Discharged radioactive waste from the British Nuclear Fuels reprocessing plant at Sellafield continues to be the dominant source of artificial radioactivity in the Irish Sea.
A new report from Ireland's nuclear watchdog found, however, that consumers' exposure to radiation through fish and shellfish appeared to have reached a plateau in recent years.
Analysis of 300 fish, shellfish, seaweed and water samples from 2000 and 2001 showed that the activity concentration of caesium-137, the artificial radionuclide giving rise to the highest radiation dose, has remained relatively stable since the mid 1990s.
Cs-137 activity concentrations in offshore Irish Sea water in 2000 ranged from 17 mBq/l to 35 mBq/l. 2001 levels ranged from 9 mBq/l to 15 mBq/l.
This is a lower level than that observed during the previous two decades. The highest activity concentrations observed are on the north-east coastline.
The Radiological Protection Institute of Ireland's Principal Scientific Officer, Dr Tony Colgan, said these doses were very small and consequently did not constitute a significant health risk.
He emphasised that it continued to be safe to eat seafood from the Irish Sea and to use the marine environment for both leisure-based and commercial purposes.
Dr Colgan commented that further reductions in these doses were being pursued through the implementation of the OSPAR Strategy with regard to Radioactive Substances.
