Natural Radioactivity

Everyone is exposed to natural radioactivity.On average people in Northern Ireland receive 2500 microsieverts of radiation a year from all sources.

The Inspectorate Pollution and Radiochemical Inspectorate, in conjunction with the Scotland and Northern Ireland Forum for Environmental Research (SNIFFER) and the Centre for Environment, Fisheries and Aquaculture Science (CEFAS), produced a report (.PDF 950Kb) on a survey of the habits of people who might be exposed to the effects of radioactive waste discharged into the Irish Sea from Sellafield as a consequence of their seafood consumption and aquatic activities.

The report shows rates for seafood consumption, coastal area occupancy and handling of commercial fishing gear, seaweed, shellfish and sediments from 821 individuals in the coastal region stretching from Portavogie to Rostrevor.

The report found that the representative group in Northern Ireland is assumed to eat 99 Kg/yr of fish, 34 Kg/yr of crustaceans, 7.7 Kg/yr of molluscs AND 10 Kg/yr of dulse together with 1100 hrs/yr occupancy over sand/mud. It was found that the representative person would receive a dose of 18 microsieverts a year, with 15 microsieverts a year due to consumption of seafood. This is the extreme case.

More typically members of the public receive between 0.05 and 3 microsieverts a year from seafood consumption and aquatic activities and this may be compared with the dose received by the average members of the Northern Ireland population of 2500 microsieverts a year which is largely due to natural radioactivity.

These doses are well within the limit recommended by the International Commission on Radiological Protection for members of the public of 1000 microsieverts a year from all artificial sources of radioactivity.