Global seafood dose 2023: assessment by an international team

It has been known for many years that ingestion dose from seafood is an important component of the background dose rates for billions of consumers worldwide and that eating seafood can contribute proportionally higher dose as compared with terrestrial-sourced foods. However, a well-supported and current estimate of the contribution of seafood to the dose of global consumers is not available. This is mainly because of the difficulty in assembling the underlying data on a global scale, but also due to the varied and dynamic nature of exposures. Global seafood consumption is increasing, diet patterns are shifting (e.g., toward more farmed products), and new inputs of radionuclides into marine systems have occurred (e.g., the Fukushima accident). A new assessment is being conducted on seafood dose in the context of the ongoing stresses on ocean resources and protection of the marine environment. Its global scale makes use of a much-expanded database on radionuclides in seafood (Marine Radioactivity Information System -MARIS) as well as global diet data and updated parameters for dose calculation. The new assessment: • Evaluates global data on 16 natural and anthropogenic radionuclides. • Draws from more than 84,856 activity concentrations data for biota. • Uses seafood consumption data representing approximately 35% of the world population drawn from national and sub-national diet studies. • Develops new correction factors for the loss of 210Po during cooking, radiological decay during storage, as well as the decreases in 210Po in maricultured seafood. • Implements a bespoke Monte Carlo application for calculating seafood dose distributions. • Compiles and evaluates 150+ seafood ingestion dose estimates published in the past 30 years. The new results indicate somewhat higher seafood dose rates for typical global consumers than previous comprehensive assessments (UNSCEAR, MARDOS). Compared with the 150+ previous individual published studies, our distribution of global dose matches closely and helps explain and interpret the previous estimates. Most background seafood dose is from naturally-sourced 210Po (~80%) followed by 210Pb (+10%) and the Ra radionuclides (~7%). A comparatively small background dose (<0.01%) comes from the ambient anthropogenic radionuclides in seafood that derive from worldwide fallout, accidents, releases from waste sites and similar sources. Study outcomes are useful in providing benchmark references for dose assessments performed on the local, regional and national scale for planned facilities or for evaluating accidental releases. They also provide a baseline for quantifying the changes in seafood dose over time. Results show that typical seafood doses are changing as they reflect trends toward more maricultured products (which can have markedly lower levels of 210Po), various stresses and impacts on world fisheries as well as the evolution of seafood production and distribution systems. Numerous researchers and organisations worldwide have provided input into the project. The assessment is being conducted within the IAEA Coordinated Research Project “Behaviour and Effects of Natural and Anthropogenic Radionuclides in the Marine Environment and their Use as Tracers for Oceanography Studies.”

Keywords

Seafood, Dose limits, Radionuclide migration, Aquatic ecosystems, Fukushima Daiichi Nuclear Power Station, Fallout

Citation

Johansen, M. P., Carpenter, J. G., Charmasson, S., Gwynn. J. P., McGinnity, P., Mori, A., Orr, B., Simon-Cornu, M., & Osvath, I. (2023). Global seafood dose 2023: assessment by an international team. Poster presentation to the ICRP 2023 7th International Symposium of the System of Radionlogical Protection, Tokyo, Japan, 6-9 November 2023. Retrieved from: https://event.fourwaves.com/icrp2023/abstracts/7a4e8dfa-e70b-4bb8-aaf1-07d30fd0c47f