A New global seafood dose assessment

Johansen, M. P.*; Carpenter, J. G.*; Charmasson, S.*; Gwynn, J. P.*; McGinnity, P.*; Mori, Airi; Orr, B.*; Simon-Cornu, M.*; Osvath, I.*

Artificial and natural radionuclides are known to accumulate in seafood worldwide and cause internal dose to seafood consumers. It has been nearly 30 years since the IAEA MARDOS global seafood dose assessment was published. Since then, world seafood consumption has increased, diet patterns have changed, and new inputs of radionuclides into marine systems have occurred. A new global assessment of seafood dose is being conducted that uses a much-expanded global 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: (i) Evaluates 16 natural and anthropogenic radionuclides. (ii) Draws from more than 84,856 global data for biota in MARIS, from which 31,665 final activity concentration data passed quality assurance screening. (iii) Uses seafood consumption data from diet studies representing approximately 35% of the world population. (iv) Develops new correction factors for the loss of Po-210 from cooking and radiological decay as well as the decreases in Po-210 in maricultured seafood. (v) Implements a bespoke Monte Carlo application for calculating seafood dose distributions. (vi) Compiles and evaluates + 150 seafood ingestion dose estimates published in the past 30 years. The results provide well-supported estimates on the mean and distribution of background seafood dose for world consumers. This important new result provides a comparative reference for local, regional and national dose assessments; for the dose rates resulting from facility and accident releases, and for quantifying the global changes in ingestion dose from seafood over time. 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."