A new approach for assessing the radioecological risk associated with the legacy discharge of oil derived natural radioactivity in the UK North Sea

DOI: 10.1016/j.marpolbul.2025.117585

Authors: F. Dal Molin (Centre for Environment, Fisheries and Aquaculture Science (UK)) , D. Hunt (Centre for Environment, Fisheries and Aquaculture Science (UK); University of the West of England) , A. Dewar (Centre for Environment, Fisheries and Aquaculture Science (UK)) , S. Lozach (Centre for Environment, Fisheries and Aquaculture Science (UK)) , C. Phillips (Centre for Environment, Fisheries and Aquaculture Science (UK)) , B. Thomas (Centre for Environment, Fisheries and Aquaculture Science (UK)) , L. Warford (Centre for Environment, Fisheries and Aquaculture Science (UK)) , J. E. Parker (Diamond Light Source) , J. Walker (Diamond Light Source) , M. Chocholek (University of St Andrews) , D. M. Paterson (University of St Andrews) , H. Woodward-Rowe (University of Essex) , N. Hicks (University of Essex)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Marine Pollution Bulletin , VOL 212

State: Published (Approved)
Published: March 2025
Diamond Proposal Number(s): 35954

Abstract: Although oil and gas (O&G) derived produced waters and drill cuttings are known to contain enhanced levels of naturally occurring radium-228 (228Ra) and radium-226 (226Ra), most relevant ecological impact assessments have excluded radiological hazards and focus on other important contaminants, such as hydrocarbons and metals. Also, due to restricted access to the delimiting safety zone around operational O&G platforms, the few previous radioecological risk assessment studies have been conducted using seawater samples collected far from the main discharge point and applying default dilution and transfer factors to estimate concentrations of contaminants in biota. In this case study, sediment cores were collected close to a former O&G platform, Northwest Hutton (NWH), that used to be in the UK North Sea (61.11N, 1.31E). The sediment materials were analysed by gamma spectrometry and ICP-MS to confirm the presence of particles enriched in natural radioactivity. Benthic macrofaunal assemblages in the surrounding seabed were also characterised and one of the dominant species was selected for additional nano-hard X-Ray Fluorescence (nano-XRF) imaging to confirm the exposure pathways and refine the radioecological risk assessment using the ERICA tool. This novel approach for estimating dose rates was found to be less conservative than more traditional approaches using the ERICA default concentration ratio for 228Ra and 226Ra. The dose rate estimations were confirmed to be significantly lower than the ERICA screening level of 10μGy/h, in agreement with findings from previous studies.

Journal Keywords: NORM; O&G structures; Radium; Barium; Sediment; Benthic macrofaunal community; ERICA dose assessment

Subject Areas: Environment, Earth Science, Materials


Instruments: I14-Hard X-ray Nanoprobe

Added On: 27/01/2025 08:41

Documents:
1-s2.0-S0025326X25000608-main.pdf

Discipline Tags:

Earth Sciences & Environment Radioactive Materials Marine science/Oceanography Materials Science Geology Geochemistry

Technical Tags:

Imaging X-ray Fluorescence (XRF)