissioning Centre, Scotland, and the University of Aberdeen. Funding Information: The authors thank Professor Claus Otto (Curtin University) and Professor Richard Neilson (National Decommissioning Centre, Aberdeen, UK.) for comments and support to the project team; and Samantha Jarvis (National Environment Resources Australia), Professor Peter Macreadie, Dr Rick Tinker, and the industry partners of the National Decommissioning Research Initiative for helpful comments to this project. This research was funded by the Australian Government's Industry Growth Centre National Energy Resources Australia (NERA) through a National Decommissioning Research Initiative (NDRI) grant to Curtin University (grant number 13266). The NDRI project was funded by eight industry partners including Shell Australia, Esso Australia, Chevron Australia, BHP Petroleum, Woodside Energy, Santos Limited, ConocoPhillips Pipeline Australia, and Vermilion Oil and Gas Australia. Astley Hastings is funded by the National Decommissioning Centre, Scotland, and the University of Aberdeen. Past research has shown that mercury associates with offshore oil and gas pipelines as well as other products associated with the infrastructure, deeming such materials “hazardous”. However, the current environmental risk assessments for decommissioning activities of such contaminated materials does not take into account the complexity of the compound's nature and the potential harmful effects on e.g. marine food webs. This review paper has outlined these gaps in our current understanding, as well as providing advice on addressing these gaps to ensure that the marine environmental risk assessments reflect the hazardous nature of mercury-contaminated offshore infrastructure. Publisher Copyright: © 2022 The AuthorsPeer reviewedPublisher PD

A review of the potential risks associated with mercury in subsea oil and gas pipelines in Australia

Peer reviewedPublisher PD

Radiological risk assessment to marine biota from exposure to NORM from a decommissioned offshore oil and gas pipeline

Scale residues can accumulate on the interior surfaces of subsea petroleum pipes and may incorporate naturally occurring radioactive materials (NORM). The persistent nature of ‘NORM scale’ may result in a radiological dose to the organisms living on or near intact pipelines. Following a scenario of in-situ decommissioning of a subsea pipeline, marine organisms occupying the exteriors or interiors of petroleum structures may have close contact with the scale or other NORM-associated contaminated substances and suffer subsequent radiological effects. This case study used radiological dose modelling software, including the ERICA Tool (v2.0), MicroShield® Pro and mathematical equations, to estimate the likely radiological doses and risks of effects from NORM-contaminated scale to marine biota from a decommissioned offshore oil and gas pipeline. Using activity concentrations of NORM (226Ra, 210Po, 210Pb, 228Ra, 228Th) from a subsea pipeline from Australia, environmental realistic exposure scenarios including radiological exposures from both an intact pipe (external only; accounting for radiation shielding by a cylindrical carbon steel pipe) and a decommissioned pipeline with corrosive breakthrough (resulting in both internal and external radiological exposure) were simulated to estimate doses to model marine organisms. Predicted dose rates for both the external only exposure (ranging from 26 μGy/h to 33 μGy/h) and a corroded pipeline (ranging from 300 μGy/h to 16,000 μGy/h) exceeded screening levels for radiological doses to environmental receptors. The study highlighted the importance of using scale-specific solubility data (i.e., Kd) values for individual NORM radionuclides for ERICA assessments. This study provides an approach for conducting marine organism dose assessments for NORM-contaminated subsea pipelines and highlights scientific gaps required to undertake risk assessments necessary to inform infrastructure decommissioning planning

Measuring and assessing the risk of metal contaminants in the Antarctic nearshore marine environment

ANTARCTICA is generally considered to be pristine; however, localised contamination around research stations is causing disturbances in the nearshore marine environment. Mixtures of metal contaminants enter the nearshore marine environment by leaching from historical waste during summer ice-melt events, in station wastewater discharge, and from anthropogenic activities such as fuel burning. To address these and other human impacts, the Protocol on Environmental Protection to the Antarctic Treaty System came into force in 1998 and required more stringent environmental management practices from nations, such as cleaning up historical waste and limiting the impact of anthropogenic activities. Despite being in place for 20 years, very few waste sites have been remediated across the continent and environmental management practices lack defined guidelines and benchmarks. Hindering good environmental management practices is the lack of Antarctic-specific environmental quality standards and contaminant monitoring tools. Organisms in the Antarctic marine ecosystem have unique adaptations to their cold environment which may influence their sensitivity to contaminants; including, longer developmental times, high lipid contents, and slower metabolic rates. These differences mean that ecotoxicological data needs to be generated using native Antarctic organisms to ensure environmental quality standards will protect the unique ecosystem. These standards also need to consider the risk of contaminants in mixtures, and the potential for toxicity from a variety of exposure pathways. Environmental quality standards should be supported by contaminant monitoring tools that account for the high variability in contaminant concentrations over time as well as environmental factors that may modify contaminant toxicity. This thesis investigated the toxicity of five common metal contaminants (cadmium, copper, nickel, lead, and zinc), singly and in mixtures, to two Antarctic marine microalgae..

Interactive effects of arsenic and antimony on Ipomoea aquatica growth and bioaccumulation in co-contaminated soil

Antimony (Sb) is an emerging contaminant and until recently it was assumed to behave in a similar way to arsenic (As). Arsenic and Sb often co-occur in contaminated sites, yet most investigations consider their toxicity to plants singly. More research is needed to understand the interactions between As and Sb in soils and plants. This study investigated the interactive effect of As and Sb in terms of soil bioavailability, plant toxicity and bioaccumulation on the commercially important agricultural plant, water spinach (Ipomoea aquatica) using a pot experiment. Plants were exposed to As and Sb individually (As (individual), Sb (individual)) and as a mixture (As + Sb (combined)) at different concentrations. Plant growth was measured using shoot and root dry mass, length and chlorophyll a content of leaves. At the end of the bioassay, bioavailable metalloids were extracted from the soil as per a sequential extraction procedure (SEP) and plant tissue was analysed for metalloid content. For As, there were no differences observed between the bioavailability of As in the As + Sb (combined) and As (individual) treatments. For Sb, no increase in bioavailability was observed with co-contamination compared to single-Sb exposures for most concentrations except at 1250 mg/kg. Single-Sb was not toxic to I. aquatica shoot dry mass and length, but there was greater shoot Sb accumulation in the As + Sb (combined) than the Sb (individual) treatment. In contrast, single-As was toxic to I. aquatica growth. When As and Sb were present together in the soil, there was a synergistic toxicity to shoot dry mass (EC50 Toxic Unit (TU) was less than 1) and additive toxicity (EC50 equal to 1 TU) to shoot length. This work shows that the co-occurrence of As and Sb in soil increases Sb bioavailability and can cause synergistic toxicity to an important agricultural crop. Co-occurrence of As and Sb in soil increases Sb bioavailability and causes synergistic toxicity to an important agricultural plant

Amelioration of copper toxicity to a tropical freshwater microalga: Effect of natural DOM source and season

© 2020 Elsevier Ltd Dissolved organic matter source, season, and concentration all modified copper toxicity to Chlorella sp. These toxicity-modifying factors were explored using copper speciation and lability techniques